AT&T Inc
AT&T IncActive Patents
0
Total Holdings
5218
Patent Holdings
Filter in Explorer →| Patent No. | Title | Status | Filing Date | Grant Date | Claims | Actions |
|---|---|---|---|---|---|---|
| EP1113631A2 | Method and device for integrated multimedia messaging servi… | Expired / Lapsed | 2000-12-22 | — | 19 | Details |
| EP0994600A2 | Method and apparatus for a secure multicast transmission | Expired / Lapsed | 1999-08-23 | — | 21 | Details |
| EP0941010A2 | Method and apparatus for provisioned and dynamic quality of… | Expired / Lapsed | 1999-03-02 | — | 29 | Details |
| EP0902569A1 | Method and system for a unicast endpoint client to access a… | Expired / Lapsed | 1998-09-01 | — | 32 | Details |
| EP0901284A2 | Internet linkage with broadcast TV | Expired / Lapsed | 1998-08-26 | — | 22 | Details |
| EP0866586A1 | Method and system for delivery of email and alerting messag… | Expired / Lapsed | 1998-03-04 | — | 15 | Details |
| EP0872990A1 | Methods and apparatus for providing a broker application se… | Expired / Lapsed | 1998-03-03 | — | 10 | Details |
| EP0854621A1 | System and method for providing peer level access control o… | Expired / Lapsed | 1998-01-09 | — | 26 | Details |
| EP0841832A2 | Promiscuous network monitoring utilizing multicasting withi… | Expired / Lapsed | 1997-10-29 | — | 16 | Details |
| EP0817526A2 | Switched voice and data ATM network with billing system | Expired / Lapsed | 1997-06-27 | — | 9 | Details |
| EP0802664A2 | System and method for controlling and monitoring communicat… | Expired / Lapsed | 1997-04-15 | — | 48 | Details |
| EP0794643A2 | Method of announcing an internet call | Expired / Lapsed | 1997-02-12 | — | 19 | Details |
| EP0785651A1 | Receiver sharing for demand priority access method repeaters | Expired / Lapsed | 1997-01-07 | — | 19 | Details |
| EP0784394A1 | Personalized greeting card system | Expired / Lapsed | 1996-12-23 | — | 15 | Details |
| EP0782361A2 | System and method for management of neighbor-channel interf… | Expired / Lapsed | 1996-12-23 | — | 9 | Details |
| EP0782303A2 | Adaptive time slot scheduling apparatus and method for end-… | Expired / Lapsed | 1996-12-05 | — | 27 | Details |
| EP0768806A2 | Data protocol for transport of ATM cells over a wireless li… | Expired / Lapsed | 1996-10-01 | — | 22 | Details |
| EP0767548A3 | Code division multiple access system providing load and int… | Expired / Lapsed | 1996-09-25 | — | 0 | Details |
| EP0767548A2 | Code division multiple access system providing load and int… | Expired / Lapsed | 1996-09-25 | — | 13 | Details |
| EP0758799A2 | InP/InGaAs monolithic integrated demultiplexer, photodetect… | Expired / Lapsed | 1996-08-07 | — | 21 | Details |
| EP0755144A2 | Prediction of a caller's motivation as a basis for selectin… | Expired / Lapsed | 1996-07-10 | — | 10 | Details |
| EP0748105A2 | System and apparatus for controlling an appliance situated … | Expired / Lapsed | 1996-05-29 | — | 20 | Details |
| EP0744856A2 | Apparatus for and method of utilizing product identifier co… | Expired / Lapsed | 1996-05-13 | — | 16 | Details |
| EP0742658A2 | Dynamic channel assignment for data transmitted via cable t… | Expired / Lapsed | 1996-05-01 | — | 12 | Details |
| EP0732835A2 | Client-server architecture using internet and public switch… | Expired / Lapsed | 1996-03-05 | — | 28 | Details |
| EP0720368A1 | Method and apparatus for channel spinning off a channel | Expired / Lapsed | 1995-12-11 | — | 14 | Details |
| EP0715423A1 | Symbol error based power control for mobile telecommunicati… | Expired / Lapsed | 1995-11-21 | — | 12 | Details |
| EP0715441A1 | Roller bar menu access system and method for cellular telep… | Expired / Lapsed | 1995-11-14 | — | 8 | Details |
| EP0710042A2 | Means and method for providing local telephone number porta… | Expired / Lapsed | 1995-10-18 | — | 20 | Details |
| CA2159973A1 | Message Filtering Techniques | Expired / Lapsed | 1995-10-05 | — | 0 | Details |
| EP0708576A2 | Broadband adaptation processing | Expired / Lapsed | 1995-10-03 | — | 12 | Details |
| EP0708572A2 | Virtual circuit management in a cellular telecommunication … | Expired / Lapsed | 1995-10-03 | — | 1 | Details |
| EP0703685A2 | Adaptive hybrid ARQ/FEC technique for multitone/multicarrie… | Expired / Lapsed | 1995-09-14 | — | 20 | Details |
| EP0696149A2 | Cellular phone interface for a simultaneous voice/data modem | Expired / Lapsed | 1995-07-19 | — | 3 | Details |
| EP0689362A2 | Sound-synchronised video system | Expired / Lapsed | 1995-06-14 | — | 8 | Details |
| EP0687124A2 | Multicast routing in selfrouting multistage networks | Expired / Lapsed | 1995-05-24 | — | 20 | Details |
| EP0680214A2 | Sending of and billing for interactive shows based upon adv… | Expired / Lapsed | 1995-04-19 | — | 7 | Details |
| EP0677801A1 | Graphical password | Expired / Lapsed | 1995-03-29 | — | 11 | Details |
| EP0674459A2 | A method of on-line permanent virtual circuit routing | Expired / Lapsed | 1995-03-16 | — | 14 | Details |
| EP0673170A2 | Video signal processing systems and methods utilizing autom… | Expired / Lapsed | 1995-03-08 | — | 13 | Details |
| EP0668579A2 | Secure money transfer techniques using smart cards | Expired / Lapsed | 1995-02-02 | — | 11 | Details |
| EP0661895A1 | Switching arrangement for handling wireless and wired termi… | Expired / Lapsed | 1994-12-14 | — | 15 | Details |
| EP0661878A2 | A network-based system enabling image communications | Expired / Lapsed | 1994-12-09 | — | 11 | Details |
| EP0660249A1 | Table of contents indexing system | Expired / Lapsed | 1994-12-07 | — | 15 | Details |
| EP0658862A2 | Method and system for mediating transactions that use porta… | Expired / Lapsed | 1994-12-01 | — | 20 | Details |
| EP0658063A2 | A signaling system for broadband communications networks | Expired / Lapsed | 1994-11-30 | — | 9 | Details |
| EP0654930A1 | Network-accessible intelligent telephone service | Expired / Lapsed | 1994-11-09 | — | 12 | Details |
| EP0647055A1 | Cellular telephone billing management system | Expired / Lapsed | 1994-09-21 | — | 9 | Details |
| EP0644513A2 | A smartcard adapted for a plurality of service providers an… | Expired / Lapsed | 1994-09-07 | — | 17 | Details |
| EP0639896A1 | Method and apparatus for operating a CDMA network using pow… | Expired / Lapsed | 1994-08-10 | — | 10 | Details |
| EP0627837A1 | Telecommunications call completion based on mutually agreed… | Expired / Lapsed | 1994-05-25 | — | 6 | Details |
| EP0625750A2 | Methods and apparatus for making and using distributed appl… | Expired / Lapsed | 1994-05-11 | — | 12 | Details |
| EP0624039A2 | Integrated television services system | Expired / Lapsed | 1994-04-20 | — | 22 | Details |
| EP0609021A2 | Capacitive position sensor | Expired / Lapsed | 1994-01-19 | — | 10 | Details |
| EP0605115A2 | Program server for interactive television system | Expired / Lapsed | 1993-12-06 | — | 29 | Details |
| EP0588519A2 | Continuous authentication using an in-band or out-of-band s… | Expired / Lapsed | 1993-08-26 | — | 22 | Details |
| EP0583094A2 | ISDN-based system for making a video call | Expired / Lapsed | 1993-07-22 | — | 17 | Details |
| EP0569166A1 | Gold-tin solder suitable for self-aligning applications | Expired / Lapsed | 1993-04-22 | — | 3 | Details |
| EP0553994A1 | Compact optical pulse source | Expired / Lapsed | 1993-01-20 | — | 8 | Details |
| EP0531046A2 | Multi-subcarrier modulation for HDTV transmission | Expired / Lapsed | 1992-08-27 | — | 17 | Details |
| EP0531048A2 | A system for providing personalized telephone calling featu… | Expired / Lapsed | 1992-08-27 | — | 20 | Details |
| EP0526104A2 | Arrangement for controlling shared-buffer-memory overflow i… | Expired / Lapsed | 1992-07-23 | — | 10 | Details |
| EP0526106A2 | Integrated wireless telecommunication and local area networ… | Expired / Lapsed | 1992-07-23 | — | 9 | Details |
| EP0510859A2 | Molded optical package utilizing leadframe technology | Expired / Lapsed | 1992-04-14 | — | 11 | Details |
| EP0494513A2 | Telecommunications network restoration architecture | Expired / Lapsed | 1991-12-10 | — | 12 | Details |
| EP0478190A2 | Fair access of multi-priority traffic to distributed-queue … | Expired / Lapsed | 1991-09-13 | — | 25 | Details |
| EP0472349A2 | Autonomous registration overload control for cellular mobil… | Expired / Lapsed | 1991-08-13 | — | 8 | Details |
| EP0467591A2 | Hypermedia arrangement using a window system and layered in… | Expired / Lapsed | 1991-07-11 | — | 18 | Details |
| EP0465090A1 | Congestion control for connectionless traffic in data netwo… | Expired / Lapsed | 1991-06-25 | — | 24 | Details |
| EP0453128A3 | Multiple call control method in a multimedia conferencing s… | Expired / Lapsed | 1991-04-03 | — | 0 | Details |
| EP0455912A2 | Electronic messaging system with multiple personal greetings | Expired / Lapsed | 1990-12-14 | — | 24 | Details |
| EP0430571A2 | Dynamic window sizing in a data network | Expired / Lapsed | 1990-11-21 | — | 32 | Details |
| EP0413505A1 | Generalized viterbi decoding algorithms | Expired / Lapsed | 1990-08-09 | — | 25 | Details |
| EP0413489A2 | Optical assembly comprising optical fiber coupling means | Expired / Lapsed | 1990-08-06 | — | 11 | Details |
| EP0413488A2 | Arrangement for regulating traffic in a high speed data net… | Expired / Lapsed | 1990-08-06 | — | 26 | Details |
| EP0366342A2 | Method for routing information in a telecommunications swit… | Expired / Lapsed | 1989-10-18 | — | 5 | Details |
| EP0335531A2 | Optical fiber coupling | Expired / Lapsed | 1989-03-16 | — | 12 | Details |
| EP0294133A2 | Protocols for very high-speed optical LANs | Expired / Lapsed | 1988-05-31 | — | 14 | Details |
| EP0275678A1 | Packet switching system arranged for congestion control thr… | Expired / Lapsed | 1987-12-18 | — | 16 | Details |
| EP0275679A1 | Packet switching system arranged for congestion control | Expired / Lapsed | 1987-12-18 | — | 9 | Details |
| EP0255767A2 | Selective broadcasting arrangement for local area networks | Expired / Lapsed | 1987-07-22 | — | 10 | Details |
| EP0217308A2 | A method of and an arrangement for forwarding a customer or… | Expired / Lapsed | 1986-09-26 | — | 27 | Details |
| EP0216381A2 | Discretionary call forwarding | Expired / Lapsed | 1986-09-25 | — | 52 | Details |
| EP0122765A2 | Network protocol for integrating synchronous and asynchrono… | Expired / Lapsed | 1984-04-09 | — | 11 | Details |
| FR2520539A1 | METHOD AND SYSTEM FOR PROCESSING SILENCES IN A SPEECH SIGNAL | Expired / Lapsed | 1983-01-21 | — | 0 | Details |
| GB2060309A | Technique for estimation of displacement and/or velocity of… | Expired / Lapsed | 1980-02-25 | — | 0 | Details |
| WO1980001336A1 | A demultiplexing photodetector | Expired / Lapsed | 1979-12-04 | — | 0 | Details |
| WO1980000639A1 | Fabrication of integrated circuits utilizing thick high-res… | Expired / Lapsed | 1979-09-07 | — | 0 | Details |
| DE2924581A1 | Optical signal communication along transmission line - conv… | Expired / Lapsed | 1979-06-19 | — | 0 | Details |
| DE2646163A1 | MEMORY REPAIR CIRCUIT | Expired / Lapsed | 1976-10-13 | — | 0 | Details |
| DE2557660A1 | METHOD AND DEVICE FOR SPLICE OF OPTICAL FIBERS | Expired / Lapsed | 1975-12-20 | — | 0 | Details |
| GB1524874A | Optical fibre waveguides | Expired / Lapsed | 1975-12-17 | — | 0 | Details |
| FR2248521A1 | FR2248521A1 - - Google Patents | Expired / Lapsed | 1974-10-17 | — | 0 | Details |
| DE2449359A1 | COUPLING DEVICE FOR OPTICAL FIBERS | Expired / Lapsed | 1974-10-17 | — | 0 | Details |
| DE2312904B2 | CIRCUIT ARRANGEMENT FOR TELEPHONE NUMBER POSITION NUMBER VA… | Expired / Lapsed | 1973-03-16 | — | 0 | Details |
| DE2250796A1 | DEVICE FOR CAPTURING MOVING AREAS IN AN IMAGE REPRESENTED B… | Expired / Lapsed | 1972-10-17 | — | 0 | Details |
| DE2241573A1 | DIGITAL DATA PROCESSING SYSTEM | Expired / Lapsed | 1972-08-24 | — | 0 | Details |
| DE2201764B2 | Circuit arrangement for converting an electrical call signa… | Expired / Lapsed | 1972-01-14 | — | 0 | Details |
| DE2163424A1 | Mobile telecommunications system | Expired / Lapsed | 1971-12-21 | — | 0 | Details |
| DE2062922A1 | Predict video coding using the measured object speed | Expired / Lapsed | 1970-12-21 | — | 0 | Details |
| DE1956850A1 | Digital signal transmission arrangement | Expired / Lapsed | 1969-11-12 | — | 0 | Details |
| DE1956843A1 | Redundancy reduction system | Expired / Lapsed | 1969-11-12 | — | 0 | Details |
| DE1941336A1 | Speech signal processing device | Expired / Lapsed | 1969-08-14 | — | 0 | Details |
| GB1240190A | Computer graphics system | Expired / Lapsed | 1968-11-13 | — | 0 | Details |
| DE1762036A1 | Digital voice display system | Expired / Lapsed | 1968-03-27 | — | 0 | Details |
| DE1690535B1 | Mercury switch | Expired / Lapsed | 1968-03-01 | — | 0 | Details |
| DE1512833A1 | Automatic setting of the load for the voice interpollation … | Expired / Lapsed | 1967-06-28 | — | 0 | Details |
| DE1573948A1 | Electromechanical converter | Expired / Lapsed | 1966-06-28 | — | 0 | Details |
| GB952226A | Wire for superconductive magnets | Expired / Lapsed | 1961-08-22 | — | 0 | Details |
| GB684079A | Improvements in or relating to magnetic recorders, particul… | Expired / Lapsed | 1951-08-24 | — | 0 | Details |
| GB625501A | Electrical resistive elements and methods of making them | Expired / Lapsed | 1947-08-01 | — | 0 | Details |
| GB632980A | Methods of treating germanium material | Expired / Lapsed | 1946-12-23 | — | 0 | Details |
| GB599341A | Improvements in electrical translating devices such as cont… | Expired / Lapsed | 1945-09-14 | — | 0 | Details |
| GB589966A | Method of and apparatus for plating surfaces with tungsten,… | Expired / Lapsed | 1944-09-26 | — | 0 | Details |
| GB588187A | Improvements in pulse echo distance measuring devices | Expired / Lapsed | 1944-06-21 | — | 0 | Details |
| GB551209A | Rectifying contact detector systems for very short electric… | Expired / Lapsed | 1941-02-04 | — | 0 | Details |
| GB466063A | High frequency electromagnetic wave transmission apparatus | Expired / Lapsed | 1936-05-08 | — | 0 | Details |
| GB437294A | Piezo electric devices | Expired / Lapsed | 1934-04-27 | — | 0 | Details |
| US7467225B2 | System, method and apparatus for network service load and r… | Expired / Lapsed | 2004-05-11 | 2008-12-16 | 32 | Details |
| US7180852B1 | Method for selecting a restoration path in a mesh network | Expired / Lapsed | 2005-09-30 | 2007-02-20 | 14 | Details |
| US6982951B2 | Method for selecting a restoration path in a mesh network | Expired / Lapsed | 2001-07-19 | 2006-01-03 | 12 | Details |
| EP0742658B1 | Dynamic channel assignment for data transmitted via cable t… | Expired / Lapsed | 1996-05-01 | 2005-02-23 | 10 | Details |
| US6760775B1 | System, method and apparatus for network service load and r… | Expired / Lapsed | 2000-03-06 | 2004-07-06 | 11 | Details |
| US6725303B1 | Method and apparatus for establishing a personalized connec… | Expired / Lapsed | 2000-08-31 | 2004-04-20 | 33 | Details |
| US6707789B1 | Flexible SONET ring with integrated cross-connect system | Expired / Lapsed | 1999-11-03 | 2004-03-16 | 17 | Details |
| US6697334B1 | Method for designing a network | Expired / Lapsed | 2000-01-18 | 2004-02-24 | 6 | Details |
| US6678705B1 | System for archiving electronic documents using messaging g… | Expired / Lapsed | 1999-11-16 | 2004-01-13 | 17 | Details |
| US6651089B1 | Surfing friendly multicasting arrangement | Expired / Lapsed | 1999-06-05 | 2003-11-18 | 42 | Details |
| US6600719B1 | Method and apparatus for restoring a network | Expired / Lapsed | 2000-01-04 | 2003-07-29 | 2 | Details |
| US6587235B1 | Method and apparatus for capacity-efficient restoration in … | Expired / Lapsed | 1999-12-16 | 2003-07-01 | 16 | Details |
| US6570847B1 | Method and system for network traffic rate control based on… | Expired / Lapsed | 1999-03-18 | 2003-05-27 | 28 | Details |
| US6567418B1 | System and method for multichannel communication | Expired / Lapsed | 1998-12-23 | 2003-05-20 | 12 | Details |
| US6515964B1 | Method and apparatus for dynamically controlling the admiss… | Expired / Lapsed | 1999-04-30 | 2003-02-04 | 6 | Details |
| US6501834B1 | Message sender status monitor | Expired / Lapsed | 2001-11-21 | 2002-12-31 | 17 | Details |
| US6501763B1 | Network-based service for originator-initiated automatic re… | Expired / Lapsed | 1999-05-06 | 2002-12-31 | 11 | Details |
| US6490347B2 | Method and apparatus for providing telecommunications trunk… | Expired / Lapsed | 1998-04-24 | 2002-12-03 | 10 | Details |
| US6473778B1 | Generating hypermedia documents from transcriptions of tele… | Expired / Lapsed | 1999-02-01 | 2002-10-29 | 33 | Details |
| EP0715423B1 | Symbol error based power control for mobile telecommunicati… | Expired / Lapsed | 1995-11-21 | 2002-10-02 | 7 | Details |
| US6459913B2 | Unified alerting device and method for alerting a subscribe… | Expired / Lapsed | 1999-05-03 | 2002-10-01 | 30 | Details |
| US6452923B1 | Cable connected wan interconnectivity services for corporat… | Expired / Lapsed | 1998-12-31 | 2002-09-17 | 15 | Details |
| US6426944B1 | Method and apparatus for controlling data messages across a… | Expired / Lapsed | 1998-12-30 | 2002-07-30 | 15 | Details |
| US6421429B1 | Network-based system enabling image communications | Expired / Lapsed | 1998-03-18 | 2002-07-16 | 30 | Details |
| US6400804B1 | On-hold activity selection apparatus and method | Expired / Lapsed | 1998-12-10 | 2002-06-04 | 6 | Details |
| US6397255B1 | Method and apparatus for providing intelligent network serv… | Expired / Lapsed | 1998-12-23 | 2002-05-28 | 27 | Details |
| US6396852B1 | Ring bundling in the design of rings for telecommunications… | Expired / Lapsed | 1997-11-18 | 2002-05-28 | 28 | Details |
| US6392996B1 | Method and apparatus for frame peeking | Expired / Lapsed | 1998-04-13 | 2002-05-21 | 32 | Details |
| US6380947B1 | Method and apparatus for displaying and tree scrolling a hi… | Expired / Lapsed | 1999-12-16 | 2002-04-30 | 19 | Details |
| US6377995B2 | Indexing multimedia communications | Expired / Lapsed | 1998-02-19 | 2002-04-23 | 21 | Details |
| US6339594B1 | Wan-based gateway | Expired / Lapsed | 1998-11-06 | 2002-01-15 | 9 | Details |
| US6330326B1 | Dynamic staffing of service centers to provide substantiall… | Expired / Lapsed | 1998-03-27 | 2001-12-11 | 21 | Details |
| US6324162B1 | Path-based restoration mesh networks | Expired / Lapsed | 1998-06-03 | 2001-11-27 | 26 | Details |
| US6314084B1 | Transmission system, method and apparatus for scheduling tr… | Expired / Lapsed | 1997-12-05 | 2001-11-06 | 10 | Details |
| US6301258B1 | Low-latency buffering for packet telephony | Expired / Lapsed | 1997-12-04 | 2001-10-09 | 58 | Details |
| US6301608B1 | Method and apparatus providing personalized mailbox filters | Expired / Lapsed | 1996-08-14 | 2001-10-09 | 29 | Details |
| US6298120B1 | Intelligent processing for establishing communication over … | Expired / Lapsed | 1996-06-28 | 2001-10-02 | 28 | Details |
| US6259701B1 | Method and system for a unicast endpoint client to access a… | Expired / Lapsed | 1997-09-11 | 2001-07-10 | 17 | Details |
| US6256675B1 | System and method for allocating requests for objects and m… | Expired / Lapsed | 1998-05-06 | 2001-07-03 | 22 | Details |
| US6256648B1 | System and method for selecting and displaying hyperlinked … | Expired / Lapsed | 1998-01-29 | 2001-07-03 | 34 | Details |
| US6252952B1 | Personal user network (closed user network) PUN/CUN | Expired / Lapsed | 1999-12-30 | 2001-06-26 | 9 | Details |
| US6253146B1 | Network-based traffic congestion notification service | Expired / Lapsed | 1999-12-06 | 2001-06-26 | 30 | Details |
| US6252857B1 | Method and apparatus for provisioned and dynamic quality of… | Expired / Lapsed | 1998-03-04 | 2001-06-26 | 10 | Details |
| US6253189B1 | System and method for completing advertising time slot tran… | Expired / Lapsed | 1997-09-15 | 2001-06-26 | 40 | Details |
| US6233686B1 | System and method for providing peer level access control o… | Expired / Lapsed | 1997-01-17 | 2001-05-15 | 21 | Details |
| EP0479478B1 | Communications network arranged to transport connection ori… | Expired / Lapsed | 1991-09-25 | 2001-05-09 | 4 | Details |
| US6229821B1 | Serial data transmission of variable length mini packets us… | Expired / Lapsed | 1997-04-22 | 2001-05-08 | 22 | Details |
| US6226744B1 | Method and apparatus for authenticating users on a network … | Expired / Lapsed | 1997-10-09 | 2001-05-01 | 30 | Details |
| US6219413B1 | Apparatus and method for called-party telephone messaging w… | Expired / Lapsed | 1997-08-07 | 2001-04-17 | 23 | Details |
| US6215859B1 | Delivery of urgent messages by integrated forced delivery a… | Expired / Lapsed | 1997-10-02 | 2001-04-10 | 18 | Details |
| US6192406B1 | Startup management system and method for networks | Expired / Lapsed | 1997-06-13 | 2001-02-20 | 14 | Details |
| US6189043B1 | Dynamic cache replication in a internet environment through… | Expired / Lapsed | 1997-06-09 | 2001-02-13 | 24 | Details |
| US6185603B1 | Method and system for delivery of e-mail and alerting messa… | Expired / Lapsed | 1997-03-13 | 2001-02-06 | 41 | Details |
| US6175858B1 | Intelligent network messaging agent and method | Expired / Lapsed | 1998-07-13 | 2001-01-16 | 32 | Details |
| US6175842B1 | System and method for providing dynamic three-dimensional m… | Expired / Lapsed | 1997-07-03 | 2001-01-16 | 31 | Details |
| US6173324B1 | Method and apparatus for fault detection and isolation in d… | Expired / Lapsed | 1998-07-15 | 2001-01-09 | 19 | Details |
| US6173364B1 | Session cache and rule caching method for a dynamic filter | Expired / Lapsed | 1997-01-15 | 2001-01-09 | 10 | Details |
| EP0673164B1 | System and method of capturing encoded data transmitted ove… | Expired / Lapsed | 1995-03-08 | 1999-05-19 | 25 | Details |
| US5754628A | Method of providing telecommunications network-based messag… | Expired / Lapsed | 1997-05-06 | 1998-05-19 | 13 | Details |
| US5689553A | Multimedia telecommunications network and service | Expired / Lapsed | 1993-04-22 | 1997-11-18 | 42 | Details |
| US5553239A | Management facility for server entry and application utiliz… | Expired / Lapsed | 1994-11-10 | 1996-09-03 | 23 | Details |
| US5550551A | Position monitoring system and method | Expired / Lapsed | 1994-07-25 | 1996-08-27 | 30 | Details |
| USD372245S | Hand-held remote control unit | Expired / Lapsed | 1995-04-03 | 1996-07-30 | 1 | Details |
| US5530802A | Input sequence reordering method for software failure recov… | Expired / Lapsed | 1994-06-22 | 1996-06-25 | 13 | Details |
| US5513339A | Concurrent fault simulation of circuits with both logic ele… | Expired / Lapsed | 1994-12-19 | 1996-04-30 | 8 | Details |
| US5487111A | Telecommunications system sequence calling | Expired / Lapsed | 1993-07-29 | 1996-01-23 | 28 | Details |
| US5479482A | Cellular terminal for providing public emergency call locat… | Expired / Lapsed | 1994-09-26 | 1995-12-26 | 63 | Details |
| US5459304A | Smart card techniques for motor vehicle record administrati… | Expired / Lapsed | 1994-09-13 | 1995-10-17 | 10 | Details |
| US5408526A | Conference calling system | Expired / Lapsed | 1992-10-29 | 1995-04-18 | 16 | Details |
| US4807108B1 | Product realization method | Expired / Lapsed | 1987-08-10 | 1995-03-28 | 0 | Details |
| US5396492A | Method and apparatus for adaptive clock recovery | Expired / Lapsed | 1993-04-28 | 1995-03-07 | 42 | Details |
| US4922348B1 | Facsimile service | Expired / Lapsed | 1989-02-10 | 1994-10-11 | 0 | Details |
| US4900214A | Method and apparatus for transporting semiconductor wafers | Expired / Lapsed | 1988-05-25 | 1990-02-13 | 9 | Details |
| US4894822A | Fast packetized data delivery for digital networks | Expired / Lapsed | 1987-11-24 | 1990-01-16 | 54 | Details |
| US4815103A | Equalizer-based timing recovery | Expired / Lapsed | 1987-10-29 | 1989-03-21 | 30 | Details |
| US4811216A | Multiprocessor memory management method | Expired / Lapsed | 1986-12-22 | 1989-03-07 | 25 | Details |
| US4775953A | Workstation with typewriter emulation | Expired / Lapsed | 1986-12-22 | 1988-10-04 | 14 | Details |
| US4769834A | Inter-exchange carrier access | Expired / Lapsed | 1987-01-30 | 1988-09-06 | 8 | Details |
| USD296328S | Overhead optical scanner | Expired / Lapsed | 1987-06-01 | 1988-06-21 | 1 | Details |
| US4731663A | Method and apparatus for color identification | Expired / Lapsed | 1987-05-20 | 1988-03-15 | 14 | Details |
| USD294500S | Telephone handset | Expired / Lapsed | 1987-03-23 | 1988-03-01 | 1 | Details |
| USD293440S | Housing for handset base of transaction telephone or simila… | Expired / Lapsed | 1987-02-13 | 1987-12-29 | 1 | Details |
| USD289643S | Housing for telephone base | Expired / Lapsed | 1985-09-20 | 1987-05-05 | 1 | Details |
| US4653048A | Method for interprocessor message accountability | Expired / Lapsed | 1984-05-14 | 1987-03-24 | 16 | Details |
| USD284764S | Telephone cradle | Expired / Lapsed | 1985-04-29 | 1986-07-22 | 1 | Details |
| US4600522A | Detergent cleaning composition | Expired / Lapsed | 1982-04-26 | 1986-07-15 | 13 | Details |
| USD284471S | Telephone handset | Expired / Lapsed | 1985-04-29 | 1986-07-01 | 1 | Details |
| USD283890S | Calling card telephone | Expired / Lapsed | 1985-04-29 | 1986-05-20 | 1 | Details |
| US4582564A | Method of providing an adherent metal coating on an epoxy s… | Expired / Lapsed | 1983-10-20 | 1986-04-15 | 18 | Details |
| USD282467S | Housing for a telephone handset | Expired / Lapsed | 1985-05-17 | 1986-02-04 | 1 | Details |
| US4541980A | Methods of producing plastic-coated metallic members | Expired / Lapsed | 1984-01-09 | 1985-09-17 | 22 | Details |
| US4537663A | Method of and apparatus for plating using controlled progre… | Expired / Lapsed | 1982-07-27 | 1985-08-27 | 13 | Details |
| US4532933A | Focusing mechanism for an ultrasound device | Expired / Lapsed | 1983-04-25 | 1985-08-06 | 16 | Details |
| USD279005S | Housing for a telephone handset or similar article | Expired / Lapsed | 1984-08-29 | 1985-05-28 | 1 | Details |
| USD279010S | Video monitor | Expired / Lapsed | 1984-06-22 | 1985-05-28 | 1 | Details |
| USD278814S | Telephone stand | Expired / Lapsed | 1984-08-29 | 1985-05-14 | 1 | Details |
| USD278816S | Housing for telephone handset | Expired / Lapsed | 1984-07-19 | 1985-05-14 | 1 | Details |
| USD278531S | Housing for a telephone or similar article | Expired / Lapsed | 1984-07-19 | 1985-04-23 | 1 | Details |
| USD277958S | Telephone instrument base for a handset | Expired / Lapsed | 1984-01-16 | 1985-03-12 | 1 | Details |
| US4502785A | Surface profiling technique | Expired / Lapsed | 1981-08-31 | 1985-03-05 | 8 | Details |
| USD277480S | Wall telephone stand or similar article | Expired / Lapsed | 1984-05-10 | 1985-02-05 | 1 | Details |
| US4489102A | Radiation-stimulated deposition of aluminum | Expired / Lapsed | 1983-04-04 | 1984-12-18 | 9 | Details |
| USD274959S | Phone enclosure | Expired / Lapsed | 1982-05-14 | 1984-08-07 | 1 | Details |
| US4456793A | Cordless telephone system | Expired / Lapsed | 1982-06-09 | 1984-06-26 | 23 | Details |
| USD273909S | Telephone stand | Expired / Lapsed | 1983-01-05 | 1984-05-22 | 1 | Details |
| US4444848A | Adherent metal coatings on rubber-modified epoxy resin surf… | Expired / Lapsed | 1982-01-04 | 1984-04-24 | 7 | Details |
| US4439760A | Method and apparatus for compiling three-dimensional digita… | Expired / Lapsed | 1981-05-19 | 1984-03-27 | 28 | Details |
| US4438530A | Adaptive cross-polarization interference cancellation system | Expired / Lapsed | 1982-06-14 | 1984-03-20 | 11 | Details |
| US4428773A | Process for treating spent fluids to recover copper and cop… | Expired / Lapsed | 1982-12-30 | 1984-01-31 | 19 | Details |
| US4425618A | Method and apparatus for introducing program changes in pro… | Expired / Lapsed | 1981-11-23 | 1984-01-10 | 17 | Details |
| US4424565A | Channel interface circuit with high speed data message head… | Expired / Lapsed | 1981-06-22 | 1984-01-03 | 23 | Details |
| US4420206A | Electrical connector | Expired / Lapsed | 1981-11-30 | 1983-12-13 | 20 | Details |
| USD271691S | Telephone stand | Expired / Lapsed | 1981-10-05 | 1983-12-06 | 1 | Details |
| US4415901A | Low power beam switchable antenna arrangement | Expired / Lapsed | 1981-09-21 | 1983-11-15 | 3 | Details |
| US4415229A | Optical fiber switch apparatus | Expired / Lapsed | 1981-08-24 | 1983-11-15 | 10 | Details |
| US4414066A | Electrochemical photoetching of compound semiconductors | Expired / Lapsed | 1982-09-10 | 1983-11-08 | 27 | Details |
| US4412123A | Laminated electric heat generating member for reflow solder… | Expired / Lapsed | 1980-05-09 | 1983-10-25 | 7 | Details |
| USD270834S | Acoustic coupler adapter | Expired / Lapsed | 1981-10-05 | 1983-10-04 | 1 | Details |
| US4403826A | Ultraviolet radiation detector | Expired / Lapsed | 1981-03-23 | 1983-09-13 | 7 | Details |
| US4401482A | Fe--Cr--Co Magnets by powder metallurgy processing | Expired / Lapsed | 1981-12-07 | 1983-08-30 | 8 | Details |
| US4400624A | Uninterruptible power supplies | Expired / Lapsed | 1982-04-29 | 1983-08-23 | 24 | Details |
| US4399555A | Cellular high capacity mobile radiotelephone system with fl… | Expired / Lapsed | 1980-04-28 | 1983-08-16 | 15 | Details |
| US4398063A | Mobile telephone interoffice handoff limiting method and ap… | Expired / Lapsed | 1980-10-24 | 1983-08-09 | 13 | Details |
| US4395594A | Method and apparatus for forcing randomization of idle chan… | Expired / Lapsed | 1981-08-24 | 1983-07-26 | 8 | Details |
| USD269432S | Housing for a telephone amplifier | Expired / Lapsed | 1980-07-07 | 1983-06-21 | 1 | Details |
| US4385208A | Multifrequency receiver | Expired / Lapsed | 1981-04-15 | 1983-05-24 | 11 | Details |
| USRE31253E | Echo cancellation in two-wire, two-way data transmission sy… | Expired / Lapsed | 1980-12-23 | 1983-05-24 | 13 | Details |
| USD269088S | Portable transceiver or similar article | Expired / Lapsed | 1980-12-05 | 1983-05-24 | 1 | Details |
| US4383315A | Idle time slot seizure and transmission facilities for loop… | Expired / Lapsed | 1981-07-20 | 1983-05-10 | 35 | Details |
| US4383332A | High capacity digital mobile radio system | Expired / Lapsed | 1980-11-21 | 1983-05-10 | 20 | Details |
| US4383323A | Spread spectrum FH-MFSK transmitter and receiver | Expired / Lapsed | 1980-06-09 | 1983-05-10 | 11 | Details |
| US4379003A | Magnetic devices by selective reduction of oxides | Expired / Lapsed | 1980-07-30 | 1983-04-05 | 9 | Details |
| US4377436A | Plasma-assisted etch process with endpoint detection | Expired / Lapsed | 1981-11-05 | 1983-03-22 | 25 | Details |
| US4377315A | Circuit board keying arrangement | Expired / Lapsed | 1981-02-09 | 1983-03-22 | 15 | Details |
| USD268342S | Stand for a portable transceiver or similar article | Expired / Lapsed | 1980-12-05 | 1983-03-22 | 1 | Details |
| US4376309A | Method and apparatus for signal-eye tracking in digital tra… | Expired / Lapsed | 1981-05-29 | 1983-03-08 | 18 | Details |
| US4375619A | FET Operational amplifier with increased output swing | Expired / Lapsed | 1980-06-26 | 1983-03-01 | 6 | Details |
| US4375083A | Signal sequence editing method and apparatus with automatic… | Expired / Lapsed | 1980-01-31 | 1983-02-22 | 42 | Details |
| US4359485A | Radiation induced deposition of metal on semiconductor surf… | Expired / Lapsed | 1981-05-01 | 1982-11-16 | 17 | Details |
| US4357493A | Method and apparatus for storing announcements in a communi… | Expired / Lapsed | 1981-02-09 | 1982-11-02 | 18 | Details |
| US4355411A | Technique for efficient spectrum utilization in mobile radi… | Expired / Lapsed | 1981-06-22 | 1982-10-19 | 16 | Details |
| US4355399A | Adaptive spread spectrum FH-MFSK transmitter and receiver | Expired / Lapsed | 1981-02-23 | 1982-10-19 | 18 | Details |
| US4353086A | Silicon integrated circuits | Expired / Lapsed | 1980-05-07 | 1982-10-05 | 9 | Details |
| USD266381S | Public telephone shelf | Expired / Lapsed | 1979-03-09 | 1982-10-05 | 1 | Details |
| US4347552A | Assembly of electrical components with substrates | Expired / Lapsed | 1980-04-14 | 1982-08-31 | 10 | Details |
| USD265401S | Telephone stand | Expired / Lapsed | 1979-10-12 | 1982-07-13 | 1 | Details |
| USD264967S | Telephone console | Expired / Lapsed | 1980-05-08 | 1982-06-15 | 1 | Details |
| US4333793A | High-selectivity plasma-assisted etching of resist-masked l… | Expired / Lapsed | 1980-10-20 | 1982-06-08 | 11 | Details |
| US4333044A | Methods of and system for aligning a device with a referenc… | Expired / Lapsed | 1980-08-29 | 1982-06-01 | 22 | Details |
| US4332433A | Termination of flat flexible cables | Expired / Lapsed | 1980-03-31 | 1982-06-01 | 10 | Details |
| US4328489A | Self-shift ac plasma panel using transport of charge cloud … | Expired / Lapsed | 1980-01-07 | 1982-05-04 | 26 | Details |
| USD263824S | General-purpose electronic telephone set base | Expired / Lapsed | 1979-06-28 | 1982-04-13 | 1 | Details |
| US4317035A | Gold monitoring procedure | Expired / Lapsed | 1979-12-20 | 1982-02-23 | 12 | Details |
| USD263046S | Telephone set | Expired / Lapsed | 1979-10-12 | 1982-02-16 | 1 | Details |
| USD263048S | Telephone handset | Expired / Lapsed | 1979-10-12 | 1982-02-16 | 1 | Details |
| US4313035A | Method of providing person locator service | Expired / Lapsed | 1980-01-18 | 1982-01-26 | 39 | Details |
| US4310722A | Mobile radiotelephone station two-way ranging system | Expired / Lapsed | 1979-12-17 | 1982-01-12 | 11 | Details |
| US4309618A | Precision optical distance measurement | Expired / Lapsed | 1980-05-05 | 1982-01-05 | 25 | Details |
| US4306289A | Digital computer having code conversion apparatus for an en… | Expired / Lapsed | 1980-02-04 | 1981-12-15 | 8 | Details |
| US4305045A | Phase locked loop clock synchronizing circuit with programm… | Expired / Lapsed | 1979-11-14 | 1981-12-08 | 16 | Details |
| US4301237A | Method for exposing substrates to X-rays | Expired / Lapsed | 1980-09-29 | 1981-11-17 | 2 | Details |
| US4300152A | Complementary field-effect transistor integrated circuit de… | Expired / Lapsed | 1980-04-07 | 1981-11-10 | 5 | Details |
| US4298237A | Printed wiring board interconnection apparatus | Expired / Lapsed | 1979-12-20 | 1981-11-03 | 24 | Details |
| US4296998A | Encapsulated light source with coupled fiberguide | Expired / Lapsed | 1979-12-17 | 1981-10-27 | 6 | Details |
| US4296282A | Incoming call identification arrangement | Expired / Lapsed | 1980-06-30 | 1981-10-20 | 4 | Details |
| US4291198A | General-purpose electronic telephone station set | Expired / Lapsed | 1979-06-28 | 1981-09-22 | 30 | Details |
| US4282267A | Methods and apparatus for generating plasmas | Expired / Lapsed | 1980-03-05 | 1981-08-04 | 28 | Details |
| US4278538A | Methods and apparatus for sorting workpieces according to t… | Expired / Lapsed | 1979-04-10 | 1981-07-14 | 30 | Details |
| US4277649A | Method and apparatus for screening telephone calls | Expired / Lapsed | 1980-01-18 | 1981-07-07 | 18 | Details |
| US4276243A | Vapor delivery control system and method | Expired / Lapsed | 1980-04-04 | 1981-06-30 | 11 | Details |
| US4276448A | Electronic tone ringer | Expired / Lapsed | 1979-08-20 | 1981-06-30 | 22 | Details |
| US4275385A | Infrared personnel locator system | Expired / Lapsed | 1979-08-13 | 1981-06-23 | 25 | Details |
| US4275313A | Current limiting output circuit with output feedback | Expired / Lapsed | 1979-04-09 | 1981-06-23 | 6 | Details |
| US4271524A | Spread spectrum FH-MFSK receiver | Expired / Lapsed | 1980-02-25 | 1981-06-02 | 8 | Details |
| US4268536A | Method for depositing a metal on a surface | Expired / Lapsed | 1980-01-02 | 1981-05-19 | 11 | Details |
| US4261018A | Progressive image transmission | Expired / Lapsed | 1979-06-18 | 1981-04-07 | 13 | Details |
| US4253583A | Closure for container | Expired / Lapsed | 1980-01-31 | 1981-03-03 | 13 | Details |
| US4253155A | Self-compensating measurement system | Expired / Lapsed | 1979-01-31 | 1981-02-24 | 18 | Details |
| US4247740A | Trunk interface circuit | Expired / Lapsed | 1979-07-19 | 1981-01-27 | 26 | Details |
| USD257978S | Telephone set base enclosure | Expired / Lapsed | 1978-07-31 | 1981-01-20 | 1 | Details |
| US4245248A | Motion estimation and encoding of video signals in the tran… | Expired / Lapsed | 1979-04-04 | 1981-01-13 | 29 | Details |
| US4243295A | Polarization-independent optical directional coupler switch… | Expired / Lapsed | 1979-09-19 | 1981-01-06 | 4 | Details |
| US4241128A | Production of piezoelectric PVDF films | Expired / Lapsed | 1979-03-20 | 1980-12-23 | 10 | Details |
| US4240196A | Fabrication of two-level polysilicon devices | Expired / Lapsed | 1978-12-29 | 1980-12-23 | 6 | Details |
| US4238694A | Healing radiation defects in semiconductors | Expired / Lapsed | 1977-05-23 | 1980-12-09 | 18 | Details |
| US4236161A | Array feed for offset satellite antenna | Expired / Lapsed | 1978-09-18 | 1980-11-25 | 15 | Details |
| US4232338A | Method and apparatus for video signal encoding with motion … | Expired / Lapsed | 1979-06-08 | 1980-11-04 | 23 | Details |
| US4229624A | Switching network control arrangement | Expired / Lapsed | 1978-12-21 | 1980-10-21 | 9 | Details |
| US4228528A | Memory with redundant rows and columns | Expired / Lapsed | 1979-02-09 | 1980-10-14 | 8 | Details |
| US4223973A | Circuit board keying arrangement | Expired / Lapsed | 1979-02-08 | 1980-09-23 | 16 | Details |
| US4222112A | Dynamic RAM organization for reducing peak current | Expired / Lapsed | 1979-02-09 | 1980-09-09 | 11 | Details |
| US4221997A | Articulated robot arm and method of moving same | Expired / Lapsed | 1978-12-18 | 1980-09-09 | 9 | Details |
| US4218704A | Method and apparatus for video signal encoding with motion … | Expired / Lapsed | 1979-03-16 | 1980-08-19 | 26 | Details |
| US4217030A | Fiberoptic-electronic connector assembly | Expired / Lapsed | 1978-07-18 | 1980-08-12 | 20 | Details |
| US4211012A | Electric-signal controlled hand-held printer | Expired / Lapsed | 1978-03-23 | 1980-07-08 | 5 | Details |
| US4210923A | Edge illuminated photodetector with optical fiber alignment | Expired / Lapsed | 1979-01-02 | 1980-07-01 | 11 | Details |
| US4207137A | Method of controlling a plasma etching process by monitorin… | Expired / Lapsed | 1979-04-13 | 1980-06-10 | 17 | Details |
| US4204093A | Variable frame rate technique for use in a time-division mu… | Expired / Lapsed | 1978-05-19 | 1980-05-20 | 16 | Details |
| US4198162A | Tunable wide angular aperture filter by degenerate four-wav… | Expired / Lapsed | 1978-05-23 | 1980-04-15 | 14 | Details |
| US4196439A | Semiconductor device drain contact configuration | Expired / Lapsed | 1978-07-03 | 1980-04-01 | 14 | Details |
| US4189208A | Zinc chloride optical fibers for transmission in the infrar… | Expired / Lapsed | 1978-03-10 | 1980-02-19 | 16 | Details |
| USD254195S | Sliding hideaway keyboard | Expired / Lapsed | 1978-03-23 | 1980-02-12 | 1 | Details |
| US4187027A | Servo-control alignment of nonlinear crystals | Expired / Lapsed | 1978-04-20 | 1980-02-05 | 7 | Details |
| US4184049A | Transform speech signal coding with pitch controlled adapti… | Expired / Lapsed | 1978-08-25 | 1980-01-15 | 18 | Details |
| US4183096A | Self checking dynamic memory system | Expired / Lapsed | 1978-05-25 | 1980-01-08 | 16 | Details |
| US4181821A | Multiple template speech recognition system | Expired / Lapsed | 1978-10-31 | 1980-01-01 | 32 | Details |
| USD253821S | Telephone stand | Expired / Lapsed | 1977-11-23 | 1980-01-01 | 1 | Details |
| US4173389A | Molded optical fiber connector | Expired / Lapsed | 1977-09-28 | 1979-11-06 | 12 | Details |
| US4171467A | Signal multiplexing circuit | Expired / Lapsed | 1978-07-20 | 1979-10-16 | 10 | Details |
| US4166254A | Switched diffraction grating | Expired / Lapsed | 1977-10-03 | 1979-08-28 | 14 | Details |
| US4161656A | Methods for measuring dopant concentrations in optical fibe… | Expired / Lapsed | 1978-03-28 | 1979-07-17 | 6 | Details |
| US4157612A | Method for improving the transmission properties of a conne… | Expired / Lapsed | 1977-12-27 | 1979-06-12 | 22 | Details |
| USD252087S | Telephone stand | Expired / Lapsed | 1977-11-23 | 1979-06-12 | 1 | Details |
| US4156200A | High reliability active-standby clock arrangement | Expired / Lapsed | 1978-03-20 | 1979-05-22 | 21 | Details |
| US4154983A | Loop carrier system for telecommunication and data services | Expired / Lapsed | 1978-03-13 | 1979-05-15 | 10 | Details |
| US4154591A | Fabrication of optical fibers with improved cross sectional… | Expired / Lapsed | 1977-12-06 | 1979-05-15 | 11 | Details |
| US4153330A | Single-mode wavelength division optical multiplexer | Expired / Lapsed | 1977-12-01 | 1979-05-08 | 14 | Details |
| US4151014A | Laser annealing | Expired / Lapsed | 1977-05-31 | 1979-04-24 | 9 | Details |
| US4150259A | Communication system conferencing arrangement | Expired / Lapsed | 1977-10-31 | 1979-04-17 | 15 | Details |
| US4147407A | Coatings for fiber waveguides | Expired / Lapsed | 1978-01-09 | 1979-04-03 | 4 | Details |
| US4144411A | Cellular radiotelephone system structured for flexible use … | Expired / Lapsed | 1976-09-22 | 1979-03-13 | 29 | Details |
| US4142312A | Station set for mobile radiotelephone units | Expired / Lapsed | 1977-07-20 | 1979-03-06 | 25 | Details |
| US4142004A | Method of coating semiconductor substrates | Expired / Lapsed | 1976-01-22 | 1979-02-27 | 2 | Details |
| US4140362A | Forming focusing diffraction gratings for integrated optics | Expired / Lapsed | 1977-07-14 | 1979-02-20 | 12 | Details |
| US4139895A | Analog computer | Expired / Lapsed | 1977-08-19 | 1979-02-13 | 5 | Details |
| USD250890S | Telephone station set base | Expired / Lapsed | 1977-04-21 | 1979-01-23 | 1 | Details |
| US4133976A | Predictive speech signal coding with reduced noise effects | Expired / Lapsed | 1978-04-07 | 1979-01-09 | 16 | Details |
| US4131767A | Echo cancellation in two-wire, two-way data transmission sy… | Expired / Lapsed | 1978-02-22 | 1978-12-26 | 13 | Details |
| US4131484A | Frequency adjusting a piezoelectric device by lasering | Expired / Lapsed | 1978-02-13 | 1978-12-26 | 12 | Details |
| US4127862A | Integrated optical detectors | Expired / Lapsed | 1977-09-06 | 1978-11-28 | 28 | Details |
| US4127320A | Multimode optical modulator/switch | Expired / Lapsed | 1977-06-29 | 1978-11-28 | 26 | Details |
| US4126794A | Semiconductor charge coupled device with split electrode co… | Expired / Lapsed | 1977-07-25 | 1978-11-21 | 14 | Details |
| USD250307S | Shelf for a public telephone or the like | Expired / Lapsed | 1976-10-29 | 1978-11-21 | 1 | Details |
| US4125748A | Communication system call transfer arrangement | Expired / Lapsed | 1977-10-31 | 1978-11-14 | 10 | Details |
| US4124774A | Telephone station coin memory and control system | Expired / Lapsed | 1977-07-27 | 1978-11-07 | 37 | Details |
| USD250108S | Telephone set base | Expired / Lapsed | 1976-09-15 | 1978-10-31 | 1 | Details |
| US4119363A | Package for optical devices including optical fiber-to-meta… | Expired / Lapsed | 1976-03-18 | 1978-10-10 | 18 | Details |
| US4117263A | Announcement generating arrangement utilizing digitally sto… | Expired / Lapsed | 1977-11-17 | 1978-09-26 | 19 | Details |
| US4111524A | Wavelength division multiplexer | Expired / Lapsed | 1977-04-14 | 1978-09-05 | 6 | Details |
| US4112247A | Gas feeder pipe assembly including electrical conductors | Expired / Lapsed | 1976-09-20 | 1978-09-05 | 5 | Details |
| US4107474A | Bipolar transistor switching network crosspoint | Expired / Lapsed | 1977-05-31 | 1978-08-15 | 16 | Details |
| US4107648A | Scan encoding of two dimensional pictorial entities | Expired / Lapsed | 1976-04-12 | 1978-08-15 | 13 | Details |
| US4105973A | Multibeam, digitally modulated, time division, switched sat… | Expired / Lapsed | 1976-10-15 | 1978-08-08 | 23 | Details |
| US4101847A | Laser control circuit | Expired / Lapsed | 1976-11-01 | 1978-07-18 | 15 | Details |
| US4099822A | Connector for making splicing, half-tap, bridging and termi… | Expired / Lapsed | 1977-01-24 | 1978-07-11 | 19 | Details |
| US4099832A | Optical fiber connector utilizing nested rod arrangement | Expired / Lapsed | 1976-12-27 | 1978-07-11 | 14 | Details |
| US4094580A | Hermaphrodite optical fiber connector | Expired / Lapsed | 1976-12-27 | 1978-06-13 | 3 | Details |
| US4095165A | Switching regulator control utilizing digital comparison te… | Expired / Lapsed | 1976-10-18 | 1978-06-13 | 11 | Details |
| US4090147A | Interferometric amplifier | Expired / Lapsed | 1977-07-20 | 1978-05-16 | 13 | Details |
| US4090221A | Apparatus for improving video signal-to-noise ratio | Expired / Lapsed | 1972-03-13 | 1978-05-16 | 13 | Details |
| USD247813S | Telephone stand | Expired / Lapsed | 1975-08-14 | 1978-05-02 | 1 | Details |
| US4084308A | Slicing method in fiber end preparation | Expired / Lapsed | 1976-11-22 | 1978-04-18 | 24 | Details |
| US4085368A | Interference canceling method and apparatus | Expired / Lapsed | 1976-08-30 | 1978-04-18 | 13 | Details |
| US4084023A | Method for depositing a metal on a surface | Expired / Lapsed | 1976-08-16 | 1978-04-11 | 15 | Details |
| US4081653A | Removal of thin films from substrates by laser induced expl… | Expired / Lapsed | 1976-12-27 | 1978-03-28 | 13 | Details |
| US4081658A | Electrically heated soldering device | Expired / Lapsed | 1976-04-28 | 1978-03-28 | 4 | Details |
| US4078255A | Sequence generator having amplitudes and phases of spectral… | Expired / Lapsed | 1977-01-06 | 1978-03-07 | 8 | Details |
| US4077693A | Panel-mountable connector block assembly | Expired / Lapsed | 1976-12-08 | 1978-03-07 | 5 | Details |
| US4076375A | Directional optical waveguide coupler and power tap arrange… | Expired / Lapsed | 1975-12-24 | 1978-02-28 | 8 | Details |
| US4074358A | Test set for measuring jitter distortion of data pulses | Expired / Lapsed | 1976-12-02 | 1978-02-14 | 21 | Details |
| US4074086A | Joint adaptive echo canceller and equalizer for two-wire fu… | Expired / Lapsed | 1976-09-07 | 1978-02-14 | 13 | Details |
| US4074072A | Multiprocessor control of a partitioned switching network b… | Expired / Lapsed | 1976-05-24 | 1978-02-14 | 26 | Details |
| US4072830A | Variable phase shifter for adaptive echo cancellers | Expired / Lapsed | 1976-10-04 | 1978-02-07 | 12 | Details |
| USD246584S | Telephone stand | Expired / Lapsed | 1975-09-18 | 1977-12-06 | 1 | Details |
| US4056719A | Two-way telephone transmission system utilizing opto-couple… | Expired / Lapsed | 1976-08-02 | 1977-11-01 | 15 | Details |
| US4054756A | Method and apparatus for automating special service call ha… | Expired / Lapsed | 1976-09-29 | 1977-10-18 | 31 | Details |
| US4053204A | Optical fiber having reduced dispersion | Expired / Lapsed | 1976-07-30 | 1977-10-11 | 7 | Details |
| US4049413A | Method for making optical fibers with variations in core di… | Expired / Lapsed | 1976-06-21 | 1977-09-20 | 13 | Details |
| US4048443A | Digital speech communication system for minimizing quantizi… | Expired / Lapsed | 1975-12-12 | 1977-09-13 | 26 | Details |
| US4046972A | Key telephone station set circuit | Expired / Lapsed | 1976-10-27 | 1977-09-06 | 17 | Details |
| US4046298A | Methods and apparatus for stripping optical fiber ribbons | Expired / Lapsed | 1975-12-29 | 1977-09-06 | 6 | Details |
| USD245602S | Telephone station handset | Expired / Lapsed | 1976-08-30 | 1977-08-30 | 1 | Details |
| US4041243A | Coin box signaling arrangement | Expired / Lapsed | 1976-09-20 | 1977-08-09 | 10 | Details |
| US4039249A | Integrated optical devices including tunable fixed grating | Expired / Lapsed | 1973-03-28 | 1977-08-02 | 6 | Details |
| USD245113S | Telephone station set base | Expired / Lapsed | 1976-08-30 | 1977-07-19 | 1 | Details |
| US4033667A | Multimode optical fiber | Expired / Lapsed | 1975-09-12 | 1977-07-05 | 5 | Details |
| US4034347A | Method and apparatus for controlling a multiprocessor system | Expired / Lapsed | 1975-08-08 | 1977-07-05 | 34 | Details |
| US4029900A | Digital synchronizing signal recovery circuits for a data r… | Expired / Lapsed | 1976-01-26 | 1977-06-14 | 31 | Details |
| US4029390A | Optical fiber group splicing technique and apparatus employ… | Expired / Lapsed | 1974-12-23 | 1977-06-14 | 12 | Details |
| US4028494A | Escrow telephone coin collection circuit and method | Expired / Lapsed | 1976-05-17 | 1977-06-07 | 16 | Details |
| US4028692A | Liquid crystal display device | Expired / Lapsed | 1975-09-15 | 1977-06-07 | 12 | Details |
| US4027247A | Receiver especially for use as a diversity combining receiv… | Expired / Lapsed | 1975-11-11 | 1977-05-31 | 10 | Details |
| US4025156A | Graded-index fiber for multimode optical communication | Expired / Lapsed | 1975-09-12 | 1977-05-24 | 6 | Details |
| US4021314A | Method of depositing a metal on a surface | Expired / Lapsed | 1976-03-25 | 1977-05-03 | 5 | Details |
| US4019048A | Regenerator for an optical transmission system | Expired / Lapsed | 1976-03-22 | 1977-04-19 | 40 | Details |
| US4019149A | Correlative data demodulator | Expired / Lapsed | 1976-01-16 | 1977-04-19 | 10 | Details |
| US4019140A | Methods and apparatus for reducing intelligible crosstalk i… | Expired / Lapsed | 1975-10-24 | 1977-04-19 | 50 | Details |
| USD243899S | Shelf for coin operated telephones | Expired / Lapsed | 1976-04-07 | 1977-04-05 | 1 | Details |
| US4013842A | Method and apparatus for interfacing digital and analog car… | Expired / Lapsed | 1976-04-15 | 1977-03-22 | 14 | Details |
| US4013000A | Optical crossbar switching network | Expired / Lapsed | 1975-11-20 | 1977-03-22 | 8 | Details |
| US4012598A | Method and means for pulse receiver synchronization | Expired / Lapsed | 1976-01-14 | 1977-03-15 | 34 | Details |
| US4010323A | Digital timing recovery | Expired / Lapsed | 1975-10-29 | 1977-03-01 | 8 | Details |
| US4010381A | No-break ac power supply | Expired / Lapsed | 1975-04-24 | 1977-03-01 | 29 | Details |
| US4006304A | Apparatus for word synchronization in an optical communicat… | Expired / Lapsed | 1975-12-10 | 1977-02-01 | 6 | Details |
| US4002389A | Self latching and unlatching connector assembly | Expired / Lapsed | 1975-07-11 | 1977-01-11 | 19 | Details |
| US3997772A | Digital phase shifter | Expired / Lapsed | 1975-09-05 | 1976-12-14 | 16 | Details |
| US3991318A | Optical detection systems utilizing organ arrays of optical… | Expired / Lapsed | 1975-03-10 | 1976-11-09 | 6 | Details |
| US3991297A | Electrically heated soldering device | Expired / Lapsed | 1975-02-27 | 1976-11-09 | 7 | Details |
| US3990006A | Digital tone detector using concatenated detection intervals | Expired / Lapsed | 1975-01-08 | 1976-11-02 | 21 | Details |
| US3990050A | Computer controlled automatic response system | Expired / Lapsed | 1974-09-25 | 1976-11-02 | 15 | Details |
| US3988535A | Automated positioning | Expired / Lapsed | 1975-11-04 | 1976-10-26 | 14 | Details |
| US3984626A | Picture signal coder | Expired / Lapsed | 1975-08-01 | 1976-10-05 | 21 | Details |
| US3983492A | Frequency scan and lock circuit for mobile radio channel se… | Expired / Lapsed | 1975-01-29 | 1976-09-28 | 6 | Details |
| US3982816A | Method for measuring the parameters of optical fibers | Expired / Lapsed | 1974-06-21 | 1976-09-28 | 23 | Details |
| US3983326A | Key pulse generator for secrecy signalling circuit | Expired / Lapsed | 1944-09-27 | 1976-09-28 | 31 | Details |
| US3982265A | Devices containing aluminum-V semiconductor and method for … | Expired / Lapsed | 1975-09-19 | 1976-09-21 | 17 | Details |
| US3982063A | Methods and apparatus for reducing the bandwidth of a video… | Expired / Lapsed | 1975-02-03 | 1976-09-21 | 12 | Details |
| US3979733A | Digital data communications system packet switch | Expired / Lapsed | 1975-05-09 | 1976-09-07 | 18 | Details |
| US3976847A | Key telephone system intercom arrangement | Expired / Lapsed | 1975-11-12 | 1976-08-24 | 15 | Details |
| US3974449A | Joint decision feedback equalization and carrier recovery a… | Expired / Lapsed | 1975-03-21 | 1976-08-10 | 8 | Details |
| US3973129A | Fluorimetric apparatus and method for analysis of body fluid | Expired / Lapsed | 1975-01-10 | 1976-08-03 | 33 | Details |
| US3971988A | AM/FM receiver using spectral parameter estimators | Expired / Lapsed | 1975-03-06 | 1976-07-27 | 16 | Details |
| US3972002A | Dual feedback amplifier | Expired / Lapsed | 1974-12-30 | 1976-07-27 | 5 | Details |
| CA993519A | Diversity receiver suitable for large scale integration | Expired / Lapsed | 1972-05-25 | 1976-07-20 | 0 | Details |
| US3969016A | Low dispersion optical fiber wave guiding structures with p… | Expired / Lapsed | 1975-05-09 | 1976-07-13 | 4 | Details |
| US3965279A | Ohmic contacts for group III-V n-type semiconductors | Expired / Lapsed | 1974-09-03 | 1976-06-22 | 18 | Details |
| US3963869A | Parity framing of pulse systems | Expired / Lapsed | 1974-12-02 | 1976-06-15 | 19 | Details |
| US3963957A | Lamp power supply arrangement for key telephone system | Expired / Lapsed | 1974-11-07 | 1976-06-15 | 12 | Details |
| US3963468A | Light guide fabrication | Expired / Lapsed | 1974-02-15 | 1976-06-15 | 17 | Details |
| US3958852A | Electrical connector | Expired / Lapsed | 1975-04-15 | 1976-05-25 | 12 | Details |
| US3958175A | Current limiting switching circuit | Expired / Lapsed | 1974-12-16 | 1976-05-18 | 10 | Details |
| USRE28811E | Interconnected loop data block transmission system | Expired / Lapsed | 1973-10-29 | 1976-05-11 | 14 | Details |
| US3952189A | Complex analog waveform generator | Expired / Lapsed | 1975-02-27 | 1976-04-20 | 7 | Details |
| US3949319A | High energy storage lasers employing perovskites containing… | Expired / Lapsed | 1974-09-12 | 1976-04-06 | 15 | Details |
| US3949121A | Method of forming a hydrophobic surface | Expired / Lapsed | 1973-12-12 | 1976-04-06 | 8 | Details |
| US3937899A | Tone detector using spectrum parameter estimation | Expired / Lapsed | 1975-01-30 | 1976-02-10 | 13 | Details |
| US3936631A | Optical fiber power tap | Expired / Lapsed | 1974-11-11 | 1976-02-03 | 12 | Details |
| US3935472A | Thin film liquid waveguide optical converter | Expired / Lapsed | 1975-03-14 | 1976-01-27 | 13 | Details |
| US3932160A | Method for forming low loss optical waveguide fibers | Expired / Lapsed | 1974-08-09 | 1976-01-13 | 15 | Details |
| US3932184A | Fabrication of microlenses | Expired / Lapsed | 1973-05-29 | 1976-01-13 | 6 | Details |
| US3926747A | Selective electrodeposition of gold on electronic devices | Expired / Lapsed | 1974-02-19 | 1975-12-16 | 10 | Details |
| US3923559A | Use of trapped hydrogen for annealing metal-oxide-semicondu… | Expired / Lapsed | 1975-01-13 | 1975-12-02 | 13 | Details |
| US3924080A | Zero suppression in pulse transmission systems | Expired / Lapsed | 1974-12-02 | 1975-12-02 | 27 | Details |
| US3924093A | Pattern delineation method and product so produced | Expired / Lapsed | 1973-05-09 | 1975-12-02 | 7 | Details |
| US3920889A | Method and apparatus for crispening video signals by the us… | Expired / Lapsed | 1974-12-05 | 1975-11-18 | 23 | Details |
| US3920912A | Hotel pbx electronic message billing arrangement | Expired / Lapsed | 1974-07-05 | 1975-11-18 | 10 | Details |
| US3919495A | Feeder distribution interface for rural areas | Expired / Lapsed | 1974-10-15 | 1975-11-11 | 12 | Details |
| US3916124A | Nodal switching network arrangement and control | Expired / Lapsed | 1973-08-31 | 1975-10-28 | 31 | Details |
| US3916182A | Periodic dielectric waveguide filter | Expired / Lapsed | 1973-08-03 | 1975-10-28 | 56 | Details |
| US3914768A | Multiple-beam Cassegrainian antenna | Expired / Lapsed | 1974-01-31 | 1975-10-21 | 11 | Details |
| US3911294A | Driver circuit for high speed gating of a field effect tran… | Expired / Lapsed | 1974-08-16 | 1975-10-07 | 16 | Details |
| US3909110A | Reduction of dispersion in a multimode fiber waveguide with… | Expired / Lapsed | 1974-11-11 | 1975-09-30 | 7 | Details |
| US3908084A | High frequency character receiver | Expired / Lapsed | 1974-10-07 | 1975-09-23 | 19 | Details |
| US3906454A | Computer monitoring system | Expired / Lapsed | 1973-05-18 | 1975-09-16 | 10 | Details |
| US3903363A | Automatic positioning system and method | Expired / Lapsed | 1974-05-31 | 1975-09-02 | 42 | Details |
| US3899634A | Video controlled positioning method and apparatus | Expired / Lapsed | 1973-07-11 | 1975-08-12 | 38 | Details |
| US3898443A | Memory fault correction system | Expired / Lapsed | 1973-10-29 | 1975-08-05 | 9 | Details |
| US3896473A | Gallium arsenide schottky barrier avalance diode array | Expired / Lapsed | 1973-12-04 | 1975-07-22 | 2 | Details |
| US3891804A | Asynchronous data transmission arrangement | Expired / Lapsed | 1973-09-12 | 1975-06-24 | 10 | Details |
| US3890493A | Circuitry for detecting faults in duplicate controllers | Expired / Lapsed | 1974-03-21 | 1975-06-17 | 21 | Details |
| US3890169A | Method of forming stable native oxide on gallium arsenide b… | Expired / Lapsed | 1973-03-26 | 1975-06-17 | 5 | Details |
| US3887769A | Frame syncrhonization of elastic data bit stores | Expired / Lapsed | 1973-04-04 | 1975-06-03 | 12 | Details |
| US3883801A | Fault testing of logic circuits | Expired / Lapsed | 1973-11-07 | 1975-05-13 | 16 | Details |
| US3883353A | Splicing optical fibers | Expired / Lapsed | 1973-05-29 | 1975-05-13 | 9 | Details |
| US3881060A | Emergency reporting system | Expired / Lapsed | 1973-06-04 | 1975-04-29 | 14 | Details |
| US3878468A | Joint equalization and carrier recovery adaptation in data … | Expired / Lapsed | 1974-01-30 | 1975-04-15 | 11 | Details |
| US3877782A | Electro-optical thin film device | Expired / Lapsed | 1974-01-23 | 1975-04-15 | 3 | Details |
| US3877781A | Electro-optical thin-film device | Expired / Lapsed | 1974-01-16 | 1975-04-15 | 11 | Details |
| US3878463A | Automatic channel switching system | Expired / Lapsed | 1973-06-06 | 1975-04-15 | 26 | Details |
| US3877054A | Semiconductor memory apparatus with a multilayer insulator … | Expired / Lapsed | 1973-11-08 | 1975-04-08 | 24 | Details |
| US3867579A | Synchronization apparatus for a time division switching sys… | Expired / Lapsed | 1973-12-21 | 1975-02-18 | 10 | Details |
| US3867217A | Methods for making electronic circuits | Expired / Lapsed | 1973-10-29 | 1975-02-18 | 11 | Details |
| US3866185A | Method and apparatus for gathering peak load traffic data | Expired / Lapsed | 1974-01-16 | 1975-02-11 | 17 | Details |
| US3865624A | Interconnection of electrical devices | Expired / Lapsed | 1970-06-29 | 1975-02-11 | 7 | Details |
| US3864019A | Optical film-fiber coupler | Expired / Lapsed | 1973-11-15 | 1975-02-04 | 9 | Details |
| US3864018A | Method and means for splicing arrays of optical fibers | Expired / Lapsed | 1973-10-18 | 1975-02-04 | 10 | Details |
| US3864161A | Method and apparatus for adjusting resonators formed on a p… | Expired / Lapsed | 1973-08-10 | 1975-02-04 | 22 | Details |
| US3860405A | Bonding of optical components | Expired / Lapsed | 1972-11-13 | 1975-01-14 | 7 | Details |
| US3859595A | Method for measuring traps in semiconductors | Expired / Lapsed | 1973-12-06 | 1975-01-07 | 13 | Details |
| US3859468A | Redundant data transmission arrangement | Expired / Lapsed | 1973-07-25 | 1975-01-07 | 14 | Details |
| US3858232A | Information storage devices | Expired / Lapsed | 1971-11-09 | 1974-12-31 | 39 | Details |
| US3854052A | Method of and apparatus for dimensionally inspecting an art… | Expired / Lapsed | 1974-01-02 | 1974-12-10 | 34 | Details |
| US3853384A | Optical transmission line | Expired / Lapsed | 1973-04-16 | 1974-12-10 | 17 | Details |
| US3849604A | Time-slot interchanger for time division multiplex system u… | Expired / Lapsed | 1973-09-28 | 1974-11-19 | 8 | Details |
| US3846822A | Methods for making field effect transistors | Expired / Lapsed | 1973-10-05 | 1974-11-05 | 14 | Details |
| US3844752A | Method for fabricating an optical fiber cable | Expired / Lapsed | 1973-08-20 | 1974-10-29 | 7 | Details |
| US3842259A | High voltage amplifier | Expired / Lapsed | 1973-09-24 | 1974-10-15 | 15 | Details |
| US3840738A | Optical communications system with means for minimizing mat… | Expired / Lapsed | 1973-05-09 | 1974-10-08 | 22 | Details |
| US3839646A | Field effect transistor logic gate with improved noise marg… | Expired / Lapsed | 1973-08-13 | 1974-10-01 | 12 | Details |
| US3839067A | Method of making a thin film wave guide employing stress in… | Expired / Lapsed | 1972-09-25 | 1974-10-01 | 4 | Details |
| US3838278A | Optical switching network utilizing organ arrays of optical… | Expired / Lapsed | 1973-09-28 | 1974-09-24 | 12 | Details |
| US3837728A | Injected carrier guided wave deflector | Expired / Lapsed | 1973-09-26 | 1974-09-24 | 7 | Details |
| US3838348A | Digital multifrequency signal generator | Expired / Lapsed | 1973-06-25 | 1974-09-24 | 19 | Details |
| US3834819A | Thickness measuring | Expired / Lapsed | 1973-07-05 | 1974-09-10 | 19 | Details |
| US3833284A | Coupling arrangements for dielectric and metal-clad optical… | Expired / Lapsed | 1973-08-27 | 1974-09-03 | 6 | Details |
| US3833287A | Guest-host liquid crystal device | Expired / Lapsed | 1973-03-08 | 1974-09-03 | 8 | Details |
| US3832030A | Delay equalizers for multimode optical fibers | Expired / Lapsed | 1973-05-23 | 1974-08-27 | 5 | Details |
| US3831038A | Periodic dielectric waveguide for backward parametric inter… | Expired / Lapsed | 1973-09-19 | 1974-08-20 | 35 | Details |
| US3831115A | Acoustic surface waveguide with graded profile cross section | Expired / Lapsed | 1973-07-20 | 1974-08-20 | 19 | Details |
| US3829340A | Methods of making a tubular member having a sealed longitud… | Expired / Lapsed | 1972-08-02 | 1974-08-13 | 0 | Details |
| US3828132A | Speech synthesis by concatenation of formant encoded words | Expired / Lapsed | 1970-10-30 | 1974-08-06 | 16 | Details |
| US3825319A | Butt-joined optical fibers | Expired / Lapsed | 1973-02-26 | 1974-07-23 | 4 | Details |
| US3825771A | Igfet inverter circuit | Expired / Lapsed | 1972-12-04 | 1974-07-23 | 18 | Details |
| US3823997A | Graded-index optical fiber | Expired / Lapsed | 1973-06-18 | 1974-07-16 | 11 | Details |
| US3823996A | Multicore, multimode optical wave transmission line | Expired / Lapsed | 1973-04-05 | 1974-07-16 | 9 | Details |
| US3822928A | Thin film light guide | Expired / Lapsed | 1973-05-29 | 1974-07-09 | 6 | Details |
| US3823352A | Field effect transistor structures and methods | Expired / Lapsed | 1972-12-13 | 1974-07-09 | 15 | Details |
| US3820901A | Measurement of concentrations of components of a gaseous mi… | Expired / Lapsed | 1973-03-06 | 1974-06-28 | 6 | Details |
| US3819989A | Printed wiring board assembly | Expired / Lapsed | 1973-07-16 | 1974-06-25 | 12 | Details |
| US3819250A | Temperature sensitive fiber-optic devices | Expired / Lapsed | 1972-12-20 | 1974-06-25 | 6 | Details |
| US3819872A | Mobile telephone cellular switching system | Expired / Lapsed | 1972-07-10 | 1974-06-25 | 33 | Details |
| US3819785A | Fine-grain alumina bodies | Expired / Lapsed | 1972-02-02 | 1974-06-25 | 0 | Details |
| US3815033A | Discrete adaptive delta modulation system | Expired / Lapsed | 1972-06-01 | 1974-06-04 | 14 | Details |
| US3813613A | Laser employing a metallic pentaphosphate | Expired / Lapsed | 1973-04-02 | 1974-05-28 | 9 | Details |
| US3810802A | Optical fiber splicing device and technique | Expired / Lapsed | 1972-03-31 | 1974-05-14 | 0 | Details |
| US3808068A | Differential etching of garnet materials | Expired / Lapsed | 1972-12-11 | 1974-04-30 | 13 | Details |
| US3808028A | Method of improving adhesive properties of a surface compri… | Expired / Lapsed | 1972-05-30 | 1974-04-30 | 34 | Details |
| US3808550A | Apparatuses for trapping and accelerating neutral particles | Expired / Lapsed | 1972-01-24 | 1974-04-30 | 11 | Details |
| US3806226A | Light-guiding interconnections for thin-film optical circui… | Expired / Lapsed | 1973-03-16 | 1974-04-23 | 9 | Details |
| US3806896A | Reduced access terminal memory system | Expired / Lapsed | 1972-11-15 | 1974-04-23 | 15 | Details |
| US3803348A | Method and apparatus for encoding color video signals | Expired / Lapsed | 1973-01-22 | 1974-04-09 | 15 | Details |
| US3801807A | Improved shift register having (n/2 - 1) stages for digital… | Expired / Lapsed | 1972-10-27 | 1974-04-02 | 9 | Details |
| US3798560A | Adaptive transversal equalizer using a time-multiplexed sec… | Expired / Lapsed | 1973-01-29 | 1974-03-19 | 10 | Details |
| US3798099A | Method for splicing optical films | Expired / Lapsed | 1972-06-12 | 1974-03-19 | 0 | Details |
| US3798145A | Technique for reducing interdiffusion rates and inhibiting … | Expired / Lapsed | 1972-05-30 | 1974-03-19 | 0 | Details |
| US3796999A | Locally erasable thermo-optic smectic liquid crystal storag… | Expired / Lapsed | 1972-10-19 | 1974-03-12 | 16 | Details |
| US3796837A | Network traffic control system | Expired / Lapsed | 1972-09-13 | 1974-03-12 | 15 | Details |
| US3794768A | Cross-office connecting scheme for interconnecting multiple… | Expired / Lapsed | 1972-05-25 | 1974-02-26 | 24 | Details |
| US3793088A | Compatible pnp and npn devices in an integrated circuit | Expired / Lapsed | 1972-11-15 | 1974-02-19 | 4 | Details |
| US3793072A | Method of depositing a metal on a surface of a substrate | Expired / Lapsed | 1971-11-26 | 1974-02-19 | 2 | Details |
| US3793541A | Optical stimulated emission devices employing optical guidi… | Expired / Lapsed | 1970-12-21 | 1974-02-19 | 35 | Details |
| US3792294A | Rectangular at-cut crystal plate | Expired / Lapsed | 1972-10-19 | 1974-02-12 | 12 | Details |
| US3791952A | Method for neutralizing charge in semiconductor bodies and … | Expired / Lapsed | 1972-07-24 | 1974-02-12 | 0 | Details |
| US3792367A | Active controllable filter circuit using variable transcond… | Expired / Lapsed | 1972-05-01 | 1974-02-12 | 10 | Details |
| US3790902A | Fundamental transverse mode operation in solid state lasers | Expired / Lapsed | 1972-09-05 | 1974-02-05 | 12 | Details |
| US3789242A | Overvoltage and undervoltage detection circuit | Expired / Lapsed | 1972-12-26 | 1974-01-29 | 4 | Details |
| US3786188A | Synthesis of pure speech from a reverberant signal | Expired / Lapsed | 1972-12-07 | 1974-01-15 | 13 | Details |
| US3785718A | Low dispersion optical fiber | Expired / Lapsed | 1972-09-11 | 1974-01-15 | 10 | Details |
| US3786196A | Toll call denial circuit | Expired / Lapsed | 1972-08-28 | 1974-01-15 | 12 | Details |
| US3786199A | Mixed traffic mobile radio system | Expired / Lapsed | 1971-10-22 | 1974-01-15 | 4 | Details |
| US3784743A | Parallel data scrambler | Expired / Lapsed | 1972-08-23 | 1974-01-08 | 13 | Details |
| US3781796A | Error detecting translator | Expired / Lapsed | 1972-10-16 | 1973-12-25 | 5 | Details |
| US3781478A | Multiplex communication system | Expired / Lapsed | 1972-07-07 | 1973-12-25 | 57 | Details |
| US3781810A | Scheme for saving and restoring register contents in a data… | Expired / Lapsed | 1972-04-26 | 1973-12-25 | 5 | Details |
| US3780230A | Multifrequency tone receiver | Expired / Lapsed | 1972-11-10 | 1973-12-18 | 18 | Details |
| US3780277A | Apparatus for propagating internal logic gate faults in a d… | Expired / Lapsed | 1972-07-13 | 1973-12-18 | 19 | Details |
| US3777149A | Signal detection and delay equalization in optical fiber tr… | Expired / Lapsed | 1972-07-17 | 1973-12-04 | 12 | Details |
| US3773404A | Telecentric lens | Expired / Lapsed | 1972-06-30 | 1973-11-20 | 2 | Details |
| US3774121A | Wavelength selective laser apparatus | Expired / Lapsed | 1971-12-13 | 1973-11-20 | 10 | Details |
| US3772617A | Method and arrangement for setting the remanent flux densit… | Expired / Lapsed | 1972-11-02 | 1973-11-13 | 18 | Details |
| US3772611A | Waveguide gas laser devices | Expired / Lapsed | 1971-12-27 | 1973-11-13 | 6 | Details |
| US3771147A | Igfet memory system | Expired / Lapsed | 1972-12-04 | 1973-11-06 | 5 | Details |
| US3770350A | Method utilizing an optical fiber raman cell | Expired / Lapsed | 1972-07-24 | 1973-11-06 | 6 | Details |
| US3770433A | High sensitivity negative electron resist | Expired / Lapsed | 1972-03-22 | 1973-11-06 | 5 | Details |
| US3770606A | Schottky barrier diodes as impedance elements and method of… | Expired / Lapsed | 1970-11-17 | 1973-11-06 | 2 | Details |
| US3769451A | Video encoder utilizing columns of samples encoded by predi… | Expired / Lapsed | 1972-08-16 | 1973-10-30 | 13 | Details |
| US3767983A | Charge transfer device with improved transfer efficiency | Expired / Lapsed | 1972-08-23 | 1973-10-23 | 11 | Details |
| US3767925A | Apparatus and method for determining the spatial distributi… | Expired / Lapsed | 1972-03-08 | 1973-10-23 | 11 | Details |
| US3767847A | Frame-to-frame redundancy reduction system which transmits … | Expired / Lapsed | 1971-07-01 | 1973-10-23 | 16 | Details |
| US3764423A | Removal of dielectric ledges on semiconductors | Expired / Lapsed | 1972-03-15 | 1973-10-09 | 0 | Details |
| US3764915A | Dynamic program control for channel assignment in mobile co… | Expired / Lapsed | 1971-06-25 | 1973-10-09 | 9 | Details |
| US3763474A | Program activated computer diagnostic system | Expired / Lapsed | 1971-12-09 | 1973-10-02 | 2 | Details |
| US3761816A | Data set employing a commutating capacitor, tracking, notch… | Expired / Lapsed | 1972-09-08 | 1973-09-25 | 16 | Details |
| US3761869A | Connector | Expired / Lapsed | 1972-03-08 | 1973-09-25 | 12 | Details |
| US3761805A | Methods of and systems for measuring capacitance using a co… | Expired / Lapsed | 1971-06-24 | 1973-09-25 | 6 | Details |
| US3761785A | Methods for making transistor structures | Expired / Lapsed | 1971-04-23 | 1973-09-25 | 18 | Details |
| US3758720A | Circuit for incrementally phasing digital signals | Expired / Lapsed | 1971-12-27 | 1973-09-11 | 11 | Details |
| US3758332A | Method of metal coating an epoxy surface | Expired / Lapsed | 1971-08-20 | 1973-09-11 | 0 | Details |
| US3756861A | Bipolar transistors and method of manufacture | Expired / Lapsed | 1972-03-13 | 1973-09-04 | 0 | Details |
| US3755738A | Passband equalizer for phase-modulated data signals | Expired / Lapsed | 1972-05-01 | 1973-08-28 | 7 | Details |
| US3753133A | Trigger circuit for recording and transmitting sampled anal… | Expired / Lapsed | 1972-04-05 | 1973-08-14 | 13 | Details |
| US3752970A | Digital attenuator | Expired / Lapsed | 1971-12-22 | 1973-08-14 | 12 | Details |
| US3751602A | Loudspeaking telephone | Expired / Lapsed | 1971-08-13 | 1973-08-07 | 8 | Details |
| US3750143A | Charge parceling integrator | Expired / Lapsed | 1972-07-18 | 1973-07-31 | 9 | Details |
| US3750149A | Multi-unit electret touch selector | Expired / Lapsed | 1972-01-18 | 1973-07-31 | 20 | Details |
| US3750058A | Waveguide structure utilizing compliant helical support | Expired / Lapsed | 1971-12-08 | 1973-07-31 | 7 | Details |
| US3749845A | Digital data communication system | Expired / Lapsed | 1971-08-27 | 1973-07-31 | 26 | Details |
| US3748649A | Translator memory decoding arrangement for a microprogram c… | Expired / Lapsed | 1972-02-29 | 1973-07-24 | 25 | Details |
| US3748246A | Dielectric circuit forming process | Expired / Lapsed | 1971-10-08 | 1973-07-24 | 0 | Details |
| US3743791A | Control arrangement for hands-free telephone operation | Expired / Lapsed | 1971-12-30 | 1973-07-03 | 16 | Details |
| US3743788A | Time coded signalling technique for writing control memorie… | Expired / Lapsed | 1971-12-02 | 1973-07-03 | 17 | Details |
| US3743941A | Diversity receiver suitable for large scale integration | Expired / Lapsed | 1971-10-28 | 1973-07-03 | 21 | Details |
| US3743792A | Message waiting lamp arrangement | Expired / Lapsed | 1971-09-15 | 1973-07-03 | 12 | Details |
| US3743797A | Stroke coded keyboard switch assembly | Expired / Lapsed | 1971-08-30 | 1973-07-03 | 20 | Details |
| US3743962A | Thin film ring lasers | Expired / Lapsed | 1971-06-01 | 1973-07-03 | 4 | Details |
| US3742154A | Continuous inband testing of trunks with automatic trunk su… | Expired / Lapsed | 1971-12-30 | 1973-06-26 | 10 | Details |
| US3742143A | Limited vocabulary speech recognition circuit for machine a… | Expired / Lapsed | 1971-03-01 | 1973-06-26 | 4 | Details |
| US3740480A | Time division multiplex switching system utilizing all time… | Expired / Lapsed | 1971-12-27 | 1973-06-19 | 19 | Details |
| US3740476A | Speech signal pitch detector using prediction error data | Expired / Lapsed | 1971-07-09 | 1973-06-19 | 13 | Details |
| US3739104A | Key telephone system signaling circuit | Expired / Lapsed | 1971-08-18 | 1973-06-12 | 14 | Details |
| US3739276A | Method of and system for measuring the speed and length of … | Expired / Lapsed | 1971-06-29 | 1973-06-12 | 9 | Details |
| US3737755A | Regulated dc to dc converter with regulated current source … | Expired / Lapsed | 1972-03-22 | 1973-06-05 | 11 | Details |
| US3737587A | Telephone switching system having call pickup service | Expired / Lapsed | 1971-10-15 | 1973-06-05 | 21 | Details |
| US3736373A | Conditional vertical subsampling in a video redundancy redu… | Expired / Lapsed | 1971-12-13 | 1973-05-29 | 15 | Details |
| US3736383A | Multicustomer centralized call diverter | Expired / Lapsed | 1971-10-28 | 1973-05-29 | 11 | Details |
| US3736381A | Time division switching system | Expired / Lapsed | 1971-10-01 | 1973-05-29 | 10 | Details |
| US3736552A | Acoustic imaging device using multiple element electret tra… | Expired / Lapsed | 1971-07-27 | 1973-05-29 | 16 | Details |
| US3735266A | Method and apparatus for reducing crosstalk on cross-polari… | Expired / Lapsed | 1971-12-20 | 1973-05-22 | 9 | Details |
| US3735055A | Method for improving the settling time of a transversal fil… | Expired / Lapsed | 1971-11-05 | 1973-05-22 | 6 | Details |
| US3733561A | High power, fundamental transverse mode operation in double… | Expired / Lapsed | 1971-07-27 | 1973-05-15 | 15 | Details |
| US3733440A | Semiautomatic call placement and message delivery arrangeme… | Expired / Lapsed | 1971-07-19 | 1973-05-15 | 22 | Details |
| US3732547A | Traffic data gathering apparatus | Expired / Lapsed | 1971-06-28 | 1973-05-08 | 13 | Details |
| US3730995A | Voice switched microphone control system | Expired / Lapsed | 1971-11-16 | 1973-05-01 | 2 | Details |
| US3731192A | Method and apparatus for analyzing semiconductors | Expired / Lapsed | 1971-05-28 | 1973-05-01 | 17 | Details |
| US3731002A | Interconnected loop data block transmission system | Expired / Lapsed | 1970-10-08 | 1973-05-01 | 13 | Details |
| US3729253A | Optical system comprising a single element having a continu… | Expired / Lapsed | 1971-05-28 | 1973-04-24 | 56 | Details |
| US3725601A | Direct station selection private intercom exchange system | Expired / Lapsed | 1971-03-05 | 1973-04-03 | 12 | Details |
| US3725602A | Machine control by acoustic energy | Expired / Lapsed | 1970-12-28 | 1973-04-03 | 11 | Details |
| US3723644A | Variable frame rate recording system using speed measurement | Expired / Lapsed | 1972-04-24 | 1973-03-27 | 8 | Details |
| US3723921A | Multimode waveguide with reduced dispersion | Expired / Lapsed | 1971-05-14 | 1973-03-27 | 5 | Details |
| US3721767A | Delay compensation in multiplex transmission systems | Expired / Lapsed | 1971-12-28 | 1973-03-20 | 16 | Details |
| US3721777A | Echo path delay simulator for use with adaptive echo cancel… | Expired / Lapsed | 1971-11-26 | 1973-03-20 | 12 | Details |
| US3720784A | Recording and display method and apparatus | Expired / Lapsed | 1971-02-12 | 1973-03-13 | 30 | Details |
| US3719462A | Light guide paths comprising densified regions in a transpa… | Expired / Lapsed | 1970-12-21 | 1973-03-06 | 0 | Details |
| US3718781A | Integrity check equipment for automatic trunk substitution | Expired / Lapsed | 1971-12-30 | 1973-02-27 | 0 | Details |
| US3718778A | Pulse train checking circuit | Expired / Lapsed | 1971-12-23 | 1973-02-27 | 0 | Details |
| US3717850A | Programmed data processing with facilitated transfers | Expired / Lapsed | 1972-03-17 | 1973-02-20 | 80 | Details |
| US3717866A | Electronic lock | Expired / Lapsed | 1971-12-23 | 1973-02-20 | 13 | Details |
| US3717814A | Cophasing diversity communication system with pilot feedback | Expired / Lapsed | 1971-09-23 | 1973-02-20 | 14 | Details |
| US3716667A | Apparatus for detecting the moving areas in a video signal | Expired / Lapsed | 1971-10-26 | 1973-02-13 | 22 | Details |
| US3715733A | Error compensating optical detector apparatus and method | Expired / Lapsed | 1972-02-11 | 1973-02-06 | 23 | Details |
| US3715670A | Adaptive dc restoration in single-sideband data systems | Expired / Lapsed | 1971-12-20 | 1973-02-06 | 8 | Details |
| US3715512A | Adaptive predictive speech signal coding system | Expired / Lapsed | 1971-12-20 | 1973-02-06 | 12 | Details |
| US3715732A | Two-terminal npn-pnp transistor memory cell | Expired / Lapsed | 1971-12-09 | 1973-02-06 | 8 | Details |
| US3715500A | Unidirectional microphones | Expired / Lapsed | 1971-07-21 | 1973-02-06 | 14 | Details |
| US3715666A | Fast start-up system for transversal equalizers | Expired / Lapsed | 1971-03-30 | 1973-02-06 | 12 | Details |
| US3715483A | Bandwidth reduction system for use with video signals | Expired / Lapsed | 1970-12-11 | 1973-02-06 | 16 | Details |
| US3712705A | Air clad optical fiber waveguide | Expired / Lapsed | 1971-05-28 | 1973-01-23 | 7 | Details |
| US3713042A | Stabilized mode-locked laser arrangement | Expired / Lapsed | 1971-05-27 | 1973-01-23 | 12 | Details |
| US3711841A | Single wall domain arrangement | Expired / Lapsed | 1971-12-22 | 1973-01-16 | 8 | Details |
| US3710279A | Apparatuses for trapping and accelerating neutral particles | Expired / Lapsed | 1969-12-15 | 1973-01-09 | 7 | Details |
| US3706076A | Programmable digital filter apparatus | Expired / Lapsed | 1970-12-21 | 1972-12-12 | 0 | Details |
| US3705312A | Preparation of electret transducer elements by application … | Expired / Lapsed | 1970-11-02 | 1972-12-05 | 10 | Details |
| US3701854A | Key telephone system call signaling and station set data tr… | Expired / Lapsed | 1970-12-21 | 1972-10-31 | 16 | Details |
| US3701851A | Switching voice and data communications simultaneously over… | Expired / Lapsed | 1970-12-09 | 1972-10-31 | 17 | Details |
| US3702008A | Program for polling party line data stations for message pi… | Expired / Lapsed | 1970-12-07 | 1972-10-31 | 16 | Details |
| US3701976A | Floating point arithmetic unit for a parallel processing co… | Expired / Lapsed | 1970-07-13 | 1972-10-31 | 18 | Details |
| US3700815A | Automatic speaker verification by non-linear time alignment… | Expired / Lapsed | 1971-04-20 | 1972-10-24 | 17 | Details |
| US3701130A | Memory access system | Expired / Lapsed | 1971-02-10 | 1972-10-24 | 18 | Details |
| US3701109A | Priority access system | Expired / Lapsed | 1970-11-09 | 1972-10-24 | 18 | Details |
| US3700890A | Measurement of gas impurity concentration by infrared absor… | Expired / Lapsed | 1970-11-02 | 1972-10-24 | 11 | Details |
| US3700850A | Method for detecting the amount of material removed by a la… | Expired / Lapsed | 1970-09-04 | 1972-10-24 | 25 | Details |
| US3698816A | Laser guidance system | Expired / Lapsed | 1970-09-16 | 1972-10-17 | 2 | Details |
| US3697682A | Video signal processing | Expired / Lapsed | 1971-06-11 | 1972-10-10 | 13 | Details |
| US3697786A | Capacitively driven charge transfer devices | Expired / Lapsed | 1971-03-29 | 1972-10-10 | 13 | Details |
| US3697757A | Arrangements for detecting distorted optical pulses using a… | Expired / Lapsed | 1971-02-08 | 1972-10-10 | 14 | Details |
| US3696985A | Methods of and apparatus for aligning and bonding workpieces | Expired / Lapsed | 1969-12-31 | 1972-10-10 | 29 | Details |
| US3696310A | Mode-locking in semiconductor lasers | Expired / Lapsed | 1970-10-01 | 1972-10-03 | 23 | Details |
| US3694053A | Nematic liquid crystal device | Expired / Lapsed | 1971-06-22 | 1972-09-26 | 8 | Details |
| US3694055A | Thin film, biaxially birefringent nonlinear devices | Expired / Lapsed | 1971-03-12 | 1972-09-26 | 12 | Details |
| US3693153A | Parity check apparatus and method for minicomputers | Expired / Lapsed | 1971-07-09 | 1972-09-19 | 39 | Details |
| US3692942A | Multiplexed information transmission system | Expired / Lapsed | 1971-06-07 | 1972-09-19 | 38 | Details |
| US3689703A | Information recording system | Expired / Lapsed | 1970-12-21 | 1972-09-05 | 13 | Details |
| US3687745A | Light-sensitive storage device including diode array and me… | Expired / Lapsed | 1971-03-15 | 1972-08-29 | 0 | Details |
| US3687514A | Reduction of dispersion in multimode waveguide | Expired / Lapsed | 1970-09-25 | 1972-08-29 | 5 | Details |
| US3688097A | Digital attenuator for non-linear pulse code modulation sig… | Expired / Lapsed | 1970-05-20 | 1972-08-29 | 20 | Details |
| US3683418A | Method of protecting data in a multiprocessor computer syst… | Expired / Lapsed | 1970-04-16 | 1972-08-08 | 30 | Details |
| US3681533A | Switching strategy for mixed delay transmission channels | Expired / Lapsed | 1969-07-24 | 1972-08-01 | 13 | Details |
| US3679832A | Three-channel fm stereo transmission | Expired / Lapsed | 1971-03-23 | 1972-07-25 | 14 | Details |
| US3680000A | Laser arrangement including a cavity defined by convex and … | Expired / Lapsed | 1971-03-19 | 1972-07-25 | 7 | Details |
| US3680056A | Use equalization on closed loop message block transmission … | Expired / Lapsed | 1970-10-08 | 1972-07-25 | 13 | Details |
| US3679472A | Method for bonding a metal pattern to a substrate | Expired / Lapsed | 1970-07-16 | 1972-07-25 | 0 | Details |
| US3680076A | Data display systems | Expired / Lapsed | 1970-07-13 | 1972-07-25 | 19 | Details |
| US3679821A | Transform coding of image difference signals | Expired / Lapsed | 1970-04-30 | 1972-07-25 | 3 | Details |
| US3679977A | Precoded ternary data transmission | Expired / Lapsed | 1969-06-24 | 1972-07-25 | 10 | Details |
| US3678467A | Multiprocessor with cooperative program execution | Expired / Lapsed | 1970-10-20 | 1972-07-18 | 21 | Details |
| US3678464A | Controlled pause and restart of magnetic disc memories and … | Expired / Lapsed | 1970-06-29 | 1972-07-18 | 14 | Details |
| US3676804A | Initialization of adaptive control systems | Expired / Lapsed | 1971-02-22 | 1972-07-11 | 10 | Details |
| US3676684A | Frequency-division multiplex communication system | Expired / Lapsed | 1970-09-23 | 1972-07-11 | 19 | Details |
| US3675985A | Optical autocorrelator for autocorrelating picosecond optic… | Expired / Lapsed | 1970-08-03 | 1972-07-11 | 0 | Details |
| US3676607A | Pushbutton telephone dial | Expired / Lapsed | 1969-11-25 | 1972-07-11 | 5 | Details |
| US3674337A | Beam coupling to and from thin film waveguide | Expired / Lapsed | 1970-12-07 | 1972-07-04 | 0 | Details |
| US3675240A | Keyboard encoding arrangement | Expired / Lapsed | 1969-12-23 | 1972-07-04 | 7 | Details |
| US3673357A | Tactile response switch with unitary control strip of indep… | Expired / Lapsed | 1971-03-29 | 1972-06-27 | 8 | Details |
| US3673355A | Common control digital echo suppression | Expired / Lapsed | 1970-09-02 | 1972-06-27 | 27 | Details |
| US3673335A | Switching of time division multiplex lines and analog trunk… | Expired / Lapsed | 1970-08-24 | 1972-06-27 | 11 | Details |
| US3672034A | Method for bonding a beam-lead device to a substrate | Expired / Lapsed | 1970-01-14 | 1972-06-27 | 25 | Details |
| US3670209A | Pulse generator comprising serially connected make and brea… | Expired / Lapsed | 1971-05-03 | 1972-06-13 | 8 | Details |
| US3670166A | Time division multiplex optical communication system | Expired / Lapsed | 1970-12-28 | 1972-06-13 | 10 | Details |
| US3669541A | Direct display of light images with picosecond resolution | Expired / Lapsed | 1970-06-19 | 1972-06-13 | 0 | Details |
| US3670335A | Arrays with nulls steered independently of main beam | Expired / Lapsed | 1967-06-08 | 1972-06-13 | 11 | Details |
| US3668417A | Touch-sensitive switch employing electret foil | Expired / Lapsed | 1970-12-28 | 1972-06-06 | 33 | Details |
| US3668317A | Automatic personal signaling system | Expired / Lapsed | 1970-05-07 | 1972-06-06 | 8 | Details |
| US3668523A | Electrical testing of dielectric layers, exhibiting voltage… | Expired / Lapsed | 1969-05-07 | 1972-06-06 | 11 | Details |
| US3666348A | Multimode waveguide | Expired / Lapsed | 1970-09-25 | 1972-05-30 | 0 | Details |
| US3665171A | Nonrecursive digital filter apparatus employing delayedadd … | Expired / Lapsed | 1970-12-14 | 1972-05-23 | 16 | Details |
| US3663762A | Mobile communication system | Expired / Lapsed | 1970-12-21 | 1972-05-16 | 23 | Details |
| US3663893A | High-efficiency diode-pumped lasers | Expired / Lapsed | 1970-07-13 | 1972-05-16 | 4 | Details |
| US3662268A | Diversity communication system using distinct spectral arra… | Expired / Lapsed | 1970-11-17 | 1972-05-09 | 20 | Details |
| US3662108A | Apparatus for reducing multipath distortion of signals util… | Expired / Lapsed | 1970-06-08 | 1972-05-09 | 14 | Details |
| US3661582A | Additives to positive photoresists which increase the sensi… | Expired / Lapsed | 1970-03-23 | 1972-05-09 | 13 | Details |
| US3661747A | Method for etching thin film materials by direct cathodic b… | Expired / Lapsed | 1969-08-11 | 1972-05-09 | 2 | Details |
| US3658420A | Photomask inspection by spatial filtering | Expired / Lapsed | 1969-12-10 | 1972-04-25 | 5 | Details |
| US3657003A | Method of rendering a non-wettable surface wettable | Expired / Lapsed | 1970-02-02 | 1972-04-18 | 23 | Details |
| US3655920A | Electrical communication switching network | Expired / Lapsed | 1970-11-16 | 1972-04-11 | 22 | Details |
| US3655261A | Deflection of electromagnetic beams from guides by acoustic… | Expired / Lapsed | 1970-03-02 | 1972-04-11 | 2 | Details |
| US3656161A | Maintaining a circularly polarized magnetic field at a movi… | Expired / Lapsed | 1969-12-31 | 1972-04-11 | 6 | Details |
| US3654499A | Charge coupled memory with storage sites | Expired / Lapsed | 1970-06-24 | 1972-04-04 | 37 | Details |
| US3654476A | Solid-state television camera devices | Expired / Lapsed | 1969-10-24 | 1972-04-04 | 8 | Details |
| US3652803A | Switching of time division multiplex lines through telephon… | Expired / Lapsed | 1970-07-30 | 1972-03-28 | 15 | Details |
| US3652993A | Rapid polling method for digital communications network | Expired / Lapsed | 1970-07-24 | 1972-03-28 | 13 | Details |
| US3652804A | Maintenance busy link map marking in a stored program contr… | Expired / Lapsed | 1969-10-24 | 1972-03-28 | 16 | Details |
| US3651509A | Light pen for display having inherent memory | Expired / Lapsed | 1970-11-06 | 1972-03-21 | 14 | Details |
| US3651349A | Monolithic semiconductor apparatus adapted for sequential c… | Expired / Lapsed | 1970-02-16 | 1972-03-21 | 21 | Details |
| US3650454A | Device for bonding with a compliant medium | Expired / Lapsed | 1969-11-21 | 1972-03-21 | 23 | Details |
| US3649957A | Electrical connector | Expired / Lapsed | 1970-05-28 | 1972-03-14 | 8 | Details |
| US3649386A | Method of fabricating semiconductor devices | Expired / Lapsed | 1968-04-23 | 1972-03-14 | 0 | Details |
| US3647406A | Method of achieving surface refractive index changes in a g… | Expired / Lapsed | 1968-11-04 | 1972-03-07 | 2 | Details |
| US3647538A | Magnetic element using isolated domains in rare earth ortho… | Expired / Lapsed | 1968-02-05 | 1972-03-07 | 8 | Details |
| US3646518A | Feedback error control system | Expired / Lapsed | 1970-05-05 | 1972-02-29 | 25 | Details |
| US3644674A | Ambient noise suppressor | Expired / Lapsed | 1969-06-30 | 1972-02-22 | 10 | Details |
| US3636319A | Circuit for displaying data keyed into data system | Expired / Lapsed | 1970-02-19 | 1972-01-18 | 3 | Details |
| US3634614A | Infrared-energized visual displays using up-converting phos… | Expired / Lapsed | 1969-04-16 | 1972-01-11 | 17 | Details |
| US3632865A | Predictive video encoding using measured subject velocity | Expired / Lapsed | 1969-12-23 | 1972-01-04 | 16 | Details |
| US3632905A | Method for improving the settling time of a transversal fil… | Expired / Lapsed | 1969-12-19 | 1972-01-04 | 10 | Details |
| US3630596A | Photomask regeneration by intensity spatial filtering | Expired / Lapsed | 1969-09-30 | 1971-12-28 | 9 | Details |
| US3631520A | Predictive coding of speech signals | Expired / Lapsed | 1968-08-19 | 1971-12-28 | 16 | Details |
| US3629842A | Multiple memory-accessing system | Expired / Lapsed | 1970-04-30 | 1971-12-21 | 25 | Details |
| US3627930A | Dial-in-handset telephone assembly | Expired / Lapsed | 1969-10-27 | 1971-12-14 | 3 | Details |
| US3628149A | Diversity switch for digital transmission | Expired / Lapsed | 1968-12-19 | 1971-12-14 | 11 | Details |
| US3626408A | Linear charge redistribution pcm coder and decoder | Expired / Lapsed | 1969-12-31 | 1971-12-07 | 8 | Details |
| US3624548A | Discharge tube configuration of metal-vapor ion laser | Expired / Lapsed | 1969-04-09 | 1971-11-30 | 4 | Details |
| US3623019A | Programmed time-out monitoring arrangement using map timing | Expired / Lapsed | 1969-11-26 | 1971-11-23 | 15 | Details |
| US3623011A | Time-shared access to computer registers | Expired / Lapsed | 1969-06-25 | 1971-11-23 | 33 | Details |
| US3619796A | Phase-matching arrangements in parametric traveling-wave de… | Expired / Lapsed | 1970-04-27 | 1971-11-09 | 10 | Details |
| US3619795A | Phase matching in dielectric waveguides to extend the inter… | Expired / Lapsed | 1970-04-10 | 1971-11-09 | 5 | Details |
| US3616406A | Preparation of glue layer for bonding gold to a substrate | Expired / Lapsed | 1969-11-03 | 1971-10-26 | 3 | Details |
| US3614198A | Thin-film optical devices | Expired / Lapsed | 1969-06-23 | 1971-10-19 | 18 | Details |
| US3614601A | Apparatus for gaging the location of contact points of swit… | Expired / Lapsed | 1969-04-24 | 1971-10-19 | 9 | Details |
| US3610727A | Coupling arrangement for thin-film optical devices | Expired / Lapsed | 1969-10-09 | 1971-10-05 | 15 | Details |
| US3609244A | Conditional replenishment video system with variable length… | Expired / Lapsed | 1969-12-18 | 1971-09-28 | 21 | Details |
| US3609704A | Memory maintenance arrangement for recognizing and isolatin… | Expired / Lapsed | 1969-10-06 | 1971-09-28 | 47 | Details |
| US3607699A | Technique for the deposition of gallium phosphide resistive… | Expired / Lapsed | 1969-08-08 | 1971-09-21 | 4 | Details |
| US3604986A | High frequency transistors with shallow emitters | Expired / Lapsed | 1970-03-17 | 1971-09-14 | 8 | Details |
| US3605015A | Method and apparatus for determining deep impurity concentr… | Expired / Lapsed | 1970-01-19 | 1971-09-14 | 6 | Details |
| US3605091A | Feedback error control arrangement | Expired / Lapsed | 1969-09-18 | 1971-09-14 | 24 | Details |
| US3605090A | Decoder for convolutional self-orthogonal error-correcting … | Expired / Lapsed | 1969-04-16 | 1971-09-14 | 6 | Details |
| US3605046A | Deflection-free waveguide arrangement | Expired / Lapsed | 1969-03-12 | 1971-09-14 | 5 | Details |
| US3603739A | Digital transmission system employing identifiable marker s… | Expired / Lapsed | 1969-12-17 | 1971-09-07 | 5 | Details |
| US3601549A | Switching circuit for cancelling the direct sound transmiss… | Expired / Lapsed | 1969-11-25 | 1971-08-24 | 9 | Details |
| US3601476A | Adjustable optical device | Expired / Lapsed | 1968-09-16 | 1971-08-24 | 2 | Details |
| US3598915A | Measurement of maximum of a series of time intervals | Expired / Lapsed | 1969-11-24 | 1971-08-10 | 17 | Details |
| US3597544A | Data switching system | Expired / Lapsed | 1969-04-17 | 1971-08-03 | 13 | Details |
| US3596267A | Digital code converter for converting a delta modulation co… | Expired / Lapsed | 1969-01-28 | 1971-07-27 | 9 | Details |
| US3594560A | Digital expandor circuit | Expired / Lapsed | 1969-01-03 | 1971-07-20 | 6 | Details |
| US3591840A | Controllable space-charge-limited impedance device for inte… | Expired / Lapsed | 1969-10-27 | 1971-07-06 | 9 | Details |
| US3589454A | Mole guidance system | Expired / Lapsed | 1968-12-27 | 1971-06-29 | 16 | Details |
| US3589794A | Optical circuits | Expired / Lapsed | 1968-08-07 | 1971-06-29 | 22 | Details |
| US3589938A | Methods for applying liquid to articles without touching th… | Expired / Lapsed | 1968-07-11 | 1971-06-29 | 0 | Details |
| US3588460A | Fast fourier transform processor | Expired / Lapsed | 1968-07-01 | 1971-06-28 | 0 | Details |
| US3587058A | Data processing system input-output arrangement | Expired / Lapsed | 1969-06-04 | 1971-06-22 | 25 | Details |
| US3586997A | Stabilized mode-locked laser arrangement | Expired / Lapsed | 1969-05-26 | 1971-06-22 | 9 | Details |
| US3586872A | Apparatus including a thin film waveguide for nonlinear int… | Expired / Lapsed | 1969-04-21 | 1971-06-22 | 5 | Details |
| US3587088A | Multilevel pulse transmission systems employing codes havin… | Expired / Lapsed | 1967-12-21 | 1971-06-22 | 7 | Details |
| US3585635A | Analog-to-digital converter | Expired / Lapsed | 1968-12-23 | 1971-06-15 | 15 | Details |
| US3584781A | Fft method and apparatus for real valued inputs | Expired / Lapsed | 1968-07-01 | 1971-06-15 | 34 | Details |
| US3584782A | Fast fourier transform method and apparatus | Expired / Lapsed | 1968-07-01 | 1971-06-15 | 67 | Details |
| US3585306A | Tandem office time division switching system | Expired / Lapsed | 1968-05-16 | 1971-06-15 | 16 | Details |
| US3584230A | Light wave coupling into thin films | Expired / Lapsed | 1969-01-24 | 1971-06-08 | 18 | Details |
| US3582943A | High-speed digital-to-analog converter | Expired / Lapsed | 1968-12-09 | 1971-06-01 | 12 | Details |
| US3582896A | Method of control for a data processor | Expired / Lapsed | 1965-01-22 | 1971-06-01 | 65 | Details |
| US3579117A | Waveform generator | Expired / Lapsed | 1968-09-27 | 1971-05-18 | 6 | Details |
| US3576453A | Monolithic electric wave filters | Expired / Lapsed | 1969-05-02 | 1971-04-27 | 7 | Details |
| US3576402A | Circuit for coin telephone set in mobile radio telephone sy… | Expired / Lapsed | 1968-03-13 | 1971-04-27 | 2 | Details |
| US3575823A | Method of making a silicon target for image storage tube | Expired / Lapsed | 1968-07-26 | 1971-04-20 | 0 | Details |
| US3575741A | Method for producing semiconductor integrated circuit devic… | Expired / Lapsed | 1968-02-05 | 1971-04-20 | 0 | Details |
| US3573667A | Automatic equalizer adjustment apparatus | Expired / Lapsed | 1969-10-08 | 1971-04-06 | 10 | Details |
| US3573381A | Time division switching system | Expired / Lapsed | 1969-03-26 | 1971-04-06 | 26 | Details |
| US3573389A | Switching system with individual register control | Expired / Lapsed | 1968-12-18 | 1971-04-06 | 24 | Details |
| US3573745A | Group queuing | Expired / Lapsed | 1968-12-04 | 1971-04-06 | 17 | Details |
| US3573622A | Partial-response signal sampling for half-speed data transm… | Expired / Lapsed | 1968-04-23 | 1971-04-06 | 7 | Details |
| US3571737A | Transmission line | Expired / Lapsed | 1968-06-07 | 1971-03-23 | 12 | Details |
| US3571794A | Automatic synchronization recovery for data systems utilizi… | Expired / Lapsed | 1967-09-27 | 1971-03-23 | 23 | Details |
| US3569996A | Optical heterodyne receiver with pulse widening or stretchi… | Expired / Lapsed | 1968-06-07 | 1971-03-09 | 11 | Details |
| US3569939A | Program controlled data processing system | Expired / Lapsed | 1967-11-24 | 1971-03-09 | 31 | Details |
| US3568063A | Sliding scale predictive coding system | Expired / Lapsed | 1969-04-02 | 1971-03-02 | 13 | Details |
| US3566021A | Real time three dimensional television system | Expired / Lapsed | 1968-11-29 | 1971-02-23 | 5 | Details |
| US3562005A | Method of generating precious metal-reducing patterns | Expired / Lapsed | 1968-04-09 | 1971-02-09 | 0 | Details |
| US3562009A | Method of providing electrically conductive substrate throu… | Expired / Lapsed | 1967-02-14 | 1971-02-09 | 0 | Details |
| US3560200A | Permanent magnetic materials | Expired / Lapsed | 1968-04-01 | 1971-02-02 | 0 | Details |
| US3558366A | Metal shielding for ion implanted semiconductor device | Expired / Lapsed | 1968-09-17 | 1971-01-26 | 0 | Details |
| US3555335A | Electroluminescent displays | Expired / Lapsed | 1969-02-27 | 1971-01-12 | 10 | Details |
| US3555181A | Automatic video level control employing iris and amplifier … | Expired / Lapsed | 1968-06-05 | 1971-01-12 | 7 | Details |
| US3555295A | Parallel counter | Expired / Lapsed | 1967-10-12 | 1971-01-12 | 16 | Details |
| US3553361A | Conditional replenishment video system with sample grouping | Expired / Lapsed | 1969-04-30 | 1971-01-05 | 10 | Details |
| US3553606A | System for providing adjusting signals to a transversal fil… | Expired / Lapsed | 1969-04-21 | 1971-01-05 | 0 | Details |
| US3553541A | Bilateral switch using combination of field effect transist… | Expired / Lapsed | 1969-04-17 | 1971-01-05 | 0 | Details |
| US3553654A | Fault isolation arrangement for distributed logic memories | Expired / Lapsed | 1969-03-28 | 1971-01-05 | 0 | Details |
| US3553385A | Queuing and automatic retry arrangements for communication … | Expired / Lapsed | 1968-10-11 | 1971-01-05 | 14 | Details |
| US3552484A | Heat transfer apparatus with rotating drum | Expired / Lapsed | 1968-10-01 | 1971-01-05 | 2 | Details |
| US3551312A | Vacuum evaporation deposition of group iii-a metal nitrides | Expired / Lapsed | 1968-05-20 | 1970-12-29 | 0 | Details |
| US3549810A | Telephone reporting set | Expired / Lapsed | 1968-04-22 | 1970-12-22 | 0 | Details |
| US3550082A | Automatic synchronization recovery techniques for nonbinary… | Expired / Lapsed | 1968-03-08 | 1970-12-22 | 0 | Details |
| US3546393A | Telephone switching system | Expired / Lapsed | 1967-09-18 | 1970-12-08 | 0 | Details |
| US3544894A | Apparatus for performing complex wave analysis | Expired / Lapsed | 1967-07-10 | 1970-12-01 | 0 | Details |
| US3544775A | Digital processor for calculating fourier coefficients | Expired / Lapsed | 1966-12-29 | 1970-12-01 | 0 | Details |
| US3543243A | Data receiving arrangement | Expired / Lapsed | 1967-09-13 | 1970-11-24 | 0 | Details |
| US3543052A | Device employing igfet in combination with schottky diode | Expired / Lapsed | 1967-06-05 | 1970-11-24 | 0 | Details |
| US3543237A | Pattern recognition apparatus and method | Expired / Lapsed | 1966-07-29 | 1970-11-24 | 0 | Details |
| US3541531A | Semiconductive memory array wherein operating power is supp… | Expired / Lapsed | 1967-02-07 | 1970-11-17 | 0 | Details |
| US3539749A | Movable contacts with oppositely inclined keying slots for … | Expired / Lapsed | 1968-12-18 | 1970-11-10 | 0 | Details |
| US3540019A | Single wall domain device | Expired / Lapsed | 1968-03-04 | 1970-11-10 | 0 | Details |
| US3539992A | Missing character detector | Expired / Lapsed | 1968-01-18 | 1970-11-10 | 0 | Details |
| US3540007A | Field effect transistor memory cell | Expired / Lapsed | 1967-10-19 | 1970-11-10 | 0 | Details |
| US3539997A | Synchronizing circuit | Expired / Lapsed | 1962-12-05 | 1970-11-10 | 2 | Details |
| US3536853A | Combination reporting and subscriber telephone | Expired / Lapsed | 1968-12-31 | 1970-10-27 | 0 | Details |
| US3537001A | Multifrequency tone detector | Expired / Lapsed | 1968-12-05 | 1970-10-27 | 0 | Details |
| US3536838A | Amplifier with voice- and line-switched gain controls in ne… | Expired / Lapsed | 1968-10-01 | 1970-10-27 | 0 | Details |
| US3535778A | Optical trimming of coated film resistors | Expired / Lapsed | 1968-03-27 | 1970-10-27 | 0 | Details |
| US3537027A | Frequency-stabilized single mode ring lasers | Expired / Lapsed | 1967-07-27 | 1970-10-27 | 0 | Details |
| US3535017A | Optical fiber waveguide structures | Expired / Lapsed | 1968-01-08 | 1970-10-20 | 0 | Details |
| US3535633A | Systems for detecting discontinuity in selected wiring circ… | Expired / Lapsed | 1967-06-21 | 1970-10-20 | 0 | Details |
| US3535473A | Self-adjusting echo canceller | Expired / Lapsed | 1966-10-31 | 1970-10-20 | 0 | Details |
| US3533676A | Hyperstereoscopic and hypostereoscopic image generation | Expired / Lapsed | 1968-04-24 | 1970-10-13 | 0 | Details |
| US3534338A | Computer graphics system | Expired / Lapsed | 1967-11-13 | 1970-10-13 | 0 | Details |
| US3534353A | Current limit detector | Expired / Lapsed | 1967-07-11 | 1970-10-13 | 0 | Details |
| US3532827A | Scanner arrangement for identifying circuits changing their… | Expired / Lapsed | 1967-10-19 | 1970-10-06 | 0 | Details |
| US3531597A | Telephone reporting set | Expired / Lapsed | 1967-02-06 | 1970-09-29 | 0 | Details |
| US3529682A | Location detection and guidance systems for burrowing device | Expired / Lapsed | 1968-10-03 | 1970-09-22 | 0 | Details |
| US3530255A | Equipment for latching interoffice trunking and switched pa… | Expired / Lapsed | 1967-08-17 | 1970-09-22 | 0 | Details |
| US3529089A | Distributed subscriber carrier-concentrator system | Expired / Lapsed | 1968-08-28 | 1970-09-15 | 0 | Details |
| US3527958A | Ultrasonic delay line memory | Expired / Lapsed | 1968-02-16 | 1970-09-08 | 0 | Details |
| US3528035A | Two-valley semiconductive devices | Expired / Lapsed | 1966-07-11 | 1970-09-08 | 0 | Details |
| US3526877A | Selective calling line controller for alternatively test po… | Expired / Lapsed | 1968-02-16 | 1970-09-01 | 0 | Details |
| US3522381A | Time division multiplex switching system | Expired / Lapsed | 1967-12-13 | 1970-07-28 | 0 | Details |
| US3521070A | Optical gate | Expired / Lapsed | 1967-11-24 | 1970-07-21 | 0 | Details |
| US3520683A | Photoresist method and products produced thereby | Expired / Lapsed | 1967-05-19 | 1970-07-14 | 0 | Details |
| US3520055A | Method for holding workpieces for radiant energy bonding | Expired / Lapsed | 1967-04-26 | 1970-07-14 | 0 | Details |
| US3519744A | Apparatus for connecting visual telephone sets in a confere… | Expired / Lapsed | 1967-06-16 | 1970-07-07 | 0 | Details |
| US3519935A | Arrangement for providing partial service on a failed seria… | Expired / Lapsed | 1966-06-21 | 1970-07-07 | 0 | Details |
| US3518108A | Polymer coating by glow discharge technique and resulting p… | Expired / Lapsed | 1967-06-08 | 1970-06-30 | 0 | Details |
| US3516731A | Beam focusing by acoustic waves | Expired / Lapsed | 1968-05-27 | 1970-06-23 | 0 | Details |
| US3517123A | Scanner control means for a stored program controlled switc… | Expired / Lapsed | 1967-11-24 | 1970-06-23 | 0 | Details |
| US3517173A | Digital processor for performing fast fourier transforms | Expired / Lapsed | 1966-12-29 | 1970-06-23 | 0 | Details |
| US3515815A | Resistance controlled pulse generator | Expired / Lapsed | 1968-02-05 | 1970-06-02 | 0 | Details |
| US3514835A | Apparatus for wrapping wire on terminals | Expired / Lapsed | 1967-12-01 | 1970-06-02 | 0 | Details |
| CA840596A | Through-connectors for circuit boards and method of applyin… | Expired / Lapsed | — | 1970-04-28 | 0 | Details |
| US3508730A | Cable securing clip | Expired / Lapsed | 1967-12-20 | 1970-04-28 | 0 | Details |
| US3508202A | Electronic combination lock | Expired / Lapsed | 1967-04-17 | 1970-04-21 | 0 | Details |
| US3506932A | Quadrature hybrid coupler | Expired / Lapsed | 1968-02-28 | 1970-04-14 | 0 | Details |
| US3506509A | Etchant for precision etching of semiconductors | Expired / Lapsed | 1967-11-01 | 1970-04-14 | 0 | Details |
| US3506331A | Optical waveguide | Expired / Lapsed | 1967-10-03 | 1970-04-14 | 0 | Details |
| US3506975A | Conductor arrangement for propagation of single wall domain… | Expired / Lapsed | 1967-06-07 | 1970-04-14 | 0 | Details |
| US3506834A | Time-division multiplex optical transmission system | Expired / Lapsed | 1967-04-17 | 1970-04-14 | 0 | Details |
| US3506779A | Laser beam typesetter | Expired / Lapsed | 1967-04-03 | 1970-04-14 | 0 | Details |
| US3503668A | Electric field dependent dichroic devices | Expired / Lapsed | 1966-04-19 | 1970-03-31 | 0 | Details |
| US3502986A | Adaptive prediction for redundancy removal in data transmis… | Expired / Lapsed | 1967-12-14 | 1970-03-24 | 0 | Details |
| US3502811A | Directional microphone with frequency independent beamwidth | Expired / Lapsed | 1967-12-11 | 1970-03-24 | 0 | Details |
| US3503054A | Domain wall propagation in magnetic shefts | Expired / Lapsed | 1967-10-12 | 1970-03-24 | 0 | Details |
| US3501826A | Apparatus for assembling a pair of articles one within the … | Expired / Lapsed | 1967-04-21 | 1970-03-24 | 0 | Details |
| US3501587A | In-line holographic arrangement for imaging a person viewin… | Expired / Lapsed | 1966-12-21 | 1970-03-17 | 0 | Details |
| US3500441A | Delta modulation with discrete companding | Expired / Lapsed | 1967-10-12 | 1970-03-10 | 0 | Details |
| US3500142A | Field effect semiconductor apparatus with memory involving … | Expired / Lapsed | 1967-06-05 | 1970-03-10 | 0 | Details |
| US3499999A | Closed loop adaptive echo canceller using generalized filte… | Expired / Lapsed | 1966-10-31 | 1970-03-10 | 0 | Details |
| US3500000A | Self-adaptive echo canceller | Expired / Lapsed | 1966-10-31 | 1970-03-10 | 0 | Details |
| US3499098A | Interconnected matrix conductors and method of making the s… | Expired / Lapsed | 1968-10-08 | 1970-03-03 | 0 | Details |
| US3497732A | Dt-cut quartz crystal | Expired / Lapsed | 1968-07-23 | 1970-02-24 | 0 | Details |
| US3497684A | Direct reading statistical distributor estimator | Expired / Lapsed | 1967-06-30 | 1970-02-24 | 0 | Details |
| US3496293A | Automatic directional control for half-duplex data transmis… | Expired / Lapsed | 1967-07-03 | 1970-02-17 | 0 | Details |
| US3496522A | Wire connecting blocks | Expired / Lapsed | 1967-04-28 | 1970-02-17 | 0 | Details |
| US3495908A | Visual telephone subscriber alignment apparatus | Expired / Lapsed | 1966-12-29 | 1970-02-17 | 0 | Details |
| US3495894A | Optical beam deflection utilizing linbo3 or litao3 | Expired / Lapsed | 1965-12-28 | 1970-02-17 | 0 | Details |
| US3495220A | Process control system including hardware element status ma… | Expired / Lapsed | 1967-05-15 | 1970-02-10 | 0 | Details |
| US3493894A | Amplitude and phase-locking of laser transitions by self-dr… | Expired / Lapsed | 1967-08-21 | 1970-02-03 | 0 | Details |
| US3493684A | Vocoder employing composite spectrum-channel and pitch anal… | Expired / Lapsed | 1966-06-15 | 1970-02-03 | 0 | Details |
| US3492440A | Direct station selection telephone set employing proximity … | Expired / Lapsed | 1967-05-25 | 1970-01-27 | 0 | Details |
| US3492432A | Pulse amplitude modulation multiplex video transmission sys… | Expired / Lapsed | 1967-03-08 | 1970-01-27 | 0 | Details |
| US3492645A | Monitoring circuit for line unit scanned on a time shared b… | Expired / Lapsed | 1966-11-02 | 1970-01-27 | 0 | Details |
| US3492433A | Equipment for automatically retrying customer-dialed calls | Expired / Lapsed | 1966-07-20 | 1970-01-27 | 0 | Details |
| US3492435A | Four-wire concentrator without separate control path | Expired / Lapsed | 1966-07-13 | 1970-01-27 | 0 | Details |
| US3492571A | Apparatus for testing an electrical circuit for opens,short… | Expired / Lapsed | 1965-12-02 | 1970-01-27 | 0 | Details |
| US3490052A | Rare earth-containing compositions and preparation of same | Expired / Lapsed | 1964-05-25 | 1970-01-13 | 0 | Details |
| US3488440A | Timing wave recovery circuit for synchronous data repeater | Expired / Lapsed | 1966-12-28 | 1970-01-06 | 0 | Details |
| US3484935A | Method of producing electrical circuit assemblies having th… | Expired / Lapsed | 1965-07-28 | 1969-12-23 | 0 | Details |
| US3484147A | Hologram storage apparatus and method using a diffusing med… | Expired / Lapsed | 1966-08-11 | 1969-12-16 | 0 | Details |
| US3484560A | Equipment for serving customer-dialed calls including those… | Expired / Lapsed | 1966-01-10 | 1969-12-16 | 0 | Details |
| US3480917A | Arrangement for transferring between program sequences in a… | Expired / Lapsed | 1967-06-01 | 1969-11-25 | 0 | Details |
| US3479269A | Method for sputter etching using a high frequency negative … | Expired / Lapsed | 1967-01-04 | 1969-11-18 | 0 | Details |
| US3479603A | A plurality of sources connected in parallel to produce a t… | Expired / Lapsed | 1966-07-28 | 1969-11-18 | 0 | Details |
| US3479237A | Etch masks on semiconductor surfaces | Expired / Lapsed | 1966-04-08 | 1969-11-18 | 0 | Details |
| US3477043A | Automatic d.c. offset compensation circuit for automatic eq… | Expired / Lapsed | 1968-01-24 | 1969-11-04 | 0 | Details |
| US3475736A | Lamellate optically responsive memory arrangement | Expired / Lapsed | 1965-12-23 | 1969-10-28 | 0 | Details |
| US3475733A | Information storage system | Expired / Lapsed | 1964-07-21 | 1969-10-28 | 0 | Details |
| US3471648A | Vocoder utilizing companding to reduce background noise cau… | Expired / Lapsed | 1966-07-28 | 1969-10-07 | 0 | Details |
| US3471686A | Error detection system for synchronized duplicate data proc… | Expired / Lapsed | 1966-01-03 | 1969-10-07 | 0 | Details |
| US3466485A | Cold cathode emitter having a mosaic of closely spaced need… | Expired / Lapsed | 1967-09-21 | 1969-09-09 | 0 | Details |
| US3466441A | Semiconductor infrared-to-visible light image converter | Expired / Lapsed | 1967-04-07 | 1969-09-09 | 0 | Details |
| US3466601A | Automatic synchronization recovery techniques for cyclic co… | Expired / Lapsed | 1966-03-17 | 1969-09-09 | 0 | Details |
| US3466566A | Optical resonator for lasers | Expired / Lapsed | 1966-02-17 | 1969-09-09 | 0 | Details |
| US3464762A | Optical wave modulator | Expired / Lapsed | 1965-12-16 | 1969-09-02 | 0 | Details |
| US3462603A | Acoustic licht modulator and variable delay device | Expired / Lapsed | 1966-05-02 | 1969-08-19 | 0 | Details |
| US3462557A | Intra-concentrator call detecting circuit | Expired / Lapsed | 1965-12-27 | 1969-08-19 | 0 | Details |
| US3461244A | Delta modulation system with continuously variable compander | Expired / Lapsed | 1966-08-16 | 1969-08-12 | 0 | Details |
| US3461245A | System for time division multiplexed signals from asynchron… | Expired / Lapsed | 1965-11-09 | 1969-08-12 | 0 | Details |
| US3460116A | Magnetic domain propagation circuit | Expired / Lapsed | 1966-09-16 | 1969-08-05 | 0 | Details |
| US3458796A | Soft start circuit for power supply circuits | Expired / Lapsed | 1968-02-06 | 1969-07-29 | 0 | Details |
| US3458661A | Arrangement for providing partial service on a failed seria… | Expired / Lapsed | 1966-06-21 | 1969-07-29 | 0 | Details |
| US3457368A | Code character keyboard sender | Expired / Lapsed | 1965-11-15 | 1969-07-22 | 0 | Details |
| US3456196A | Digital automatic frequency control system | Expired / Lapsed | 1966-12-30 | 1969-07-15 | 0 | Details |
| US3452330A | Asynchronous data transmission system with error detection … | Expired / Lapsed | 1967-07-25 | 1969-06-24 | 0 | Details |
| US3452222A | Circuits employing semiconductive devices characterized by … | Expired / Lapsed | 1967-02-01 | 1969-06-24 | 0 | Details |
| US3449577A | Controlled transmission of waves through inhomogeneous media | Expired / Lapsed | 1965-10-23 | 1969-06-10 | 0 | Details |
| US3448280A | Apparatus for positioning workpiece to aline a cavity there… | Expired / Lapsed | 1966-11-02 | 1969-06-03 | 2 | Details |
| US3447036A | Assembly for mounting and aligning modules | Expired / Lapsed | 1967-04-21 | 1969-05-27 | 0 | Details |
| US3447103A | System for initially adjusting a signal equalizing device | Expired / Lapsed | 1966-12-19 | 1969-05-27 | 0 | Details |
| US3447084A | Correction of frequency shift in carrier systems | Expired / Lapsed | 1966-01-03 | 1969-05-27 | 0 | Details |
| US3446917A | Time division switching system | Expired / Lapsed | 1965-06-07 | 1969-05-27 | 0 | Details |
| US3442432A | Bonding a beam-leaded device to a substrate | Expired / Lapsed | 1967-06-15 | 1969-05-06 | 0 | Details |
| US3443243A | Frequency selective laser | Expired / Lapsed | 1965-06-23 | 1969-05-06 | 0 | Details |
| US3443210A | Test circuit for evaluating magnetic memory devices | Expired / Lapsed | 1964-08-26 | 1969-05-06 | 0 | Details |
| US3441747A | Detector for bipolar digital signals | Expired / Lapsed | 1965-12-13 | 1969-04-29 | 0 | Details |
| US3441337A | Thermal gaseous waveguide with gascooling compartments long… | Expired / Lapsed | 1965-07-02 | 1969-04-29 | 0 | Details |
| US3440477A | Multiple readout electron beam device | Expired / Lapsed | 1967-10-18 | 1969-04-22 | 0 | Details |
| US3440618A | Information processing system | Expired / Lapsed | 1967-07-07 | 1969-04-22 | 0 | Details |
| US3440511A | D.c. motor control system | Expired / Lapsed | 1967-02-14 | 1969-04-22 | 0 | Details |
| US3440351A | Telephone transmitter circuit employing variable capacitanc… | Expired / Lapsed | 1966-09-09 | 1969-04-22 | 0 | Details |
| US3440425A | Gunn-effect devices | Expired / Lapsed | 1966-04-27 | 1969-04-22 | 0 | Details |
| US3439753A | Reduced bandwidth pulse modulation scheme using dual mode e… | Expired / Lapsed | 1966-04-19 | 1969-04-22 | 2 | Details |
| US3440547A | Synchronizer for modifying the advance of timing wave count… | Expired / Lapsed | 1966-04-11 | 1969-04-22 | 0 | Details |
| US3438873A | Anodic treatment to alter solubility of dielectric films | Expired / Lapsed | 1966-05-11 | 1969-04-15 | 0 | Details |
| US3439340A | Sequential access memory system | Expired / Lapsed | 1965-07-30 | 1969-04-15 | 0 | Details |
| US3439169A | Tunable solid state laser | Expired / Lapsed | 1965-02-11 | 1969-04-15 | 0 | Details |
| US3437757A | Speech analysis system | Expired / Lapsed | 1966-06-15 | 1969-04-08 | 0 | Details |
| US3437927A | Peak detection system for arbitrary portions of repetitive … | Expired / Lapsed | 1966-02-02 | 1969-04-08 | 0 | Details |
| US3437995A | Error control decoding system | Expired / Lapsed | 1965-03-15 | 1969-04-08 | 0 | Details |
| US3436486A | Error detection system | Expired / Lapsed | 1965-12-21 | 1969-04-01 | 0 | Details |
| US3435159A | Circuit and method for testing complex systems | Expired / Lapsed | 1966-01-03 | 1969-03-25 | 0 | Details |
| US3434774A | Waveguide for millimeter and optical waves | Expired / Lapsed | 1965-02-02 | 1969-03-25 | 0 | Details |
| US3434056A | Distortion monitoring by comparing square and cubic law dis… | Expired / Lapsed | 1966-05-31 | 1969-03-18 | 0 | Details |
| US3433901A | Apparatus for controlling the establishment of call connect… | Expired / Lapsed | 1965-09-27 | 1969-03-18 | 0 | Details |
| US3430001A | Scanning circuit employing shift registers | Expired / Lapsed | 1965-06-15 | 1969-02-25 | 0 | Details |
| US3428388A | Layered structure ultraviolet polarizer | Expired / Lapsed | 1965-09-29 | 1969-02-18 | 2 | Details |
| US3428754A | Conference system wherein transmitting and receiving termin… | Expired / Lapsed | 1965-08-06 | 1969-02-18 | 0 | Details |
| US3427589A | On-line delivery of data messages from a transmitter to rec… | Expired / Lapsed | 1967-06-29 | 1969-02-11 | 0 | Details |
| US3427588A | Distribution of messages to data station receivers on multi… | Expired / Lapsed | 1967-06-29 | 1969-02-11 | 0 | Details |
| US3427403A | Automatic reporting telephone with message transmission res… | Expired / Lapsed | 1964-12-22 | 1969-02-11 | 0 | Details |
| US3427402A | Automatic reporting telephone with response detection means | Expired / Lapsed | 1964-12-22 | 1969-02-11 | 0 | Details |
| US3426252A | Semiconductive device including beam leads | Expired / Lapsed | 1966-05-03 | 1969-02-04 | 0 | Details |
| US3426218A | Pulse generator employing two sequentially gated monostable… | Expired / Lapsed | 1966-04-08 | 1969-02-04 | 0 | Details |
| US3426153A | System for synchronizing digital communication apparatus | Expired / Lapsed | 1963-12-18 | 1969-02-04 | 0 | Details |
| US3424934A | Electroluminescent cell comprising zinc-doped gallium arsen… | Expired / Lapsed | 1966-08-10 | 1969-01-28 | 0 | Details |
| US3424532A | Angle-lap techniques for measuring layer thicknesses | Expired / Lapsed | 1964-12-29 | 1969-01-28 | 2 | Details |
| US3424868A | Combined time division and space division switching system … | Expired / Lapsed | 1964-10-07 | 1969-01-28 | 0 | Details |
| US3423686A | Optical devices utilizing substantially tetragonal ferroele… | Expired / Lapsed | 1967-07-11 | 1969-01-21 | 0 | Details |
| US3423532A | Intercommunication system for school-to-home teaching | Expired / Lapsed | 1965-11-01 | 1969-01-21 | 0 | Details |
| US3423538A | Telephone conference circuit | Expired / Lapsed | 1964-12-28 | 1969-01-21 | 0 | Details |
| US3423534A | Transmission of supervisory information | Expired / Lapsed | 1963-11-21 | 1969-01-21 | 4 | Details |
| US3422419A | Generation of graphic arts images | Expired / Lapsed | 1965-10-19 | 1969-01-14 | 0 | Details |
| US3422227A | Dual code differential encoding scheme for video signals | Expired / Lapsed | 1965-09-30 | 1969-01-14 | 0 | Details |
| US3422232A | Speech pattern rearranging communication system | Expired / Lapsed | 1964-10-08 | 1969-01-14 | 0 | Details |
| US3420955A | Automatic peak selector | Expired / Lapsed | 1965-11-19 | 1969-01-07 | 1 | Details |
| US3417837A | Signal processor for multipath signals | Expired / Lapsed | 1966-09-30 | 1968-12-24 | 0 | Details |
| US3414845A | Automatic equalizer for digital transmission systems utiliz… | Expired / Lapsed | 1965-09-28 | 1968-12-03 | 0 | Details |
| US3414819A | Digital adaptive equalizer system | Expired / Lapsed | 1965-08-27 | 1968-12-03 | 0 | Details |
| US3414839A | Unidirectional ring laser | Expired / Lapsed | 1965-06-18 | 1968-12-03 | 2 | Details |
| US3414814A | Method of and apparatus for testing cross section and conti… | Expired / Lapsed | 1964-12-31 | 1968-12-03 | 0 | Details |
| US3413449A | Rate registering circuit | Expired / Lapsed | 1965-04-26 | 1968-11-26 | 0 | Details |
| US3412251A | Mode locking in a synchronously modulated maser | Expired / Lapsed | 1964-04-24 | 1968-11-19 | 0 | Details |
| US3411135A | Error control decoding system | Expired / Lapsed | 1965-03-15 | 1968-11-12 | 0 | Details |
| US3409848A | Elastic surface waveguide | Expired / Lapsed | 1967-10-30 | 1968-11-05 | 0 | Details |
| US3409879A | Computer organization employing plural operand storage | Expired / Lapsed | 1966-03-30 | 1968-11-05 | 0 | Details |
| US3409877A | Automatic maintenance arrangement for data processing syste… | Expired / Lapsed | 1964-11-27 | 1968-11-05 | 0 | Details |
| US3407309A | Generation of second harmonic optical wave energy | Expired / Lapsed | 1963-08-01 | 1968-10-22 | 2 | Details |
| US3406256A | Coin telephone emergency service | Expired / Lapsed | 1965-06-02 | 1968-10-15 | 0 | Details |
| US3405992A | Low reflection lenses and prisms | Expired / Lapsed | 1964-11-10 | 1968-10-15 | 0 | Details |
| US3406043A | Integrated circuit containing multilayer tantalum compounds | Expired / Lapsed | 1964-11-09 | 1968-10-15 | 0 | Details |
| US3406257A | Parallel tasi system with common means for call assignment … | Expired / Lapsed | 1964-10-07 | 1968-10-15 | 0 | Details |
| US3406344A | Transmission of low frequency signals by modulation of voic… | Expired / Lapsed | 1964-07-01 | 1968-10-15 | 0 | Details |
| US3405371A | Fluorescent garnet compositions and optical maser devices u… | Expired / Lapsed | 1966-04-01 | 1968-10-08 | 2 | Details |
| US3404231A | Framing of pulse code transmission systems by use of an add… | Expired / Lapsed | 1965-01-05 | 1968-10-01 | 2 | Details |
| US3404232A | Stabilized pulse regenerator | Expired / Lapsed | 1964-12-01 | 1968-10-01 | 0 | Details |
| US3404349A | Optical maser for higher order modes | Expired / Lapsed | 1964-04-28 | 1968-10-01 | 0 | Details |
| US3403284A | Target structure storage device using diode array | Expired / Lapsed | 1966-12-29 | 1968-09-24 | 2 | Details |
| US3403340A | Automatic mean-square equalizer | Expired / Lapsed | 1966-11-21 | 1968-09-24 | 2 | Details |
| US3403226A | Reduced bandwidth dual mode encoding of video signals | Expired / Lapsed | 1965-09-30 | 1968-09-24 | 0 | Details |
| US3402633A | Long path multiple beam interferometer | Expired / Lapsed | 1965-03-30 | 1968-09-24 | 2 | Details |
| US3403369A | Connector | Expired / Lapsed | 1965-02-18 | 1968-09-24 | 2 | Details |
| US3403383A | Integrated analog-digital switching system with modular mes… | Expired / Lapsed | 1964-05-28 | 1968-09-24 | 0 | Details |
| US3401359A | Transistor switching modulators and demodulators | Expired / Lapsed | 1966-03-04 | 1968-09-10 | 2 | Details |
| US3401379A | False code generator | Expired / Lapsed | 1966-01-10 | 1968-09-10 | 0 | Details |
| US3401360A | Phased transducer arrays for elastic wave transmission | Expired / Lapsed | 1965-09-13 | 1968-09-10 | 2 | Details |
| US3400456A | Methods of manufacturing thin film components | Expired / Lapsed | 1965-08-30 | 1968-09-10 | 0 | Details |
| US3401340A | Diversity receiver with revertive action to a preferred sel… | Expired / Lapsed | 1965-03-03 | 1968-09-10 | 0 | Details |
| US3400341A | Elastic dispersive delay line | Expired / Lapsed | 1966-03-08 | 1968-09-03 | 2 | Details |
| US3399385A | Activity reporting system | Expired / Lapsed | 1965-12-07 | 1968-08-27 | 0 | Details |
| US3395396A | Information-dependent signal shifting for data processing s… | Expired / Lapsed | 1965-11-23 | 1968-07-30 | 0 | Details |
| US3395365A | Frequency stabilized optical maser | Expired / Lapsed | 1965-02-24 | 1968-07-30 | 0 | Details |
| US3395255A | Loudspeaking telephone | Expired / Lapsed | 1964-07-01 | 1968-07-30 | 0 | Details |
| US3394355A | Information storage timing arrangement | Expired / Lapsed | 1966-04-15 | 1968-07-23 | 2 | Details |
| US3394312A | System for converting two-level signal to three-bit-coded d… | Expired / Lapsed | 1965-09-08 | 1968-07-23 | 2 | Details |
| US3394268A | Logic switching circuit | Expired / Lapsed | 1965-02-01 | 1968-07-23 | 1 | Details |
| US3394231A | Communications network control system | Expired / Lapsed | 1964-11-18 | 1968-07-23 | 0 | Details |
| US3390844A | Dispensing packages for coils of strand material | Expired / Lapsed | 1967-02-27 | 1968-07-02 | 0 | Details |
| US3391341A | Receiving system for suppressed carrier waves | Expired / Lapsed | 1965-09-23 | 1968-07-02 | 2 | Details |
| US3391339A | Phase-locked quadrature modulation transmission system | Expired / Lapsed | 1964-11-06 | 1968-07-02 | 0 | Details |
| US3391390A | Information storage and processing system utilizing associa… | Expired / Lapsed | 1964-09-09 | 1968-07-02 | 0 | Details |
| US3387909A | Aperture-limited optical wave coupler | Expired / Lapsed | 1963-08-07 | 1968-06-11 | 0 | Details |
| US3387278A | Data processor with simultaneous testing and indexing on co… | Expired / Lapsed | 1965-10-20 | 1968-06-04 | 0 | Details |
| US3387206A | Bridge circuit for amplifier gain versus temperature compen… | Expired / Lapsed | 1965-09-29 | 1968-06-04 | 0 | Details |
| US3387099A | Telephone repertory dialer | Expired / Lapsed | 1964-12-28 | 1968-06-04 | 0 | Details |
| US3387091A | Alarm system for telephone pay stations | Expired / Lapsed | 1964-10-05 | 1968-06-04 | 0 | Details |
| US3385935A | Key telephone system | Expired / Lapsed | 1964-10-19 | 1968-05-28 | 0 | Details |
| US3386043A | Dielectric waveguide, maser amplifier and oscillator | Expired / Lapsed | 1964-07-31 | 1968-05-28 | 0 | Details |
| US3384717A | Cordless dispatch telephone switching system having confere… | Expired / Lapsed | 1964-08-03 | 1968-05-21 | 0 | Details |
| US3384814A | Ridge waveguide resonant cavity for measuring dielectric co… | Expired / Lapsed | 1963-09-25 | 1968-05-21 | 2 | Details |
| US3383664A | Electro-optical storage arrangement | Expired / Lapsed | 1967-03-31 | 1968-05-14 | 0 | Details |
| US3382022A | Lens guided optical transmission path with diffraction corr… | Expired / Lapsed | 1964-10-12 | 1968-05-07 | 0 | Details |
| US3381270A | Error detection circuits | Expired / Lapsed | 1964-08-05 | 1968-04-30 | 0 | Details |
| US3378845A | Generation of beacon signals for communication satellite | Expired / Lapsed | 1965-04-13 | 1968-04-16 | 0 | Details |
| US3378792A | Temperature stable elastic wave delay device | Expired / Lapsed | 1965-03-22 | 1968-04-16 | 0 | Details |
| US3376555A | Two-dimensional associative memory system | Expired / Lapsed | 1965-06-18 | 1968-04-02 | 0 | Details |
| US3375408A | Test fixture for keyed printed circuit board | Expired / Lapsed | 1965-11-15 | 1968-03-26 | 0 | Details |
| US3375473A | Automatic equalizer for analog channels having means for co… | Expired / Lapsed | 1965-07-15 | 1968-03-26 | 2 | Details |
| US3374531A | Method of soldering with radiant energy | Expired / Lapsed | 1965-04-21 | 1968-03-26 | 0 | Details |
| US3375499A | Telephone switching system control and memory apparatus org… | Expired / Lapsed | 1964-10-14 | 1968-03-26 | 0 | Details |
| US3374435A | Reduction of the effect of impulse noise bursts | Expired / Lapsed | 1965-07-29 | 1968-03-19 | 1 | Details |
| US3374413A | System for maintaining a motor at a predetermined speed | Expired / Lapsed | 1965-05-06 | 1968-03-19 | 0 | Details |
| US3374463A | Shift and rotate circuit for a data processor | Expired / Lapsed | 1964-12-23 | 1968-03-19 | 0 | Details |
| US3372244A | Semiconductive transducers | Expired / Lapsed | 1966-07-07 | 1968-03-05 | 0 | Details |
| US3372070A | Fabrication of semiconductor integrated devices with a pn j… | Expired / Lapsed | 1965-07-30 | 1968-03-05 | 2 | Details |
| US3372381A | Digital computer teaching machine | Expired / Lapsed | 1965-01-06 | 1968-03-05 | 0 | Details |
| US3372239A | Voice-switched interphone system | Expired / Lapsed | 1964-07-01 | 1968-03-05 | 0 | Details |
| US3371220A | Optical parametric device using third-order nonlinearity | Expired / Lapsed | 1966-10-25 | 1968-02-27 | 0 | Details |
| US3371165A | Telephone central office loop-around test security circuit | Expired / Lapsed | 1965-04-15 | 1968-02-27 | 2 | Details |
| US3370274A | Data processor control utilizing tandem signal operations | Expired / Lapsed | 1964-12-30 | 1968-02-20 | 0 | Details |
| US3370270A | Information checking system | Expired / Lapsed | 1963-04-10 | 1968-02-20 | 2 | Details |
| US3369229A | Multilevel pulse transmission system | Expired / Lapsed | 1964-12-14 | 1968-02-13 | 0 | Details |
| US3368168A | Adaptive equalizer for digital transmission systems having … | Expired / Lapsed | 1965-06-02 | 1968-02-06 | 2 | Details |
| US3368167A | Apparatus for equalizing a transmission system | Expired / Lapsed | 1965-05-07 | 1968-02-06 | 2 | Details |
| US3366895A | Apparatus for optimum distortion correction of a communicat… | Expired / Lapsed | 1965-04-14 | 1968-01-30 | 2 | Details |
| US3366931A | Information storage system | Expired / Lapsed | 1965-03-23 | 1968-01-30 | 0 | Details |
| US3366778A | Pulse register circuit | Expired / Lapsed | 1964-11-16 | 1968-01-30 | 2 | Details |
| US3365581A | Optical modulators | Expired / Lapsed | — | 1968-01-23 | 0 | Details |
| US3365554A | Prevention of dialing by a telephone switchhook | Expired / Lapsed | 1964-10-16 | 1968-01-23 | 0 | Details |
| US3364433A | Molecular swarm liquid crystal optical parametric devices | Expired / Lapsed | 1967-03-10 | 1968-01-16 | 0 | Details |
| US3364079A | Method of making low resistance ohmic contact to p-type lea… | Expired / Lapsed | 1965-06-25 | 1968-01-16 | 0 | Details |
| US3363063A | Circuit arrangement which enables subscriber controlled spe… | Expired / Lapsed | 1964-12-24 | 1968-01-09 | 2 | Details |
| US3363061A | Automatic equalization of noise levels in conference teleph… | Expired / Lapsed | 1964-11-12 | 1968-01-09 | 0 | Details |
| US3361990A | Frequency stabilization apparatus for optical masers | Expired / Lapsed | 1964-06-22 | 1968-01-02 | 2 | Details |
| US3360749A | Elastic wave delay device | Expired / Lapsed | 1964-12-09 | 1967-12-26 | 2 | Details |
| US3360610A | Bandwidth compression utilizing magnitude and phase coded s… | Expired / Lapsed | 1964-05-07 | 1967-12-26 | 2 | Details |
| US3359369A | Systems for processing data over telephone networks | Expired / Lapsed | 1964-02-26 | 1967-12-19 | 2 | Details |
| US3355579A | Correlation apparatus | Expired / Lapsed | 1965-10-20 | 1967-11-28 | 2 | Details |
| US3354792A | Pressure actuated seal | Expired / Lapsed | 1965-06-03 | 1967-11-28 | 2 | Details |
| US3354542A | Enclosing a metal support with a printed circuit containing… | Expired / Lapsed | 1965-05-10 | 1967-11-28 | 2 | Details |
| US3355556A | Automatic mobile radio telephone switching system | Expired / Lapsed | 1964-05-18 | 1967-11-28 | 2 | Details |
| US3354260A | Through-connectors for circuit boards and method of applyin… | Expired / Lapsed | 1966-07-18 | 1967-11-21 | 2 | Details |
| US3354005A | Methods of applying doping compositions to base materials | Expired / Lapsed | 1965-10-23 | 1967-11-21 | 2 | Details |
| US3354267A | Differential pcm system employing digital integration | Expired / Lapsed | 1965-01-13 | 1967-11-21 | 2 | Details |
| US3354316A | Optoelectronic device using light emitting diode and photod… | Expired / Lapsed | 1965-01-06 | 1967-11-21 | 2 | Details |
| US3354404A | End pumped optical maser | Expired / Lapsed | 1961-08-29 | 1967-11-21 | 2 | Details |
| US3351868A | Phase locked loop with fast frequency pull-in | Expired / Lapsed | 1966-02-02 | 1967-11-07 | 2 | Details |
| US3350692A | Fast register control circuit | Expired / Lapsed | 1964-07-06 | 1967-10-31 | 1 | Details |
| US3349403A | Ground station antenna pointing system for satellite commun… | Expired / Lapsed | 1965-04-29 | 1967-10-24 | 2 | Details |
| US3349191A | Talk-off protection for in-band telephone signaling systems | Expired / Lapsed | 1965-01-07 | 1967-10-24 | 2 | Details |
| US3349297A | Surface barrier semiconductor translating device | Expired / Lapsed | 1964-06-23 | 1967-10-24 | 2 | Details |
| US3348211A | Return address system for a data processor | Expired / Lapsed | 1964-12-10 | 1967-10-17 | 2 | Details |
| US3348210A | Digital computer employing plural processors | Expired / Lapsed | 1964-12-07 | 1967-10-17 | 2 | Details |
| US3346067A | System for determining acoustic reflection coefficients | Expired / Lapsed | 1966-03-16 | 1967-10-10 | 2 | Details |
| US3344387A | Variable thin film electrical component | Expired / Lapsed | 1964-10-07 | 1967-09-26 | 2 | Details |
| US3344349A | Apparatus for analyzing the spectra of complex waves | Expired / Lapsed | 1963-10-07 | 1967-09-26 | 0 | Details |
| US3343139A | Abbreviated mask instructions for a digital data processor | Expired / Lapsed | 1964-10-07 | 1967-09-19 | 1 | Details |
| US3342934A | Private branch exchange telephone system with dial transfer… | Expired / Lapsed | 1964-09-02 | 1967-09-19 | 2 | Details |
| US3342944A | Multichannel intercom system with common signaling channel | Expired / Lapsed | 1964-04-29 | 1967-09-19 | 2 | Details |
| US3340514A | Delay line assembler of data characters | Expired / Lapsed | 1964-10-21 | 1967-09-05 | 2 | Details |
| US3340479A | Laser tunable by junction coupling | Expired / Lapsed | 1963-06-14 | 1967-09-05 | 2 | Details |
| US3337813A | Phase-controlled oscillator having a bistable circuit in th… | Expired / Lapsed | 1965-12-27 | 1967-08-22 | 2 | Details |
| US3335338A | Integrated circuit device and method | Expired / Lapsed | 1964-08-07 | 1967-08-08 | 2 | Details |
| US3335229A | Arrangement for controlling traffic in a switching network | Expired / Lapsed | 1963-11-05 | 1967-08-08 | 2 | Details |
| US3334959A | Adjustable optical device | Expired / Lapsed | 1963-10-17 | 1967-08-08 | 2 | Details |
| US3334190A | Centralized repertory system for multifrequency signaling t… | Expired / Lapsed | 1964-07-09 | 1967-08-01 | 2 | Details |
| US3334241A | Stabilized transistor regulator | Expired / Lapsed | 1964-05-13 | 1967-08-01 | 2 | Details |
| US3334183A | Teletypewriter receiver for receiving data asynchronously o… | Expired / Lapsed | 1963-10-24 | 1967-08-01 | 2 | Details |
| US3333188A | Circuit for indicating predetermined voltage conditions on … | Expired / Lapsed | 1964-02-17 | 1967-07-25 | 1 | Details |
| US3330910A | Formant analysis and speech reconstruction | Expired / Lapsed | 1964-05-06 | 1967-07-11 | 2 | Details |
| US3330909A | Pulse communication system | Expired / Lapsed | 1964-01-02 | 1967-07-11 | 2 | Details |
| US3331030A | Automatic gain control circuit | Expired / Lapsed | 1963-08-20 | 1967-07-11 | 2 | Details |
| US3328723A | Optical frequency parametric oscillators and modulators wit… | Expired / Lapsed | 1965-12-23 | 1967-06-27 | 2 | Details |
| US3328766A | Buffering circuit for repetitive transmission of data chara… | Expired / Lapsed | 1965-01-12 | 1967-06-27 | 2 | Details |
| US3328528A | Apparatus for interchanging time and frequency signals | Expired / Lapsed | 1963-11-04 | 1967-06-27 | 2 | Details |
| US3327064A | Small hotel-motel private branch exchange | Expired / Lapsed | 1964-01-06 | 1967-06-20 | 2 | Details |
| US3323947A | Method for making electrode connections to potassium tantal… | Expired / Lapsed | 1964-12-17 | 1967-06-06 | 2 | Details |
| US3324246A | Crosstalk reduction in a time division multiplex switching … | Expired / Lapsed | 1963-07-16 | 1967-06-06 | 2 | Details |
| US3322902A | Telephone subscriber's line circuit | Expired / Lapsed | 1963-12-23 | 1967-05-30 | 2 | Details |
| US3322026A | Attenuation measuring device using an optical maser | Expired / Lapsed | 1963-10-21 | 1967-05-30 | 2 | Details |
| US3317863A | Variable ferromagnetic attenuator having a constant phase s… | Expired / Lapsed | 1965-05-07 | 1967-05-02 | 1 | Details |
| US3315171A | Digitalized transversal filter | Expired / Lapsed | 1963-12-24 | 1967-04-18 | 1 | Details |
| US3315039A | Telephone signaling conversion circuit for pulses and tones | Expired / Lapsed | 1963-09-30 | 1967-04-18 | 2 | Details |
| US3315232A | Resonant circuit timed translator matrix employing transist… | Expired / Lapsed | 1962-05-16 | 1967-04-18 | 2 | Details |
| US3313893A | Break-in circuitry for echo suppressors | Expired / Lapsed | 1963-12-12 | 1967-04-11 | 2 | Details |
| US3314015A | Digitally synthesized artificial transfer networks | Expired / Lapsed | 1963-09-16 | 1967-04-11 | 2 | Details |
| US3313017A | Fabrication of electrical apparatus | Expired / Lapsed | 1962-10-12 | 1967-04-11 | 2 | Details |
| US3312947A | Plural memory system with internal memory transfer and dupl… | Expired / Lapsed | 1963-12-31 | 1967-04-04 | 1 | Details |
| US3311890A | Apparatus for testing a storage system | Expired / Lapsed | 1963-08-20 | 1967-03-28 | 2 | Details |
| US3308243A | Establishing intraconcentrator connections in a remote line… | Expired / Lapsed | 1963-12-16 | 1967-03-07 | 2 | Details |
| US3308342A | Power supply for negative-resistance arc-discharge lamps | Expired / Lapsed | 1963-09-24 | 1967-03-07 | 2 | Details |
| US3306830A | Printed circuit boards and their fabrication | Expired / Lapsed | 1963-06-13 | 1967-02-28 | 2 | Details |
| US3305798A | Phase equalizer concatenated with transversal equalizer whe… | Expired / Lapsed | 1963-12-27 | 1967-02-21 | 2 | Details |
| US3305646A | Echo suppressor with improved break-in circuitry | Expired / Lapsed | 1963-11-13 | 1967-02-21 | 1 | Details |
| US3304489A | High frequency switching regulator | Expired / Lapsed | 1963-04-15 | 1967-02-14 | 2 | Details |
| US3302193A | Pulse transmission system | Expired / Lapsed | 1964-01-02 | 1967-01-31 | 2 | Details |
| US3301962A | Directional conference system | Expired / Lapsed | 1963-04-29 | 1967-01-31 | 2 | Details |
| US3301957A | Unattended automatic dialing of telephone numbers | Expired / Lapsed | 1962-12-06 | 1967-01-31 | 2 | Details |
| US3300554A | Method of making cellular articles | Expired / Lapsed | 1963-09-27 | 1967-01-24 | 2 | Details |
| US3299362A | Recovery of nonlinearly distorted signals | Expired / Lapsed | 1963-09-13 | 1967-01-17 | 2 | Details |
| US3299404A | Detection circuit responsive to pulse duration and frequency | Expired / Lapsed | 1962-12-28 | 1967-01-17 | 2 | Details |
| US3296099A | Method of making printed circuits | Expired / Lapsed | 1966-05-16 | 1967-01-03 | 0 | Details |
| US3296419A | Heat control circuit generating pulses synchronized to a. c… | Expired / Lapsed | 1964-05-06 | 1967-01-03 | 2 | Details |
| US3294670A | Apparatus for processing materials in a controlled atmosphe… | Expired / Lapsed | 1963-10-07 | 1966-12-27 | 4 | Details |
| US3295117A | Position sensing apparatus | Expired / Lapsed | 1963-03-21 | 1966-12-27 | 2 | Details |
| US3295064A | Ultrasonic pulse modifier | Expired / Lapsed | 1962-06-20 | 1966-12-27 | 1 | Details |
| US3293106A | Connection for attaching metal foil to plastic substrate | Expired / Lapsed | 1964-09-08 | 1966-12-20 | 2 | Details |
| US3291972A | Digital error correcting systems | Expired / Lapsed | 1965-11-01 | 1966-12-13 | 2 | Details |
| US3292110A | Transversal equalizer for digital transmission systems wher… | Expired / Lapsed | 1964-09-16 | 1966-12-13 | 2 | Details |
| US3290753A | Method of making semiconductor integrated circuit elements | Expired / Lapsed | 1963-08-19 | 1966-12-13 | 2 | Details |
| US3291913A | Telephone system signal converter | Expired / Lapsed | 1963-05-17 | 1966-12-13 | 2 | Details |
| US3289014A | Digital time compressor with self-biased threshold | Expired / Lapsed | 1965-12-16 | 1966-11-29 | 1 | Details |
| US3289114A | Tapped ultrasonic delay line and uses therefor | Expired / Lapsed | 1963-12-24 | 1966-11-29 | 2 | Details |
| US3288945A | Apparatus for visually identifying conductor pairs in a mul… | Expired / Lapsed | 1963-10-10 | 1966-11-29 | 2 | Details |
| US3289100A | Niobate maser materials and devices made therefrom | Expired / Lapsed | 1963-04-25 | 1966-11-29 | 2 | Details |
| US3287243A | Deposition of insulating films by cathode sputtering in an … | Expired / Lapsed | 1965-03-29 | 1966-11-22 | 2 | Details |
| US3286740A | Method and apparatus for transferring electrical components… | Expired / Lapsed | 1964-02-25 | 1966-11-22 | 2 | Details |
| US3287612A | Semiconductor contacts and protective coatings for planar d… | Expired / Lapsed | 1963-12-17 | 1966-11-22 | 2 | Details |
| US3286045A | Cover assembly for switches | Expired / Lapsed | 1965-03-16 | 1966-11-15 | 1 | Details |
| US3284779A | Associative memory including means for retrieving one of a … | Expired / Lapsed | 1963-04-09 | 1966-11-08 | 2 | Details |
| US3283131A | Digital signal generator | Expired / Lapsed | 1963-09-25 | 1966-11-01 | 1 | Details |
| US3283307A | Detection of erroneous data processing transfers | Expired / Lapsed | 1963-01-03 | 1966-11-01 | 2 | Details |
| US3281539A | Control system for communication switching systems | Expired / Lapsed | 1963-07-16 | 1966-10-25 | 2 | Details |
| US3280274A | Echo suppressor for communication systems having extended t… | Expired / Lapsed | 1963-10-30 | 1966-10-18 | 2 | Details |
| US3280266A | Synthesis of artificial speech | Expired / Lapsed | 1963-05-15 | 1966-10-18 | 1 | Details |
| US3277566A | Methods of and apparatus for metalcoating articles | Expired / Lapsed | 1963-03-19 | 1966-10-11 | 5 | Details |
| US3277404A | Ultrasonic delay device | Expired / Lapsed | 1963-08-23 | 1966-10-04 | 0 | Details |
| US3277225A | Methods and apparatus for multiple extrusion of plastics | Expired / Lapsed | 1963-02-13 | 1966-10-04 | 2 | Details |
| US3274670A | Semiconductor contact | Expired / Lapsed | 1965-03-18 | 1966-09-27 | 2 | Details |
| US3275754A | Call distributing circuit | Expired / Lapsed | 1963-06-12 | 1966-09-27 | 2 | Details |
| US3274511A | Frequency stabilized sweep frequency generator | Expired / Lapsed | 1963-12-30 | 1966-09-20 | 1 | Details |
| US3274345A | Call transmitter | Expired / Lapsed | 1963-07-01 | 1966-09-20 | 1 | Details |
| US3273151A | Antenna system | Expired / Lapsed | 1961-12-26 | 1966-09-13 | 1 | Details |
| US3271124A | Semiconductor encapsulation | Expired / Lapsed | 1963-09-16 | 1966-09-06 | 2 | Details |
| US3271703A | Transversal filter | Expired / Lapsed | 1962-12-21 | 1966-09-06 | 1 | Details |
| US3270293A | Two terminal semiconductor high frequency oscillator | Expired / Lapsed | 1965-02-16 | 1966-08-30 | 2 | Details |
| US3270132A | Optical scanning device utilizing optical fibers disposed i… | Expired / Lapsed | 1964-06-01 | 1966-08-30 | 2 | Details |
| US3268902A | Dual frequency microwave aperturetype antenna providing sim… | Expired / Lapsed | 1963-12-05 | 1966-08-23 | 2 | Details |
| US3267804A | Optical circulator | Expired / Lapsed | 1963-01-03 | 1966-08-23 | 2 | Details |
| US3266018A | Telemetering system for reading remotely loacted utility me… | Expired / Lapsed | 1962-10-04 | 1966-08-09 | 2 | Details |
| US3264918A | Apparatus for testing electrical components | Expired / Lapsed | 1961-10-11 | 1966-08-09 | 2 | Details |
| US3264415A | Switching system for outpulsing on pbx trunks | Expired / Lapsed | 1962-11-28 | 1966-08-02 | 2 | Details |
| US3264105A | Method of using a master art drawing to produce a two-sided… | Expired / Lapsed | 1962-05-31 | 1966-08-02 | 3 | Details |
| US3264584A | Adjustable impedance matching transformers | Expired / Lapsed | 1961-11-15 | 1966-08-02 | 2 | Details |
| US3262058A | Nonlinear devices utilizing linbo3 | Expired / Lapsed | 1964-11-27 | 1966-07-19 | 4 | Details |
| US3261922A | Fdm data trunking system having a common tdm supervisory ch… | Expired / Lapsed | 1962-12-28 | 1966-07-19 | 2 | Details |
| US3261920A | Asynchronous pulse multiplexing | Expired / Lapsed | 1961-12-01 | 1966-07-19 | 2 | Details |
| US3260115A | Temperature sensitive element | Expired / Lapsed | 1962-05-18 | 1966-07-12 | 2 | Details |
| US3259697A | Telephone signaling system | Expired / Lapsed | 1962-11-28 | 1966-07-05 | 2 | Details |
| US3259014A | Light modulator using a variable spacing diffraction grating | Expired / Lapsed | 1961-06-30 | 1966-07-05 | 2 | Details |
| US3257628A | Resetting circuitry for a square-loop ferromagnetic core ut… | Expired / Lapsed | 1963-05-21 | 1966-06-21 | 1 | Details |
| US3254342A | Antenna system wherein beamwidth variation is achieved by c… | Expired / Lapsed | 1963-07-09 | 1966-05-31 | 2 | Details |
| US3252183A | Channelled extrusion die | Expired / Lapsed | 1964-01-08 | 1966-05-24 | 2 | Details |
| US3253191A | Nb-zr superconductor and process of making the same | Expired / Lapsed | 1961-10-11 | 1966-05-24 | 1 | Details |
| US3253220A | Test apparatus including balanced transformers for detectin… | Expired / Lapsed | 1961-10-06 | 1966-05-24 | 1 | Details |
| US3253259A | Plural channel data transmission system having means for ut… | Expired / Lapsed | 1961-09-19 | 1966-05-24 | 2 | Details |
| US3253134A | Digit by digit series high-low limit comparator having mean… | Expired / Lapsed | 1961-03-15 | 1966-05-24 | 2 | Details |
| US3252103A | Nd3+-yag laser amplifier and oscillator | Expired / Lapsed | 1964-05-14 | 1966-05-17 | 2 | Details |
| US3252007A | Stabilized non-linear feedback amplifier | Expired / Lapsed | 1963-10-03 | 1966-05-17 | 2 | Details |
| US3249221A | Apparatus for securing threaded members and for detecting i… | Expired / Lapsed | 1964-06-22 | 1966-05-03 | 2 | Details |
| US3247467A | Diffraction limited optical maser | Expired / Lapsed | 1962-09-28 | 1966-04-19 | 2 | Details |
| US3245314A | Optical rotation devices employing a ferromagnetic chromium… | Expired / Lapsed | 1962-06-28 | 1966-04-12 | 2 | Details |
| US3246328A | Precision radar system | Expired / Lapsed | 1961-12-07 | 1966-04-12 | 2 | Details |
| US3246231A | Frequency conversion system utilizing controlled frequency … | Expired / Lapsed | 1961-11-10 | 1966-04-12 | 1 | Details |
| US3245040A | Data receiving circuit | Expired / Lapsed | 1958-04-21 | 1966-04-05 | 2 | Details |
| US3243699A | Measuring set with compensation for standard attenuator cal… | Expired / Lapsed | 1961-05-05 | 1966-03-29 | 2 | Details |
| US3242470A | Automation of telephone information service | Expired / Lapsed | 1962-08-21 | 1966-03-22 | 2 | Details |
| US3242439A | Visible output gaseous optical maser with mode pattern sele… | Expired / Lapsed | 1962-06-21 | 1966-03-22 | 1 | Details |
| US3240885A | Multiple switching apparatus | Expired / Lapsed | 1963-05-07 | 1966-03-15 | 2 | Details |
| US3241009A | Multiple resistance semiconductor elements | Expired / Lapsed | 1961-11-06 | 1966-03-15 | 2 | Details |
| US3239765A | Phase shift counting circuits | Expired / Lapsed | 1963-09-25 | 1966-03-08 | 2 | Details |
| US3238316A | Spherical shaped multiple contact switch with pivot arm and… | Expired / Lapsed | 1963-11-12 | 1966-03-01 | 2 | Details |
| US3237271A | Method of fabricating semiconductor devices | Expired / Lapsed | 1963-08-07 | 1966-03-01 | 2 | Details |
| US3235813A | Optical maser amplifiers with optimum signal to noise ratio | Expired / Lapsed | 1963-06-25 | 1966-02-15 | 1 | Details |
| US3235428A | Method of making integrated semiconductor devices | Expired / Lapsed | 1963-04-10 | 1966-02-15 | 1 | Details |
| US3235746A | Nonsaturating transistor switching circuit | Expired / Lapsed | 1960-10-11 | 1966-02-15 | 2 | Details |
| US3234482A | Stabilized ultrasonic amplifier | Expired / Lapsed | 1963-04-23 | 1966-02-08 | 2 | Details |
| US3234337A | Aid for blind switchboard attendant | Expired / Lapsed | 1962-07-20 | 1966-02-08 | 2 | Details |
| US3234475A | Efficient optical harmonic generation, parametric amplifica… | Expired / Lapsed | 1961-12-11 | 1966-02-08 | 2 | Details |
| US3234488A | Light modulable circuit element | Expired / Lapsed | 1960-09-12 | 1966-02-08 | 2 | Details |
| US3233042A | Interchannel crosstalk reduction in dual processing multich… | Expired / Lapsed | 1962-02-02 | 1966-02-01 | 2 | Details |
| US3233112A | Preference circuit employing magnetic elements | Expired / Lapsed | 1960-02-04 | 1966-02-01 | 2 | Details |
| US3231683A | Ferrod gate scanning circuit | Expired / Lapsed | 1963-01-11 | 1966-01-25 | 1 | Details |
| US3231421A | Semiconductor contact | Expired / Lapsed | 1962-06-29 | 1966-01-25 | 2 | Details |
| US3231822A | Frequency modulation feedback receiver | Expired / Lapsed | 1961-12-22 | 1966-01-25 | 2 | Details |
| US3231858A | Data storage interrogation error prevention system | Expired / Lapsed | 1961-11-22 | 1966-01-25 | 2 | Details |
| US3231866A | Traffic data processing system | Expired / Lapsed | 1961-09-08 | 1966-01-25 | 2 | Details |
| US3231819A | Intermodulation distortion correction of angle modulated tr… | Expired / Lapsed | 1961-09-07 | 1966-01-25 | 2 | Details |
| US3230457A | Digital demodulator for frequencyshift keyed signals | Expired / Lapsed | 1961-09-25 | 1966-01-18 | 2 | Details |
| US3227999A | Continuous digital error-correcting system | Expired / Lapsed | 1962-06-15 | 1966-01-04 | 1 | Details |
| US3226484A | Time division telephone signaling | Expired / Lapsed | 1961-11-17 | 1965-12-28 | 2 | Details |
| US3225144A | Telephone switching system | Expired / Lapsed | 1962-05-16 | 1965-12-21 | 2 | Details |
| US3224330A | Optical reflecting system for redirecting energy | Expired / Lapsed | 1961-12-22 | 1965-12-21 | 2 | Details |
| US3223784A | Time division switching system | Expired / Lapsed | 1962-04-24 | 1965-12-14 | 2 | Details |
| US3223976A | Data communication system | Expired / Lapsed | 1961-05-26 | 1965-12-14 | 2 | Details |
| US3223785A | Electronic telephone switching system | Expired / Lapsed | 1959-12-30 | 1965-12-14 | 3 | Details |
| US3219585A | Diffusion technique for making composite optical maser crys… | Expired / Lapsed | 1961-10-31 | 1965-11-23 | 2 | Details |
| US3217212A | Semiconductor pin junction microwave limiter | Expired / Lapsed | 1961-05-26 | 1965-11-09 | 2 | Details |
| US3215568A | Semiconductor devices | Expired / Lapsed | 1961-08-04 | 1965-11-02 | 2 | Details |
| US3215949A | Optical maser using internal reflection | Expired / Lapsed | 1960-10-25 | 1965-11-02 | 2 | Details |
| US3210743A | Binary core memory circuit | Expired / Lapsed | 1962-04-19 | 1965-10-05 | 2 | Details |
| US3207904A | Electro-optical article positioning system | Expired / Lapsed | 1962-04-09 | 1965-09-21 | 2 | Details |
| US3206554A | Information verification circuit | Expired / Lapsed | 1962-11-26 | 1965-09-14 | 2 | Details |
| US3206670A | Semiconductor devices having dielectric coatings | Expired / Lapsed | 1960-03-08 | 1965-09-14 | 2 | Details |
| US3205370A | Stabilized optical maser amplifier | Expired / Lapsed | 1962-02-23 | 1965-09-07 | 2 | Details |
| US3205442A | Automatic adjustable equalizer for signal amplitude variati… | Expired / Lapsed | 1961-12-21 | 1965-09-07 | 2 | Details |
| US3204129A | Negative resistance diode trigger circuit | Expired / Lapsed | 1960-11-10 | 1965-08-31 | 2 | Details |
| US3202765A | Synchronization of frequency multiplex systems | Expired / Lapsed | 1961-08-23 | 1965-08-24 | 2 | Details |
| US3202887A | Mesa-transistor with impurity concentration in the base dec… | Expired / Lapsed | 1961-05-15 | 1965-08-24 | 2 | Details |
| US3201849A | Method of winding helices | Expired / Lapsed | 1959-11-03 | 1965-08-24 | 2 | Details |
| US3201690A | Wave transient time interval measuring circuit with wave co… | Expired / Lapsed | 1960-03-09 | 1965-08-17 | 1 | Details |
| US3200308A | Current pulse generator exhibiting fast rise time | Expired / Lapsed | 1962-07-02 | 1965-08-10 | 1 | Details |
| US3200201A | Interpolation signaling | Expired / Lapsed | 1961-12-29 | 1965-08-10 | 2 | Details |
| US3196438A | Antenna system | Expired / Lapsed | 1961-12-26 | 1965-07-20 | 2 | Details |
| US3195047A | Frequency modulation communication system having automatic … | Expired / Lapsed | 1961-12-29 | 1965-07-13 | 2 | Details |
| US3194979A | Transistor switching circuit | Expired / Lapsed | 1961-09-29 | 1965-07-13 | 2 | Details |
| US3195137A | Cassegrainian antenna with aperture blocking correction | Expired / Lapsed | 1960-12-27 | 1965-07-13 | 2 | Details |
| US3190961A | Telephone answering and recording system | Expired / Lapsed | 1961-12-21 | 1965-06-22 | 2 | Details |
| US3189973A | Method of fabricating a semiconductor device | Expired / Lapsed | 1961-11-27 | 1965-06-22 | 0 | Details |
| US3189832A | Pulse train repetition rate divider that divides by n+1/2 w… | Expired / Lapsed | 1962-09-18 | 1965-06-15 | 2 | Details |
| US3188569A | Receiver input unit-synchronizing circuit | Expired / Lapsed | 1962-12-14 | 1965-06-08 | 2 | Details |
| US3188453A | Modular carry generating circuits | Expired / Lapsed | 1961-12-14 | 1965-06-08 | 1 | Details |
| US3188639A | Satellite stabilization and attitude control | Expired / Lapsed | 1961-09-29 | 1965-06-08 | 2 | Details |
| US3185965A | Information storage system | Expired / Lapsed | 1962-04-30 | 1965-05-25 | 1 | Details |
| US3184742A | Balloon communication satellite | Expired / Lapsed | 1960-12-22 | 1965-05-18 | 2 | Details |
| US3182492A | Stabilized tunnel diode stress sensing devices | Expired / Lapsed | 1962-10-04 | 1965-05-11 | 2 | Details |
| US3183359A | Optical modulator employing reflection from piezolelectric-… | Expired / Lapsed | 1961-12-21 | 1965-05-11 | 2 | Details |
| US3182134A | Circuit for interconnecting a number of calling lines | Expired / Lapsed | 1959-12-11 | 1965-05-04 | 2 | Details |
| US3178988A | Screw head driver slot having unequal torque areas | Expired / Lapsed | 1963-12-23 | 1965-04-20 | 2 | Details |
| US3179931A | Alarm transfer system | Expired / Lapsed | 1960-11-18 | 1965-04-20 | 2 | Details |
| US3179883A | Point matrix display unit for testing logic circuit | Expired / Lapsed | 1960-11-08 | 1965-04-20 | 2 | Details |
| US3178313A | Epitaxial growth of binary semiconductors | Expired / Lapsed | 1961-07-05 | 1965-04-13 | 2 | Details |
| US3178564A | Digital to analog converter | Expired / Lapsed | 1960-12-15 | 1965-04-13 | 1 | Details |
| US3178698A | Regulator alarm circuit | Expired / Lapsed | 1960-09-14 | 1965-04-13 | 2 | Details |
| US3176226A | Elimination of frequency shift in suppressed carrier systems | Expired / Lapsed | 1961-11-28 | 1965-03-30 | 2 | Details |
| US3175157A | Statistical framing of code words in a pulse code receiver | Expired / Lapsed | 1961-07-24 | 1965-03-23 | 2 | Details |
| US3175088A | Optical frequency modulation and heterodyne recovery system | Expired / Lapsed | 1961-06-22 | 1965-03-23 | 2 | Details |
| US3174044A | Light frequency modulator | Expired / Lapsed | 1961-05-09 | 1965-03-16 | 1 | Details |
| US3173100A | Ultrasonic wave amplifier | Expired / Lapsed | 1961-04-26 | 1965-03-09 | 2 | Details |
| US3173130A | Memory circuit | Expired / Lapsed | 1960-08-08 | 1965-03-09 | 2 | Details |
| US3171985A | Transistor pulse stretching circuit timed by an l-c ringing… | Expired / Lapsed | 1962-12-20 | 1965-03-02 | 1 | Details |
| US3171901A | Loud-speaking telephone | Expired / Lapsed | 1960-10-04 | 1965-03-02 | 2 | Details |
| US3170810A | Methods of and apparatus for forming substances on preselec… | Expired / Lapsed | 1962-05-24 | 1965-02-23 | 2 | Details |
| US3171031A | Optical maser modulators | Expired / Lapsed | 1961-07-31 | 1965-02-23 | 2 | Details |
| US3169245A | Passive repeaters for satellite communication systems | Expired / Lapsed | 1959-05-15 | 1965-02-09 | 1 | Details |
| US3166736A | Data sensing apparatus including means for replacing incorr… | Expired / Lapsed | 1960-08-25 | 1965-01-19 | 2 | Details |
| US3165725A | Protected amplifying device | Expired / Lapsed | 1960-12-28 | 1965-01-12 | 2 | Details |
| US3164728A | Magnetic switching circuit | Expired / Lapsed | 1962-03-30 | 1965-01-05 | 2 | Details |
| US3164824A | Encoding and storage apparatus for traffic measuring | Expired / Lapsed | 1960-01-11 | 1965-01-05 | 2 | Details |
| US3164831A | Automatic gain control circuits for directive receiving sys… | Expired / Lapsed | 1956-05-09 | 1965-01-05 | 2 | Details |
| US3163747A | Circuit for analyzing selected patterns of multiple intelli… | Expired / Lapsed | 1962-05-15 | 1964-12-29 | 2 | Details |
| US3163820A | Satellite communication system employing a retrograding orb… | Expired / Lapsed | 1961-05-22 | 1964-12-29 | 1 | Details |
| US3160876A | Serial to parallel converter for data signals | Expired / Lapsed | 1963-05-28 | 1964-12-08 | 1 | Details |
| US3158901A | Continuous extruder | Expired / Lapsed | 1963-02-08 | 1964-12-01 | 2 | Details |
| US3159707A | Gas optical maser | Expired / Lapsed | 1962-06-15 | 1964-12-01 | 2 | Details |
| US3159753A | Gate circuit having phase shift and storage means effecting… | Expired / Lapsed | 1962-06-05 | 1964-12-01 | 1 | Details |
| US3159811A | Parity synchronization of pulse code systems | Expired / Lapsed | 1961-06-29 | 1964-12-01 | 2 | Details |
| US3158692A | Channel selecting circuit utilizing diode connection means | Expired / Lapsed | 1961-09-19 | 1964-11-24 | 1 | Details |
| US3158027A | Electronic thermometer | Expired / Lapsed | 1961-07-05 | 1964-11-24 | 2 | Details |
| US3158685A | Synthesis of speech from code signals | Expired / Lapsed | 1961-05-04 | 1964-11-24 | 2 | Details |
| US3158738A | Digital-to-analog combinational converters | Expired / Lapsed | 1957-10-21 | 1964-11-24 | 2 | Details |
| US3157741A | Data transmission system | Expired / Lapsed | 1961-08-29 | 1964-11-17 | 2 | Details |
| US3156651A | Light transparent ferrimagnetic garnets | Expired / Lapsed | 1962-03-28 | 1964-11-10 | 4 | Details |
| US3155772A | Method for measuring data signal impairment | Expired / Lapsed | 1962-02-07 | 1964-11-03 | 2 | Details |
| US3155818A | Error-correcting systems | Expired / Lapsed | 1961-05-15 | 1964-11-03 | 2 | Details |
| US3153974A | Method of and device for indicating a predetermined pressur… | Expired / Lapsed | 1961-04-26 | 1964-10-27 | 2 | Details |
| US3153207A | Means for improving the quality of received television imag… | Expired / Lapsed | 1961-10-31 | 1964-10-13 | 2 | Details |
| US3152085A | Rare ewarth orthovanadate optical maser materials | Expired / Lapsed | 1961-08-07 | 1964-10-06 | 2 | Details |
| US3152219A | Multiconductor terminal frame with wire harnessing means | Expired / Lapsed | 1961-07-21 | 1964-10-06 | 1 | Details |
| US3152305A | Bipolar binary digital data vestigial sideband system | Expired / Lapsed | 1961-06-16 | 1964-10-06 | 2 | Details |
| US3152296A | Regulated power conversion system | Expired / Lapsed | 1959-11-30 | 1964-10-06 | 2 | Details |
| US3150341A | Piezoresistive stress transducers | Expired / Lapsed | 1961-04-25 | 1964-09-22 | 2 | Details |
| US3149395A | Method of making a varactor diode by epitaxial growth and d… | Expired / Lapsed | 1960-09-20 | 1964-09-22 | 2 | Details |
| US3149323A | Three-level binary code transmission | Expired / Lapsed | 1962-07-25 | 1964-09-15 | 2 | Details |
| US3149290A | Gas optical maser | Expired / Lapsed | 1960-12-28 | 1964-09-15 | 2 | Details |
| US3145454A | Fabrication of low impedance diode structures | Expired / Lapsed | 1960-07-14 | 1964-08-25 | 2 | Details |
| US3145341A | Correlation means for a direction finding system | Expired / Lapsed | 1961-01-03 | 1964-08-18 | 2 | Details |
| US3144617A | Optical maser with convex negative temperature medium extre… | Expired / Lapsed | 1961-12-29 | 1964-08-11 | 2 | Details |
| US3144517A | Add-on circuit for step-by-step systems | Expired / Lapsed | 1960-10-27 | 1964-08-11 | 2 | Details |
| US3143601A | Automatic number intercept identification system | Expired / Lapsed | 1962-09-20 | 1964-08-04 | 2 | Details |
| US3143666A | System for maintaining predetermined time relationship betw… | Expired / Lapsed | 1962-04-27 | 1964-08-04 | 2 | Details |
| US3142055A | Translator circuit | Expired / Lapsed | 1962-05-11 | 1964-07-21 | 2 | Details |
| US3141931A | Telephone answering equipment | Expired / Lapsed | 1962-01-19 | 1964-07-21 | 2 | Details |
| US3141928A | Discrete address time division multiplex data transmission … | Expired / Lapsed | 1955-11-28 | 1964-07-21 | 1 | Details |
| US3140451A | Optical maser device | Expired / Lapsed | 1960-10-25 | 1964-07-07 | 2 | Details |
| US3139615A | Three-level binary code transmission | Expired / Lapsed | 1962-07-25 | 1964-06-30 | 2 | Details |
| US3139487A | Bandwidth reduction system | Expired / Lapsed | 1960-12-27 | 1964-06-30 | 2 | Details |
| US3138720A | Ferromagnetic sensing device | Expired / Lapsed | 1962-07-30 | 1964-06-23 | 2 | Details |
| US3137834A | Piezoresistive stress gages | Expired / Lapsed | 1961-03-17 | 1964-06-16 | 2 | Details |
| US3137853A | Polarization measurement for determination of the attitude … | Expired / Lapsed | 1960-01-04 | 1964-06-16 | 2 | Details |
| US3136861A | Pcm network synchronization | Expired / Lapsed | 1962-10-18 | 1964-06-09 | 2 | Details |
| US3136847A | Narrow band television with interlace conversion | Expired / Lapsed | 1962-07-20 | 1964-06-09 | 2 | Details |
| US3135945A | Information checking system utilizing odd and even digit ch… | Expired / Lapsed | 1961-12-20 | 1964-06-02 | 2 | Details |
| US3135909A | Regulated voltage converter circuit | Expired / Lapsed | 1961-12-14 | 1964-06-02 | 2 | Details |
| US3135862A | Digital target information transmission system with paralla… | Expired / Lapsed | 1953-09-29 | 1964-06-02 | 1 | Details |
| US3134837A | Optical maser | Expired / Lapsed | 1961-10-16 | 1964-05-26 | 2 | Details |
| US3134962A | Serial buffer | Expired / Lapsed | 1959-06-08 | 1964-05-26 | 1 | Details |
| CA686737A | Ultrasonic delay lines | Expired / Lapsed | — | 1964-05-19 | 0 | Details |
| US3133840A | Stabilization of junction devices with phosphorous tribromi… | Expired / Lapsed | 1962-03-08 | 1964-05-19 | 2 | Details |
| US3133994A | Conference circuit for telephone switching systems | Expired / Lapsed | 1962-03-08 | 1964-05-19 | 2 | Details |
| US3133271A | Magnetic memory circuits | Expired / Lapsed | 1961-09-11 | 1964-05-12 | 1 | Details |
| US3132913A | Wire formed solderless multiple connector | Expired / Lapsed | 1961-07-14 | 1964-05-12 | 2 | Details |
| US3133155A | Signal converter circuit | Expired / Lapsed | 1960-09-27 | 1964-05-12 | 2 | Details |
| US3133266A | Automatic recognition of handwriting | Expired / Lapsed | 1960-06-14 | 1964-05-12 | 2 | Details |
| US3130277A | Order wire and alarm circuits | Expired / Lapsed | 1960-12-29 | 1964-04-21 | 2 | Details |
| US3129407A | Switching network control system | Expired / Lapsed | 1961-11-24 | 1964-04-14 | 2 | Details |
| US3128353A | Transmission control in signaling system | Expired / Lapsed | 1962-03-06 | 1964-04-07 | 2 | Details |
| US3128342A | Phase-modulation transmitter | Expired / Lapsed | 1961-06-28 | 1964-04-07 | 1 | Details |
| US3127669A | Article feeding apparatus | Expired / Lapsed | 1961-03-14 | 1964-04-07 | 2 | Details |
| US3128349A | Multifrequency signal receiver | Expired / Lapsed | 1960-08-22 | 1964-04-07 | 1 | Details |
| US3128449A | Error detecting and correcting system | Expired / Lapsed | 1960-06-14 | 1964-04-07 | 0 | Details |
| US3128351A | Repertory dialer | Expired / Lapsed | 1960-03-02 | 1964-04-07 | 1 | Details |
| US3128452A | Magnetic storage circuits | Expired / Lapsed | 1959-05-22 | 1964-04-07 | 2 | Details |
| US3127601A | Analog-to-digital converter | Expired / Lapsed | 1960-11-01 | 1964-03-31 | 2 | Details |
| US3127604A | Aircraft radar system with feedback of range signal to ante… | Expired / Lapsed | 1960-10-11 | 1964-03-31 | 1 | Details |
| US3122817A | Fabrication of semiconductor devices | Expired / Lapsed | 1963-02-04 | 1964-03-03 | 2 | Details |
| US3121255A | Apparatus for extruding plastic compounds | Expired / Lapsed | 1960-11-18 | 1964-02-18 | 1 | Details |
| US3121197A | Voice-frequency binary data transmission system with return… | Expired / Lapsed | 1960-03-08 | 1964-02-11 | 2 | Details |
| US3120584A | Multisurface cross point switching mechanisms | Expired / Lapsed | 1960-11-29 | 1964-02-04 | 2 | Details |
| US3118979A | Electrostatic transducer | Expired / Lapsed | 1961-08-07 | 1964-01-21 | 2 | Details |
| US3118722A | Indication recording system | Expired / Lapsed | 1960-12-30 | 1964-01-21 | 2 | Details |
| US3118022A | Electroacoustic transducer | Expired / Lapsed | 1962-05-22 | 1964-01-14 | 2 | Details |
| US3118019A | Telephone signaling circuit | Expired / Lapsed | 1960-08-23 | 1964-01-14 | 1 | Details |
| US3118133A | Information storage matrix utilizing a dielectric of pressu… | Expired / Lapsed | 1960-04-05 | 1964-01-14 | 2 | Details |
| US3118018A | Mobile radio telephone integrated system | Expired / Lapsed | 1959-03-02 | 1964-01-14 | 2 | Details |
| US3117013A | Glass composition | Expired / Lapsed | 1961-11-06 | 1964-01-07 | 2 | Details |
| US3116443A | Semiconductor device | Expired / Lapsed | 1961-01-16 | 1963-12-31 | 2 | Details |
| US3115552A | Telephone switching system | Expired / Lapsed | 1961-11-28 | 1963-12-24 | 2 | Details |
| US3114142A | Selective paging system | Expired / Lapsed | 1960-08-03 | 1963-12-10 | 2 | Details |
| US3113219A | Variable reset time monostable multivibrator | Expired / Lapsed | 1960-07-06 | 1963-12-03 | 2 | Details |
| US3113204A | Parity checked shift register counting circuits | Expired / Lapsed | 1958-03-31 | 1963-12-03 | 2 | Details |
| US3112450A | Pulse resolution circuit with gated delay means and flip-fl… | Expired / Lapsed | 1962-08-15 | 1963-11-26 | 1 | Details |
| US3112373A | Private branch telephone system with camp on facilities | Expired / Lapsed | 1961-05-08 | 1963-11-26 | 1 | Details |
| US3112372A | Telephone marker translating system | Expired / Lapsed | 1960-10-03 | 1963-11-26 | 1 | Details |
| US3111646A | Method and apparatus for reading cursive script | Expired / Lapsed | 1960-05-31 | 1963-11-19 | 2 | Details |
| US3111624A | Automatic system for selectively substituting spare channel… | Expired / Lapsed | 1960-01-04 | 1963-11-19 | 2 | Details |
| US3111561A | Intercept equipment | Expired / Lapsed | 1959-11-23 | 1963-11-19 | 2 | Details |
| US3109997A | Double circuit coaxial jack with automatic cross-connection… | Expired / Lapsed | 1961-07-10 | 1963-11-05 | 2 | Details |
| US3109963A | Insulated superconducting wire | Expired / Lapsed | 1960-08-29 | 1963-11-05 | 2 | Details |
| US3109897A | Synchronization of pulse transmission systems | Expired / Lapsed | 1960-05-20 | 1963-11-05 | 2 | Details |
| US3109758A | Improved tunnel diode | Expired / Lapsed | 1959-10-26 | 1963-11-05 | 0 | Details |
| US3109128A | Servo-mechanism control circuit | Expired / Lapsed | 1960-09-19 | 1963-10-29 | 2 | Details |
| US3109070A | Pitch synchronous autocorrelation vocoder | Expired / Lapsed | 1960-08-09 | 1963-10-29 | 2 | Details |
| US3109071A | Telephone call transmitter | Expired / Lapsed | 1959-12-18 | 1963-10-29 | 2 | Details |
| US3108198A | Blocking oscillator frequency divider | Expired / Lapsed | 1961-08-18 | 1963-10-22 | 2 | Details |
| US3108254A | Machine reading of handwritten characters | Expired / Lapsed | 1957-08-14 | 1963-10-22 | 2 | Details |
| US3107303A | Positive or negative high gain image amplifier | Expired / Lapsed | 1960-12-28 | 1963-10-15 | 2 | Details |
| US3107344A | Self-synchronizing delay line data translation | Expired / Lapsed | 1959-09-29 | 1963-10-15 | 1 | Details |
| US3106699A | Spatially oriented data processing apparatus | Expired / Lapsed | 1958-10-07 | 1963-10-08 | 0 | Details |
| US3106698A | Parallel data processing apparatus | Expired / Lapsed | 1958-04-25 | 1963-10-08 | 2 | Details |
| US3105177A | Semiconductive device utilizing quantum-mechanical tunneling | Expired / Lapsed | 1959-11-23 | 1963-09-24 | 0 | Details |
| US3105121A | Repertory dialer | Expired / Lapsed | 1959-04-21 | 1963-09-24 | 2 | Details |
| US3102928A | Vocoder excitation generator | Expired / Lapsed | 1960-12-23 | 1963-09-03 | 2 | Details |
| US3102230A | Electric field controlled semiconductor device | Expired / Lapsed | 1960-05-31 | 1963-08-27 | 2 | Details |
| US3101393A | Cordless type switchboard | Expired / Lapsed | 1961-05-17 | 1963-08-20 | 2 | Details |
| US3100554A | Decelerating circuit | Expired / Lapsed | 1961-09-22 | 1963-08-13 | 1 | Details |
| US3100868A | Light gas detector using thin walled glass tubes for diffus… | Expired / Lapsed | 1958-08-20 | 1963-08-13 | 2 | Details |
| US3099719A | Private branch exchange telephone system including conferen… | Expired / Lapsed | 1961-12-08 | 1963-07-30 | 2 | Details |
| US3099579A | Growing and determining epitaxial layer thickness | Expired / Lapsed | 1960-09-09 | 1963-07-30 | 1 | Details |
| US3099819A | Traffic measurement apparatus | Expired / Lapsed | 1960-01-11 | 1963-07-30 | 2 | Details |
| US3099717A | Line concentrator system | Expired / Lapsed | 1959-12-24 | 1963-07-30 | 2 | Details |
| US3096474A | Microwave frequency converter | Expired / Lapsed | 1960-12-23 | 1963-07-02 | 2 | Details |
| US3095332A | Photosensitive gas phase etching of semiconductors by selec… | Expired / Lapsed | 1961-06-30 | 1963-06-25 | 1 | Details |
| US3093758A | Piezoelectric devices utilizing cadmium sulfide | Expired / Lapsed | 1960-04-13 | 1963-06-11 | 2 | Details |
| US3091665A | Autocorrelation vocoder equalizer | Expired / Lapsed | 1960-06-03 | 1963-05-28 | 2 | Details |
| US3091707A | Piezoelectric devices utilizing zinc oxide | Expired / Lapsed | 1960-04-07 | 1963-05-28 | 2 | Details |
| US3090931A | Waveguide elbow | Expired / Lapsed | 1962-03-08 | 1963-05-21 | 2 | Details |
| US3090873A | Integrated semiconductor switching device | Expired / Lapsed | 1960-06-21 | 1963-05-21 | 1 | Details |
| US3090876A | Piezoelectric devices utilizing aluminum nitride | Expired / Lapsed | 1960-04-13 | 1963-05-21 | 2 | Details |
| US3090942A | Number comparison and display circuits | Expired / Lapsed | 1958-12-18 | 1963-05-21 | 2 | Details |
| US3090943A | Serial digital data processing circuit | Expired / Lapsed | 1957-05-31 | 1963-05-21 | 2 | Details |
| US3090008A | Predictive quantization and coding of vision signals | Expired / Lapsed | 1960-10-24 | 1963-05-14 | 2 | Details |
| US3089918A | Telewriting apparatus | Expired / Lapsed | 1960-09-09 | 1963-05-14 | 2 | Details |
| US3089921A | Multiplex message transmission | Expired / Lapsed | 1960-07-07 | 1963-05-14 | 2 | Details |
| US3090014A | Negative resistance device modulator | Expired / Lapsed | 1959-12-17 | 1963-05-14 | 2 | Details |
| US3089137A | Polarization tracking receiver | Expired / Lapsed | 1959-07-01 | 1963-05-07 | 2 | Details |
| US3087374A | Optical maser elements | Expired / Lapsed | 1961-07-03 | 1963-04-30 | 2 | Details |
| US3088056A | Logic and memory circuit units | Expired / Lapsed | 1959-12-09 | 1963-04-30 | 0 | Details |
| US3087150A | Analog-to-digital encoder | Expired / Lapsed | 1960-09-14 | 1963-04-23 | 2 | Details |
| US3086203A | Communication system using polarized waves and employing co… | Expired / Lapsed | 1961-03-07 | 1963-04-16 | 1 | Details |
| US3085231A | Electroluminescent storage systems | Expired / Lapsed | 1961-06-28 | 1963-04-09 | 1 | Details |
| US3085033A | Fabrication of semiconductor devices | Expired / Lapsed | 1960-03-08 | 1963-04-09 | 2 | Details |
| US3085032A | Treatment of gallium arsenide | Expired / Lapsed | 1960-02-26 | 1963-04-09 | 2 | Details |
| US3084336A | Magnetic memory construction and circuits | Expired / Lapsed | 1960-03-09 | 1963-04-02 | 2 | Details |
| US3082859A | Mechanism for intermittently advancing and positioning arti… | Expired / Lapsed | 1960-12-05 | 1963-03-26 | 2 | Details |
| US3083267A | Pcm telephone signaling | Expired / Lapsed | 1960-10-20 | 1963-03-26 | 1 | Details |
| US3083264A | Sum and difference stereophonic transmission with negative … | Expired / Lapsed | 1959-12-10 | 1963-03-26 | 2 | Details |
| US3083353A | Magnetic memory devices | Expired / Lapsed | 1957-08-01 | 1963-03-26 | 2 | Details |
| US3081434A | Multibranch circuits for translating frequency characterist… | Expired / Lapsed | 1960-04-18 | 1963-03-12 | 4 | Details |
| US3080489A | Pulse generator circuit employing diode and inductor to red… | Expired / Lapsed | 1960-12-27 | 1963-03-05 | 1 | Details |
| US3079347A | Terbium and cerium activated calcium fluoride optical maser… | Expired / Lapsed | 1960-10-25 | 1963-02-26 | 2 | Details |
| US3079513A | Ring counter employing nor stages with parallel inputs and … | Expired / Lapsed | 1959-09-25 | 1963-02-26 | 0 | Details |
| US3078373A | Electroluminescent matrix and access device | Expired / Lapsed | 1960-04-21 | 1963-02-19 | 2 | Details |
| US3078196A | Semiconductive switch | Expired / Lapsed | 1959-06-17 | 1963-02-19 | 2 | Details |
| US3076732A | Uniform n-type silicon | Expired / Lapsed | 1959-12-15 | 1963-02-05 | 2 | Details |
| US3076601A | Electronic binary counter and converter | Expired / Lapsed | 1959-08-27 | 1963-02-05 | 2 | Details |
| US3075282A | Semiconductor device contact | Expired / Lapsed | 1959-07-24 | 1963-01-29 | 2 | Details |
| US3076059A | Signaling system | Expired / Lapsed | 1958-06-20 | 1963-01-29 | 2 | Details |
| US3072748A | Line protection in radio relay systems | Expired / Lapsed | 1961-02-28 | 1963-01-08 | 2 | Details |
| US3072894A | Telemetering system | Expired / Lapsed | 1960-06-22 | 1963-01-08 | 1 | Details |
| US3072804A | Pulse position detector utilizing the storage effect of pnp… | Expired / Lapsed | 1959-12-14 | 1963-01-08 | 2 | Details |
| US3071727A | Bandwidth reduction system | Expired / Lapsed | 1961-05-08 | 1963-01-01 | 2 | Details |
| US3071739A | Digital phase equalizer, automatically operative, in accord… | Expired / Lapsed | 1961-04-21 | 1963-01-01 | 2 | Details |
| US3071652A | Time domain vocoder | Expired / Lapsed | 1959-05-08 | 1963-01-01 | 2 | Details |
| US3070666A | Distributed line concentrator system | Expired / Lapsed | 1960-07-22 | 1962-12-25 | 0 | Details |
| US3069507A | Autocorrelation vocoder | Expired / Lapsed | 1960-08-09 | 1962-12-18 | 0 | Details |
| US3068403A | Test probe | Expired / Lapsed | 1960-01-27 | 1962-12-11 | 0 | Details |
| US3067485A | Semiconductor diode | Expired / Lapsed | 1958-08-13 | 1962-12-11 | 2 | Details |
| US3067363A | Pulse frequency divider | Expired / Lapsed | 1959-11-19 | 1962-12-04 | 0 | Details |
| US3066633A | Signal translating systems | Expired / Lapsed | 1945-12-27 | 1962-12-04 | 0 | Details |
| US3065636A | Pressure transducers | Expired / Lapsed | 1960-05-10 | 1962-11-27 | 0 | Details |
| US3064890A | Parallel input fast carry binary counter with feedback rese… | Expired / Lapsed | 1961-05-29 | 1962-11-20 | 0 | Details |
| US3065422A | Nonlinear pcm encoders | Expired / Lapsed | 1959-11-18 | 1962-11-20 | 0 | Details |
| US3064090A | Line testing circuit | Expired / Lapsed | 1960-09-29 | 1962-11-13 | 0 | Details |
| US3064072A | Connector for insulated conductors | Expired / Lapsed | 1960-06-10 | 1962-11-13 | 0 | Details |
| US3064084A | Telephone substation apparatus | Expired / Lapsed | 1959-12-16 | 1962-11-13 | 0 | Details |
| US3061666A | Splice closure for sheathed cable | Expired / Lapsed | 1961-03-17 | 1962-10-30 | 0 | Details |
| US3061739A | Multiple channel field effect semiconductor | Expired / Lapsed | 1958-12-11 | 1962-10-30 | 0 | Details |
| US3061797A | Shifting reference transistor oscillator | Expired / Lapsed | 1957-11-07 | 1962-10-30 | 0 | Details |
| US3061818A | Magnetic core register circuits | Expired / Lapsed | 1956-12-12 | 1962-10-30 | 0 | Details |
| US3060273A | Standby transfer control circuitry | Expired / Lapsed | 1959-11-25 | 1962-10-23 | 0 | Details |
| US3060411A | Magnetic memory circuits | Expired / Lapsed | 1959-10-14 | 1962-10-23 | 0 | Details |
| US3060327A | Transistor having emitter reversebiased beyond breakdown an… | Expired / Lapsed | 1959-07-02 | 1962-10-23 | 0 | Details |
| US3060275A | Telephone system signaling | Expired / Lapsed | 1958-11-07 | 1962-10-23 | 0 | Details |
| US3059117A | Optical maser | Expired / Lapsed | 1960-01-11 | 1962-10-16 | 0 | Details |
| US3059158A | Protected semiconductor device and method of making it | Expired / Lapsed | 1959-02-09 | 1962-10-16 | 0 | Details |
| US3057960A | Normalized sound control system | Expired / Lapsed | 1961-03-13 | 1962-10-09 | 0 | Details |
| US3057965A | Braille telephone switchboard unit | Expired / Lapsed | 1960-12-07 | 1962-10-09 | 0 | Details |
| US3057959A | Timing wave generator | Expired / Lapsed | 1960-11-02 | 1962-10-09 | 0 | Details |
| US3057964A | Multifrequency signaling receiver | Expired / Lapsed | 1959-12-14 | 1962-10-09 | 0 | Details |
| US3058106A | Space satellites for use as radio system repeaters | Expired / Lapsed | 1959-05-21 | 1962-10-09 | 0 | Details |
| US3056888A | Semiconductor triode | Expired / Lapsed | 1960-08-17 | 1962-10-02 | 0 | Details |
| US3055257A | Optical maser cavity | Expired / Lapsed | 1960-10-07 | 1962-09-25 | 0 | Details |
| US3056100A | Temperature compensated field effect resistor | Expired / Lapsed | 1959-12-04 | 1962-09-25 | 0 | Details |
| US3056129A | Scanning antenna system | Expired / Lapsed | 1957-05-03 | 1962-09-25 | 0 | Details |
| US3054237A | Apparatus for selectively inserting articles into magazines | Expired / Lapsed | 1961-04-06 | 1962-09-18 | 0 | Details |
| US3054949A | Method of and apparatus for identifying discrete tip and ri… | Expired / Lapsed | 1958-12-02 | 1962-09-18 | 0 | Details |
| US3053134A | Optical pulse echo system | Expired / Lapsed | 1948-04-01 | 1962-09-11 | 0 | Details |
| US3051784A | Error-correcting system | Expired / Lapsed | 1961-05-12 | 1962-08-28 | 0 | Details |
| US3051778A | Sequential scan television with line interpolation | Expired / Lapsed | 1960-10-20 | 1962-08-28 | 0 | Details |
| US3050843A | Method of bonding metallic members | Expired / Lapsed | 1959-04-15 | 1962-08-28 | 0 | Details |
| US3051941A | Analog-digital converter and register | Expired / Lapsed | 1958-10-24 | 1962-08-28 | 0 | Details |
| US3051901A | Encoder for pulse code modulation | Expired / Lapsed | 1958-06-24 | 1962-08-28 | 0 | Details |
| US3050581A | Line tracing system | Expired / Lapsed | 1960-08-30 | 1962-08-21 | 0 | Details |
| US3050698A | Semiconductor hall effect devices | Expired / Lapsed | 1960-02-12 | 1962-08-21 | 0 | Details |
| US3050713A | Output selecting circuit | Expired / Lapsed | 1959-12-16 | 1962-08-21 | 0 | Details |
| US3050711A | Automatic character analyzer | Expired / Lapsed | 1959-02-26 | 1962-08-21 | 0 | Details |
| US3048778A | High frequency power meter | Expired / Lapsed | 1959-07-21 | 1962-08-07 | 0 | Details |
| US3048781A | Reduction of quantizing error in quantized transmission sys… | Expired / Lapsed | 1957-12-26 | 1962-08-07 | 0 | Details |
| US3047746A | Surge suppression for power supplies | Expired / Lapsed | 1959-12-08 | 1962-07-31 | 0 | Details |
| US3047667A | Transistor crosspoint switching network | Expired / Lapsed | 1958-02-24 | 1962-07-31 | 0 | Details |
| US3046346A | Multiplex signaling system | Expired / Lapsed | 1958-12-17 | 1962-07-24 | 0 | Details |
| US3046525A | Supervisory control system | Expired / Lapsed | 1958-09-16 | 1962-07-24 | 0 | Details |
| US3045129A | Semiconductor tunnel device | Expired / Lapsed | 1960-12-08 | 1962-07-17 | 0 | Details |
| US3045215A | Electrical control circuits | Expired / Lapsed | 1959-06-25 | 1962-07-17 | 0 | Details |
| US3042740A | Mounting board for electric circuit elements | Expired / Lapsed | 1960-11-30 | 1962-07-03 | 0 | Details |
| US3042751A | Pulse transmission system | Expired / Lapsed | 1959-03-10 | 1962-07-03 | 0 | Details |
| US3042859A | Capacitance measuring circuit | Expired / Lapsed | 1957-03-13 | 1962-07-03 | 0 | Details |
| US3041537A | Transistor test set | Expired / Lapsed | 1959-11-27 | 1962-06-26 | 0 | Details |
| US3041556A | Ultrasonic strip delay line | Expired / Lapsed | 1959-07-01 | 1962-06-26 | 0 | Details |
| US3041540A | Data signal distortion measuring circuit | Expired / Lapsed | 1959-06-03 | 1962-06-26 | 0 | Details |
| US3040305A | Magnetic memory circuits | Expired / Lapsed | 1959-11-02 | 1962-06-19 | 0 | Details |
| US3039438A | Wet rest for inking stylus | Expired / Lapsed | 1958-12-23 | 1962-06-19 | 0 | Details |
| US3038029A | Pulse transmission of alternate interchange code | Expired / Lapsed | 1959-06-15 | 1962-06-05 | 0 | Details |
| US3037086A | Private branch exchange telephone system | Expired / Lapsed | 1960-08-01 | 1962-05-29 | 0 | Details |
| US3037068A | Retractile tinsel cordage | Expired / Lapsed | 1959-05-04 | 1962-05-29 | 0 | Details |
| US3036290A | Error rate alarm circuit | Expired / Lapsed | 1959-11-12 | 1962-05-22 | 0 | Details |
| US3036161A | Line concentrator control circuit | Expired / Lapsed | 1959-10-26 | 1962-05-22 | 0 | Details |
| US3035258A | Pulse code modulation encoder | Expired / Lapsed | 1960-11-14 | 1962-05-15 | 0 | Details |
| US3035257A | Cumulative code translator | Expired / Lapsed | 1959-09-29 | 1962-05-15 | 0 | Details |
| US3035186A | Semiconductor switching apparatus | Expired / Lapsed | 1959-06-15 | 1962-05-15 | 0 | Details |
| US3034345A | Gauges using piezoresistive elements | Expired / Lapsed | 1959-05-19 | 1962-05-15 | 0 | Details |
| US3035185A | Transistor tree ring counter | Expired / Lapsed | 1959-04-22 | 1962-05-15 | 0 | Details |
| US3035211A | Subscriber calling apparatus | Expired / Lapsed | 1958-10-21 | 1962-05-15 | 0 | Details |
| US3035175A | Radiant-energy translation system | Expired / Lapsed | 1947-11-06 | 1962-05-15 | 0 | Details |
| US3033937A | Line concentrator signaling system | Expired / Lapsed | 1959-10-26 | 1962-05-08 | 0 | Details |
| US3033452A | Counter | Expired / Lapsed | 1959-08-19 | 1962-05-08 | 0 | Details |
| US3034077A | Ultrasonic delay lines | Expired / Lapsed | 1959-04-02 | 1962-05-08 | 0 | Details |
| US3032610A | Encoders for pcm codes of base greater than two | Expired / Lapsed | 1960-03-22 | 1962-05-01 | 0 | Details |
| US3031629A | Power supply system | Expired / Lapsed | 1960-08-16 | 1962-04-24 | 0 | Details |
| US3030700A | Retaining ring setting tool | Expired / Lapsed | 1959-10-26 | 1962-04-24 | 0 | Details |
| US3030448A | Pcm telephone signaling | Expired / Lapsed | 1960-12-30 | 1962-04-17 | 0 | Details |
| US3030450A | Band compression system | Expired / Lapsed | 1958-11-17 | 1962-04-17 | 0 | Details |
| US3030609A | Data storage and retrieval | Expired / Lapsed | 1957-10-11 | 1962-04-17 | 0 | Details |
| US3029348A | Electro-optical servo system for coarse and fine positionin… | Expired / Lapsed | 1959-10-02 | 1962-04-10 | 0 | Details |
| US3028084A | Reversible counting relay chain | Expired / Lapsed | 1958-09-11 | 1962-04-03 | 0 | Details |
| US3027524A | Signal transmission gate | Expired / Lapsed | 1959-08-21 | 1962-03-27 | 0 | Details |
| US3027427A | Electronic switching network | Expired / Lapsed | 1958-06-06 | 1962-03-27 | 0 | Details |
| US3027550A | Signal pulse detector and register | Expired / Lapsed | 1956-12-31 | 1962-03-27 | 0 | Details |
| US3027547A | Magnetic core circuits | Expired / Lapsed | 1956-12-06 | 1962-03-27 | 0 | Details |
| US3026375A | Transmission of quantized signals | Expired / Lapsed | 1958-05-09 | 1962-03-20 | 0 | Details |
| US3023627A | Strain gauges and accelerometers | Expired / Lapsed | 1960-04-25 | 1962-03-06 | 0 | Details |
| US3023484A | Device for stripping and winding insulated conductors | Expired / Lapsed | 1959-12-17 | 1962-03-06 | 0 | Details |
| US3024119A | Glass composition and coated article | Expired / Lapsed | 1959-06-03 | 1962-03-06 | 2 | Details |
| US3022381A | Credit card operated telephone | Expired / Lapsed | 1959-02-26 | 1962-02-20 | 0 | Details |
| US3022472A | Variable equalizer employing semiconductive element | Expired / Lapsed | 1958-01-22 | 1962-02-20 | 0 | Details |
| US3022375A | Synchronizing start-stop digital transmission system | Expired / Lapsed | 1955-09-22 | 1962-02-20 | 0 | Details |
| US3021517A | Analog-to-digital converter | Expired / Lapsed | 1960-08-22 | 1962-02-13 | 0 | Details |
| US3021384A | Time divisdion multiplexing of television and telephone mes… | Expired / Lapsed | 1959-12-28 | 1962-02-13 | 0 | Details |
| US3021478A | Wave analysis and representation | Expired / Lapsed | 1951-11-21 | 1962-02-13 | 0 | Details |
| US3020792A | Reflector optical system | Expired / Lapsed | 1947-09-23 | 1962-02-13 | 0 | Details |
| US3021488A | Monostable multivibrator responsive to positive and negativ… | Expired / Lapsed | 1944-12-29 | 1962-02-13 | 0 | Details |
| US3019853A | Separation of gases by diffusion | Expired / Lapsed | 1958-06-30 | 1962-02-06 | 2 | Details |
| US3020525A | Record controlled translator | Expired / Lapsed | 1958-04-04 | 1962-02-06 | 0 | Details |
| US3020510A | Electrical connector for preformed panel circuit arrangemen… | Expired / Lapsed | 1957-12-26 | 1962-02-06 | 0 | Details |
| US3018431A | Alternating current voltage regulator | Expired / Lapsed | 1960-01-04 | 1962-01-23 | 0 | Details |
| US3017025A | Apparatus for distributing an article to one of several rec… | Expired / Lapsed | 1960-04-26 | 1962-01-16 | 0 | Details |
| US3017091A | Digital error correcting systems | Expired / Lapsed | 1957-03-26 | 1962-01-16 | 0 | Details |
| US3016502A | Spurious mode suppressing wave guide | Expired / Lapsed | 1959-12-23 | 1962-01-09 | 0 | Details |
| US3016470A | Shift register | Expired / Lapsed | 1959-04-14 | 1962-01-09 | 0 | Details |
| US3015809A | Magnetic memory matrix | Expired / Lapsed | 1959-06-19 | 1962-01-02 | 0 | Details |
| US3012203A | Traveling wave parametric amplifier | Expired / Lapsed | 1960-03-07 | 1961-12-05 | 0 | Details |
| US3012240A | Digital-to-analog converter | Expired / Lapsed | 1958-10-28 | 1961-12-05 | 0 | Details |
| US3012226A | Selective signaling device | Expired / Lapsed | 1956-11-14 | 1961-12-05 | 0 | Details |
| US3011089A | Solid state light sensitive storage device | Expired / Lapsed | 1958-04-16 | 1961-11-28 | 0 | Details |
| US3011155A | Electrical memory circuit | Expired / Lapsed | 1957-11-07 | 1961-11-28 | 0 | Details |
| US3011151A | Signal comparison system | Expired / Lapsed | 1956-04-27 | 1961-11-28 | 0 | Details |
| US3010102A | Combination radar and thermalenergy detection system | Expired / Lapsed | 1947-07-05 | 1961-11-21 | 0 | Details |
| US3009089A | Power supply system | Expired / Lapsed | 1960-05-25 | 1961-11-14 | 0 | Details |
| US3008668A | Guidance control system | Expired / Lapsed | 1955-06-06 | 1961-11-14 | 0 | Details |
| US3008087A | Signal synchronizing system utilizing adjustable delay appa… | Expired / Lapsed | 1958-04-24 | 1961-11-07 | 0 | Details |
| US3008089A | Semiconductive device comprising p-i-n conductivity layers | Expired / Lapsed | 1958-02-20 | 1961-11-07 | 2 | Details |
| US3008088A | Synchronized multivibrator with selectable clamping means f… | Expired / Lapsed | 1957-11-07 | 1961-11-07 | 0 | Details |
| US3006067A | Thermo-compression bonding of metal to semiconductors, and … | Expired / Lapsed | 1956-10-31 | 1961-10-31 | 4 | Details |
| US3007145A | Synchronizing circuit for magnetic drum | Expired / Lapsed | 1956-05-22 | 1961-10-31 | 0 | Details |
| US3005055A | Tilting dial circuit selector | Expired / Lapsed | 1957-10-08 | 1961-10-17 | 0 | Details |
| US3005053A | Telephone signaling system | Expired / Lapsed | 1957-09-09 | 1961-10-17 | 0 | Details |
| US3005050A | Telautograph system | Expired / Lapsed | 1956-12-28 | 1961-10-17 | 0 | Details |
| US3003143A | Selecting circuit | Expired / Lapsed | 1959-05-28 | 1961-10-03 | 0 | Details |
| US3003112A | Process for growing and apparatus for utilizing paramagneti… | Expired / Lapsed | 1959-05-25 | 1961-10-03 | 0 | Details |
| US3003111A | Pulse generator having means for independently controlling,… | Expired / Lapsed | 1958-05-29 | 1961-10-03 | 0 | Details |
| US2999172A | Transistor trigger circuit | Expired / Lapsed | 1957-12-20 | 1961-09-05 | 0 | Details |
| US2999169A | Non-saturating transistor pulse amplifier | Expired / Lapsed | 1956-12-28 | 1961-09-05 | 0 | Details |
| US2998034A | Wire unwrapping tool | Expired / Lapsed | 1958-06-02 | 1961-08-29 | 0 | Details |
| US2998489A | Automatic telephone message service | Expired / Lapsed | 1958-03-25 | 1961-08-29 | 0 | Details |
| US2997577A | Synchronous carrier production | Expired / Lapsed | 1960-01-04 | 1961-08-22 | 0 | Details |
| US2996578A | Bipolar pulse transmission and regeneration | Expired / Lapsed | 1959-01-19 | 1961-08-15 | 0 | Details |
| US2996248A | Supervisory system for an electronic counter | Expired / Lapsed | 1957-12-31 | 1961-08-15 | 0 | Details |
| US2996663A | Magnetic field gradiometer | Expired / Lapsed | 1945-09-29 | 1961-08-15 | 0 | Details |
| US2995101A | Steering apparatus for torpedoes | Expired / Lapsed | 1944-11-20 | 1961-08-08 | 0 | Details |
| US2993266A | Method of making a capacitor employing film-forming metal e… | Expired / Lapsed | 1958-06-16 | 1961-07-25 | 0 | Details |
| US2993154A | Semiconductor switch | Expired / Lapsed | 1960-06-10 | 1961-07-18 | 0 | Details |
| US2992339A | Binary adder circuits | Expired / Lapsed | 1956-11-27 | 1961-07-11 | 0 | Details |
| US2992421A | Induction type translator | Expired / Lapsed | 1956-03-29 | 1961-07-11 | 0 | Details |
| US2992410A | Selector for switching network | Expired / Lapsed | 1956-02-28 | 1961-07-11 | 0 | Details |
| US2992399A | Oscillator amplitude control | Expired / Lapsed | 1954-09-17 | 1961-07-11 | 0 | Details |
| US2991422A | Pcm decoders with bipolar output | Expired / Lapsed | 1959-05-13 | 1961-07-04 | 0 | Details |
| US2989784A | Method of forming a plug of high melting point plastic bond… | Expired / Lapsed | 1957-10-04 | 1961-06-27 | 0 | Details |
| US2989622A | Hybrid sideband frequency modulation system | Expired / Lapsed | 1958-12-29 | 1961-06-20 | 0 | Details |
| US2989650A | Semiconductor capacitor | Expired / Lapsed | 1958-12-24 | 1961-06-20 | 0 | Details |
| US2989385A | Process for ion bombarding and etching metal | Expired / Lapsed | 1957-05-14 | 1961-06-20 | 0 | Details |
| US2986723A | Synchronization in a system of interconnected units | Expired / Lapsed | 1960-02-26 | 1961-05-30 | 0 | Details |
| US2986724A | Negative resistance oscillator | Expired / Lapsed | 1959-05-27 | 1961-05-30 | 0 | Details |
| US2986603A | Telephone signaling apparatus | Expired / Lapsed | 1957-10-14 | 1961-05-30 | 0 | Details |
| US2984789A | Pulse monitoring circuit | Expired / Lapsed | 1958-08-13 | 1961-05-16 | 0 | Details |
| US2984706A | Insertion of framing information in pulse modulation systems | Expired / Lapsed | 1957-12-24 | 1961-05-16 | 0 | Details |
| US2984749A | Electroluminescent switching apparatus | Expired / Lapsed | 1957-05-31 | 1961-05-16 | 0 | Details |
| US2983904A | Sorting method and apparatus | Expired / Lapsed | 1957-10-04 | 1961-05-09 | 0 | Details |
| US2982926A | Delay line | Expired / Lapsed | 1959-07-06 | 1961-05-02 | 0 | Details |
| US2982869A | Semiconductor trigger circuit | Expired / Lapsed | 1959-02-25 | 1961-05-02 | 0 | Details |
| US2979662A | Electrical wave synchronizing circuit | Expired / Lapsed | 1958-11-28 | 1961-04-11 | 0 | Details |
| US2979556A | Semiautomatic teletypewriter tape relay system | Expired / Lapsed | 1956-10-02 | 1961-04-11 | 0 | Details |
| US2978675A | Character recognition system | Expired / Lapsed | 1959-12-10 | 1961-04-04 | 0 | Details |
| US2977632A | Centripetal extruder | Expired / Lapsed | 1959-04-10 | 1961-04-04 | 0 | Details |
| US2978680A | Precession storage delay circuit | Expired / Lapsed | 1957-12-06 | 1961-04-04 | 0 | Details |
| US2978390A | Gold plating solutions | Expired / Lapsed | 1957-07-22 | 1961-04-04 | 2 | Details |
| US2977575A | Cryotron circuits | Expired / Lapsed | 1957-02-15 | 1961-03-28 | 0 | Details |
| US2976367A | Two-stage line concentrator system | Expired / Lapsed | 1958-12-23 | 1961-03-21 | 0 | Details |
| US2976487A | Stabilized timing circuit | Expired / Lapsed | 1958-08-07 | 1961-03-21 | 0 | Details |
| US2974367A | Apparatus for making splicing-sleeve assemblies | Expired / Lapsed | 1958-04-23 | 1961-03-14 | 0 | Details |
| US2974568A | Light modulator | Expired / Lapsed | 1957-02-15 | 1961-03-14 | 0 | Details |
| US2974195A | Economy in television transmission | Expired / Lapsed | 1958-10-30 | 1961-03-07 | 0 | Details |
| US2974203A | Ceramic electromechanical transducers | Expired / Lapsed | 1958-04-29 | 1961-03-07 | 2 | Details |
| US2974281A | Selective signal recognition system | Expired / Lapsed | 1957-11-01 | 1961-03-07 | 0 | Details |
| US2974075A | Treatment of semiconductive devices | Expired / Lapsed | 1957-10-28 | 1961-03-07 | 2 | Details |
| US2973506A | Magnetic translation circuits | Expired / Lapsed | 1958-06-10 | 1961-02-28 | 0 | Details |
| US2971711A | Apparatus for reeling strand | Expired / Lapsed | 1958-12-31 | 1961-02-14 | 0 | Details |
| US2972064A | Zero phase marker indicator | Expired / Lapsed | 1958-11-05 | 1961-02-14 | 0 | Details |
| US2970310A | Light pulse generator | Expired / Lapsed | 1947-09-23 | 1961-01-31 | 0 | Details |
| US2969296A | Thermal expansion fixture for spacing vaporized contacts on… | Expired / Lapsed | 1958-12-08 | 1961-01-24 | 2 | Details |
| US2969216A | Clamps for securing and supporting articles | Expired / Lapsed | 1958-04-25 | 1961-01-24 | 0 | Details |
| US2969419A | Retractile cords | Expired / Lapsed | 1954-09-07 | 1961-01-24 | 0 | Details |
| US2966570A | Slide switch | Expired / Lapsed | 1959-07-09 | 1960-12-27 | 0 | Details |
| US2966659A | Signaling system | Expired / Lapsed | 1953-12-30 | 1960-12-27 | 0 | Details |
| US2965851A | Tapped ultrasonic delay line | Expired / Lapsed | 1957-12-26 | 1960-12-20 | 0 | Details |
| US2965855A | Electrical circuit | Expired / Lapsed | 1957-04-08 | 1960-12-20 | 0 | Details |
| US2965894A | Altitude control system | Expired / Lapsed | 1956-12-26 | 1960-12-20 | 0 | Details |
| US2963911A | Piezoresistive accelerometer | Expired / Lapsed | 1959-02-18 | 1960-12-13 | 0 | Details |
| US2964648A | Semiconductor capacitor | Expired / Lapsed | 1958-12-24 | 1960-12-13 | 0 | Details |
| US2964689A | Switching transistors | Expired / Lapsed | 1958-07-17 | 1960-12-13 | 0 | Details |
| US2964735A | Electronic selector circuit | Expired / Lapsed | 1957-08-14 | 1960-12-13 | 0 | Details |
| US2964653A | Diode-transistor switching circuits | Expired / Lapsed | 1957-02-27 | 1960-12-13 | 0 | Details |
| US2964651A | Electrical circuit employing transistor | Expired / Lapsed | 1956-03-29 | 1960-12-13 | 0 | Details |
| US2963592A | Transistor switching circuit | Expired / Lapsed | 1956-05-11 | 1960-12-06 | 0 | Details |
| US2962552A | Switching system | Expired / Lapsed | 1958-09-17 | 1960-11-29 | 0 | Details |
| US2961350A | Glass coating of circuit elements | Expired / Lapsed | 1959-03-20 | 1960-11-22 | 2 | Details |
| US2961354A | Surface treatment of semiconductive devices | Expired / Lapsed | 1958-10-28 | 1960-11-22 | 1 | Details |
| US2961488A | Permutation code selecting circuit | Expired / Lapsed | 1957-12-31 | 1960-11-22 | 0 | Details |
| US2959505A | High speed rectifier | Expired / Lapsed | 1959-07-10 | 1960-11-08 | 2 | Details |
| US2959758A | Printed circuit board | Expired / Lapsed | 1955-12-29 | 1960-11-08 | 0 | Details |
| US2958254A | Optical gaging system | Expired / Lapsed | 1958-03-11 | 1960-11-01 | 0 | Details |
| US2957946A | Speech interpolation system | Expired / Lapsed | 1958-09-23 | 1960-10-25 | 0 | Details |
| US2957949A | Pcm time division telephone switching system | Expired / Lapsed | 1958-09-11 | 1960-10-25 | 0 | Details |
| US2957952A | Code generator | Expired / Lapsed | 1958-05-09 | 1960-10-25 | 0 | Details |
| US2957945A | Timing circuit | Expired / Lapsed | 1957-12-24 | 1960-10-25 | 0 | Details |
| US2957948A | Frequency band compression | Expired / Lapsed | 1956-07-20 | 1960-10-25 | 0 | Details |
| US2957047A | Automatic telephone system | Expired / Lapsed | 1958-12-05 | 1960-10-18 | 0 | Details |
| US2957142A | Ultrasonic delay line | Expired / Lapsed | 1956-07-20 | 1960-10-18 | 0 | Details |
| US2956180A | Pulse shift monitoring circuit | Expired / Lapsed | 1958-06-26 | 1960-10-11 | 0 | Details |
| US2956124A | Continuous digital error correcting system | Expired / Lapsed | 1958-05-01 | 1960-10-11 | 0 | Details |
| US2956276A | Diversity system | Expired / Lapsed | 1957-09-16 | 1960-10-11 | 0 | Details |
| US2956274A | Object location system | Expired / Lapsed | 1945-08-20 | 1960-10-11 | 0 | Details |
| US2955267A | Electromechanical torsional band pass wave filter | Expired / Lapsed | 1958-08-20 | 1960-10-04 | 0 | Details |
| US2955165A | Electronic telephone switching system | Expired / Lapsed | 1957-10-07 | 1960-10-04 | 0 | Details |
| US2955279A | Selective paging system | Expired / Lapsed | 1955-02-11 | 1960-10-04 | 0 | Details |
| US2954433A | Multiple error correction circuitry | Expired / Lapsed | 1957-10-30 | 1960-09-27 | 0 | Details |
| US2954266A | Precision measuring device | Expired / Lapsed | 1957-10-18 | 1960-09-27 | 0 | Details |
| US2953486A | Junction formation by thermal oxidation of semiconductive m… | Expired / Lapsed | 1959-06-01 | 1960-09-20 | 2 | Details |
| US2953647A | Magnetic drum repertory dialer | Expired / Lapsed | 1956-11-09 | 1960-09-20 | 0 | Details |
| US2953778A | Office code translator | Expired / Lapsed | 1956-09-21 | 1960-09-20 | 0 | Details |
| US2951229A | Error-detecting and correcting system | Expired / Lapsed | 1959-04-27 | 1960-08-30 | 0 | Details |
| US2951235A | Statistical data accumulator | Expired / Lapsed | 1958-01-15 | 1960-08-30 | 0 | Details |
| US2951240A | Magnetic core circuit | Expired / Lapsed | 1956-10-16 | 1960-08-30 | 0 | Details |
| US2951230A | Shift register counter | Expired / Lapsed | 1955-10-06 | 1960-08-30 | 0 | Details |
| US2951200A | Calibration indicator | Expired / Lapsed | 1954-10-29 | 1960-08-30 | 0 | Details |
| US2949547A | Delay timer | Expired / Lapsed | 1958-06-13 | 1960-08-16 | 0 | Details |
| US2949503A | Pulse modulation system framing circuit | Expired / Lapsed | 1958-05-21 | 1960-08-16 | 0 | Details |
| US2949505A | Reduced bandwith transmission system | Expired / Lapsed | 1957-08-14 | 1960-08-16 | 0 | Details |
| US2948864A | Broad-band electromagnetic wave coupler | Expired / Lapsed | 1957-10-02 | 1960-08-09 | 0 | Details |
| US2948261A | Apparatus for producing printed wiring by metal vaporization | Expired / Lapsed | 1956-12-07 | 1960-08-09 | 0 | Details |
| US2947803A | Clock controlled automatic recycling switching circuit | Expired / Lapsed | 1957-04-24 | 1960-08-02 | 0 | Details |
| US2947816A | Telegraph repeater | Expired / Lapsed | 1956-08-22 | 1960-08-02 | 0 | Details |
| US2946984A | Tape-to-card converter circuit | Expired / Lapsed | 1956-05-31 | 1960-07-26 | 0 | Details |
| US2946897A | Direct coupled transistor logic circuits | Expired / Lapsed | 1956-03-29 | 1960-07-26 | 0 | Details |
| US2946884A | Automatic frequency control for radio receiver | Expired / Lapsed | 1954-10-08 | 1960-07-26 | 0 | Details |
| US2945914A | Vapor seal leadin | Expired / Lapsed | 1958-12-16 | 1960-07-19 | 0 | Details |
| US2945828A | Composite materials for producing cellular polyethylene art… | Expired / Lapsed | 1957-02-20 | 1960-07-19 | 2 | Details |
| US2946033A | Polarized connector for printed circuit cards | Expired / Lapsed | 1956-05-15 | 1960-07-19 | 0 | Details |
| US2944321A | Method of fabricating semiconductor devices | Expired / Lapsed | 1958-12-31 | 1960-07-12 | 0 | Details |
| US2942266A | Antenna with means for preventing re-radiation into feed gu… | Expired / Lapsed | 1957-07-16 | 1960-06-21 | 0 | Details |
| US2941089A | Magnetic core counter circuits | Expired / Lapsed | 1958-09-10 | 1960-06-14 | 0 | Details |
| US2941154A | Parallel transistor amplifiers | Expired / Lapsed | 1957-12-10 | 1960-06-14 | 0 | Details |
| US2941053A | Testing apparatus | Expired / Lapsed | 1957-11-07 | 1960-06-14 | 0 | Details |
| US2941074A | Time division multiplex communication systems | Expired / Lapsed | 1957-10-28 | 1960-06-14 | 0 | Details |
| US2940042A | Pulse phase detector | Expired / Lapsed | 1957-02-25 | 1960-06-07 | 0 | Details |
| US2939317A | Variable resistance semiconductive devices | Expired / Lapsed | 1955-10-31 | 1960-06-07 | 0 | Details |
| US2939109A | Signaling system | Expired / Lapsed | 1957-12-16 | 1960-05-31 | 0 | Details |
| US2938424A | Reflection sensing system | Expired / Lapsed | 1957-07-11 | 1960-05-31 | 0 | Details |
| US2938194A | Ferroelectric storage circuits | Expired / Lapsed | 1955-07-25 | 1960-05-24 | 0 | Details |
| US2937368A | Means for detecting marking and bypassing defective areas i… | Expired / Lapsed | 1956-12-12 | 1960-05-17 | 0 | Details |
| US2936381A | Light beam apparatus | Expired / Lapsed | 1958-04-09 | 1960-05-10 | 0 | Details |
| US2936338A | Switching circuit | Expired / Lapsed | 1957-12-11 | 1960-05-10 | 0 | Details |
| US2936117A | High speed switching circuits employing slow acting compone… | Expired / Lapsed | 1957-05-31 | 1960-05-10 | 0 | Details |
| US2936407A | Mounting and connecting apparatus | Expired / Lapsed | 1957-05-15 | 1960-05-10 | 0 | Details |
| US2936337A | Switching circuit | Expired / Lapsed | 1957-01-09 | 1960-05-10 | 0 | Details |
| US2936380A | Light valve logic circuits | Expired / Lapsed | 1955-12-07 | 1960-05-10 | 0 | Details |
| US2936336A | Automatic telephone answering and message recording device | Expired / Lapsed | 1953-01-14 | 1960-05-10 | 0 | Details |
| US2935569A | Time assignment speech interpolation system | Expired / Lapsed | 1957-09-26 | 1960-05-03 | 0 | Details |
| US2934723A | Attenuator | Expired / Lapsed | 1956-10-24 | 1960-04-26 | 0 | Details |
| US2933563A | Signal translating circuit | Expired / Lapsed | 1957-11-20 | 1960-04-19 | 0 | Details |
| US2933437A | Chemical lapping method | Expired / Lapsed | 1956-05-29 | 1960-04-19 | 2 | Details |
| US2933292A | Heat abstracting and shielding means for electron discharge… | Expired / Lapsed | 1955-12-02 | 1960-04-19 | 0 | Details |
| US2932772A | Circuitry systems and methods of making the same | Expired / Lapsed | 1956-06-11 | 1960-04-12 | 0 | Details |
| US2930722A | Method of treating silicon | Expired / Lapsed | 1959-02-03 | 1960-03-29 | 1 | Details |
| US2931027A | Visual display apparatus | Expired / Lapsed | 1956-10-19 | 1960-03-29 | 0 | Details |
| US2929922A | Masers and maser communications system | Expired / Lapsed | 1958-07-30 | 1960-03-22 | 0 | Details |
| US2929030A | Transistor multivibrator frequency control | Expired / Lapsed | 1957-12-06 | 1960-03-15 | 0 | Details |
| US2928901A | Transmission and reconstruction of artificial speech | Expired / Lapsed | 1956-04-13 | 1960-03-15 | 0 | Details |
| US2929034A | Magnetic transmission systems | Expired / Lapsed | 1953-04-29 | 1960-03-15 | 0 | Details |
| US2927971A | Subscriber call transmitting system | Expired / Lapsed | 1957-12-30 | 1960-03-08 | 0 | Details |
| US2927967A | Negative impedance repeater | Expired / Lapsed | 1957-10-14 | 1960-03-08 | 0 | Details |
| US2928075A | Ferroelectric storage circuits | Expired / Lapsed | 1955-04-14 | 1960-03-08 | 0 | Details |
| US2927962A | Transmission systems employing quantization | Expired / Lapsed | 1954-04-26 | 1960-03-08 | 0 | Details |
| US2926075A | Continuous zone refining using cross-flow | Expired / Lapsed | 1958-03-05 | 1960-02-23 | 2 | Details |
| US2926334A | Error detection circuit | Expired / Lapsed | 1955-04-20 | 1960-02-23 | 0 | Details |
| US2926336A | Ferroelectric device | Expired / Lapsed | 1955-04-14 | 1960-02-23 | 0 | Details |
| US2926239A | Composite image forming apparatus for visible and invisible… | Expired / Lapsed | 1944-09-18 | 1960-02-23 | 0 | Details |
| US2925467A | Electrographic transmitter | Expired / Lapsed | 1958-10-31 | 1960-02-16 | 0 | Details |
| US2924725A | Pulse steering circuit | Expired / Lapsed | 1957-12-16 | 1960-02-09 | 0 | Details |
| US2924666A | Telephone system calling stations identifier | Expired / Lapsed | 1957-09-19 | 1960-02-09 | 0 | Details |
| US2924667A | Reduction of transmission loss in bridged subscriber loops | Expired / Lapsed | 1957-08-13 | 1960-02-09 | 0 | Details |
| US2924788A | Linear voltage-to-frequency converter | Expired / Lapsed | 1957-03-14 | 1960-02-09 | 0 | Details |
| US2924711A | Multilevel quantizer | Expired / Lapsed | 1956-11-21 | 1960-02-09 | 0 | Details |
| US2922987A | Information storage system | Expired / Lapsed | 1957-08-05 | 1960-01-26 | 0 | Details |
| US2922965A | Aperture equalizer and phase correction for television | Expired / Lapsed | 1956-08-09 | 1960-01-26 | 0 | Details |
| US2922084A | High-voltage testing apparatus | Expired / Lapsed | 1957-09-20 | 1960-01-19 | 0 | Details |
| US2922145A | Magnetic core switching circuit | Expired / Lapsed | 1956-10-16 | 1960-01-19 | 0 | Details |
| US2921124A | Method and apparatus for reducing television bandwidth | Expired / Lapsed | 1956-12-10 | 1960-01-12 | 0 | Details |
| US2919307A | Order wire alarm and control circuit | Expired / Lapsed | 1958-09-24 | 1959-12-29 | 0 | Details |
| US2919358A | Apparatus for converting radiant energy to electromechanica… | Expired / Lapsed | 1955-03-23 | 1959-12-29 | 0 | Details |
| US2917583A | Time separation communication system | Expired / Lapsed | 1953-06-26 | 1959-12-15 | 0 | Details |
| US2916553A | High speed delta modulation encoder | Expired / Lapsed | 1957-05-31 | 1959-12-08 | 0 | Details |
| US2915808A | Methods of making electrical capacitors | Expired / Lapsed | 1956-04-09 | 1959-12-08 | 0 | Details |
| US2915647A | Semiconductive switch and negative resistance | Expired / Lapsed | 1955-07-13 | 1959-12-01 | 0 | Details |
| US2913578A | Multivibrator circuits | Expired / Lapsed | 1954-03-17 | 1959-11-17 | 0 | Details |
| US2912602A | Magnetic pulse generator | Expired / Lapsed | 1958-10-16 | 1959-11-10 | 0 | Details |
| US2912485A | Automatic teletypewriter station control system | Expired / Lapsed | 1957-04-05 | 1959-11-10 | 0 | Details |
| US2912679A | Translator | Expired / Lapsed | 1954-11-29 | 1959-11-10 | 0 | Details |
| US2912677A | Electrical circuits employing sensing wires threading magne… | Expired / Lapsed | 1953-12-31 | 1959-11-10 | 0 | Details |
| US2911463A | High resolution scanning system | Expired / Lapsed | 1957-12-30 | 1959-11-03 | 0 | Details |
| US2911539A | Photocell array | Expired / Lapsed | 1957-12-18 | 1959-11-03 | 0 | Details |
| US2911588A | Bridge circuits | Expired / Lapsed | 1955-12-23 | 1959-11-03 | 0 | Details |
| US2911544A | Shift register circuit controlled by a pulse generating cir… | Expired / Lapsed | 1955-10-06 | 1959-11-03 | 0 | Details |
| US2910959A | Apparatus for impregnating articles | Expired / Lapsed | 1955-01-13 | 1959-11-03 | 0 | Details |
| US2911554A | Non-reciprocal wave transmission device | Expired / Lapsed | 1953-06-17 | 1959-11-03 | 0 | Details |
| US2909623A | Interlaced feedback amplifier | Expired / Lapsed | 1957-06-27 | 1959-10-20 | 0 | Details |
| US2909600A | Two-way television over telephone lines | Expired / Lapsed | 1956-07-26 | 1959-10-20 | 0 | Details |
| US2909678A | Transistor control circuits | Expired / Lapsed | 1956-06-11 | 1959-10-20 | 0 | Details |
| US2909676A | Transistor comparator circuit for analog to digital code co… | Expired / Lapsed | 1955-08-15 | 1959-10-20 | 0 | Details |
| US2909675A | Bistable frequency divider | Expired / Lapsed | 1955-05-10 | 1959-10-20 | 0 | Details |
| US2909620A | Mu-beta measurement in feedback systems | Expired / Lapsed | 1954-01-05 | 1959-10-20 | 0 | Details |
| US2908874A | Automatic phase equalizer | Expired / Lapsed | 1957-08-07 | 1959-10-13 | 0 | Details |
| US2908873A | Automatic phase equalizer | Expired / Lapsed | 1957-08-05 | 1959-10-13 | 0 | Details |
| US2908871A | Negative resistance semiconductive apparatus | Expired / Lapsed | 1954-10-26 | 1959-10-13 | 0 | Details |
| US2907984A | Ferroelectric storage circuit | Expired / Lapsed | 1956-05-10 | 1959-10-06 | 0 | Details |
| US2906941A | Current supply apparatus | Expired / Lapsed | 1958-06-10 | 1959-09-29 | 0 | Details |
| US2906816A | Method and apparatus for reducing television bandwidth | Expired / Lapsed | 1956-07-24 | 1959-09-29 | 0 | Details |
| US2906893A | Transistor blocking oscillator | Expired / Lapsed | 1956-07-06 | 1959-09-29 | 0 | Details |
| US2907019A | Code translator | Expired / Lapsed | 1955-09-06 | 1959-09-29 | 0 | Details |
| US2906998A | Signaling system | Expired / Lapsed | 1955-08-19 | 1959-09-29 | 0 | Details |
| US2906996A | Electronic station selecting circuit | Expired / Lapsed | 1953-05-18 | 1959-09-29 | 0 | Details |
| US2905771A | Piezoresistive semiconductor microphone | Expired / Lapsed | 1957-05-15 | 1959-09-22 | 0 | Details |
| US2905756A | Method and apparatus for reducing television bandwidth | Expired / Lapsed | 1956-11-30 | 1959-09-22 | 0 | Details |
| US2904742A | Current supply apparatus | Expired / Lapsed | 1957-09-16 | 1959-09-15 | 0 | Details |
| US2904674A | Radiant energy highway communication system with controlled… | Expired / Lapsed | 1956-11-29 | 1959-09-15 | 0 | Details |
| US2903598A | Beam positioning system | Expired / Lapsed | 1956-03-26 | 1959-09-08 | 0 | Details |
| US2903676A | Binary counter transistor circuit | Expired / Lapsed | 1955-10-18 | 1959-09-08 | 0 | Details |
| US2902558A | Laminated core dry reed relay | Expired / Lapsed | 1955-02-17 | 1959-09-01 | 0 | Details |
| US2901381A | Method of making electrical resistors | Expired / Lapsed | 1956-10-12 | 1959-08-25 | 2 | Details |
| US2901602A | Binary half adder | Expired / Lapsed | 1953-11-19 | 1959-08-25 | 0 | Details |
| US2898477A | Piezoelectric field effect semiconductor device | Expired / Lapsed | 1955-10-31 | 1959-08-04 | 0 | Details |
| US2897369A | Radiation sensitive scanning system | Expired / Lapsed | 1944-12-28 | 1959-07-28 | 0 | Details |
| US2896133A | Magnetizing apparatus | Expired / Lapsed | 1956-04-13 | 1959-07-21 | 0 | Details |
| US2896160A | Time interval encoder | Expired / Lapsed | 1954-09-20 | 1959-07-21 | 0 | Details |
| US2895109A | Negative resistance semiconductive element | Expired / Lapsed | 1955-06-20 | 1959-07-14 | 0 | Details |
| US2895005A | Two-way television over telephone lines | Expired / Lapsed | 1954-09-30 | 1959-07-14 | 0 | Details |
| US2892888A | Digital system with error elimination | Expired / Lapsed | 1958-02-10 | 1959-06-30 | 0 | Details |
| US2892508A | Separation of gases by diffusion | Expired / Lapsed | 1957-04-17 | 1959-06-30 | 0 | Details |
| US2890940A | Electromagnetic stirring method | Expired / Lapsed | 1957-06-25 | 1959-06-16 | 2 | Details |
| US2889409A | Volume compression and expansion in pulse code transmission | Expired / Lapsed | 1956-12-31 | 1959-06-02 | 0 | Details |
| US2888557A | Frequency divider circuits | Expired / Lapsed | 1954-09-17 | 1959-05-26 | 0 | Details |
| US2887664A | Faraday-effect device for electro-magnetic waves | Expired / Lapsed | 1955-09-13 | 1959-05-19 | 0 | Details |
| US2887665A | High frequency isolator | Expired / Lapsed | 1953-12-31 | 1959-05-19 | 0 | Details |
| US2886802A | Timing pulse generator circuit for magnetic drum | Expired / Lapsed | 1955-12-20 | 1959-05-12 | 0 | Details |
| US2885572A | Transistor pulse transmission circuits | Expired / Lapsed | 1955-10-20 | 1959-05-05 | 0 | Details |
| US2885506A | Fluid pressure sensitive control devices | Expired / Lapsed | 1955-04-28 | 1959-05-05 | 0 | Details |
| US2885593A | Coupled lines systems | Expired / Lapsed | 1954-12-07 | 1959-05-05 | 0 | Details |
| US2884607A | Semiconductor nonlinear capacitance diode | Expired / Lapsed | 1958-04-18 | 1959-04-28 | 0 | Details |
| US2884491A | Message-waiting signal for telephone subscribers | Expired / Lapsed | 1958-01-24 | 1959-04-28 | 0 | Details |
| US2884613A | Electrical terminal block | Expired / Lapsed | 1955-03-25 | 1959-04-28 | 0 | Details |
| US2883457A | Multistation telephone intercommunicating and conference sy… | Expired / Lapsed | 1957-05-28 | 1959-04-21 | 0 | Details |
| US2883463A | Telephone pay station | Expired / Lapsed | 1956-12-31 | 1959-04-21 | 0 | Details |
| US2883470A | Communication switching network | Expired / Lapsed | 1956-10-19 | 1959-04-21 | 0 | Details |
| US2883467A | Communication switching system employing gas tubes | Expired / Lapsed | 1954-04-29 | 1959-04-21 | 0 | Details |
| US2883257A | Electron beam recording | Expired / Lapsed | 1953-05-15 | 1959-04-21 | 0 | Details |
| US2881392A | D. c. voltage ratio measuring system | Expired / Lapsed | 1955-01-10 | 1959-04-07 | 0 | Details |
| US2880334A | Ferroelectric torsional transducer | Expired / Lapsed | 1955-06-13 | 1959-03-31 | 0 | Details |
| US2880330A | Non-saturating transistor trigger circuits | Expired / Lapsed | 1954-06-29 | 1959-03-31 | 0 | Details |
| US2879190A | Fabrication of silicon devices | Expired / Lapsed | 1957-03-22 | 1959-03-24 | 2 | Details |
| US2878556A | Devices for assembling articles | Expired / Lapsed | 1956-07-25 | 1959-03-24 | 0 | Details |
| US2879183A | Insulating coatings and a method for their production | Expired / Lapsed | 1955-12-15 | 1959-03-24 | 2 | Details |
| US2878310A | Two-way television over telephone lines | Expired / Lapsed | 1955-05-05 | 1959-03-17 | 0 | Details |
| US2877359A | Semiconductor signal storage device | Expired / Lapsed | 1956-04-20 | 1959-03-10 | 0 | Details |
| US2877343A | Radiant energy communication system with carrier control | Expired / Lapsed | 1955-05-18 | 1959-03-10 | 0 | Details |
| US2876352A | Self-correcting pulse circuits | Expired / Lapsed | 1955-12-27 | 1959-03-03 | 0 | Details |
| US2875505A | Semiconductor translating device | Expired / Lapsed | 1952-12-11 | 1959-03-03 | 0 | Details |
| US2874313A | Data processing apparatus | Expired / Lapsed | 1956-08-07 | 1959-02-17 | 0 | Details |
| US2874341A | Ohmic contacts to silicon bodies | Expired / Lapsed | 1954-11-30 | 1959-02-17 | 2 | Details |
| US2873372A | Electric circuit interrupters | Expired / Lapsed | 1957-12-12 | 1959-02-10 | 0 | Details |
| US2873222A | Vapor-solid diffusion of semiconductive material | Expired / Lapsed | 1957-11-07 | 1959-02-10 | 2 | Details |
| US2873385A | Transistor data storage and gate circuit | Expired / Lapsed | 1955-10-06 | 1959-02-10 | 0 | Details |
| US2872703A | Extrusion apparatus | Expired / Lapsed | 1955-01-24 | 1959-02-10 | 0 | Details |
| US2871283A | Cable termination | Expired / Lapsed | 1956-10-11 | 1959-01-27 | 0 | Details |
| US2871376A | Temperature sensitive transistor control circuit | Expired / Lapsed | 1953-12-31 | 1959-01-27 | 0 | Details |
| US2870271A | Automatic transmission regulation | Expired / Lapsed | 1956-10-11 | 1959-01-20 | 0 | Details |
| US2870328A | Proportional amplitude discriminator | Expired / Lapsed | 1953-06-12 | 1959-01-20 | 0 | Details |
| US2868880A | Remote control of telephone answering and message recording… | Expired / Lapsed | 1957-02-07 | 1959-01-13 | 0 | Details |
| US2869076A | Apparatus for testing a plurality of circuits | Expired / Lapsed | 1955-08-22 | 1959-01-13 | 0 | Details |
| US2867149A | Method of determining surface flatness | Expired / Lapsed | 1953-10-05 | 1959-01-06 | 0 | Details |
| US2866913A | Multipole pair resolver | Expired / Lapsed | 1956-06-27 | 1958-12-30 | 0 | Details |
| US2866852A | Automatic telephone answering and message-recording system | Expired / Lapsed | 1956-05-29 | 1958-12-30 | 0 | Details |
| US2866949A | Microwave circulators, isolators, and branching filters | Expired / Lapsed | 1953-10-29 | 1958-12-30 | 0 | Details |
| US2866103A | Diode gate and sampling circuit | Expired / Lapsed | 1956-08-22 | 1958-12-23 | 0 | Details |
| US2866014A | Piezoresistive acoustic transducer | Expired / Lapsed | 1955-10-31 | 1958-12-23 | 0 | Details |
| US2864975A | Transistor circuit for operating a relay | Expired / Lapsed | 1957-07-12 | 1958-12-16 | 0 | Details |
| US2864159A | Method of making splicing sleeve assemblies | Expired / Lapsed | 1954-09-29 | 1958-12-16 | 0 | Details |
| US2864008A | Relay selecting circuit | Expired / Lapsed | 1955-12-28 | 1958-12-09 | 0 | Details |
| US2864002A | Transistor detector | Expired / Lapsed | 1953-09-16 | 1958-12-09 | 0 | Details |
| US2862992A | Electrical network assembly | Expired / Lapsed | 1954-05-03 | 1958-12-02 | 0 | Details |
| US2862115A | Semiconductor circuit controlling devices | Expired / Lapsed | 1955-07-13 | 1958-11-25 | 0 | Details |
| US2861676A | Reciprocable feed mechanism for advancing articles step by … | Expired / Lapsed | 1954-10-28 | 1958-11-25 | 0 | Details |
| US2861185A | Compensated plate type limiter | Expired / Lapsed | 1956-01-27 | 1958-11-18 | 0 | Details |
| US2861029A | Methods of making printed wiring circuits | Expired / Lapsed | 1955-12-14 | 1958-11-18 | 0 | Details |
| US2861018A | Fabrication of semiconductive devices | Expired / Lapsed | 1955-06-20 | 1958-11-18 | 2 | Details |
| US2861181A | Delay circuits | Expired / Lapsed | 1953-06-01 | 1958-11-18 | 0 | Details |
| US2860187A | Artificial reconstruction of speech | Expired / Lapsed | 1955-12-08 | 1958-11-11 | 0 | Details |
| US2860284A | Cathode ray tube circuit to maintain uniform trace intensity | Expired / Lapsed | 1955-11-22 | 1958-11-11 | 0 | Details |
| US2860258A | Transistor decade counter | Expired / Lapsed | 1954-09-17 | 1958-11-11 | 0 | Details |
| US2860265A | Ferroelectric device | Expired / Lapsed | 1954-06-21 | 1958-11-11 | 0 | Details |
| US2859283A | Communication switching network | Expired / Lapsed | 1956-10-19 | 1958-11-04 | 0 | Details |
| US2859414A | Delay network | Expired / Lapsed | 1954-02-04 | 1958-11-04 | 0 | Details |
| US2859415A | Ultrasonic acoustic wave transmission delay lines | Expired / Lapsed | 1952-09-03 | 1958-11-04 | 0 | Details |
| US2858246A | Silicon single crystal conductor devices | Expired / Lapsed | 1957-04-22 | 1958-10-28 | 2 | Details |
| US2857626A | Methods of encapsulating articles | Expired / Lapsed | 1955-07-18 | 1958-10-28 | 0 | Details |
| US2858524A | Recording scanner | Expired / Lapsed | 1953-11-13 | 1958-10-28 | 0 | Details |
| US2857465A | Vocoder transmission system | Expired / Lapsed | 1955-11-21 | 1958-10-21 | 0 | Details |
| US2856544A | Semiconductive pulse translator | Expired / Lapsed | 1956-04-18 | 1958-10-14 | 0 | Details |
| US2855539A | Light position indicating system | Expired / Lapsed | 1956-04-27 | 1958-10-07 | 0 | Details |
| US2855540A | Beam positioning system | Expired / Lapsed | 1956-04-27 | 1958-10-07 | 0 | Details |
| US2855463A | Telephone system involving the dialing of extension station… | Expired / Lapsed | 1956-02-21 | 1958-10-07 | 0 | Details |
| US2855524A | Semiconductive switch | Expired / Lapsed | 1955-11-22 | 1958-10-07 | 0 | Details |
| US2855146A | Magnetic drum computer | Expired / Lapsed | 1952-09-18 | 1958-10-07 | 0 | Details |
| US2854590A | Counting circuits employing ferroelectric capacitors | Expired / Lapsed | 1955-12-12 | 1958-09-30 | 0 | Details |
| US2854542A | Vibratory signaling device | Expired / Lapsed | 1955-05-24 | 1958-09-30 | 0 | Details |
| US2854603A | Magnetrons | Expired / Lapsed | 1955-05-23 | 1958-09-30 | 0 | Details |
| US2854191A | Computation of correlation | Expired / Lapsed | 1953-11-23 | 1958-09-30 | 0 | Details |
| US2853553A | Line scanner | Expired / Lapsed | 1955-12-28 | 1958-09-23 | 0 | Details |
| US2853694A | Electron discharge tube circuit | Expired / Lapsed | 1952-06-11 | 1958-09-23 | 0 | Details |
| US2852677A | High frequency negative resistance device | Expired / Lapsed | 1955-06-28 | 1958-09-16 | 0 | Details |
| US2851657A | Comparison type electrical test set | Expired / Lapsed | 1955-02-04 | 1958-09-09 | 0 | Details |
| US2850650A | Transistor current limiter | Expired / Lapsed | 1956-03-29 | 1958-09-02 | 0 | Details |
| US2850694A | Current supply apparatus for load voltage regulation | Expired / Lapsed | 1954-07-07 | 1958-09-02 | 0 | Details |
| US2849539A | Magnetic core circuits | Expired / Lapsed | 1956-12-13 | 1958-08-26 | 0 | Details |
| US2848739A | Methods of and apparatus for making cellular plastic produc… | Expired / Lapsed | 1955-09-30 | 1958-08-26 | 0 | Details |
| US2849626A | Monostable circuit | Expired / Lapsed | 1955-04-15 | 1958-08-26 | 0 | Details |
| US2849692A | Dielectric guide for electromagnetic waves | Expired / Lapsed | 1954-08-18 | 1958-08-26 | 0 | Details |
| US2849689A | Directional filter | Expired / Lapsed | 1954-01-29 | 1958-08-26 | 0 | Details |
| US2849685A | Non-reciprocal multibranch wave guide component | Expired / Lapsed | 1953-08-17 | 1958-08-26 | 0 | Details |
| US2849686A | Ferromagnetic devices | Expired / Lapsed | 1953-08-17 | 1958-08-26 | 0 | Details |
| US2849684A | Non-reciprocal wave transmission | Expired / Lapsed | 1953-07-31 | 1958-08-26 | 0 | Details |
| US2848545A | Radiant energy signaling system | Expired / Lapsed | 1955-09-27 | 1958-08-19 | 0 | Details |
| US2848714A | Antenna coupling circuits | Expired / Lapsed | 1955-06-08 | 1958-08-19 | 0 | Details |
| US2847287A | Etching processes and solutions | Expired / Lapsed | 1956-07-20 | 1958-08-12 | 2 | Details |
| US2846512A | Party line station identifying impulse transmitter | Expired / Lapsed | 1956-12-31 | 1958-08-05 | 0 | Details |
| US2846680A | Directive antennas | Expired / Lapsed | 1946-06-29 | 1958-08-05 | 0 | Details |
| US2844693A | Wire-wound vitreous enamel resistors | Expired / Lapsed | 1954-10-25 | 1958-07-22 | 2 | Details |
| US2842831A | Manufacture of semiconductor devices | Expired / Lapsed | 1956-08-30 | 1958-07-15 | 0 | Details |
| US2843745A | Tone generator | Expired / Lapsed | 1956-05-11 | 1958-07-15 | 0 | Details |
| US2843838A | Ferromagnetic translating apparatus | Expired / Lapsed | 1955-08-23 | 1958-07-15 | 0 | Details |
| US2843813A | Magnetic amplifiers | Expired / Lapsed | 1953-12-28 | 1958-07-15 | 0 | Details |
| US2843447A | Probability oscillograph | Expired / Lapsed | 1951-11-01 | 1958-07-15 | 0 | Details |
| US2842463A | Vapor deposited metal films | Expired / Lapsed | 1953-09-04 | 1958-07-08 | 2 | Details |
| US2840728A | Non-saturating transistor circuits | Expired / Lapsed | 1955-04-26 | 1958-06-24 | 0 | Details |
| US2840820A | Artificial medium of variable dielectric constant | Expired / Lapsed | 1954-04-14 | 1958-06-24 | 0 | Details |
| US2840784A | Method of testing electrical devices | Expired / Lapsed | 1953-12-01 | 1958-06-24 | 0 | Details |
| US2840495A | Method of processing semiconductive materials | Expired / Lapsed | 1953-08-21 | 1958-06-24 | 2 | Details |
| US2839816A | Method of making stacked type capacitors | Expired / Lapsed | 1953-01-12 | 1958-06-24 | 0 | Details |
| US2838797A | Method of and apparatus for sealing electrical components i… | Expired / Lapsed | 1954-05-06 | 1958-06-17 | 0 | Details |
| US2839727A | Encoder for pulse code modulation | Expired / Lapsed | 1953-02-11 | 1958-06-17 | 0 | Details |
| US2838687A | Nonlinear resonant circuit devices | Expired / Lapsed | 1955-08-09 | 1958-06-10 | 0 | Details |
| US2837642A | Pulse rate discriminator | Expired / Lapsed | 1953-12-17 | 1958-06-03 | 0 | Details |
| US2837448A | Method of fabricating semiconductor pn junctions | Expired / Lapsed | 1953-10-26 | 1958-06-03 | 2 | Details |
| US2836523A | Manufacture of semiconductive devices | Expired / Lapsed | 1956-08-02 | 1958-05-27 | 2 | Details |
| US2836787A | Condenser discharge welding system | Expired / Lapsed | 1956-05-10 | 1958-05-27 | 0 | Details |
| US2835927A | Methods of producing cellular plastics | Expired / Lapsed | 1953-05-07 | 1958-05-27 | 2 | Details |
| US2835741A | Magnetic core signal generator | Expired / Lapsed | 1956-11-01 | 1958-05-20 | 0 | Details |
| US2835828A | Regenerative transistor amplifiers | Expired / Lapsed | 1953-08-07 | 1958-05-20 | 0 | Details |
| US2834697A | Process for vapor-solid diffusion of a conductivity-type de… | Expired / Lapsed | 1956-05-18 | 1958-05-13 | 2 | Details |
| US2834943A | Mechanically coupled electromechanical and magnetomechanica… | Expired / Lapsed | 1953-09-16 | 1958-05-13 | 0 | Details |
| US2833921A | Automatic continuous zero-setting of a balanced detector | Expired / Lapsed | 1954-12-30 | 1958-05-06 | 0 | Details |
| US2831311A | Uncoiling apparatus | Expired / Lapsed | 1956-06-26 | 1958-04-22 | 0 | Details |
| US2831986A | Semiconductor trigger circuit | Expired / Lapsed | 1955-09-07 | 1958-04-22 | 0 | Details |
| US2832013A | Printed wire circuit card inter-connection apparatus | Expired / Lapsed | 1954-11-12 | 1958-04-22 | 0 | Details |
| US2832051A | Push-pull transistor modulator | Expired / Lapsed | 1953-06-01 | 1958-04-22 | 0 | Details |
| US2831983A | Trigger circuit | Expired / Lapsed | 1952-06-11 | 1958-04-22 | 0 | Details |
| US2830642A | Tool for forming tabs on cylindrical shell by cutting and b… | Expired / Lapsed | 1956-01-25 | 1958-04-15 | 0 | Details |
| US2831113A | Transistor relaxation circuits | Expired / Lapsed | 1954-10-14 | 1958-04-15 | 0 | Details |
| US2831126A | Bistable transistor coincidence gate | Expired / Lapsed | 1954-08-13 | 1958-04-15 | 0 | Details |
| US2830285A | Storage system | Expired / Lapsed | 1955-10-18 | 1958-04-08 | 0 | Details |
| US2829422A | Methods of fabricating semiconductor signal translating dev… | Expired / Lapsed | 1952-05-21 | 1958-04-08 | 2 | Details |
| US2829203A | Electronic telephone subscriber's line circuit for neutrali… | Expired / Lapsed | 1955-11-03 | 1958-04-01 | 0 | Details |
| US2829320A | Encapsulation for electrical components and method of manuf… | Expired / Lapsed | 1955-01-12 | 1958-04-01 | 2 | Details |
| US2829280A | Stair-step wave form generator | Expired / Lapsed | 1953-03-05 | 1958-04-01 | 0 | Details |
| US2829300A | Traveling wave device | Expired / Lapsed | 1951-08-15 | 1958-04-01 | 0 | Details |
| US2828362A | Digit data transmission system | Expired / Lapsed | 1956-01-24 | 1958-03-25 | 0 | Details |
| US2828414A | Demodulation of vestigial sideband signals | Expired / Lapsed | 1953-01-21 | 1958-03-25 | 0 | Details |
| US2828071A | Selectable base counter | Expired / Lapsed | 1951-12-27 | 1958-03-25 | 0 | Details |
| US2827436A | Method of improving the minority carrier lifetime in a sing… | Expired / Lapsed | 1956-01-16 | 1958-03-18 | 2 | Details |
| US2827626A | Electromagnetic positioning device | Expired / Lapsed | 1955-12-27 | 1958-03-18 | 0 | Details |
| US2827233A | Digital to analog converter | Expired / Lapsed | 1954-12-13 | 1958-03-18 | 0 | Details |
| US2826638A | Signaling system | Expired / Lapsed | 1952-04-26 | 1958-03-11 | 0 | Details |
| US2825764A | Cross-control compandor used as echo suppressors | Expired / Lapsed | 1954-02-24 | 1958-03-04 | 0 | Details |
| US2824228A | Pulse train modification circuits | Expired / Lapsed | 1954-12-30 | 1958-02-18 | 0 | Details |
| US2824173A | Transistor selective ringing, dialing, and party identifica… | Expired / Lapsed | 1954-11-18 | 1958-02-18 | 0 | Details |
| US2823333A | Traveling wave tube | Expired / Lapsed | 1954-10-29 | 1958-02-11 | 0 | Details |
| US2820987A | Methods of and apparatus for controlling the application of… | Expired / Lapsed | 1955-06-07 | 1958-01-28 | 0 | Details |
| US2821597A | Register relay | Expired / Lapsed | 1955-03-18 | 1958-01-28 | 0 | Details |
| US2820932A | Contact structure | Expired / Lapsed | 1956-03-07 | 1958-01-21 | 1 | Details |
| US2820155A | Negative impedance bistable signaloperated switch | Expired / Lapsed | 1955-03-09 | 1958-01-14 | 0 | Details |
| US2818470A | Compensated transistor circuit | Expired / Lapsed | 1956-03-29 | 1957-12-31 | 0 | Details |
| US2818558A | Key pulsing circuit | Expired / Lapsed | 1954-06-17 | 1957-12-31 | 0 | Details |
| US2818514A | Stressed ferrite cores | Expired / Lapsed | 1952-10-02 | 1957-12-31 | 2 | Details |
| US2817711A | Band compression system | Expired / Lapsed | 1954-05-10 | 1957-12-24 | 0 | Details |
| US2817828A | Multifrequency high speed signaling system employing pulses… | Expired / Lapsed | 1953-10-07 | 1957-12-24 | 0 | Details |
| US2817477A | Electronic computer | Expired / Lapsed | 1948-04-23 | 1957-12-24 | 0 | Details |
| US2817078A | Binary digital-to-analog converter for synchro devices | Expired / Lapsed | 1956-05-25 | 1957-12-17 | 0 | Details |
| US2817079A | Switching network using diodes and transformers | Expired / Lapsed | 1956-05-22 | 1957-12-17 | 0 | Details |
| US2817061A | Asymmetrical delta modulation system | Expired / Lapsed | 1955-06-07 | 1957-12-17 | 0 | Details |
| US2814779A | Microwave detector | Expired / Lapsed | 1954-12-14 | 1957-11-26 | 0 | Details |
| US2813233A | Semiconductive device | Expired / Lapsed | 1954-07-01 | 1957-11-12 | 0 | Details |
| US2813048A | Temperature gradient zone-melting | Expired / Lapsed | 1954-06-24 | 1957-11-12 | 2 | Details |
| US2813149A | Telegraph transmission error register | Expired / Lapsed | 1954-04-19 | 1957-11-12 | 0 | Details |
| US2812446A | Photo-resistance device | Expired / Lapsed | 1954-03-05 | 1957-11-05 | 1 | Details |
| US2812468A | Spatial harmonic traveling wave tube | Expired / Lapsed | 1952-12-30 | 1957-11-05 | 0 | Details |
| US2812467A | Electron beam system | Expired / Lapsed | 1952-10-10 | 1957-11-05 | 0 | Details |
| US2812499A | Helix assembly for traveling wave tube | Expired / Lapsed | 1952-07-11 | 1957-11-05 | 0 | Details |
| US2812133A | Electronic computing device | Expired / Lapsed | 1952-06-19 | 1957-11-05 | 0 | Details |
| US2811700A | Electrical connector for printed wiring board | Expired / Lapsed | 1956-05-14 | 1957-10-29 | 0 | Details |
| US2811707A | Matching circuit | Expired / Lapsed | 1955-12-29 | 1957-10-29 | 0 | Details |
| US2811682A | Silicon power rectifier | Expired / Lapsed | 1955-03-03 | 1957-10-29 | 2 | Details |
| US2811586A | Intercommunication system | Expired / Lapsed | 1954-04-02 | 1957-10-29 | 0 | Details |
| US2811673A | Traveling wave tube | Expired / Lapsed | 1953-05-14 | 1957-10-29 | 0 | Details |
| US2810854A | Serpentine traveling wave tube | Expired / Lapsed | 1951-10-06 | 1957-10-22 | 0 | Details |
| US2810090A | Cathodes for electron discharge devices | Expired / Lapsed | 1953-06-15 | 1957-10-15 | 0 | Details |
| US2808509A | Frequency controlled variable oscillator | Expired / Lapsed | 1954-03-19 | 1957-10-01 | 0 | Details |
| US2808584A | Directional radiator | Expired / Lapsed | 1954-01-29 | 1957-10-01 | 0 | Details |
| US2807868A | Method of manufacture of contact springs | Expired / Lapsed | 1953-06-26 | 1957-10-01 | 0 | Details |
| US2806997A | Circulating pulse coders | Expired / Lapsed | 1956-03-28 | 1957-09-17 | 0 | Details |
| US2806950A | Circulating pulse decoder | Expired / Lapsed | 1956-03-28 | 1957-09-17 | 0 | Details |
| US2806200A | Ambient temperature compensation of thermistors | Expired / Lapsed | 1952-12-17 | 1957-09-10 | 0 | Details |
| US2805370A | Alloyed connections to semiconductors | Expired / Lapsed | 1956-04-26 | 1957-09-03 | 1 | Details |
| US2805347A | Semiconductive devices | Expired / Lapsed | 1954-05-27 | 1957-09-03 | 2 | Details |
| US2805397A | Semiconductor signal translating devices | Expired / Lapsed | 1952-10-31 | 1957-09-03 | 0 | Details |
| US2804405A | Manufacture of silicon devices | Expired / Lapsed | 1954-12-24 | 1957-08-27 | 2 | Details |
| US2802760A | Oxidation of semiconductive surfaces for controlled diffusi… | Expired / Lapsed | 1955-12-02 | 1957-08-13 | 2 | Details |
| US2802905A | Electromagnetic transducer mounting | Expired / Lapsed | 1953-07-30 | 1957-08-13 | 0 | Details |
| US2802940A | Multivibrator circuit | Expired / Lapsed | 1953-06-26 | 1957-08-13 | 0 | Details |
| US2802118A | Transistor amplifier circuits | Expired / Lapsed | 1954-06-17 | 1957-08-06 | 0 | Details |
| US2802149A | Contact protection circuits | Expired / Lapsed | 1953-12-30 | 1957-08-06 | 0 | Details |
| US2801287A | Control of regular and distant talking subscribers sets | Expired / Lapsed | 1954-07-16 | 1957-07-30 | 0 | Details |
| US2801296A | D.-c. summing amplifier drift correction | Expired / Lapsed | 1954-02-09 | 1957-07-30 | 0 | Details |
| US2801281A | Communication system employing pulse code modulation | Expired / Lapsed | 1952-09-17 | 1957-07-30 | 0 | Details |
| US2801361A | High frequency amplifier | Expired / Lapsed | 1950-11-24 | 1957-07-30 | 0 | Details |
| US2801413A | Directive dielectric antennas | Expired / Lapsed | 1949-03-30 | 1957-07-30 | 0 | Details |
| US2799006A | Multiplexing various modes in composite conductors | Expired / Lapsed | 1953-03-24 | 1957-07-09 | 0 | Details |
| US2797862A | Digital computer | Expired / Lapsed | 1951-11-08 | 1957-07-02 | 0 | Details |
| US2797171A | Method of uniformly applying lacquer to paper strips | Expired / Lapsed | 1951-04-25 | 1957-06-25 | 0 | Details |
| US2796512A | Assembly fixture | Expired / Lapsed | 1955-11-29 | 1957-06-18 | 0 | Details |
| US2796563A | Semiconductive devices | Expired / Lapsed | 1955-06-10 | 1957-06-18 | 2 | Details |
| US2795742A | Semiconductive translating devices utilizing selected natur… | Expired / Lapsed | 1952-12-12 | 1957-06-11 | 0 | Details |
| US2795648A | Dielectric amplifier employing ferroelectric materials | Expired / Lapsed | 1952-10-17 | 1957-06-11 | 0 | Details |
| US2794970A | Identification of serial stored information | Expired / Lapsed | 1955-07-05 | 1957-06-04 | 0 | Details |
| US2794535A | Sensing devices for selective delivery conveyors | Expired / Lapsed | 1955-01-20 | 1957-06-04 | 0 | Details |
| US2794959A | Directional coupler for all-dielectric waveguide | Expired / Lapsed | 1952-03-01 | 1957-06-04 | 0 | Details |
| US2794863A | Semiconductor translating device and circuit | Expired / Lapsed | 1951-07-20 | 1957-06-04 | 0 | Details |
| US2793420A | Electrical contacts to silicon | Expired / Lapsed | 1955-04-22 | 1957-05-28 | 1 | Details |
| US2793807A | Pulse code resolution | Expired / Lapsed | 1952-10-18 | 1957-05-28 | 0 | Details |
| US2792540A | Junction transistor | Expired / Lapsed | 1955-08-04 | 1957-05-14 | 0 | Details |
| US2792538A | Semiconductor translating devices with embedded electrode | Expired / Lapsed | 1950-09-14 | 1957-05-14 | 2 | Details |
| US2791758A | Semiconductive translating device | Expired / Lapsed | 1955-02-18 | 1957-05-07 | 2 | Details |
| US2791760A | Semiconductive translating device | Expired / Lapsed | 1955-02-18 | 1957-05-07 | 2 | Details |
| US2791759A | Semiconductive device | Expired / Lapsed | 1955-02-18 | 1957-05-07 | 2 | Details |
| US2790940A | Silicon rectifier and method of manufacture | Expired / Lapsed | 1955-04-22 | 1957-04-30 | 1 | Details |
| US2790037A | Semiconductor signal translating devices | Expired / Lapsed | 1952-03-14 | 1957-04-23 | 0 | Details |
| US2789254A | Lightning protection circuits | Expired / Lapsed | 1954-04-23 | 1957-04-16 | 0 | Details |
| US2789267A | System for testing pulse generators | Expired / Lapsed | 1953-05-26 | 1957-04-16 | 0 | Details |
| US2787564A | Forming semiconductive devices by ionic bombardment | Expired / Lapsed | 1954-10-28 | 1957-04-02 | 2 | Details |
| US2787712A | Transistor multivibrator circuits | Expired / Lapsed | 1954-10-04 | 1957-04-02 | 0 | Details |
| US2785322A | Stable liquid electrodes | Expired / Lapsed | 1953-08-04 | 1957-03-12 | 2 | Details |
| US2782985A | Tape control arrangement for computer | Expired / Lapsed | 1952-06-12 | 1957-02-26 | 0 | Details |
| US2782259A | Calling subscriber identifier using transistor oscillator i… | Expired / Lapsed | 1953-12-23 | 1957-02-19 | 0 | Details |
| US2780765A | Solar energy converting apparatus | Expired / Lapsed | 1954-03-05 | 1957-02-05 | 2 | Details |
| US2779545A | Continuous strand reeling apparatus | Expired / Lapsed | 1955-03-30 | 1957-01-29 | 0 | Details |
| US2779822A | Communication switching system employing gas tubes | Expired / Lapsed | 1955-03-25 | 1957-01-29 | 0 | Details |
| US2779539A | Multiple code wheel analogue-digital translator | Expired / Lapsed | 1954-04-19 | 1957-01-29 | 0 | Details |
| US2779094A | Method of assembling bushings in a shell | Expired / Lapsed | 1951-08-16 | 1957-01-29 | 0 | Details |
| US2779191A | Frequency discriminator employing multiply resonant piezoel… | Expired / Lapsed | 1950-10-28 | 1957-01-29 | 0 | Details |
| US2778743A | Method of making electrical carbonfilm resistors | Expired / Lapsed | 1954-11-16 | 1957-01-22 | 2 | Details |
| US2778885A | Semiconductor signal translating devices | Expired / Lapsed | 1952-10-31 | 1957-01-22 | 0 | Details |
| US2778956A | Semiconductor signal translating devices | Expired / Lapsed | 1952-10-31 | 1957-01-22 | 0 | Details |
| US2778978A | Multivibrator load circuit | Expired / Lapsed | 1952-09-19 | 1957-01-22 | 0 | Details |
| US2778878A | Repetition telephone dialing by pulse code modulated carrier | Expired / Lapsed | 1950-04-26 | 1957-01-22 | 0 | Details |
| US2777974A | Protection of semiconductive devices by gaseous ambients | Expired / Lapsed | 1955-06-08 | 1957-01-15 | 0 | Details |
| US2777956A | Square wave generator | Expired / Lapsed | 1954-07-02 | 1957-01-15 | 0 | Details |
| US2777906A | Asymmetric wave guide structure | Expired / Lapsed | 1953-06-26 | 1957-01-15 | 0 | Details |
| US2777162A | Pressing punch and die | Expired / Lapsed | 1952-10-29 | 1957-01-15 | 0 | Details |
| US2776380A | Electrical circuits employing magnetic cores | Expired / Lapsed | 1954-04-27 | 1957-01-01 | 0 | Details |
| US2776405A | Electrical circuit analyzer | Expired / Lapsed | 1953-05-18 | 1957-01-01 | 0 | Details |
| US2776371A | Quantizing system employing cathode ray tube | Expired / Lapsed | 1952-07-18 | 1957-01-01 | 0 | Details |
| US2775727A | Digital to analogue converter with digital feedback control | Expired / Lapsed | 1954-12-08 | 1956-12-25 | 0 | Details |
| US2774872A | Phase shifting circuit | Expired / Lapsed | 1952-12-17 | 1956-12-18 | 0 | Details |
| US2774890A | Nonreciprocal transmitting devices | Expired / Lapsed | 1952-08-30 | 1956-12-18 | 0 | Details |
| US2774051A | Electrical unit | Expired / Lapsed | 1953-02-16 | 1956-12-11 | 0 | Details |
| US2773980A | Amplitude sensitive multistate device | Expired / Lapsed | 1950-12-30 | 1956-12-11 | 0 | Details |
| US2771519A | Routine trunk test circuit | Expired / Lapsed | 1955-06-29 | 1956-11-20 | 0 | Details |
| US2771382A | Method of fabricating semiconductors for signal translating… | Expired / Lapsed | 1951-12-12 | 1956-11-20 | 0 | Details |
| US2770761A | Semiconductor translators containing enclosed active juncti… | Expired / Lapsed | 1954-12-16 | 1956-11-13 | 0 | Details |
| US2769861A | Reduction of interference in pulse reception | Expired / Lapsed | 1953-10-21 | 1956-11-06 | 0 | Details |
| US2769875A | Mercury contact switch | Expired / Lapsed | 1953-09-25 | 1956-11-06 | 0 | Details |
| US2769908A | Negative impedance transistor circuits | Expired / Lapsed | 1952-11-22 | 1956-11-06 | 0 | Details |
| US2768322A | Interdigital filter circuit | Expired / Lapsed | 1951-06-08 | 1956-10-23 | 0 | Details |
| US2767358A | Semiconductor signal translating devices | Expired / Lapsed | 1952-12-16 | 1956-10-16 | 0 | Details |
| US2767375A | Automatic meter calibrator | Expired / Lapsed | 1952-12-09 | 1956-10-16 | 0 | Details |
| US2766481A | Methods of and apparatus for extruding cellular plastics | Expired / Lapsed | 1952-08-28 | 1956-10-16 | 0 | Details |
| US2766480A | Methods of and apparatus for extruding cellular plastics | Expired / Lapsed | 1952-08-28 | 1956-10-16 | 0 | Details |
| US2767373A | Measurement of envelope delay distortion | Expired / Lapsed | 1952-06-07 | 1956-10-16 | 0 | Details |
| US2767246A | Automatic message accounting system | Expired / Lapsed | 1952-01-04 | 1956-10-16 | 0 | Details |
| US2765441A | Apparatus for monitoring and extruding plastic materials | Expired / Lapsed | 1953-09-03 | 1956-10-02 | 0 | Details |
| US2764642A | Semiconductor signal translating devices | Expired / Lapsed | 1952-10-31 | 1956-09-25 | 0 | Details |
| US2764636A | Dial telephone system arranged for operator or machine anno… | Expired / Lapsed | 1952-02-27 | 1956-09-25 | 0 | Details |
| US2764634A | Magnetic recording dial pulse storage register | Expired / Lapsed | 1950-09-07 | 1956-09-25 | 0 | Details |
| US2763726A | Telephone ringing-signal transmission system | Expired / Lapsed | 1954-09-10 | 1956-09-18 | 0 | Details |
| US2763840A | Variable bandwidth transmission system | Expired / Lapsed | 1952-12-18 | 1956-09-18 | 0 | Details |
| US2763845A | Short circuiting plug for coaxial line | Expired / Lapsed | 1952-11-28 | 1956-09-18 | 0 | Details |
| US2763837A | Electronic square-law meter circuit | Expired / Lapsed | 1952-07-26 | 1956-09-18 | 0 | Details |
| US2763731A | Semiconductor signal translating devices | Expired / Lapsed | 1952-02-09 | 1956-09-18 | 0 | Details |
| US2762867A | Subscriber telephone circuit | Expired / Lapsed | 1953-06-16 | 1956-09-11 | 0 | Details |
| FR1122425A | Transistor trigger circuits | Expired / Lapsed | 1955-02-24 | 1956-09-06 | 0 | Details |
| US2761909A | Multifrequency oscillator | Expired / Lapsed | 1953-01-28 | 1956-09-04 | 0 | Details |
| US2761900A | Telephone system of the coin controlled type | Expired / Lapsed | 1952-07-17 | 1956-09-04 | 0 | Details |
| US2761020A | Frequency selective semiconductor circuit elements | Expired / Lapsed | 1951-09-12 | 1956-08-28 | 0 | Details |
| US2759861A | Process of making photoconductive compounds | Expired / Lapsed | 1954-09-22 | 1956-08-21 | 2 | Details |
| US2760007A | Two-stage transistor feedback amplifier | Expired / Lapsed | 1953-08-06 | 1956-08-21 | 0 | Details |
| US2760087A | Transistor memory circuits | Expired / Lapsed | 1951-11-19 | 1956-08-21 | 0 | Details |
| US2759142A | Transistor and electromagnetic control apparatus | Expired / Lapsed | 1953-04-07 | 1956-08-14 | 0 | Details |
| US2759179A | Ringing circuit | Expired / Lapsed | 1952-12-05 | 1956-08-14 | 0 | Details |
| US2758787A | Serial binary digital multiplier | Expired / Lapsed | 1951-11-27 | 1956-08-14 | 0 | Details |
| US2758788A | Binary code translator, adder, and register | Expired / Lapsed | 1951-11-10 | 1956-08-14 | 0 | Details |
| US2759047A | Pulse transmission system and regenerative repeater therefor | Expired / Lapsed | 1950-12-27 | 1956-08-14 | 0 | Details |
| US2759044A | Beam aperature correction in horizontal and vertical direct… | Expired / Lapsed | 1950-11-24 | 1956-08-14 | 0 | Details |
| US2757243A | Transistor circuits | Expired / Lapsed | 1951-09-17 | 1956-07-31 | 0 | Details |
| US2756285A | Semiconductor signal translating devices | Expired / Lapsed | 1951-08-24 | 1956-07-24 | 0 | Details |
| US2756390A | Precision phase measuring circuit | Expired / Lapsed | 1950-10-04 | 1956-07-24 | 0 | Details |
| US2755436A | Method and apparatus for making insertion loss measurements | Expired / Lapsed | 1952-05-09 | 1956-07-17 | 0 | Details |
| US2754230A | Method of making electrical capacitors | Expired / Lapsed | 1952-10-25 | 1956-07-10 | 2 | Details |
| US2754368A | Telephone system | Expired / Lapsed | 1952-05-03 | 1956-07-10 | 0 | Details |
| US2753526A | Transmission line distortion correction | Expired / Lapsed | 1953-02-06 | 1956-07-03 | 0 | Details |
| US2753281A | Method of preparing germanium for translating devices | Expired / Lapsed | 1951-07-13 | 1956-07-03 | 1 | Details |
| US2750626A | Apparatus for plasticizing and straining organic plastic co… | Expired / Lapsed | 1954-10-06 | 1956-06-19 | 2 | Details |
| US2750627A | Apparatus for working and advancing a plastic material | Expired / Lapsed | 1954-10-06 | 1956-06-19 | 2 | Details |
| US2751526A | Magnetizing apparatus | Expired / Lapsed | 1954-04-13 | 1956-06-19 | 1 | Details |
| US2751549A | Current supply apparatus | Expired / Lapsed | 1954-02-25 | 1956-06-19 | 0 | Details |
| US2751550A | Current supply apparatus | Expired / Lapsed | 1953-10-12 | 1956-06-19 | 0 | Details |
| US2751518A | Frequency stabilized oscillator | Expired / Lapsed | 1953-10-01 | 1956-06-19 | 0 | Details |
| US2751545A | Transistor circuits | Expired / Lapsed | 1953-03-10 | 1956-06-19 | 0 | Details |
| US2750921A | Tension control apparatus for thermal vaporizing coating de… | Expired / Lapsed | 1953-01-12 | 1956-06-19 | 1 | Details |
| US2750541A | Semiconductor translating device | Expired / Lapsed | 1950-01-31 | 1956-06-12 | 1 | Details |
| US2750544A | Silicon translating devices and methods of manufacture | Expired / Lapsed | 1950-01-11 | 1956-06-12 | 1 | Details |
| US2748864A | Control for punch press | Expired / Lapsed | 1953-09-04 | 1956-06-05 | 0 | Details |
| US2748352A | Non-reciprocal wave transmission networks | Expired / Lapsed | 1951-12-27 | 1956-05-29 | 0 | Details |
| US2748350A | Ultra-high frequency selective mode directional coupler | Expired / Lapsed | 1951-09-05 | 1956-05-29 | 0 | Details |
| US2745958A | Translating arrangement | Expired / Lapsed | 1953-03-09 | 1956-05-15 | 0 | Details |
| US2746028A | Air raid warning system | Expired / Lapsed | 1952-08-05 | 1956-05-15 | 0 | Details |
| US2746036A | Device for coupling between free space and an electron stre… | Expired / Lapsed | 1952-03-25 | 1956-05-15 | 0 | Details |
| US2745010A | Transistor oscillators | Expired / Lapsed | 1951-09-12 | 1956-05-08 | 0 | Details |
| US2744970A | Semiconductor signal translating devices | Expired / Lapsed | 1951-08-24 | 1956-05-08 | 2 | Details |
| US2745012A | Transistor blocking oscillators | Expired / Lapsed | 1951-08-18 | 1956-05-08 | 0 | Details |
| US2744308A | Semi-conductor translating device and method of manufacture | Expired / Lapsed | 1950-11-17 | 1956-05-08 | 0 | Details |
| US2745069A | Microwave magnetized ferrite attenuator | Expired / Lapsed | 1950-05-17 | 1956-05-08 | 1 | Details |
| US2744198A | Transistor trigger circuits | Expired / Lapsed | 1951-11-02 | 1956-05-01 | 0 | Details |
| US2743367A | Frequency multiplier apparatus | Expired / Lapsed | 1953-04-23 | 1956-04-24 | 0 | Details |
| US2743322A | Solid state amplifier | Expired / Lapsed | 1952-11-29 | 1956-04-24 | 0 | Details |
| US2743362A | Automatic frequency control | Expired / Lapsed | 1951-05-24 | 1956-04-24 | 0 | Details |
| US2743419A | Frequency measuring apparatus | Expired / Lapsed | 1950-10-04 | 1956-04-24 | 0 | Details |
| US2742611A | Automatic indicator for testing equipment | Expired / Lapsed | 1951-06-13 | 1956-04-17 | 0 | Details |
| US2740700A | Method for portraying p-n junctions in silicon | Expired / Lapsed | 1954-05-14 | 1956-04-03 | 2 | Details |
| US2740901A | Differential photocell detector using junction semiconducto… | Expired / Lapsed | 1951-12-29 | 1956-04-03 | 2 | Details |
| US2740838A | Pulse transmission system | Expired / Lapsed | 1951-08-17 | 1956-04-03 | 0 | Details |
| US2740940A | High speed negative resistance | Expired / Lapsed | 1950-12-08 | 1956-04-03 | 0 | Details |
| US2740003A | Rotational use of register circuits in telephone switching … | Expired / Lapsed | 1952-10-25 | 1956-03-27 | 0 | Details |
| US2739298A | Multifrequency high speed calling signal generator | Expired / Lapsed | 1953-01-07 | 1956-03-20 | 0 | Details |
| US2739046A | Continuous process for separating fusible materials | Expired / Lapsed | 1952-08-06 | 1956-03-20 | 2 | Details |
| US2739190A | Transistor amplifiers and circuit arrangements therefor | Expired / Lapsed | 1951-05-26 | 1956-03-20 | 2 | Details |
| US2738382A | Magnetic drum dial pulse recording and storage registers | Expired / Lapsed | 1951-01-27 | 1956-03-13 | 0 | Details |
| US2737598A | Photoelectric relay device | Expired / Lapsed | 1950-10-27 | 1956-03-06 | 0 | Details |
| US2736894A | Directive antenna systems | Expired / Lapsed | 1946-01-22 | 1956-02-28 | 0 | Details |
| US2730617A | Timing circuit | Expired / Lapsed | 1951-12-05 | 1956-01-10 | 0 | Details |
| US2730576A | Miniaturized transistor amplifier circuit | Expired / Lapsed | 1951-09-17 | 1956-01-10 | 0 | Details |
| US2730579A | Order wire and alarm circuits for carrier systems | Expired / Lapsed | 1950-11-25 | 1956-01-10 | 0 | Details |
| US2730470A | Method of making semi-conductor crystals | Expired / Lapsed | 1950-06-15 | 1956-01-10 | 2 | Details |
| US2727214A | Acoustic delay line using solid rods | Expired / Lapsed | 1949-11-02 | 1955-12-13 | 0 | Details |
| US2726291A | Traveling wave tube | Expired / Lapsed | 1953-12-07 | 1955-12-06 | 0 | Details |
| US2726370A | Negative impedance converters employing transistors | Expired / Lapsed | 1952-09-17 | 1955-12-06 | 0 | Details |
| US2726328A | Binary storage system | Expired / Lapsed | 1950-06-20 | 1955-12-06 | 0 | Details |
| US2726074A | Acceleration measuring system | Expired / Lapsed | 1950-05-19 | 1955-12-06 | 0 | Details |
| US2725315A | Method of fabricating semiconductive bodies | Expired / Lapsed | 1952-11-14 | 1955-11-29 | 2 | Details |
| US2725317A | Method of fabricating and heat treating semiconductors | Expired / Lapsed | 1952-04-24 | 1955-11-29 | 2 | Details |
| US2725499A | High frequency amplifying device | Expired / Lapsed | 1949-06-21 | 1955-11-29 | 0 | Details |
| US2725555A | Automatic frequency control | Expired / Lapsed | 1948-07-16 | 1955-11-29 | 0 | Details |
| US2724780A | Inhibited trigger circuits | Expired / Lapsed | 1951-10-31 | 1955-11-22 | 0 | Details |
| US2724742A | Suppressed-carrier amplitude modulation | Expired / Lapsed | 1951-05-05 | 1955-11-22 | 0 | Details |
| US2724740A | Quantized transmission with variable quanta | Expired / Lapsed | 1950-06-29 | 1955-11-22 | 0 | Details |
| US2724103A | Electrical circuits employing magnetic core memory elements | Expired / Lapsed | 1953-12-31 | 1955-11-15 | 0 | Details |
| US2723312A | Magnetic drum dial pulse recording and storage registers | Expired / Lapsed | 1954-09-15 | 1955-11-08 | 0 | Details |
| US2723308A | Automatic transcribing system | Expired / Lapsed | 1953-03-19 | 1955-11-08 | 0 | Details |
| US2723311A | Common control telephone systems | Expired / Lapsed | 1953-03-05 | 1955-11-08 | 0 | Details |
| US2723355A | Diode gate circuit | Expired / Lapsed | 1952-12-23 | 1955-11-08 | 0 | Details |
| US2722603A | Peak voltage limiter | Expired / Lapsed | 1951-11-03 | 1955-11-01 | 0 | Details |
| US2722490A | Germanium elements and methods of preparing same | Expired / Lapsed | 1950-07-24 | 1955-11-01 | 1 | Details |
| US2721935A | Duplex radio telephone system | Expired / Lapsed | 1951-12-28 | 1955-10-25 | 0 | Details |
| US2720557A | Time division pulse code modulation system employing contin… | Expired / Lapsed | 1948-12-24 | 1955-10-11 | 0 | Details |
| US2719960A | Alarm sending system | Expired / Lapsed | 1954-04-30 | 1955-10-04 | 0 | Details |
| US2719961A | Electrical circuit employing magnetic cores | Expired / Lapsed | 1954-04-27 | 1955-10-04 | 0 | Details |
| US2719962A | Electrical circuit employing magnetic cores | Expired / Lapsed | 1954-04-27 | 1955-10-04 | 0 | Details |
| US2719773A | Electrical circuit employing magnetic cores | Expired / Lapsed | 1953-11-20 | 1955-10-04 | 0 | Details |
| US2719964A | Magnetic surface writing circuit utilizing magnetic cores | Expired / Lapsed | 1953-11-20 | 1955-10-04 | 0 | Details |
| US2719917A | Precision sweep calibrator | Expired / Lapsed | 1952-03-14 | 1955-10-04 | 0 | Details |
| US2719289A | Electrical conversion system with high and low voltage alarm | Expired / Lapsed | 1952-05-16 | 1955-09-27 | 0 | Details |
| US2719270A | Transmission regulation | Expired / Lapsed | 1952-01-23 | 1955-09-27 | 0 | Details |
| US2719188A | Non-synchronous time division multiplex telephone transmiss… | Expired / Lapsed | 1950-05-05 | 1955-09-27 | 0 | Details |
| US2718613A | Transistor circuit for operating a relay | Expired / Lapsed | 1952-10-08 | 1955-09-20 | 0 | Details |
| US2718589A | Radio relay system | Expired / Lapsed | 1950-06-29 | 1955-09-20 | 0 | Details |
| US2717956A | Reduction of quadrature distortion | Expired / Lapsed | 1952-11-29 | 1955-09-13 | 0 | Details |
| US2717342A | Semiconductor translating devices | Expired / Lapsed | 1952-10-28 | 1955-09-06 | 0 | Details |
| US2717279A | Multiparty selective signaling and identification system | Expired / Lapsed | 1951-12-28 | 1955-09-06 | 0 | Details |
| US2717373A | Ferroelectric storage device and circuit | Expired / Lapsed | 1951-12-14 | 1955-09-06 | 0 | Details |
| US2717372A | Ferroelectric storage device and circuit | Expired / Lapsed | 1951-11-01 | 1955-09-06 | 0 | Details |
| US2716729A | Transistor circuits with constant output current | Expired / Lapsed | 1951-11-24 | 1955-08-30 | 0 | Details |
| US2714642A | High speed relay of electromechanical transducer material | Expired / Lapsed | 1952-07-10 | 1955-08-02 | 0 | Details |
| US2714702A | Circuits, including semiconductor device | Expired / Lapsed | 1951-02-16 | 1955-08-02 | 0 | Details |
| US2714182A | Hall effect devices | Expired / Lapsed | 1952-06-21 | 1955-07-26 | 2 | Details |
| US2711511A | Electrical hygrometer | Expired / Lapsed | 1952-05-23 | 1955-06-21 | 2 | Details |
| US2711515A | Delay line | Expired / Lapsed | 1950-09-29 | 1955-06-21 | 0 | Details |
| US2709787A | Semiconductor signal translating device | Expired / Lapsed | 1953-09-24 | 1955-05-31 | 1 | Details |
| US2709780A | Constant voltage semiconductor devices | Expired / Lapsed | 1952-10-11 | 1955-05-31 | 2 | Details |
| US2709722A | Service observing on toll cords and trunks | Expired / Lapsed | 1952-10-02 | 1955-05-31 | 0 | Details |
| US2709147A | Methods for bonding silica bodies | Expired / Lapsed | 1951-09-12 | 1955-05-24 | 2 | Details |
| US2708748A | Code conversion | Expired / Lapsed | 1954-04-13 | 1955-05-17 | 0 | Details |
| US2708720A | Transistor trigger circuit | Expired / Lapsed | 1950-06-07 | 1955-05-17 | 0 | Details |
| US2708236A | Microwave amplifiers | Expired / Lapsed | 1950-03-18 | 1955-05-10 | 0 | Details |
| US2707759A | Electronic amplifier | Expired / Lapsed | 1948-12-10 | 1955-05-03 | 0 | Details |
| US2707235A | Frequency selective systems | Expired / Lapsed | 1947-04-26 | 1955-04-26 | 0 | Details |
| US2706326A | Polarization process for pseudocubic ferroelectrics | Expired / Lapsed | 1952-04-23 | 1955-04-19 | 0 | Details |
| US2706765A | Control circuits | Expired / Lapsed | 1952-03-20 | 1955-04-19 | 0 | Details |
| US2706223A | Polytonic high speed calling signal generator | Expired / Lapsed | 1953-05-27 | 1955-04-12 | 0 | Details |
| US2706264A | Storage tube circuit | Expired / Lapsed | 1949-12-17 | 1955-04-12 | 0 | Details |
| US2705768A | Semiconductor signal translating devices and method of fabr… | Expired / Lapsed | 1953-05-11 | 1955-04-05 | 0 | Details |
| US2705742A | High speed continuous spectrum analysis | Expired / Lapsed | 1951-09-15 | 1955-04-05 | 0 | Details |
| US2704782A | Retractile cords and methods of making the same | Expired / Lapsed | 1950-08-30 | 1955-03-22 | 0 | Details |
| US2703368A | Pulse regeneration | Expired / Lapsed | 1953-10-21 | 1955-03-01 | 0 | Details |
| FR1087946A | Semiconductor material production process | Expired / Lapsed | 1953-09-04 | 1955-03-01 | 0 | Details |
| US2703296A | Method of producing a semiconductor element | Expired / Lapsed | 1950-06-20 | 1955-03-01 | 2 | Details |
| US2703280A | Counting circuit control for electrophotographic printers | Expired / Lapsed | 1950-05-17 | 1955-03-01 | 2 | Details |
| US2703344A | Cutaneous signaling | Expired / Lapsed | 1949-04-28 | 1955-03-01 | 0 | Details |
| US2702838A | Semiconductor signal translating device | Expired / Lapsed | 1951-11-15 | 1955-02-22 | 0 | Details |
| US2702760A | Method of applying metallic stripes to a web of paper | Expired / Lapsed | 1951-04-25 | 1955-02-22 | 2 | Details |
| US2702186A | Accelerometer | Expired / Lapsed | 1947-07-07 | 1955-02-15 | 0 | Details |
| US2701392A | Method of manufacture of incapsulated electrical apparatus | Expired / Lapsed | 1950-12-19 | 1955-02-08 | 0 | Details |
| US2701279A | Multifrequency signaling system | Expired / Lapsed | 1953-10-21 | 1955-02-01 | 0 | Details |
| US2701305A | Recognition circuit | Expired / Lapsed | 1951-09-15 | 1955-02-01 | 0 | Details |
| US2701357A | Capacitive commutator transmitter | Expired / Lapsed | 1950-12-22 | 1955-02-01 | 0 | Details |
| US2701274A | Signal predicting apparatus | Expired / Lapsed | 1950-06-29 | 1955-02-01 | 0 | Details |
| US2701326A | Semiconductor translating device | Expired / Lapsed | 1949-12-30 | 1955-02-01 | 0 | Details |
| US2701309A | Semiconductor oscillation generator | Expired / Lapsed | 1948-12-24 | 1955-02-01 | 0 | Details |
| US2700626A | Secondary electron emissive electrodes | Expired / Lapsed | 1949-12-09 | 1955-01-25 | 2 | Details |
| US2700148A | Magnetic drum dial pulse recording and storage register | Expired / Lapsed | 1950-12-16 | 1955-01-18 | 0 | Details |
| US2699529A | Electronic timer | Expired / Lapsed | 1949-08-26 | 1955-01-11 | 0 | Details |
| US2698879A | Class of service determining circuit | Expired / Lapsed | 1949-11-30 | 1955-01-04 | 0 | Details |
| US2698414A | Current supply apparatus | Expired / Lapsed | 1952-03-05 | 1954-12-28 | 0 | Details |
| US2697269A | Method of making semiconductor translating devices | Expired / Lapsed | 1950-07-24 | 1954-12-21 | 1 | Details |
| US2697052A | Fabricating of semiconductor translating devices | Expired / Lapsed | 1953-07-24 | 1954-12-14 | 2 | Details |
| US2697028A | Methods of producing dehydrogenated hydrocarbon bodies | Expired / Lapsed | 1951-04-28 | 1954-12-14 | 2 | Details |
| US2696599A | Check circuits | Expired / Lapsed | 1953-02-12 | 1954-12-07 | 0 | Details |
| US2696529A | Voice-operated switching system | Expired / Lapsed | 1950-09-02 | 1954-12-07 | 0 | Details |
| US2695930A | High-frequency transistor circuit | Expired / Lapsed | 1952-06-19 | 1954-11-30 | 0 | Details |
| US2695956A | Gating circuit | Expired / Lapsed | 1952-05-10 | 1954-11-30 | 0 | Details |
| US2695422A | Apparatus for advancing and working elastomer compounds | Expired / Lapsed | 1951-12-12 | 1954-11-30 | 0 | Details |
| US2695398A | Ferroelectric storage circuits | Expired / Lapsed | 1953-06-16 | 1954-11-23 | 0 | Details |
| US2695396A | Ferroelectric storage device | Expired / Lapsed | 1952-05-06 | 1954-11-23 | 0 | Details |
| US2694801A | Pulse counting and registration system | Expired / Lapsed | 1951-12-18 | 1954-11-16 | 0 | Details |
| US2694024A | Semiconductor bodies for signal translating devices | Expired / Lapsed | 1952-07-26 | 1954-11-09 | 2 | Details |
| US2694040A | Methods of selectively plating p-type material of a semicon… | Expired / Lapsed | 1951-12-28 | 1954-11-09 | 2 | Details |
| US2694140A | Selection of low interference radio channels | Expired / Lapsed | 1951-11-24 | 1954-11-09 | 0 | Details |
| US2694186A | Wave filter | Expired / Lapsed | 1951-01-04 | 1954-11-09 | 0 | Details |
| US2694112A | Amplifier utilizing bombardment induced conductivity | Expired / Lapsed | 1950-12-30 | 1954-11-09 | 0 | Details |
| US2694154A | Card translator optical system | Expired / Lapsed | 1950-08-25 | 1954-11-09 | 0 | Details |
| US2694142A | Signal-to-noise energy detection unit | Expired / Lapsed | 1949-11-10 | 1954-11-09 | 0 | Details |
| US2694050A | Thermally sensitive resistor | Expired / Lapsed | 1949-09-01 | 1954-11-09 | 0 | Details |
| US2694160A | Expandable straight line trajectory radar and sonar indicat… | Expired / Lapsed | 1948-08-31 | 1954-11-09 | 0 | Details |
| US2693572A | Current and voltage regulation | Expired / Lapsed | 1953-03-31 | 1954-11-02 | 0 | Details |
| US2693568A | Current and voltage regulation | Expired / Lapsed | 1952-03-05 | 1954-11-02 | 0 | Details |
| US2692952A | Semiconductive light valve | Expired / Lapsed | 1952-03-14 | 1954-10-26 | 0 | Details |
| US2692950A | Valve for infrared energy | Expired / Lapsed | 1952-01-04 | 1954-10-26 | 0 | Details |
| US2692839A | Method of fabricating germanium bodies | Expired / Lapsed | 1951-03-07 | 1954-10-26 | 2 | Details |
| US2692961A | Isothermal electromagnetic apparatus | Expired / Lapsed | 1950-12-12 | 1954-10-26 | 0 | Details |
| US2692303A | Speech interpolated communication system | Expired / Lapsed | 1950-12-19 | 1954-10-19 | 0 | Details |
| US2692336A | Aperture antenna | Expired / Lapsed | 1949-11-26 | 1954-10-19 | 0 | Details |
| US2692337A | Oscillation generator | Expired / Lapsed | 1948-12-29 | 1954-10-19 | 0 | Details |
| US2691736A | Electrical translation device, including semiconductor | Expired / Lapsed | 1950-12-27 | 1954-10-12 | 0 | Details |
| US2691738A | Electrical device embodying ferroelectric lanthanum-contain… | Expired / Lapsed | 1949-04-08 | 1954-10-12 | 2 | Details |
| US2691750A | Semiconductor amplifier | Expired / Lapsed | 1948-08-14 | 1954-10-12 | 0 | Details |
| US2690980A | Carbonyl process | Expired / Lapsed | 1951-03-14 | 1954-10-05 | 2 | Details |
| US2690299A | Testing system | Expired / Lapsed | 1948-08-13 | 1954-09-28 | 0 | Details |
| US2689399A | Plated article and method of making it | Expired / Lapsed | 1950-12-05 | 1954-09-21 | 2 | Details |
| US2688582A | Method of forming laminated sheets | Expired / Lapsed | 1952-07-31 | 1954-09-07 | 2 | Details |
| US2688658A | Call data recording telephone system | Expired / Lapsed | 1947-07-07 | 1954-09-07 | 0 | Details |
| US2688110A | Semiconductor translating device | Expired / Lapsed | 1950-11-30 | 1954-08-31 | 0 | Details |
| US2686843A | Call distributing service desk | Expired / Lapsed | 1951-04-26 | 1954-08-17 | 0 | Details |
| US2686838A | Translator | Expired / Lapsed | 1950-04-06 | 1954-08-17 | 0 | Details |
| US2686256A | Signal transmission system | Expired / Lapsed | 1951-02-06 | 1954-08-10 | 0 | Details |
| US2685683A | Fault signaling system for counting chain | Expired / Lapsed | 1950-08-31 | 1954-08-03 | 0 | Details |
| US2685063A | Method of and system for measuring phase shift | Expired / Lapsed | 1952-10-20 | 1954-07-27 | 0 | Details |
| US2684405A | Telephone selecting system employing combined selecting and… | Expired / Lapsed | 1950-12-19 | 1954-07-20 | 0 | Details |
| US2683794A | Infrared energy source | Expired / Lapsed | 1951-12-27 | 1954-07-13 | 0 | Details |
| US2683676A | Production of germanium rods having longitudinal crystal bo… | Expired / Lapsed | 1950-01-13 | 1954-07-13 | 2 | Details |
| US2683219A | Variable-frequency relaxation oscillator | Expired / Lapsed | 1951-08-28 | 1954-07-06 | 0 | Details |
| US2682687A | Method of making indicia plaques | Expired / Lapsed | 1950-05-11 | 1954-07-06 | 0 | Details |
| US2683238A | Microwave amplifier | Expired / Lapsed | 1949-06-17 | 1954-07-06 | 0 | Details |
| US2682063A | Wiring tool | Expired / Lapsed | 1951-06-30 | 1954-06-29 | 0 | Details |
| US2682575A | Time division multiplex system | Expired / Lapsed | 1944-10-19 | 1954-06-29 | 0 | Details |
| US2682003A | Accelerometer | Expired / Lapsed | 1950-11-28 | 1954-06-22 | 0 | Details |
| US2681996A | Transistor oscillator | Expired / Lapsed | 1950-09-12 | 1954-06-22 | 0 | Details |
| US2681993A | Circuit element utilizing semiconductive materials | Expired / Lapsed | 1949-05-05 | 1954-06-22 | 0 | Details |
| US2681385A | Reduction of signal redundancy | Expired / Lapsed | 1950-06-29 | 1954-06-15 | 0 | Details |
| US2680781A | Translating arrangement | Expired / Lapsed | 1949-11-08 | 1954-06-08 | 0 | Details |
| US2680162A | Automatic line testing and switching circuit | Expired / Lapsed | 1953-02-06 | 1954-06-01 | 0 | Details |
| US2680160A | Bias circuit for transistor amplifiers | Expired / Lapsed | 1951-09-15 | 1954-06-01 | 0 | Details |
| US2679977A | Calculator sign control circuit | Expired / Lapsed | 1946-12-17 | 1954-06-01 | 0 | Details |
| US2679633A | Wave transmission network utilizing impedance inversion | Expired / Lapsed | 1952-10-22 | 1954-05-25 | 0 | Details |
| US2679551A | Capacitative commutator | Expired / Lapsed | 1950-09-21 | 1954-05-25 | 0 | Details |
| US2678997A | Pulse transmission | Expired / Lapsed | 1949-12-31 | 1954-05-18 | 0 | Details |
| US2678400A | Photomultiplier utilizing bombardment induced conductivity | Expired / Lapsed | 1950-12-30 | 1954-05-11 | 0 | Details |
| US2678435A | Signal sender comprising motor driven capacitative commutat… | Expired / Lapsed | 1950-09-27 | 1954-05-11 | 0 | Details |
| US2677726A | Signaling system for carrier telephone transmission | Expired / Lapsed | 1950-07-26 | 1954-05-04 | 0 | Details |
| US2677019A | Magnetic head and method of making same | Expired / Lapsed | 1951-12-22 | 1954-04-27 | 0 | Details |
| US2677011A | Teletypewriter message identification system | Expired / Lapsed | 1950-09-12 | 1954-04-27 | 0 | Details |
| US2676271A | Transistor gate | Expired / Lapsed | 1952-01-25 | 1954-04-20 | 0 | Details |
| US2676206A | Computation and display of correlation | Expired / Lapsed | 1951-12-06 | 1954-04-20 | 0 | Details |
| US2676228A | Conditioning of semiconductor translators | Expired / Lapsed | 1951-10-06 | 1954-04-20 | 0 | Details |
| US2676197A | Glass to metal seal for deep-sea electric cable | Expired / Lapsed | 1950-11-17 | 1954-04-20 | 0 | Details |
| US2676199A | Telegraph switching system | Expired / Lapsed | 1949-12-29 | 1954-04-20 | 0 | Details |
| US2676209A | Coin-controlled telephone system in which tariff rates for … | Expired / Lapsed | 1949-09-01 | 1954-04-20 | 0 | Details |
| US2675427A | Electrostatic scanning mechanism for scanning both tips and… | Expired / Lapsed | 1951-12-21 | 1954-04-13 | 0 | Details |
| US2675499A | Cathode-ray device | Expired / Lapsed | 1948-07-10 | 1954-04-13 | 0 | Details |
| US2674659A | Magnetic head and method of making same | Expired / Lapsed | 1951-11-02 | 1954-04-06 | 0 | Details |
| US2673936A | Diode gate | Expired / Lapsed | 1952-04-28 | 1954-03-30 | 0 | Details |
| US2672508A | Teletypewriter line feed transmitting and counting apparatus | Expired / Lapsed | 1950-10-04 | 1954-03-16 | 0 | Details |
| US2672590A | Delay line | Expired / Lapsed | 1950-03-22 | 1954-03-16 | 0 | Details |
| US2672515A | Calling station identification circuit | Expired / Lapsed | 1950-01-28 | 1954-03-16 | 0 | Details |
| US2672518A | Station identifier | Expired / Lapsed | 1949-05-28 | 1954-03-16 | 0 | Details |
| US2672528A | Semiconductor translating device | Expired / Lapsed | 1949-05-28 | 1954-03-16 | 0 | Details |
| US2671739A | Plating with sulfides, selenides, and tellurides of chromiu… | Expired / Lapsed | 1949-06-22 | 1954-03-09 | 2 | Details |
| US2670445A | Regenerative transistor amplifier | Expired / Lapsed | 1951-11-06 | 1954-02-23 | 0 | Details |
| US2670435A | Radiotelephone communication system | Expired / Lapsed | 1951-02-02 | 1954-02-23 | 0 | Details |
| US2670441A | Alpha particle counter | Expired / Lapsed | 1949-09-07 | 1954-02-23 | 0 | Details |
| US2669635A | Semiconductive photoelectric transducer | Expired / Lapsed | 1952-11-13 | 1954-02-16 | 0 | Details |
| US2669656A | Triangular wave generator | Expired / Lapsed | 1951-11-15 | 1954-02-16 | 0 | Details |
| US2668985A | Molding apparatus | Expired / Lapsed | 1951-01-04 | 1954-02-16 | 0 | Details |
| US2669654A | Limiter amplifier circuit | Expired / Lapsed | 1950-06-27 | 1954-02-16 | 0 | Details |
| US2669706A | Code selector | Expired / Lapsed | 1950-05-09 | 1954-02-16 | 0 | Details |
| US2669657A | Electromagnetic lens | Expired / Lapsed | 1949-11-19 | 1954-02-16 | 0 | Details |
| US2669500A | Plotting board | Expired / Lapsed | 1946-06-26 | 1954-02-16 | 0 | Details |
| US2668931A | Electronic register for telephone switching systems | Expired / Lapsed | 1949-12-20 | 1954-02-09 | 0 | Details |
| US2668877A | Electromechanical translator | Expired / Lapsed | 1947-11-04 | 1954-02-09 | 0 | Details |
| US2667970A | Automatic limit bridge | Expired / Lapsed | 1948-09-01 | 1954-02-02 | 0 | Details |
| US2667607A | Semiconductor circuit element | Expired / Lapsed | 1952-04-26 | 1954-01-26 | 0 | Details |
| US2666977A | Reversible semiconductor and method of making it | Expired / Lapsed | 1948-12-31 | 1954-01-26 | 0 | Details |
| US2667260A | Conveyer system | Expired / Lapsed | 1948-09-11 | 1954-01-26 | 0 | Details |
| US2666819A | Balanced amplifier employing transistors of complementary c… | Expired / Lapsed | 1951-09-18 | 1954-01-19 | 0 | Details |
| US2666818A | Transistor amplifier | Expired / Lapsed | 1951-09-13 | 1954-01-19 | 0 | Details |
| US2666356A | Servo system for nonintermittent film projectors | Expired / Lapsed | 1950-06-13 | 1954-01-19 | 0 | Details |
| US2666814A | Semiconductor translating device | Expired / Lapsed | 1949-04-27 | 1954-01-19 | 0 | Details |
| US2665845A | Transistor trigger circuit for operating relays | Expired / Lapsed | 1952-10-08 | 1954-01-12 | 0 | Details |
| US2666099A | Loss measurement in two-way electrical transmission systems | Expired / Lapsed | 1950-06-20 | 1954-01-12 | 0 | Details |
| US2666196A | Frequency station calling system using bifurcated piezoelec… | Expired / Lapsed | 1949-06-07 | 1954-01-12 | 0 | Details |
| US2664504A | Cathode-ray decoder for pulse code modulation | Expired / Lapsed | 1950-04-11 | 1953-12-29 | 0 | Details |
| US2663806A | Semiconductor signal translating device | Expired / Lapsed | 1952-05-09 | 1953-12-22 | 0 | Details |
| US2663857A | Curve follower | Expired / Lapsed | 1951-10-25 | 1953-12-22 | 0 | Details |
| US2663844A | Contact fixture | Expired / Lapsed | 1951-03-29 | 1953-12-22 | 0 | Details |
| US2663796A | Low-input impedance transistor circuits | Expired / Lapsed | 1950-11-09 | 1953-12-22 | 0 | Details |
| US2663782A | Circuit regulating device | Expired / Lapsed | 1950-09-12 | 1953-12-22 | 0 | Details |
| US2663766A | Transistor amplifier with conjugate input and output circui… | Expired / Lapsed | 1950-06-28 | 1953-12-22 | 0 | Details |
| US2662997A | Mounting for semiconductors | Expired / Lapsed | 1951-11-23 | 1953-12-15 | 2 | Details |
| US2662974A | Arragngement for single-channel time sharing | Expired / Lapsed | 1949-11-19 | 1953-12-15 | 0 | Details |
| US2662120A | Magnetic head | Expired / Lapsed | 1950-02-18 | 1953-12-08 | 0 | Details |
| US2662122A | Two-way transistor electrical transmission system | Expired / Lapsed | 1949-06-01 | 1953-12-08 | 0 | Details |
| US2662124A | Transistor amplifier circuit | Expired / Lapsed | 1949-06-01 | 1953-12-08 | 0 | Details |
| US2660680A | Crystal temperature control means | Expired / Lapsed | 1950-08-09 | 1953-11-24 | 0 | Details |
| US2660676A | Signal generating device | Expired / Lapsed | 1950-02-15 | 1953-11-24 | 0 | Details |
| US2659813A | Frequency modulation repeater | Expired / Lapsed | 1950-02-11 | 1953-11-17 | 0 | Details |
| US2659774A | Bidirectional transistor amplifier | Expired / Lapsed | 1949-06-07 | 1953-11-17 | 0 | Details |
| US2659773A | Inverted grounded emitter transistor amplifier | Expired / Lapsed | 1949-06-07 | 1953-11-17 | 0 | Details |
| US2659817A | Translation of electromagnetic waves | Expired / Lapsed | 1948-12-31 | 1953-11-17 | 0 | Details |
| US2658114A | Magnetic recording-reproducing device | Expired / Lapsed | 1952-08-26 | 1953-11-03 | 0 | Details |
| US2658188A | Pulse position dialing system with direct time measuring ap… | Expired / Lapsed | 1948-06-29 | 1953-11-03 | 0 | Details |
| US2657360A | Four-electrode transistor modulator | Expired / Lapsed | 1952-08-15 | 1953-10-27 | 0 | Details |
| US2657318A | Electronic switch | Expired / Lapsed | 1952-03-22 | 1953-10-27 | 0 | Details |
| US2657261A | Error-indicating code mechanism | Expired / Lapsed | 1951-12-13 | 1953-10-27 | 0 | Details |
| US2657377A | Reproduction of signals from magnetic records | Expired / Lapsed | 1951-05-25 | 1953-10-27 | 0 | Details |
| US2657378A | Pulse translation apparatus | Expired / Lapsed | 1951-05-25 | 1953-10-27 | 0 | Details |
| US2657272A | Electronic induction translator | Expired / Lapsed | 1951-03-03 | 1953-10-27 | 0 | Details |
| US2657307A | Positive feedback pulse generator | Expired / Lapsed | 1950-07-01 | 1953-10-27 | 0 | Details |
| US2657271A | Line identification trouble indicator | Expired / Lapsed | 1950-05-19 | 1953-10-27 | 0 | Details |
| US2656496A | Semiconductor translating device | Expired / Lapsed | 1951-07-31 | 1953-10-20 | 0 | Details |
| US2656404A | Laminated ring lead-in for electron discharge devices | Expired / Lapsed | 1950-12-01 | 1953-10-20 | 0 | Details |
| US2655690A | Method of and apparatus for continuously making vulcanized … | Expired / Lapsed | 1950-08-09 | 1953-10-20 | 0 | Details |
| US2656460A | Bidirectional counter | Expired / Lapsed | 1949-10-28 | 1953-10-20 | 0 | Details |
| US2655603A | Power supply apparatus for alternately supplying a load | Expired / Lapsed | 1952-08-14 | 1953-10-13 | 0 | Details |
| US2655646A | Supervisory alarm system | Expired / Lapsed | 1952-08-14 | 1953-10-13 | 0 | Details |
| US2655609A | Bistable circuits, including transistors | Expired / Lapsed | 1952-07-22 | 1953-10-13 | 0 | Details |
| US2655610A | Semiconductor signal translating device | Expired / Lapsed | 1952-07-22 | 1953-10-13 | 0 | Details |
| US2655608A | Semiconductor circuit controlling device | Expired / Lapsed | 1952-07-22 | 1953-10-13 | 0 | Details |
| US2655625A | Semiconductor circuit element | Expired / Lapsed | 1952-04-26 | 1953-10-13 | 0 | Details |
| US2654797A | Teletypewriter switching system | Expired / Lapsed | 1949-09-01 | 1953-10-06 | 0 | Details |
| US2654059A | Semiconductor signal translating device | Expired / Lapsed | 1951-05-26 | 1953-09-29 | 0 | Details |
| US2653207A | Adjustable potentiometer termination | Expired / Lapsed | 1950-12-15 | 1953-09-22 | 0 | Details |
| US2652493A | Unipolarized wave refractor | Expired / Lapsed | 1951-05-10 | 1953-09-15 | 0 | Details |
| US2652460A | Transistor amplifier circuits | Expired / Lapsed | 1950-09-12 | 1953-09-15 | 0 | Details |
| US2651021A | Fault detector | Expired / Lapsed | 1951-04-20 | 1953-09-01 | 0 | Details |
| US2649574A | Hall-effect wave translating device | Expired / Lapsed | 1951-04-05 | 1953-08-18 | 0 | Details |
| US2649569A | Semiconductor magnetoresistive device | Expired / Lapsed | 1950-09-28 | 1953-08-18 | 0 | Details |
| US2649570A | Test equipment and method for measuring reflection coeffici… | Expired / Lapsed | 1950-06-29 | 1953-08-18 | 0 | Details |
| US2649568A | Magnetometer | Expired / Lapsed | 1949-07-12 | 1953-08-18 | 0 | Details |
| US2649558A | Mounting head for coil terminals | Expired / Lapsed | 1949-06-09 | 1953-08-18 | 0 | Details |
| US2649027A | Electrooptical system | Expired / Lapsed | 1947-02-18 | 1953-08-18 | 0 | Details |
| US2648773A | Polyphase oscillator | Expired / Lapsed | 1950-03-23 | 1953-08-11 | 0 | Details |
| US2648823A | Thermoelectric translation device | Expired / Lapsed | 1950-01-06 | 1953-08-11 | 0 | Details |
| US2648836A | Apparatus for generating time position dial pulses | Expired / Lapsed | 1949-11-17 | 1953-08-11 | 0 | Details |
| US2648589A | Magnetic recorder | Expired / Lapsed | 1949-07-19 | 1953-08-11 | 0 | Details |
| US2647958A | Voltage and current bias of transistors | Expired / Lapsed | 1949-10-25 | 1953-08-04 | 0 | Details |
| US2647957A | Transistor circuit | Expired / Lapsed | 1949-06-01 | 1953-08-04 | 0 | Details |
| US2645700A | Semiconductor of mixed nickel, manganese, and iron oxides | Expired / Lapsed | 1949-08-27 | 1953-07-14 | 2 | Details |
| US2644914A | Multicontact semiconductor translating device | Expired / Lapsed | 1949-08-17 | 1953-07-07 | 0 | Details |
| US2643632A | Coaxial dial locking device | Expired / Lapsed | 1950-10-06 | 1953-06-30 | 0 | Details |
| US2641800A | Apparatus for advancing and working plastic compounds | Expired / Lapsed | 1951-06-21 | 1953-06-16 | 0 | Details |
| US2641997A | Control circuit for continuously operating electrophotograp… | Expired / Lapsed | 1950-09-21 | 1953-06-16 | 0 | Details |
| US2642493A | Automatic message accounting system | Expired / Lapsed | 1947-02-27 | 1953-06-16 | 0 | Details |
| US2641712A | Photoelectric device | Expired / Lapsed | 1951-07-13 | 1953-06-09 | 0 | Details |
| US2641713A | Semiconductor photoelectric device | Expired / Lapsed | 1951-03-21 | 1953-06-09 | 0 | Details |
| US2641757A | Automatic multichannel selection | Expired / Lapsed | 1950-05-17 | 1953-06-09 | 0 | Details |
| US2640137A | Temperature control system | Expired / Lapsed | 1950-11-15 | 1953-05-26 | 0 | Details |
| US2640162A | Electronic transmission system | Expired / Lapsed | 1947-05-16 | 1953-05-26 | 0 | Details |
| US2639326A | Electromagnetic wave microwave frequency structure using hy… | Expired / Lapsed | 1951-03-06 | 1953-05-19 | 0 | Details |
| US2635810A | Multicathode gaseous discharge device and circuits | Expired / Lapsed | 1952-02-15 | 1953-04-21 | 0 | Details |
| US2635975A | Method of bonding polyethylene to vulcanized rubber and art… | Expired / Lapsed | 1951-02-27 | 1953-04-21 | 4 | Details |
| US2636133A | Diode gate | Expired / Lapsed | 1950-12-01 | 1953-04-21 | 0 | Details |
| US2636081A | Supervisory circuits for pulse code modulation | Expired / Lapsed | 1950-07-27 | 1953-04-21 | 0 | Details |
| US2636080A | Balanced diode clamper circuit for low-frequency restoration | Expired / Lapsed | 1949-01-26 | 1953-04-21 | 0 | Details |
| US2636125A | Selective electromagnetic wave system | Expired / Lapsed | 1948-04-10 | 1953-04-21 | 0 | Details |
| US2636135A | Stress-coupled core and crystal transformer | Expired / Lapsed | 1947-10-29 | 1953-04-21 | 0 | Details |
| US2635146A | Speech analyzing and synthesizing communication system | Expired / Lapsed | 1949-12-15 | 1953-04-14 | 0 | Details |
| US2634931A | Material handling pallet | Expired / Lapsed | 1948-10-06 | 1953-04-14 | 0 | Details |
| US2634413A | Velocity measuring system utilizing radio technique | Expired / Lapsed | 1948-04-08 | 1953-04-07 | 0 | Details |
| US2634028A | Mercury dispenser | Expired / Lapsed | 1947-12-31 | 1953-04-07 | 0 | Details |
| US2634366A | Light repeater for pulse communication systems | Expired / Lapsed | 1947-11-28 | 1953-04-07 | 0 | Details |
| US2633492A | Guided wave frequency range, frequency selective and equali… | Expired / Lapsed | 1948-12-30 | 1953-03-31 | 0 | Details |
| US2633498A | Selecting and two-way translating system | Expired / Lapsed | 1948-12-29 | 1953-03-31 | 0 | Details |
| US2632101A | Reduction of noise in transmission systems | Expired / Lapsed | 1950-10-23 | 1953-03-17 | 0 | Details |
| US2632062A | Semiconductor transducer | Expired / Lapsed | 1949-06-15 | 1953-03-17 | 0 | Details |
| US2632147A | Communication system employing pulse code modulation | Expired / Lapsed | 1949-02-09 | 1953-03-17 | 0 | Details |
| US2632058A | Pulse code communication | Expired / Lapsed | 1947-11-13 | 1953-03-17 | 0 | Details |
| US2632057A | Signal transmission | Expired / Lapsed | 1944-04-12 | 1953-03-17 | 0 | Details |
| US2630482A | Tuned vibrating reed selective circuit | Expired / Lapsed | 1948-07-10 | 1953-03-03 | 0 | Details |
| US2629772A | Reduction of phase distortion | Expired / Lapsed | 1951-09-21 | 1953-02-24 | 0 | Details |
| US2629834A | Gate and trigger circuits employing transistors | Expired / Lapsed | 1951-09-15 | 1953-02-24 | 0 | Details |
| US2629833A | Transistor trigger circuits | Expired / Lapsed | 1951-04-28 | 1953-02-24 | 0 | Details |
| US2629800A | Semiconductor signal translating device | Expired / Lapsed | 1950-04-15 | 1953-02-24 | 2 | Details |
| US2629672A | Method of making semiconductive translating devices | Expired / Lapsed | 1949-07-07 | 1953-02-24 | 1 | Details |
| US2629778A | Visual representation of complex waves | Expired / Lapsed | 1946-05-10 | 1953-02-24 | 0 | Details |
| US2629021A | Coordinate switching and lock-out circuit in interpolated s… | Expired / Lapsed | 1950-12-19 | 1953-02-17 | 0 | Details |
| US2629010A | Television system having reduced transmission bandwidth | Expired / Lapsed | 1949-12-30 | 1953-02-17 | 0 | Details |
| US2628999A | Continuity, polarity, and breakdown test device | Expired / Lapsed | 1949-04-07 | 1953-02-17 | 0 | Details |
| US2629016A | Automatic toll-ticketing system | Expired / Lapsed | 1942-06-27 | 1953-02-17 | 0 | Details |
| US2627769A | Swaging pliers for electrical connections | Expired / Lapsed | 1949-01-12 | 1953-02-10 | 0 | Details |
| US2628263A | Quick detachable connector for interconnecting terminals | Expired / Lapsed | 1948-12-24 | 1953-02-10 | 0 | Details |
| US2627645A | Method of manufacturing condensers | Expired / Lapsed | 1947-03-11 | 1953-02-10 | 0 | Details |
| US2626983A | Magnetic testing apparatus | Expired / Lapsed | 1951-03-06 | 1953-01-27 | 0 | Details |
| US2627039A | Gating circuits | Expired / Lapsed | 1950-05-29 | 1953-01-27 | 0 | Details |
| US2626427A | Apparatus for controlling the plasticity of extrudable mate… | Expired / Lapsed | 1950-01-31 | 1953-01-27 | 0 | Details |
| US2626992A | Signal delay device | Expired / Lapsed | 1949-02-26 | 1953-01-27 | 0 | Details |
| US2626448A | Apparatus for and method of treating selenium rectifiers | Expired / Lapsed | 1947-08-26 | 1953-01-27 | 0 | Details |
| US2625587A | Automatic bridge | Expired / Lapsed | 1950-11-09 | 1953-01-13 | 0 | Details |
| US2623105A | Semiconductor translating device having controlled gain | Expired / Lapsed | 1951-09-21 | 1952-12-23 | 0 | Details |
| US2622469A | Method of and apparatus for controlling the temperature of … | Expired / Lapsed | 1951-05-04 | 1952-12-23 | 0 | Details |
| US2623103A | Semiconductor signal translating device | Expired / Lapsed | 1949-06-09 | 1952-12-23 | 0 | Details |
| US2623102A | Circuit element utilizing semiconductive materials | Expired / Lapsed | 1949-05-05 | 1952-12-23 | 0 | Details |
| US2622213A | Transistor circuit for pulse amplifier delay and the like | Expired / Lapsed | 1951-09-19 | 1952-12-16 | 0 | Details |
| US2622212A | Bistable circuit | Expired / Lapsed | 1951-09-15 | 1952-12-16 | 0 | Details |
| US2622211A | Stabilized transistor trigger circuit | Expired / Lapsed | 1951-04-28 | 1952-12-16 | 0 | Details |
| US2622127A | Indicating apparatus | Expired / Lapsed | 1948-12-14 | 1952-12-16 | 0 | Details |
| US2621295A | Electrical wave producing circuit | Expired / Lapsed | 1949-02-15 | 1952-12-09 | 0 | Details |
| US2620448A | Transistor trigger circuits | Expired / Lapsed | 1950-09-12 | 1952-12-02 | 0 | Details |
| US2620399A | Telephone switching system employing repetitive impulsing | Expired / Lapsed | 1948-06-29 | 1952-12-02 | 0 | Details |
| US2618686A | Distortion indicator | Expired / Lapsed | 1948-03-01 | 1952-11-18 | 0 | Details |
| US2617855A | Automatic measurement of transmission characteristics | Expired / Lapsed | 1950-11-10 | 1952-11-11 | 0 | Details |
| US2617865A | Semiconductor amplifier and electrode structures therefor | Expired / Lapsed | 1949-09-15 | 1952-11-11 | 0 | Details |
| US2617704A | Recording system | Expired / Lapsed | 1947-07-15 | 1952-11-11 | 0 | Details |
| US2616971A | Automatic volume control | Expired / Lapsed | 1949-03-05 | 1952-11-04 | 0 | Details |
| US2616627A | Counter circuit | Expired / Lapsed | 1948-10-06 | 1952-11-04 | 0 | Details |
| US2616625A | Electrical computing system | Expired / Lapsed | 1946-07-26 | 1952-11-04 | 0 | Details |
| US2616060A | Cathode-ray coding tube | Expired / Lapsed | 1948-07-03 | 1952-10-28 | 0 | Details |
| US2614632A | Apparatus for recording numerals in code | Expired / Lapsed | 1948-07-27 | 1952-10-21 | 0 | Details |
| US2614140A | Trigger circuit | Expired / Lapsed | 1950-05-26 | 1952-10-14 | 0 | Details |
| US2614141A | Counting circuit | Expired / Lapsed | 1950-05-26 | 1952-10-14 | 0 | Details |
| US2614211A | Frequency controlled radio relaying system | Expired / Lapsed | 1950-05-13 | 1952-10-14 | 0 | Details |
| US2614176A | Electronic induction number group translator | Expired / Lapsed | 1950-05-06 | 1952-10-14 | 0 | Details |
| US2614152A | Dielectric test circuit | Expired / Lapsed | 1949-04-29 | 1952-10-14 | 0 | Details |
| US2614175A | Translating and selecting system | Expired / Lapsed | 1949-04-28 | 1952-10-14 | 0 | Details |
| US2612566A | Magnetic recording and reproducing system | Expired / Lapsed | 1951-06-05 | 1952-09-30 | 0 | Details |
| US2612561A | Half-duplex telegraph repeater | Expired / Lapsed | 1949-10-25 | 1952-09-30 | 0 | Details |
| US2610297A | Automatic frequency control circuit | Expired / Lapsed | 1948-12-14 | 1952-09-09 | 0 | Details |
| US2610295A | Pulse code modulation communication system | Expired / Lapsed | 1947-10-30 | 1952-09-09 | 0 | Details |
| US2609256A | Ball bearing | Expired / Lapsed | 1951-04-28 | 1952-09-02 | 2 | Details |
| US2609447A | Frequency discriminator | Expired / Lapsed | 1950-11-03 | 1952-09-02 | 0 | Details |
| US2608674A | Multicathode glow discharge device | Expired / Lapsed | 1951-02-09 | 1952-08-26 | 0 | Details |
| US2608668A | Magnetically focused electron gun | Expired / Lapsed | 1950-06-17 | 1952-08-26 | 0 | Details |
| US2608617A | Television converter system | Expired / Lapsed | 1950-06-14 | 1952-08-26 | 0 | Details |
| US2608539A | Metallized ceramic coating composition | Expired / Lapsed | 1950-03-22 | 1952-08-26 | 2 | Details |
| US2608610A | Transformer | Expired / Lapsed | 1950-01-28 | 1952-08-26 | 0 | Details |
| US2608621A | Magnetic record detector | Expired / Lapsed | 1949-10-08 | 1952-08-26 | 0 | Details |
| US2608623A | Wave transmission amplifier | Expired / Lapsed | 1949-06-18 | 1952-08-26 | 0 | Details |
| US2607891A | Translating circuits utilizing glow discharge devices | Expired / Lapsed | 1950-06-10 | 1952-08-19 | 0 | Details |
| US2607216A | Torsional interferometer | Expired / Lapsed | 1949-04-07 | 1952-08-19 | 0 | Details |
| US2607272A | Composite wave plate for light | Expired / Lapsed | 1949-02-11 | 1952-08-19 | 0 | Details |
| US2607843A | Remote control and supervisory system | Expired / Lapsed | 1948-11-12 | 1952-08-19 | 0 | Details |
| US2607858A | Electromechanical transducer | Expired / Lapsed | 1948-06-19 | 1952-08-19 | 2 | Details |
| US2606960A | Semiconductor translating device | Expired / Lapsed | 1949-06-01 | 1952-08-12 | 0 | Details |
| US2607010A | Wave guide antenna system | Expired / Lapsed | 1945-04-23 | 1952-08-12 | 0 | Details |
| US2606288A | Timing pulse generator | Expired / Lapsed | 1950-10-04 | 1952-08-05 | 0 | Details |
| US2605361A | Differential quantization of communication signals | Expired / Lapsed | 1950-06-29 | 1952-07-29 | 0 | Details |
| US2603694A | Semiconductor signal translating device | Expired / Lapsed | 1951-05-05 | 1952-07-15 | 0 | Details |
| US2603693A | Semiconductor signal translating device | Expired / Lapsed | 1950-10-10 | 1952-07-15 | 0 | Details |
| US2603716A | Decoder and translator with readily changeable translations | Expired / Lapsed | 1949-12-23 | 1952-07-15 | 0 | Details |
| US2603715A | Pulse position call or dial receiver | Expired / Lapsed | 1948-06-29 | 1952-07-15 | 0 | Details |
| US2603692A | Rectifier and method of making it | Expired / Lapsed | 1948-05-22 | 1952-07-15 | 0 | Details |
| US2602872A | Apparatus for equipping crystals with wires | Expired / Lapsed | 1948-12-30 | 1952-07-08 | 0 | Details |
| US2602763A | Preparation of semiconductive materials for translating dev… | Expired / Lapsed | 1948-12-29 | 1952-07-08 | 2 | Details |
| US2602853A | Selective signaling system | Expired / Lapsed | 1947-08-08 | 1952-07-08 | 0 | Details |
| US2602211A | Rectifier and method of making it | Expired / Lapsed | 1945-12-29 | 1952-07-08 | 0 | Details |
| US2602033A | Carbonyl process | Expired / Lapsed | 1950-01-18 | 1952-07-01 | 2 | Details |
| US2602148A | High-frequency amplifier | Expired / Lapsed | 1946-10-22 | 1952-07-01 | 0 | Details |
| US2601415A | Vertical sweep synchronizing circuit | Expired / Lapsed | 1949-06-30 | 1952-06-24 | 0 | Details |
| US2601403A | Electric circuit | Expired / Lapsed | 1948-03-19 | 1952-06-24 | 0 | Details |
| US2600500A | Semiconductor signal translating device with controlled car… | Expired / Lapsed | 1948-09-24 | 1952-06-17 | 0 | Details |
| US2600482A | Electric delay circuit | Expired / Lapsed | 1948-05-13 | 1952-06-17 | 0 | Details |
| US2600466A | Wave guide attenuator | Expired / Lapsed | 1943-05-07 | 1952-06-17 | 0 | Details |
| US2599746A | Endless conveyer for supporting conductors or cables in vul… | Expired / Lapsed | 1949-11-30 | 1952-06-10 | 0 | Details |
| US2598677A | Multicathode glow discharge device | Expired / Lapsed | 1949-12-15 | 1952-06-03 | 0 | Details |
| US2599097A | Radiotelephone station identifying system | Expired / Lapsed | 1948-12-30 | 1952-06-03 | 0 | Details |
| US2599368A | Beam switching system | Expired / Lapsed | 1948-05-10 | 1952-06-03 | 0 | Details |
| US2599392A | Recording device | Expired / Lapsed | 1947-09-05 | 1952-06-03 | 0 | Details |
| US2597428A | Checking means for pulse counting circuit | Expired / Lapsed | 1951-03-31 | 1952-05-20 | 0 | Details |
| US2597028A | Semiconductor signal translating device | Expired / Lapsed | 1949-11-30 | 1952-05-20 | 0 | Details |
| US2597071A | Signal monitoring | Expired / Lapsed | 1948-08-14 | 1952-05-20 | 0 | Details |
| US2596199A | Error correction in sequential code pulse transmission | Expired / Lapsed | 1951-02-19 | 1952-05-13 | 0 | Details |
| US2596237A | Mounting for circuit elements | Expired / Lapsed | 1949-05-06 | 1952-05-13 | 0 | Details |
| US2595680A | Constant resistance pseudohybrid channel branching microwav… | Expired / Lapsed | 1951-02-03 | 1952-05-06 | 0 | Details |
| US2595667A | Sweep circuit | Expired / Lapsed | 1949-12-24 | 1952-05-06 | 0 | Details |
| US2595701A | Recording system | Expired / Lapsed | 1948-12-31 | 1952-05-06 | 0 | Details |
| US2595646A | Television test signal generator | Expired / Lapsed | 1947-06-02 | 1952-05-06 | 0 | Details |
| US2594449A | Transistor switching device | Expired / Lapsed | 1950-12-30 | 1952-04-29 | 0 | Details |
| US2595208A | Transistor pulse divider | Expired / Lapsed | 1950-12-29 | 1952-04-29 | 0 | Details |
| US2594336A | Electrical counter circuit | Expired / Lapsed | 1950-10-17 | 1952-04-29 | 0 | Details |
| US2594890A | Contact protection arrangement | Expired / Lapsed | 1950-08-16 | 1952-04-29 | 0 | Details |
| US2594530A | Amplifying system | Expired / Lapsed | 1948-10-02 | 1952-04-29 | 0 | Details |
| US2594389A | Double-lockout interconnecting system | Expired / Lapsed | 1948-08-04 | 1952-04-29 | 0 | Details |
| US2594923A | Call data recording telephone system | Expired / Lapsed | 1948-06-16 | 1952-04-29 | 0 | Details |
| US2594495A | Magnetic recording system for call data in automatic teleph… | Expired / Lapsed | 1947-09-04 | 1952-04-29 | 0 | Details |
| US2595106A | Recording telephone system | Expired / Lapsed | 1947-06-18 | 1952-04-29 | 0 | Details |
| US2594409A | Directive antenna | Expired / Lapsed | 1943-07-27 | 1952-04-29 | 0 | Details |
| US2593694A | Wave analyzer for determining fundamental frequency of a co… | Expired / Lapsed | 1948-03-26 | 1952-04-22 | 0 | Details |
| US2592683A | Storage device utilizing semiconductor | Expired / Lapsed | 1950-12-30 | 1952-04-15 | 0 | Details |
| US2592652A | Magnetic transducer head | Expired / Lapsed | 1950-02-18 | 1952-04-15 | 0 | Details |
| US2592549A | Anode structure for electron discharge devices | Expired / Lapsed | 1949-08-03 | 1952-04-15 | 0 | Details |
| US2593136A | Apparatus for extruding and straining compounds | Expired / Lapsed | 1949-05-21 | 1952-04-15 | 0 | Details |
| US2591842A | Electron discharge apparatus | Expired / Lapsed | 1949-07-06 | 1952-04-08 | 0 | Details |
| US2592308A | Nonlinear pulse code modulation system | Expired / Lapsed | 1948-09-01 | 1952-04-08 | 0 | Details |
| US2592228A | Decoder for pulse code modulation receivers | Expired / Lapsed | 1947-07-07 | 1952-04-08 | 0 | Details |
| US2591557A | Apparatus for dipping articles in liquid | Expired / Lapsed | 1949-10-05 | 1952-04-01 | 0 | Details |
| US2590996A | Relay | Expired / Lapsed | 1947-11-21 | 1952-04-01 | 0 | Details |
| US2589704A | Semiconductor signal translating device | Expired / Lapsed | 1950-08-03 | 1952-03-18 | 0 | Details |
| US2589800A | Telephone signaling system | Expired / Lapsed | 1950-05-19 | 1952-03-18 | 0 | Details |
| US2589658A | Semiconductor amplifier and electrode structures therefor | Expired / Lapsed | 1949-09-15 | 1952-03-18 | 0 | Details |
| US2589711A | Off-channel squelch circuit for radio receivers | Expired / Lapsed | 1948-05-05 | 1952-03-18 | 0 | Details |
| US2589662A | Radiotelephone receiving system | Expired / Lapsed | 1946-04-23 | 1952-03-18 | 0 | Details |
| US2588375A | Automatic accounting device | Expired / Lapsed | 1949-06-24 | 1952-03-11 | 0 | Details |
| US2589130A | Permutation code group selector | Expired / Lapsed | 1949-06-24 | 1952-03-11 | 0 | Details |
| US2589158A | Mobile-radio and wire system | Expired / Lapsed | 1948-04-02 | 1952-03-11 | 0 | Details |
| US2587014A | Charge and tax determining equipment for telephone systems | Expired / Lapsed | 1948-12-29 | 1952-02-26 | 0 | Details |
| US2587482A | Piezoelectric type switching relay | Expired / Lapsed | 1946-09-06 | 1952-02-26 | 0 | Details |
| US2587036A | Process and apparatus for semicontinuous plating | Expired / Lapsed | 1946-03-12 | 1952-02-26 | 0 | Details |
| US2586080A | Semiconductive signal translating device | Expired / Lapsed | 1949-10-11 | 1952-02-19 | 0 | Details |
| US2586597A | Oscillation generator | Expired / Lapsed | 1949-09-15 | 1952-02-19 | 0 | Details |
| US2585904A | Crossbar telephone system | Expired / Lapsed | 1948-10-29 | 1952-02-19 | 0 | Details |
| US2585890A | Delay-action filter circuit | Expired / Lapsed | 1949-10-22 | 1952-02-12 | 0 | Details |
| US2585722A | Frequency divider | Expired / Lapsed | 1949-10-06 | 1952-02-12 | 0 | Details |
| US2584990A | Transitor counting system | Expired / Lapsed | 1949-03-26 | 1952-02-12 | 0 | Details |
| US2585545A | Signaling system | Expired / Lapsed | 1948-11-09 | 1952-02-12 | 0 | Details |
| US2585078A | Negative resistance device utilizing semiconductor amplifier | Expired / Lapsed | 1948-11-06 | 1952-02-12 | 0 | Details |
| US2585077A | Control of impedance of semiconductor amplifier circuits | Expired / Lapsed | 1948-11-06 | 1952-02-12 | 0 | Details |
| US2584736A | Telegraph switching system | Expired / Lapsed | 1950-05-02 | 1952-02-05 | 0 | Details |
| US2583088A | Alarm signaling system | Expired / Lapsed | 1950-09-13 | 1952-01-22 | 0 | Details |
| US2583102A | Counting system | Expired / Lapsed | 1950-07-24 | 1952-01-22 | 0 | Details |
| US2583008A | Asymmetric electrical conducting device | Expired / Lapsed | 1948-04-22 | 1952-01-22 | 0 | Details |
| US2583328A | Circuit for controlling the release of a relay | Expired / Lapsed | 1948-03-27 | 1952-01-22 | 0 | Details |
| US2582959A | Electron-tube controlled switching system | Expired / Lapsed | 1947-10-29 | 1952-01-22 | 0 | Details |
| US2582481A | Temperature-controlled soldering iron | Expired / Lapsed | 1950-12-16 | 1952-01-15 | 0 | Details |
| US2582498A | Negative impedance repeater and loading system | Expired / Lapsed | 1949-08-30 | 1952-01-15 | 0 | Details |
| US2580685A | Color television with reduced band width | Expired / Lapsed | 1949-12-30 | 1952-01-01 | 0 | Details |
| US2580668A | Elastomer mold sealing device | Expired / Lapsed | 1949-04-16 | 1952-01-01 | 0 | Details |
| US2580673A | Saw-tooth generator and system utilizing it | Expired / Lapsed | 1947-11-14 | 1952-01-01 | 0 | Details |
| US2580095A | Electronic code pulse transmitting circuit | Expired / Lapsed | 1950-10-17 | 1951-12-25 | 0 | Details |
| US2580073A | Time multiplex television in color | Expired / Lapsed | 1948-05-01 | 1951-12-25 | 0 | Details |
| US2580093A | Call data recording telephone system | Expired / Lapsed | 1947-12-16 | 1951-12-25 | 0 | Details |
| US2580083A | Contrast pattern generator | Expired / Lapsed | 1947-10-08 | 1951-12-25 | 0 | Details |
| US2579336A | Stabilized transistor trigger circuit | Expired / Lapsed | 1950-09-15 | 1951-12-18 | 0 | Details |
| US2578701A | Coordinate selecting and lockout circuit | Expired / Lapsed | 1949-09-15 | 1951-12-18 | 0 | Details |
| US2579302A | Decoder for pulse code modulation | Expired / Lapsed | 1948-01-17 | 1951-12-18 | 0 | Details |
| US2579327A | High-frequency energy absorbing variable coupling device | Expired / Lapsed | 1946-01-30 | 1951-12-18 | 0 | Details |
| US2577151A | Regulated rectifying apparatus | Expired / Lapsed | 1949-10-11 | 1951-12-04 | 0 | Details |
| US2577609A | Call data recording automatic telephone system | Expired / Lapsed | 1949-05-05 | 1951-12-04 | 0 | Details |
| US2577137A | Time-delay circuit | Expired / Lapsed | 1947-09-09 | 1951-12-04 | 0 | Details |
| US2577619A | Metallic structure for delaying unipolarized waves | Expired / Lapsed | 1947-05-16 | 1951-12-04 | 0 | Details |
| US2576267A | Preparation of germanium rectifier material | Expired / Lapsed | 1948-10-27 | 1951-11-27 | 2 | Details |
| US2576249A | Level ratio measuring system | Expired / Lapsed | 1947-08-28 | 1951-11-27 | 0 | Details |
| US2576026A | Electronic switch | Expired / Lapsed | 1950-06-28 | 1951-11-20 | 0 | Details |
| US2575990A | Automatic volume control | Expired / Lapsed | 1949-12-31 | 1951-11-20 | 0 | Details |
| US2575910A | Voice-operated signaling system | Expired / Lapsed | 1949-09-21 | 1951-11-20 | 0 | Details |
| US2575372A | Cold cathode gaseous discharge device | Expired / Lapsed | 1949-08-09 | 1951-11-20 | 0 | Details |
| US2575909A | Voice-operated system | Expired / Lapsed | 1949-07-01 | 1951-11-20 | 0 | Details |
| US2575370A | Cold cathode gaseous discharge device | Expired / Lapsed | 1949-06-25 | 1951-11-20 | 0 | Details |
| US2576040A | Cathode-ray device | Expired / Lapsed | 1948-03-10 | 1951-11-20 | 0 | Details |
| US2575383A | High-frequency amplifying device | Expired / Lapsed | 1946-10-22 | 1951-11-20 | 0 | Details |
| US2573744A | Regulated current supply apparatus | Expired / Lapsed | 1949-06-11 | 1951-11-06 | 0 | Details |
| US2573168A | Mechanical impedance transformer | Expired / Lapsed | 1950-05-23 | 1951-10-30 | 0 | Details |
| US2572831A | Communication system | Expired / Lapsed | 1947-11-24 | 1951-10-30 | 0 | Details |
| US2573150A | Frequency divider | Expired / Lapsed | 1946-02-28 | 1951-10-30 | 0 | Details |
| US2572586A | Sweep circuit | Expired / Lapsed | 1950-03-18 | 1951-10-23 | 0 | Details |
| US2572618A | Maintenance bracket | Expired / Lapsed | 1950-02-11 | 1951-10-23 | 0 | Details |
| US2572104A | Private branch exchange telephone system | Expired / Lapsed | 1949-04-29 | 1951-10-23 | 0 | Details |
| US2572132A | Transcribing and summarizing system | Expired / Lapsed | 1949-04-27 | 1951-10-23 | 0 | Details |
| US2571680A | Pulse code modulation system employing code substitution | Expired / Lapsed | 1949-02-11 | 1951-10-16 | 0 | Details |
| US2570225A | Series electronic switch | Expired / Lapsed | 1950-03-13 | 1951-10-09 | 0 | Details |
| US2570978A | Semiconductor translating device | Expired / Lapsed | 1949-10-11 | 1951-10-09 | 0 | Details |
| US2569443A | Telegraph storage system | Expired / Lapsed | 1946-06-06 | 1951-10-02 | 0 | Details |
| US2569347A | Circuit element utilizing semiconductive material | Expired / Lapsed | 1948-06-26 | 1951-09-25 | 0 | Details |
| US2567970A | Semiconductor comprising silicon and method of making it | Expired / Lapsed | 1947-12-24 | 1951-09-18 | 0 | Details |
| US2567797A | Current supply apparatus | Expired / Lapsed | 1950-02-18 | 1951-09-11 | 0 | Details |
| US2567812A | Code transmitter | Expired / Lapsed | 1948-03-26 | 1951-09-11 | 0 | Details |
| US2566846A | Apparatus for insulating conductors | Expired / Lapsed | 1949-03-30 | 1951-09-04 | 0 | Details |
| US2566426A | Relay selecting and indicating circuit | Expired / Lapsed | 1948-12-18 | 1951-09-04 | 0 | Details |
| US2564784A | Condenser | Expired / Lapsed | 1948-11-06 | 1951-08-21 | 0 | Details |
| US2564017A | Clamp circuit | Expired / Lapsed | 1949-06-04 | 1951-08-14 | 0 | Details |
| US2564125A | Selecting system | Expired / Lapsed | 1948-07-09 | 1951-08-14 | 0 | Details |
| US2564010A | Unattended repeater testing by causing the repeaters to osc… | Expired / Lapsed | 1947-07-07 | 1951-08-14 | 0 | Details |
| US2564419A | Time division multiplex system for signals of different ban… | Expired / Lapsed | 1947-04-14 | 1951-08-14 | 0 | Details |
| US2564439A | Standard frequency system | Expired / Lapsed | 1946-10-30 | 1951-08-14 | 0 | Details |
| US2563990A | Wave guide switching arrangement | Expired / Lapsed | 1944-09-23 | 1951-08-14 | 0 | Details |
| US2562277A | Metallic lens directive antenna system | Expired / Lapsed | 1946-04-08 | 1951-07-31 | 0 | Details |
| US2562281A | Directive pickup for transmission lines | Expired / Lapsed | 1944-06-14 | 1951-07-31 | 0 | Details |
| US2561411A | Semiconductor signal translating device | Expired / Lapsed | 1950-03-08 | 1951-07-24 | 0 | Details |
| US2561722A | Signaling system | Expired / Lapsed | 1948-03-06 | 1951-07-24 | 0 | Details |
| US2561476A | Magnetic recorder | Expired / Lapsed | 1947-09-29 | 1951-07-24 | 0 | Details |
| US2560606A | Photoresistive translating device | Expired / Lapsed | 1949-04-06 | 1951-07-17 | 0 | Details |
| US2560594A | Semiconductor translator and method of making it | Expired / Lapsed | 1948-09-24 | 1951-07-17 | 0 | Details |
| US2560792A | Electrolytic surface treatment of germanium | Expired / Lapsed | 1948-02-26 | 1951-07-17 | 0 | Details |
| US2561196A | Soldering fixture | Expired / Lapsed | 1947-01-21 | 1951-07-17 | 0 | Details |
| US2560353A | Cavity resonator | Expired / Lapsed | 1945-03-16 | 1951-07-10 | 0 | Details |
| US2558187A | Selective signaling generator in which coded information is… | Expired / Lapsed | 1949-12-15 | 1951-06-26 | 0 | Details |
| US2558577A | Electromechanical translator | Expired / Lapsed | 1946-10-31 | 1951-06-26 | 0 | Details |
| US2556296A | High-frequency transistor oscillator | Expired / Lapsed | 1949-04-26 | 1951-06-12 | 0 | Details |
| US2556286A | Oscillation generator | Expired / Lapsed | 1948-12-29 | 1951-06-12 | 0 | Details |
| US2556978A | Linear accelerator for charged particles | Expired / Lapsed | 1948-10-07 | 1951-06-12 | 0 | Details |
| US2556669A | Microwave transmission system | Expired / Lapsed | 1948-02-21 | 1951-06-12 | 0 | Details |
| US2556958A | Translator circuit | Expired / Lapsed | 1948-02-10 | 1951-06-12 | 0 | Details |
| US2556276A | Apparatus for simultaneously advancing and working organic … | Expired / Lapsed | 1947-11-28 | 1951-06-12 | 2 | Details |
| US2556711A | Method of producing rectifiers and rectifier material | Expired / Lapsed | 1947-10-29 | 1951-06-12 | 0 | Details |
| US2556377A | Detecting system for frequency modulated waves | Expired / Lapsed | 1946-08-06 | 1951-06-12 | 0 | Details |
| US2556964A | Ground trainer for aircraft personnel | Expired / Lapsed | 1945-11-16 | 1951-06-12 | 0 | Details |
| US2555959A | Nonlinear reactance circuits utilizing high dielectric cons… | Expired / Lapsed | 1946-10-18 | 1951-06-05 | 0 | Details |
| US2554549A | Recorder failure indicator | Expired / Lapsed | 1948-10-29 | 1951-05-29 | 0 | Details |
| US2554834A | Coupling for telephone receivers and hearing aid sets | Expired / Lapsed | 1948-06-29 | 1951-05-29 | 0 | Details |
| US2554835A | Recording system | Expired / Lapsed | 1947-06-25 | 1951-05-29 | 0 | Details |
| US2554582A | Magnetic recorder | Expired / Lapsed | 1947-06-06 | 1951-05-29 | 0 | Details |
| US2555001A | Bonded article and method of bonding | Expired / Lapsed | 1947-02-04 | 1951-05-29 | 0 | Details |
| US2553749A | Sealing fixture for the manufacture of electron discharge d… | Expired / Lapsed | 1948-05-05 | 1951-05-22 | 0 | Details |
| US2553752A | Combined multivibrator and sweep circuit | Expired / Lapsed | 1947-04-15 | 1951-05-22 | 0 | Details |
| US2554155A | Ground trainer for training aircraft crews | Expired / Lapsed | 1946-12-13 | 1951-05-22 | 0 | Details |
| US2553491A | Acoustic transducer utilizing semiconductors | Expired / Lapsed | 1950-04-27 | 1951-05-15 | 0 | Details |
| US2552629A | Error-detecting and correcting system | Expired / Lapsed | 1950-01-11 | 1951-05-15 | 0 | Details |
| US2552619A | Electron beam coder for pulse code modulation | Expired / Lapsed | 1949-03-05 | 1951-05-15 | 0 | Details |
| US2553490A | Magnetic control of semiconductor currents | Expired / Lapsed | 1949-02-21 | 1951-05-15 | 0 | Details |
| US2553255A | Telephone substation apparatus | Expired / Lapsed | 1948-09-28 | 1951-05-15 | 0 | Details |
| US2552626A | Silicon-germanium resistor and method of making it | Expired / Lapsed | 1948-02-17 | 1951-05-15 | 2 | Details |
| US2553245A | Electronic tracing system | Expired / Lapsed | 1946-06-04 | 1951-05-15 | 0 | Details |
| US2551402A | Apparatus for assembling and sealing glass and metal parts | Expired / Lapsed | 1946-09-26 | 1951-05-01 | 0 | Details |
| US2550518A | Control of impedance of semiconductor amplifier circuits | Expired / Lapsed | 1949-11-15 | 1951-04-24 | 0 | Details |
| US2550555A | Apparatus for extruding materials on cores under vacuum | Expired / Lapsed | 1949-05-11 | 1951-04-24 | 0 | Details |
| US2550600A | Indicating circuit | Expired / Lapsed | 1948-11-22 | 1951-04-24 | 0 | Details |
| US2549872A | Focusing ultrasonic radiator | Expired / Lapsed | 1948-03-26 | 1951-04-24 | 0 | Details |
| US2550605A | Circuit closing device | Expired / Lapsed | 1945-07-25 | 1951-04-24 | 0 | Details |
| US2549422A | Decoder for multiple carrier pulse code modulation signals | Expired / Lapsed | 1949-01-06 | 1951-04-17 | 0 | Details |
| US2549505A | Phase or frequency modulation system | Expired / Lapsed | 1948-09-09 | 1951-04-17 | 0 | Details |
| US2549551A | Grid electrode structure and manufacturing method therefor | Expired / Lapsed | 1948-01-15 | 1951-04-17 | 0 | Details |
| US2549504A | Method of sealing glass to metal | Expired / Lapsed | 1946-03-15 | 1951-04-17 | 0 | Details |
| US2548661A | Elastic time division multiplex system | Expired / Lapsed | 1949-02-10 | 1951-04-10 | 0 | Details |
| US2548187A | Method of determining the oxygen content of copper | Expired / Lapsed | 1945-07-19 | 1951-04-10 | 2 | Details |
| US2547386A | Current storage device utilizing semiconductor | Expired / Lapsed | 1949-03-31 | 1951-04-03 | 0 | Details |
| US2547406A | Method and means for controlling the resistance of oxidic s… | Expired / Lapsed | 1947-05-08 | 1951-04-03 | 2 | Details |
| US2547416A | Dielectric lens | Expired / Lapsed | 1946-12-19 | 1951-04-03 | 0 | Details |
| US2547539A | Signal wave duplexing system | Expired / Lapsed | 1946-06-27 | 1951-04-03 | 0 | Details |
| US2546316A | Synchronization of pulse communication systems | Expired / Lapsed | 1949-06-07 | 1951-03-27 | 0 | Details |
| US2546321A | Piezoelectric crystal apparatus | Expired / Lapsed | 1949-02-12 | 1951-03-27 | 0 | Details |
| US2546829A | Magnetic recorder and reproducer | Expired / Lapsed | 1948-12-18 | 1951-03-27 | 0 | Details |
| US2546371A | Generation of pulses of alternately opposite polarities | Expired / Lapsed | 1947-12-22 | 1951-03-27 | 0 | Details |
| US2546824A | Electrical protective apparatus | Expired / Lapsed | 1947-12-11 | 1951-03-27 | 0 | Details |
| US2546814A | Indicating apparatus | Expired / Lapsed | 1947-09-05 | 1951-03-27 | 0 | Details |
| US2546840A | Wave guide phase shifter | Expired / Lapsed | 1945-04-26 | 1951-03-27 | 0 | Details |
| US2545551A | Automatic electronic detecting and testing apparatus for sw… | Expired / Lapsed | 1947-12-31 | 1951-03-20 | 0 | Details |
| US2544753A | Electron camera tube | Expired / Lapsed | 1948-01-29 | 1951-03-13 | 0 | Details |
| US2544754A | Electron camera tube | Expired / Lapsed | 1948-01-29 | 1951-03-13 | 0 | Details |
| US2544755A | Electron camera tube | Expired / Lapsed | 1948-01-29 | 1951-03-13 | 0 | Details |
| US2544330A | Selective signaling device | Expired / Lapsed | 1947-11-04 | 1951-03-06 | 0 | Details |
| US2543531A | Counting apparatus | Expired / Lapsed | 1948-02-19 | 1951-02-27 | 0 | Details |
| US2543039A | Bombardment induced conductivity in solid insulators | Expired / Lapsed | 1947-12-04 | 1951-02-27 | 0 | Details |
| US2542727A | Etching processes and solutions | Expired / Lapsed | 1949-12-29 | 1951-02-20 | 2 | Details |
| US2542800A | Variable timed release for registers controlled by register… | Expired / Lapsed | 1948-10-29 | 1951-02-20 | 0 | Details |
| US2542672A | Coordinate selecting and lockout circuit | Expired / Lapsed | 1948-10-27 | 1951-02-20 | 0 | Details |
| US2542644A | Multistage ring circuit | Expired / Lapsed | 1948-09-01 | 1951-02-20 | 0 | Details |
| US2542183A | Transmission privacy synchronizing and equalizing system | Expired / Lapsed | 1948-07-10 | 1951-02-20 | 0 | Details |
| US2541322A | Control of impedance of semiconductor amplifier circuits | Expired / Lapsed | 1949-11-15 | 1951-02-13 | 0 | Details |
| US2541348A | Time division multiplex telephone system | Expired / Lapsed | 1948-07-24 | 1951-02-13 | 0 | Details |
| US2541932A | Multiplex speech interpolation system | Expired / Lapsed | 1948-05-19 | 1951-02-13 | 0 | Details |
| US2541910A | Directional coupler | Expired / Lapsed | 1947-09-18 | 1951-02-13 | 0 | Details |
| US2540835A | Cathode-ray device | Expired / Lapsed | 1949-12-31 | 1951-02-06 | 0 | Details |
| US2540488A | Microwave filter | Expired / Lapsed | 1948-04-30 | 1951-02-06 | 0 | Details |
| US2539623A | Communication system | Expired / Lapsed | 1947-02-12 | 1951-01-30 | 0 | Details |
| US2539535A | Source of electrical energy | Expired / Lapsed | 1946-03-16 | 1951-01-30 | 0 | Details |
| US2539556A | Variable delay speech privacy system | Expired / Lapsed | 1941-07-11 | 1951-01-30 | 0 | Details |
| US2538615A | Decoder for reflected binary codes | Expired / Lapsed | 1948-02-10 | 1951-01-16 | 0 | Details |
| US2538636A | Digital computer | Expired / Lapsed | 1947-12-31 | 1951-01-16 | 0 | Details |
| US2538266A | Communication system employing pulse code modulation | Expired / Lapsed | 1945-05-10 | 1951-01-16 | 0 | Details |
| US2537843A | Pulse regeneration apparatus | Expired / Lapsed | 1947-09-09 | 1951-01-09 | 0 | Details |
| US2537388A | Beam amplifier | Expired / Lapsed | 1947-05-14 | 1951-01-09 | 0 | Details |
| US2537255A | Light-sensitive electric device | Expired / Lapsed | 1946-03-20 | 1951-01-09 | 2 | Details |
| US2535303A | Electronic switch | Expired / Lapsed | 1949-10-21 | 1950-12-26 | 0 | Details |
| US2535400A | Multicontact dry reed relay | Expired / Lapsed | 1949-08-25 | 1950-12-26 | 0 | Details |
| US2534372A | Cathode-ray device | Expired / Lapsed | 1948-11-19 | 1950-12-19 | 0 | Details |
| US2534850A | Telephone system having preset transmitter | Expired / Lapsed | 1947-10-17 | 1950-12-19 | 0 | Details |
| US2534354A | Plug-in magnetic switch housing | Expired / Lapsed | 1947-10-08 | 1950-12-19 | 0 | Details |
| US2534392A | Method of making glass window seals | Expired / Lapsed | 1946-07-08 | 1950-12-19 | 0 | Details |
| US2534862A | Radio ranging system with selective automatic volume contro… | Expired / Lapsed | 1942-06-23 | 1950-12-19 | 0 | Details |
| US2533543A | Off-channel squelch circuit for radio receivers | Expired / Lapsed | 1947-12-06 | 1950-12-12 | 0 | Details |
| US2531660A | Fabrication of piezoelectric crystal units | Expired / Lapsed | 1949-08-27 | 1950-11-28 | 2 | Details |
| US2531622A | Automatic accounting device | Expired / Lapsed | 1949-06-24 | 1950-11-28 | 0 | Details |
| US2532125A | Selective station ringing system | Expired / Lapsed | 1949-01-28 | 1950-11-28 | 0 | Details |
| US2532098A | Automatic sound reproducing control system | Expired / Lapsed | 1948-03-23 | 1950-11-28 | 0 | Details |
| US2531447A | Hybrid channel-branching microwave filter | Expired / Lapsed | 1947-12-05 | 1950-11-28 | 0 | Details |
| US2531642A | Magnetic transducing system | Expired / Lapsed | 1947-10-30 | 1950-11-28 | 0 | Details |
| US2532097A | Decentralized line switch arrangement | Expired / Lapsed | 1946-12-31 | 1950-11-28 | 0 | Details |
| US2530538A | Vernier pulse code communication system | Expired / Lapsed | 1948-12-18 | 1950-11-21 | 0 | Details |
| US2530745A | Transistor microphone with conductive grains | Expired / Lapsed | 1948-12-10 | 1950-11-21 | 0 | Details |
| US2530890A | Radar antenna driving mechanism | Expired / Lapsed | 1947-07-26 | 1950-11-21 | 0 | Details |
| US2530961A | Stepping device | Expired / Lapsed | 1947-07-19 | 1950-11-21 | 0 | Details |
| US2530824A | Secret carrier signaling method and system | Expired / Lapsed | 1946-08-20 | 1950-11-21 | 0 | Details |
| US2530693A | Panoramic signal receiving system | Expired / Lapsed | 1944-06-17 | 1950-11-21 | 0 | Details |
| US2530217A | Conductive coating compositions | Expired / Lapsed | 1946-04-04 | 1950-11-14 | 0 | Details |
| US2527650A | Synchronization of pulse transmission systems | Expired / Lapsed | 1949-03-31 | 1950-10-31 | 0 | Details |
| US2527649A | Synchronization of pulse transmission systems | Expired / Lapsed | 1949-02-18 | 1950-10-31 | 0 | Details |
| US2527652A | Storage tube | Expired / Lapsed | 1948-01-29 | 1950-10-31 | 0 | Details |
| US2527632A | Storage tube | Expired / Lapsed | 1948-01-29 | 1950-10-31 | 0 | Details |
| US2527835A | Telautograph system | Expired / Lapsed | 1947-11-04 | 1950-10-31 | 0 | Details |
| US2527638A | Pulse skip synchronization of pulse transmission systems | Expired / Lapsed | 1947-09-26 | 1950-10-31 | 0 | Details |
| US2528446A | Current control circuit | Expired / Lapsed | 1947-07-07 | 1950-10-31 | 0 | Details |
| US2528086A | Relay contacts of conducting rubber | Expired / Lapsed | 1946-11-08 | 1950-10-31 | 0 | Details |
| US2528100A | Electronic calculator | Expired / Lapsed | 1946-05-31 | 1950-10-31 | 0 | Details |
| US2527166A | Electrode assembly for electron discharge devices | Expired / Lapsed | 1948-08-02 | 1950-10-24 | 0 | Details |
| US2527145A | Magnetic recorder and transmitter | Expired / Lapsed | 1946-12-06 | 1950-10-24 | 0 | Details |
| US2527136A | Fluid mixing apparatus | Expired / Lapsed | 1946-08-16 | 1950-10-24 | 0 | Details |
| US2527138A | Apparatus for making resistance measurements | Expired / Lapsed | 1945-03-08 | 1950-10-24 | 0 | Details |
| US2526595A | Precision pulse failure alarm circuit | Expired / Lapsed | 1945-10-11 | 1950-10-17 | 0 | Details |
| US2524035A | Three-electrode circuit element utilizing semiconductive ma… | Expired / Lapsed | 1948-06-17 | 1950-10-03 | 0 | Details |
| US2524034A | Three-electrode circuit element utilizing semiconductor mat… | Expired / Lapsed | 1948-02-26 | 1950-10-03 | 0 | Details |
| US2523365A | Testing system for cathode-ray telephone switching apparatus | Expired / Lapsed | 1948-05-10 | 1950-09-26 | 0 | Details |
| US2523904A | Record sensing and translating device | Expired / Lapsed | 1946-10-11 | 1950-09-26 | 0 | Details |
| US2523717A | Correction of distortion in telegraph signals | Expired / Lapsed | 1946-08-20 | 1950-09-26 | 0 | Details |
| US2522521A | Thermal transistor microphone | Expired / Lapsed | 1949-01-14 | 1950-09-19 | 0 | Details |
| US2522539A | Frequency control for synthesizing systems | Expired / Lapsed | 1948-07-02 | 1950-09-19 | 0 | Details |
| US2522259A | Electrode temperature regulation | Expired / Lapsed | 1948-05-06 | 1950-09-12 | 0 | Details |
| US2522124A | Frequency-controlled oscillator | Expired / Lapsed | 1947-10-08 | 1950-09-12 | 0 | Details |
| US2522130A | Carrier telegraph receiving circuit | Expired / Lapsed | 1947-06-19 | 1950-09-12 | 0 | Details |
| US2521828A | Coaxial line attenuator | Expired / Lapsed | 1946-06-25 | 1950-09-12 | 0 | Details |
| US2522291A | Cathode-ray tube with target controlled deflecting plates | Expired / Lapsed | 1945-09-20 | 1950-09-12 | 0 | Details |
| US2522000A | Recording telephone system | Expired / Lapsed | 1943-05-05 | 1950-09-12 | 0 | Details |
| US2521545A | Electron discharge device | Expired / Lapsed | 1946-06-28 | 1950-09-05 | 0 | Details |
| US2519426A | Alternating current control device | Expired / Lapsed | 1948-02-26 | 1950-08-22 | 0 | Details |
| US2520007A | Testing circuit for carrier communication system with autom… | Expired / Lapsed | 1947-11-21 | 1950-08-22 | 0 | Details |
| US2519688A | Signal code translator | Expired / Lapsed | 1946-11-08 | 1950-08-22 | 0 | Details |
| US2519667A | Motor control circuit | Expired / Lapsed | 1945-05-16 | 1950-08-22 | 0 | Details |
| US2520008A | Radio marker system | Expired / Lapsed | 1940-04-05 | 1950-08-22 | 0 | Details |
| US2519262A | Differential analyzer | Expired / Lapsed | 1948-09-09 | 1950-08-15 | 0 | Details |
| US2519233A | Aircraft trainer | Expired / Lapsed | 1944-06-30 | 1950-08-15 | 0 | Details |
| US2518022A | Translator | Expired / Lapsed | 1948-09-30 | 1950-08-08 | 0 | Details |
| US2518331A | Piezoelectric crystal mounting | Expired / Lapsed | 1948-05-06 | 1950-08-08 | 0 | Details |
| US2516587A | Correction of errors in pulse code communication | Expired / Lapsed | 1947-12-03 | 1950-07-25 | 0 | Details |
| US2516765A | Tracking control | Expired / Lapsed | 1944-02-24 | 1950-07-25 | 0 | Details |
| US2516069A | Observer-controlled television system | Expired / Lapsed | 1947-07-29 | 1950-07-18 | 0 | Details |
| US2516047A | Stable curable polyorganosiloxane compositions | Expired / Lapsed | 1945-11-15 | 1950-07-18 | 2 | Details |
| US2516058A | Apparatus for plating of metals | Expired / Lapsed | 1943-09-30 | 1950-07-18 | 0 | Details |
| US2515332A | Object locating system | Expired / Lapsed | 1943-08-12 | 1950-07-18 | 0 | Details |
| US2515054A | Light modulating system | Expired / Lapsed | 1948-08-11 | 1950-07-11 | 0 | Details |
| US2514671A | Decoder for pulse code modulation | Expired / Lapsed | 1947-09-23 | 1950-07-11 | 0 | Details |
| US2514633A | Variable-density push-pull sound recording system | Expired / Lapsed | 1946-05-07 | 1950-07-11 | 0 | Details |
| US2514678A | Wave guide system | Expired / Lapsed | 1942-06-30 | 1950-07-11 | 0 | Details |
| US2514080A | Method of obtaining high velocity with crystals | Expired / Lapsed | 1945-01-10 | 1950-07-04 | 0 | Details |
| US2511986A | Apparatus for extruding organic plastic material | Expired / Lapsed | 1948-04-30 | 1950-06-20 | 0 | Details |
| US2511195A | Recording pen check mechanism | Expired / Lapsed | 1948-04-30 | 1950-06-13 | 0 | Details |
| US2511121A | Method of recording information on stationary magnetic mate… | Expired / Lapsed | 1948-02-14 | 1950-06-13 | 0 | Details |
| US2510061A | Code translator and printer control circuit | Expired / Lapsed | 1949-01-21 | 1950-06-06 | 0 | Details |
| US2509889A | Differential altimeter | Expired / Lapsed | 1948-01-13 | 1950-05-30 | 0 | Details |
| US2509477A | Coin control device for telephone coin collectors | Expired / Lapsed | 1948-01-08 | 1950-05-30 | 0 | Details |
| US2509909A | Conductive device | Expired / Lapsed | 1946-12-31 | 1950-05-30 | 0 | Details |
| US2508547A | Calibration system | Expired / Lapsed | 1948-07-27 | 1950-05-23 | 0 | Details |
| US2509068A | Polarimetric method and means of determining the degree of … | Expired / Lapsed | 1948-02-20 | 1950-05-23 | 0 | Details |
| US2508511A | Resistor coated with ceramic composition | Expired / Lapsed | 1946-12-12 | 1950-05-23 | 2 | Details |
| US2508508A | Mercury contact for electrical switches | Expired / Lapsed | 1946-08-10 | 1950-05-23 | 0 | Details |
| US2508622A | Pulse code modulation communication system | Expired / Lapsed | 1945-07-09 | 1950-05-23 | 0 | Details |
| US2508509A | Apparatus for coating hollow objects | Expired / Lapsed | 1945-01-13 | 1950-05-23 | 0 | Details |
| US2508053A | Automatic monitor for comparing designations received and t… | Expired / Lapsed | 1948-12-31 | 1950-05-16 | 0 | Details |
| US2507566A | Electrical testing apparatus | Expired / Lapsed | 1948-08-30 | 1950-05-16 | 0 | Details |
| US2506437A | Combined voice and facsimile system | Expired / Lapsed | 1946-06-01 | 1950-05-02 | 0 | Details |
| US2506429A | Selective signaling system | Expired / Lapsed | 1946-05-31 | 1950-05-02 | 0 | Details |
| US2506130A | Metalized ceramic coating composition | Expired / Lapsed | 1945-08-14 | 1950-05-02 | 2 | Details |
| US2505029A | Decoder for pulse code modulation | Expired / Lapsed | 1949-02-09 | 1950-04-25 | 0 | Details |
| US2505040A | Regenerative relay repeater | Expired / Lapsed | 1948-06-04 | 1950-04-25 | 0 | Details |
| US2505531A | Magnetic jig for electroplating | Expired / Lapsed | 1947-12-31 | 1950-04-25 | 0 | Details |
| US2505370A | Piezoelectric crystal unit | Expired / Lapsed | 1947-11-08 | 1950-04-25 | 0 | Details |
| US2505566A | Signaling system | Expired / Lapsed | 1945-07-23 | 1950-04-25 | 0 | Details |
| US2504354A | Phase controlled multivibrator | Expired / Lapsed | 1947-12-24 | 1950-04-18 | 0 | Details |
| US2504621A | Enciphering and deciphering device for secret telegraph sys… | Expired / Lapsed | 1946-12-03 | 1950-04-18 | 0 | Details |
| US2503371A | Selective signaling system | Expired / Lapsed | 1949-02-21 | 1950-04-11 | 0 | Details |
| US2503831A | Fine wire delay line | Expired / Lapsed | 1949-01-07 | 1950-04-11 | 0 | Details |
| US2503391A | Automatic volume control | Expired / Lapsed | 1949-01-06 | 1950-04-11 | 0 | Details |
| US2503846A | Telephone set | Expired / Lapsed | 1946-12-27 | 1950-04-11 | 0 | Details |
| US2503405A | Control and indicator apparatus for rectifiers | Expired / Lapsed | 1946-12-21 | 1950-04-11 | 0 | Details |
| US2503559A | Electrical terminal | Expired / Lapsed | 1946-05-01 | 1950-04-11 | 0 | Details |
| US2503837A | Electrical translating device | Expired / Lapsed | 1945-07-27 | 1950-04-11 | 0 | Details |
| US2503429A | Metallic casing for electrical units | Expired / Lapsed | 1944-09-26 | 1950-04-11 | 0 | Details |
| US2502488A | Semiconductor amplifier | Expired / Lapsed | 1948-09-24 | 1950-04-04 | 0 | Details |
| US2502970A | Electrical device | Expired / Lapsed | 1946-10-11 | 1950-04-04 | 0 | Details |
| US2502837A | Position indicating system | Expired / Lapsed | 1943-11-24 | 1950-04-04 | 0 | Details |
| US2500424A | Negative feedback amplifier | Expired / Lapsed | 1947-12-03 | 1950-03-14 | 0 | Details |
| US2500643A | Condenser transducer independent of ambient atmospheric con… | Expired / Lapsed | 1946-12-07 | 1950-03-14 | 0 | Details |
| US2500431A | Visual representation of complex waves | Expired / Lapsed | 1946-12-06 | 1950-03-14 | 0 | Details |
| US2500638A | Aid for the blind | Expired / Lapsed | 1946-04-26 | 1950-03-14 | 0 | Details |
| US2499759A | Location of faults in electrical transmission systems | Expired / Lapsed | 1947-07-31 | 1950-03-07 | 0 | Details |
| US2499720A | Method of and apparatus for testing insulation | Expired / Lapsed | 1945-11-30 | 1950-03-07 | 0 | Details |
| US2499000A | Frequency modulation system for locating impedance irregula… | Expired / Lapsed | 1946-10-16 | 1950-02-28 | 0 | Details |
| US2498103A | Differential detector | Expired / Lapsed | 1949-02-16 | 1950-02-21 | 0 | Details |
| US2497770A | Transistor-microphone | Expired / Lapsed | 1948-12-29 | 1950-02-14 | 0 | Details |
| US2496633A | Multitarget cathode-ray device | Expired / Lapsed | 1947-12-24 | 1950-02-07 | 0 | Details |
| US2496970A | Cathode-ray tube circuit | Expired / Lapsed | 1947-08-26 | 1950-02-07 | 0 | Details |
| US2495683A | Communication system | Expired / Lapsed | 1940-12-24 | 1950-01-31 | 0 | Details |
| US2493819A | Stabilized feed-back condenser microphone | Expired / Lapsed | 1947-11-25 | 1950-01-10 | 0 | Details |
| US2494483A | Centrifugal force compensating mechanism | Expired / Lapsed | 1947-11-12 | 1950-01-10 | 0 | Details |
| US2494323A | Signal receiving apparatus | Expired / Lapsed | 1943-03-12 | 1950-01-10 | 0 | Details |
| US2493183A | Artillery director | Expired / Lapsed | 1942-05-21 | 1950-01-03 | 0 | Details |
| US2492351A | Smoothing network | Expired / Lapsed | 1944-02-23 | 1949-12-27 | 0 | Details |
| US2492062A | Device for portrayal of complex waves | Expired / Lapsed | 1946-11-05 | 1949-12-20 | 0 | Details |
| US2491644A | Attenuator | Expired / Lapsed | 1945-08-24 | 1949-12-20 | 0 | Details |
| US2491662A | Attenuator | Expired / Lapsed | 1945-03-30 | 1949-12-20 | 0 | Details |
| US2491276A | Radio transmission control | Expired / Lapsed | 1948-04-20 | 1949-12-13 | 0 | Details |
| US2491284A | Electrode for electron discharge devices and method of maki… | Expired / Lapsed | 1946-12-13 | 1949-12-13 | 0 | Details |
| US2490441A | Calling line and party identification in automatic telephony | Expired / Lapsed | 1947-05-22 | 1949-12-06 | 0 | Details |
| US2489883A | Pulse code modulation receiver employing cathode-ray tube d… | Expired / Lapsed | 1946-12-28 | 1949-11-29 | 0 | Details |
| US2489865A | Directional microwave antenna | Expired / Lapsed | 1944-07-31 | 1949-11-29 | 0 | Details |
| US2488580A | Temperature control system | Expired / Lapsed | 1946-03-07 | 1949-11-22 | 0 | Details |
| US2487781A | Signaling system | Expired / Lapsed | 1947-04-25 | 1949-11-15 | 0 | Details |
| US2488341A | Detection system | Expired / Lapsed | 1945-09-25 | 1949-11-15 | 0 | Details |
| US2488373A | Motor speed control apparatus | Expired / Lapsed | 1945-06-12 | 1949-11-15 | 0 | Details |
| US2488448A | Computing circuit for determining bomb release points | Expired / Lapsed | 1945-04-27 | 1949-11-15 | 0 | Details |
| US2486776A | Self-biased electric translating device | Expired / Lapsed | 1948-04-21 | 1949-11-01 | 0 | Details |
| US2486491A | Gate distributor circuits | Expired / Lapsed | 1946-02-08 | 1949-11-01 | 0 | Details |
| US2486482A | Sealed container for electrode assemblies | Expired / Lapsed | 1945-10-18 | 1949-11-01 | 0 | Details |
| US2486809A | Biquinary system calculator | Expired / Lapsed | 1945-09-29 | 1949-11-01 | 0 | Details |
| US2486187A | Piezoelectric crystal apparatus | Expired / Lapsed | 1947-04-09 | 1949-10-25 | 0 | Details |
| US2484829A | Crystal growing apparatus | Expired / Lapsed | 1945-06-11 | 1949-10-18 | 0 | Details |
| US2485069A | Translating material of silicon base | Expired / Lapsed | 1944-07-20 | 1949-10-18 | 0 | Details |
| US2484226A | Indicating circuit | Expired / Lapsed | 1947-10-17 | 1949-10-11 | 0 | Details |
| US2484626A | Electromechanical transducer | Expired / Lapsed | 1946-07-26 | 1949-10-11 | 0 | Details |
| US2484612A | Directory number calling line identifier | Expired / Lapsed | 1946-05-17 | 1949-10-11 | 0 | Details |
| US2484635A | Piezoelectric crystal apparatus | Expired / Lapsed | 1945-12-24 | 1949-10-11 | 0 | Details |
| US2484623A | Thickness measurement | Expired / Lapsed | 1944-10-17 | 1949-10-11 | 0 | Details |
| US2484618A | Wave receiving system | Expired / Lapsed | 1944-08-26 | 1949-10-11 | 0 | Details |
| US2483594A | Pulse operated system | Expired / Lapsed | 1945-03-19 | 1949-10-04 | 0 | Details |
| CA460016A | Method of making resistors | Expired / Lapsed | — | 1949-09-27 | 0 | Details |
| US2482178A | Composite structure for forming a seal with glass | Expired / Lapsed | 1944-02-29 | 1949-09-20 | 0 | Details |
| US2482162A | Directive microwave antenna | Expired / Lapsed | 1943-06-05 | 1949-09-20 | 0 | Details |
| US2481932A | Supervisory signaling in telephone systems | Expired / Lapsed | 1946-12-27 | 1949-09-13 | 0 | Details |
| US2481648A | Apparatus for combining variable quantities | Expired / Lapsed | 1943-09-15 | 1949-09-13 | 0 | Details |
| US2481247A | Visual representation of complex waves | Expired / Lapsed | 1946-10-10 | 1949-09-06 | 0 | Details |
| US2481112A | Teletypewriter permutation code signal combination counter | Expired / Lapsed | 1946-09-13 | 1949-09-06 | 0 | Details |
| US2480038A | Compensation of distortion in guided waves | Expired / Lapsed | 1946-06-08 | 1949-08-23 | 0 | Details |
| US2479909A | Computing circuit for determining bomb release course | Expired / Lapsed | 1945-04-27 | 1949-08-23 | 0 | Details |
| US2479924A | Method of making electrical conductor cables | Expired / Lapsed | 1944-04-25 | 1949-08-23 | 0 | Details |
| US2478414A | Breakdown testing apparatus | Expired / Lapsed | 1944-01-07 | 1949-08-09 | 0 | Details |
| US2477309A | Selective telegraph station calling system | Expired / Lapsed | 1948-10-29 | 1949-07-26 | 0 | Details |
| US2477047A | Frequency divider circuit | Expired / Lapsed | 1946-09-21 | 1949-07-26 | 0 | Details |
| US2477076A | Frequency control system | Expired / Lapsed | 1945-10-12 | 1949-07-26 | 0 | Details |
| US2477246A | Submarine signaling device | Expired / Lapsed | 1945-05-16 | 1949-07-26 | 0 | Details |
| US2477232A | Cavity resonator | Expired / Lapsed | 1945-03-28 | 1949-07-26 | 0 | Details |
| US2477337A | Magnetic detector | Expired / Lapsed | 1944-07-31 | 1949-07-26 | 0 | Details |
| US2476323A | Multielectrode modulator | Expired / Lapsed | 1948-05-19 | 1949-07-19 | 0 | Details |
| US2476844A | Motor control circuit | Expired / Lapsed | 1946-04-03 | 1949-07-19 | 0 | Details |
| US2476747A | Electrical computing system | Expired / Lapsed | 1942-04-25 | 1949-07-19 | 0 | Details |
| US2476034A | Conformal grating resonant cavity | Expired / Lapsed | 1945-07-16 | 1949-07-12 | 0 | Details |
| US2476032A | Doppler effect speed and drift indicating system | Expired / Lapsed | 1944-03-08 | 1949-07-12 | 0 | Details |
| US2475188A | Sweep amplifier | Expired / Lapsed | 1944-12-20 | 1949-07-05 | 0 | Details |
| US2475434A | Apparatus for masking articles | Expired / Lapsed | 1944-06-20 | 1949-07-05 | 0 | Details |
| US2474898A | Electromagnetic resonator of the magnetron type | Expired / Lapsed | 1944-04-05 | 1949-07-05 | 0 | Details |
| US2472782A | Wave modifying reflector | Expired / Lapsed | 1945-09-07 | 1949-06-14 | 0 | Details |
| US2472930A | Electrical heating unit | Expired / Lapsed | 1945-08-23 | 1949-06-14 | 0 | Details |
| US2472715A | Piezoelectric crystal apparatus | Expired / Lapsed | 1947-01-21 | 1949-06-07 | 0 | Details |
| US2472753A | Piezoelectric crystal apparatus | Expired / Lapsed | 1946-08-16 | 1949-06-07 | 0 | Details |
| US2471970A | Wiring device | Expired / Lapsed | 1947-04-23 | 1949-05-31 | 0 | Details |
| US2471516A | Plan position indicating system and method | Expired / Lapsed | 1941-12-20 | 1949-05-31 | 0 | Details |
| US2470826A | Fixed capacitor | Expired / Lapsed | 1947-11-06 | 1949-05-24 | 0 | Details |
| US2471262A | Means for multiplying voltages | Expired / Lapsed | 1946-10-24 | 1949-05-24 | 0 | Details |
| US2471268A | Index pulse generating circuit | Expired / Lapsed | 1945-05-22 | 1949-05-24 | 0 | Details |
| US2470825A | Electrical contact protection network | Expired / Lapsed | 1945-04-10 | 1949-05-24 | 0 | Details |
| US2471264A | Radio object location system | Expired / Lapsed | 1945-01-01 | 1949-05-24 | 0 | Details |
| US2471315A | Aircraft trainer for aerial gunners | Expired / Lapsed | 1944-02-03 | 1949-05-24 | 0 | Details |
| US2470145A | Multifrequency signaling system | Expired / Lapsed | 1947-09-25 | 1949-05-17 | 0 | Details |
| US2469837A | Wave translating system | Expired / Lapsed | 1946-09-26 | 1949-05-10 | 0 | Details |
| US2469539A | Radio control system | Expired / Lapsed | 1946-02-23 | 1949-05-10 | 0 | Details |
| US2469569A | Point contact negative resistance devices | Expired / Lapsed | 1945-03-02 | 1949-05-10 | 0 | Details |
| US2468462A | Telegraph transmitter control mechanism | Expired / Lapsed | 1945-07-04 | 1949-04-26 | 0 | Details |
| US2468224A | Magnetic reproducer using endless tape records | Expired / Lapsed | 1945-05-11 | 1949-04-26 | 0 | Details |
| US2468179A | Tracking device | Expired / Lapsed | 1943-07-17 | 1949-04-26 | 0 | Details |
| US2467347A | Regulated current supply apparatus | Expired / Lapsed | 1947-02-06 | 1949-04-12 | 0 | Details |
| US2467325A | Electrooptical light valve of ammonium dihydrogen phosphate… | Expired / Lapsed | 1946-12-31 | 1949-04-12 | 0 | Details |
| US2466904A | Stabilized oscillator | Expired / Lapsed | 1945-02-13 | 1949-04-12 | 0 | Details |
| US2467299A | High-frequency transmission system | Expired / Lapsed | 1942-11-12 | 1949-04-12 | 0 | Details |
| US2466354A | Directional radio system | Expired / Lapsed | 1944-06-28 | 1949-04-05 | 0 | Details |
| US2465540A | Electrical connector | Expired / Lapsed | 1946-03-26 | 1949-03-29 | 0 | Details |
| US2465531A | Transmission control system | Expired / Lapsed | 1945-06-08 | 1949-03-29 | 0 | Details |
| US2464594A | Phase and amplitude control circuit for wide band amplifiers | Expired / Lapsed | 1946-04-06 | 1949-03-15 | 0 | Details |
| US2464607A | Pulse code modulation communication system | Expired / Lapsed | 1945-07-09 | 1949-03-15 | 0 | Details |
| US2463535A | Electron discharge device | Expired / Lapsed | 1946-12-13 | 1949-03-08 | 0 | Details |
| US2462218A | Electrical translator and method of making it | Expired / Lapsed | 1945-04-17 | 1949-02-22 | 0 | Details |
| US2462162A | Metallic oxide resistor | Expired / Lapsed | 1944-07-03 | 1949-02-22 | 0 | Details |
| US2461878A | Metallizing composition | Expired / Lapsed | 1944-11-01 | 1949-02-15 | 0 | Details |
| US2460702A | Registration system | Expired / Lapsed | 1948-01-30 | 1949-02-01 | 0 | Details |
| US2460688A | Apparatus for locating faults in cables | Expired / Lapsed | 1944-05-04 | 1949-02-01 | 0 | Details |
| US2460401A | Directive microwave radio antenna | Expired / Lapsed | 1943-04-01 | 1949-02-01 | 0 | Details |
| US2460090A | Frequency selective apparatus | Expired / Lapsed | 1945-11-26 | 1949-01-25 | 0 | Details |
| US2460064A | Motor control circuit | Expired / Lapsed | 1945-05-16 | 1949-01-25 | 0 | Details |
| US2459306A | Contact protection for mercury wetted switch contacts | Expired / Lapsed | 1944-07-21 | 1949-01-18 | 0 | Details |
| US2458599A | Circuit for sampling balanced signals | Expired / Lapsed | 1946-12-04 | 1949-01-11 | 0 | Details |
| US2458552A | Method of making electrical contacting elements | Expired / Lapsed | 1946-11-09 | 1949-01-11 | 0 | Details |
| US2458601A | Method of and apparatus for measuring pressure | Expired / Lapsed | 1944-03-24 | 1949-01-11 | 0 | Details |
| US2458654A | System for and method of utilizing microwave radiation from… | Expired / Lapsed | 1943-12-27 | 1949-01-11 | 0 | Details |
| US2458556A | Coupled cavity resonator and wave guide apparatus | Expired / Lapsed | 1942-03-05 | 1949-01-11 | 0 | Details |
| US2457986A | Synchronization of time division multiplex communication sy… | Expired / Lapsed | 1945-12-11 | 1949-01-04 | 0 | Details |
| US2458030A | Selective signaling apparatus and system | Expired / Lapsed | 1944-08-29 | 1949-01-04 | 0 | Details |
| US2458175A | Directive antenna control system | Expired / Lapsed | 1944-07-27 | 1949-01-04 | 0 | Details |
| US2457524A | Wave guide repeater | Expired / Lapsed | 1945-05-26 | 1948-12-28 | 0 | Details |
| US2457559A | Repeater for pulse communication system | Expired / Lapsed | 1945-02-15 | 1948-12-28 | 0 | Details |
| US2457218A | Method of manufacturing sealed contact devices | Expired / Lapsed | 1944-12-14 | 1948-12-28 | 0 | Details |
| US2456973A | Trace blanking circuit for cathoderay oscilloscopes | Expired / Lapsed | 1945-10-10 | 1948-12-21 | 0 | Details |
| US2456305A | Closure device for crystal converters | Expired / Lapsed | 1944-09-22 | 1948-12-14 | 0 | Details |
| US2455387A | Thermostat-controlled heater circuit | Expired / Lapsed | 1946-10-02 | 1948-12-07 | 0 | Details |
| US2455472A | Method and system for electronically generating complex sig… | Expired / Lapsed | 1945-04-10 | 1948-12-07 | 0 | Details |
| US2455520A | Temperature controlled test system | Expired / Lapsed | 1944-03-24 | 1948-12-07 | 0 | Details |
| US2455035A | Averaging mechanism | Expired / Lapsed | 1946-01-30 | 1948-11-30 | 0 | Details |
| US2455052A | Signal receiving system | Expired / Lapsed | 1944-06-17 | 1948-11-30 | 0 | Details |
| US2454329A | Take-up mechanism | Expired / Lapsed | 1947-11-28 | 1948-11-23 | 0 | Details |
| US2454301A | Telegraph system | Expired / Lapsed | 1943-04-07 | 1948-11-23 | 0 | Details |
| US2454045A | Amplifier | Expired / Lapsed | 1945-05-16 | 1948-11-16 | 0 | Details |
| US2453743A | Signaling system and training device for target tracking | Expired / Lapsed | 1943-12-06 | 1948-11-16 | 0 | Details |
| US2454089A | Regenerative repeater | Expired / Lapsed | 1942-10-06 | 1948-11-16 | 0 | Details |
| US2453454A | Coder for code modulation transmission | Expired / Lapsed | 1946-08-31 | 1948-11-09 | 0 | Details |
| US2453461A | Code modulation communication system | Expired / Lapsed | 1946-06-19 | 1948-11-09 | 0 | Details |
| US2453435A | Piezoelectric crystal apparatus | Expired / Lapsed | 1945-12-28 | 1948-11-09 | 0 | Details |
| US2453243A | Frequency modulating and harmonic producer apparatus | Expired / Lapsed | 1943-10-21 | 1948-11-09 | 0 | Details |
| US2452655A | Cathode-ray oscilloscope circuit | Expired / Lapsed | 1947-04-25 | 1948-11-02 | 0 | Details |
| US2452052A | Selectively responsive device | Expired / Lapsed | 1946-12-30 | 1948-10-26 | 0 | Details |
| US2452051A | Relay system | Expired / Lapsed | 1945-03-15 | 1948-10-26 | 0 | Details |
| US2451465A | Transversal filter | Expired / Lapsed | 1947-02-27 | 1948-10-19 | 0 | Details |
| US2451572A | Radiant energy measuring apparatus | Expired / Lapsed | 1945-12-27 | 1948-10-19 | 0 | Details |
| US2451489A | Progressive selecting circuit | Expired / Lapsed | 1945-05-15 | 1948-10-19 | 0 | Details |
| US2451632A | Control voltage means in pulse receiver | Expired / Lapsed | 1944-02-24 | 1948-10-19 | 0 | Details |
| US2451484A | Cathode-ray signal utilizing means | Expired / Lapsed | 1943-10-05 | 1948-10-19 | 0 | Details |
| US2451044A | Communication system employing pulse code modulation | Expired / Lapsed | 1945-07-09 | 1948-10-12 | 0 | Details |
| US2450516A | Telemetric data transmission system | Expired / Lapsed | 1944-01-11 | 1948-10-05 | 0 | Details |
| US2449848A | Pulse-actuated circuit | Expired / Lapsed | 1943-08-12 | 1948-09-21 | 0 | Details |
| US2449467A | Communication system employing pulse code modulation | Expired / Lapsed | 1944-09-16 | 1948-09-14 | 0 | Details |
| US2448581A | Testing circuits for piezoelectric crystals | Expired / Lapsed | 1945-01-27 | 1948-09-07 | 0 | Details |
| US2448365A | Projector and receiver of supersonic frequencies | Expired / Lapsed | 1945-07-27 | 1948-08-31 | 0 | Details |
| US2447533A | Automatic toll ticketing system | Expired / Lapsed | 1942-06-27 | 1948-08-24 | 0 | Details |
| US2446672A | Method of machining article blanks | Expired / Lapsed | 1944-07-26 | 1948-08-10 | 0 | Details |
| US2446674A | Cathode-ray device mounting | Expired / Lapsed | 1944-02-18 | 1948-08-10 | 0 | Details |
| US2445896A | Dielectric wave guide coupling arrangement for use in two-w… | Expired / Lapsed | 1945-03-06 | 1948-07-27 | 0 | Details |
| US2445895A | Coupling arrangement for use in wave transmission systems | Expired / Lapsed | 1942-12-31 | 1948-07-27 | 0 | Details |
| US2445406A | Circuit maker and breaker | Expired / Lapsed | 1944-07-21 | 1948-07-20 | 0 | Details |
| US2444751A | Method and apparatus for sorting magnetic materials accordi… | Expired / Lapsed | 1946-02-12 | 1948-07-06 | 0 | Details |
| US2444435A | Frequency control of magnetron oscillators | Expired / Lapsed | 1942-05-01 | 1948-07-06 | 0 | Details |
| US2444349A | Cyrstal oscillator circuits | Expired / Lapsed | 1945-10-31 | 1948-06-29 | 0 | Details |
| US2444060A | Wave translating device | Expired / Lapsed | 1945-07-27 | 1948-06-29 | 0 | Details |
| US2444338A | Oscilloscope circuit | Expired / Lapsed | 1945-06-04 | 1948-06-29 | 0 | Details |
| US2444069A | System for receiving sounds in the presence of disturbing n… | Expired / Lapsed | 1945-03-02 | 1948-06-29 | 0 | Details |
| US2444078A | Trouble alarm system | Expired / Lapsed | 1942-06-10 | 1948-06-29 | 0 | Details |
| US2443638A | Regulated rectifier | Expired / Lapsed | 1946-04-18 | 1948-06-22 | 0 | Details |
| US2443643A | Wave modifying device | Expired / Lapsed | 1945-09-07 | 1948-06-22 | 0 | Details |
| US2443619A | Pulse generator of the shockexcited type | Expired / Lapsed | 1945-02-08 | 1948-06-22 | 0 | Details |
| US2443613A | Polyethylene isopropylene sebacate adhesive compositions an… | Expired / Lapsed | 1943-10-23 | 1948-06-22 | 0 | Details |
| US2443612A | Frequency selective system | Expired / Lapsed | 1943-08-17 | 1948-06-22 | 0 | Details |
| US2443623A | Data transmitting and indicating system | Expired / Lapsed | 1942-07-22 | 1948-06-22 | 0 | Details |
| US2443624A | Range computer | Expired / Lapsed | 1942-04-23 | 1948-06-22 | 0 | Details |
| US2443534A | Space discharge voltage regulation circuit | Expired / Lapsed | 1945-06-15 | 1948-06-15 | 0 | Details |
| US2443542A | Light-sensitive electric device including silicon | Expired / Lapsed | 1942-09-17 | 1948-06-15 | 0 | Details |
| US2442808A | Magnetizing fixture | Expired / Lapsed | 1946-08-27 | 1948-06-08 | 0 | Details |
| US2442752A | Method of and apparatus for examining quartz | Expired / Lapsed | 1945-04-20 | 1948-06-08 | 0 | Details |
| US2442766A | Circuit controlling switch | Expired / Lapsed | 1945-03-08 | 1948-06-08 | 0 | Details |
| US2442378A | Electron discharge device | Expired / Lapsed | 1945-09-24 | 1948-06-01 | 0 | Details |
| US2442702A | Selective signaling system | Expired / Lapsed | 1945-09-20 | 1948-06-01 | 0 | Details |
| US2442351A | Training device for object locating signaling systems | Expired / Lapsed | 1943-12-06 | 1948-06-01 | 0 | Details |
| US2442638A | Thick protective coatings on permanent magnets | Expired / Lapsed | 1943-09-01 | 1948-06-01 | 0 | Details |
| US2442330A | Methods of vulcanizing saturated linear polymers and vulcan… | Expired / Lapsed | 1943-04-30 | 1948-06-01 | 0 | Details |
| US2442662A | High-frequency translating apparatus | Expired / Lapsed | 1942-04-15 | 1948-06-01 | 0 | Details |
| US2441596A | Mechanism for adjusting the amount of travel of riders on l… | Expired / Lapsed | 1945-09-01 | 1948-05-18 | 0 | Details |
| US2441557A | Selective signaling system | Expired / Lapsed | 1945-02-08 | 1948-05-18 | 0 | Details |
| US2441598A | Wave transmission | Expired / Lapsed | 1944-06-16 | 1948-05-18 | 0 | Details |
| US2441603A | Electrical translating materials and method of making them | Expired / Lapsed | 1943-07-28 | 1948-05-18 | 0 | Details |
| US2441139A | Piezoelectric crystal mounting | Expired / Lapsed | 1946-04-29 | 1948-05-11 | 0 | Details |
| US2440270A | Electrical connector | Expired / Lapsed | 1946-07-03 | 1948-04-27 | 0 | Details |
| US2440480A | Electrical insulation testing apparatus | Expired / Lapsed | 1944-03-31 | 1948-04-27 | 0 | Details |
| US2439381A | Computing bomb sight | Expired / Lapsed | 1943-07-17 | 1948-04-13 | 0 | Details |
| US2438974A | Extruding apparatus | Expired / Lapsed | 1944-05-11 | 1948-04-06 | 0 | Details |
| US2438893A | Translating device | Expired / Lapsed | 1943-12-29 | 1948-04-06 | 0 | Details |
| US2438888A | Radio object detector training device | Expired / Lapsed | 1943-12-06 | 1948-04-06 | 0 | Details |
| US2438940A | Range and azimuth simulating system for radar instruction | Expired / Lapsed | 1943-12-06 | 1948-04-06 | 0 | Details |
| US2438897A | Method of plating contact surfaces of magnetic reeds | Expired / Lapsed | 1943-08-26 | 1948-04-06 | 0 | Details |
| US2438947A | Electronic modulation and modulation correction circuits | Expired / Lapsed | 1943-07-28 | 1948-04-06 | 0 | Details |
| US2438892A | Electrical translating materials and devices and methods of… | Expired / Lapsed | 1943-07-28 | 1948-04-06 | 0 | Details |
| US2438954A | Electronic oscillator of the cavity resonator type | Expired / Lapsed | 1941-11-12 | 1948-04-06 | 0 | Details |
| US2438492A | Signaling system | Expired / Lapsed | 1944-08-17 | 1948-03-30 | 0 | Details |
| US2438110A | Electrical translating materials and devices and method of … | Expired / Lapsed | 1943-07-28 | 1948-03-23 | 0 | Details |
| US2438112A | Bombsight computer | Expired / Lapsed | 1943-06-29 | 1948-03-23 | 0 | Details |
| US2437707A | Communication system employing pulse code modulation | Expired / Lapsed | 1945-12-27 | 1948-03-16 | 0 | Details |
| US2437695A | Three-dimension radio direction finder | Expired / Lapsed | 1943-08-30 | 1948-03-16 | 0 | Details |
| US2437268A | Intermittently operating automatic frequency control | Expired / Lapsed | 1944-10-11 | 1948-03-09 | 0 | Details |
| US2437269A | Translating device and method of making it | Expired / Lapsed | 1944-04-10 | 1948-03-09 | 0 | Details |
| US2437270A | Magnetostrictive compressional wave transmitter or receiver | Expired / Lapsed | 1943-11-05 | 1948-03-09 | 0 | Details |
| US2436809A | Electric combination lock | Expired / Lapsed | 1945-05-19 | 1948-03-02 | 0 | Details |
| US2436393A | Cathode-ray tube with discharge to deflecting plates | Expired / Lapsed | 1944-12-29 | 1948-02-24 | 0 | Details |
| US2436377A | Ultrasonic compressional wave transmission | Expired / Lapsed | 1943-12-27 | 1948-02-24 | 0 | Details |
| US2436398A | Ultra high frequency oscillator | Expired / Lapsed | 1943-08-28 | 1948-02-24 | 0 | Details |
| US2435598A | Electric pulse delay circuit | Expired / Lapsed | 1943-12-28 | 1948-02-10 | 0 | Details |
| US2435585A | High-frequency relay employing an electron discharge device | Expired / Lapsed | 1941-12-20 | 1948-02-10 | 0 | Details |
| US2435207A | Phase synchronized pulsed trigger circuit | Expired / Lapsed | 1945-09-28 | 1948-02-03 | 0 | Details |
| US2435262A | Self-modulated oscillator | Expired / Lapsed | 1944-01-26 | 1948-02-03 | 0 | Details |
| US2435195A | Data smoothing network | Expired / Lapsed | 1942-06-20 | 1948-02-03 | 0 | Details |
| US2434898A | Digit registering means responsive to selective frequencies | Expired / Lapsed | 1946-01-16 | 1948-01-27 | 0 | Details |
| US2434959A | Call transmitter for interstate telephone communication | Expired / Lapsed | 1945-09-15 | 1948-01-27 | 0 | Details |
| US2434946A | Tone supply test circuit | Expired / Lapsed | 1944-03-16 | 1948-01-27 | 0 | Details |
| US2434646A | Wave guide branching arrangement | Expired / Lapsed | 1945-09-07 | 1948-01-20 | 0 | Details |
| US2434645A | Wave guide bend | Expired / Lapsed | 1945-08-17 | 1948-01-20 | 0 | Details |
| US2434681A | Remotely controlled electrical calculator | Expired / Lapsed | 1943-02-13 | 1948-01-20 | 0 | Details |
| US2434336A | Continuity and short-circuit test set | Expired / Lapsed | 1946-05-15 | 1948-01-13 | 0 | Details |
| US2434264A | Cathode-ray oscilloscope circuit with timing marks | Expired / Lapsed | 1944-10-17 | 1948-01-13 | 0 | Details |
| US2434274A | Artillery computer | Expired / Lapsed | 1944-04-11 | 1948-01-13 | 0 | Details |
| US2434259A | Circuit arrangement utilizing a plurality of electron disch… | Expired / Lapsed | 1943-06-22 | 1948-01-13 | 0 | Details |
| US2434273A | Wave translating system | Expired / Lapsed | 1943-01-21 | 1948-01-13 | 0 | Details |
| US2433836A | Telephone call transmitter | Expired / Lapsed | 1945-04-04 | 1948-01-06 | 0 | Details |
| US2433863A | Pulse generation circuit | Expired / Lapsed | 1943-05-13 | 1948-01-06 | 0 | Details |
| US2433340A | Phase correcting arrangement for electronic type selecting … | Expired / Lapsed | 1945-07-06 | 1947-12-30 | 0 | Details |
| US2433382A | Recorder system with electromagnetically attracted electric… | Expired / Lapsed | 1944-09-11 | 1947-12-30 | 0 | Details |
| US2433385A | Submarine locating system | Expired / Lapsed | 1942-11-05 | 1947-12-30 | 0 | Details |
| US2433383A | Crystal microphone | Expired / Lapsed | 1942-06-24 | 1947-12-30 | 0 | Details |
| US2433002A | Pulse-type position indicator | Expired / Lapsed | 1944-09-29 | 1947-12-23 | 0 | Details |
| US2432984A | Electromagnetic wave reflection system | Expired / Lapsed | 1940-04-05 | 1947-12-23 | 0 | Details |
| US2432516A | Keyed pulse generator | Expired / Lapsed | 1943-12-30 | 1947-12-16 | 0 | Details |
| US2432504A | Target azimuth device | Expired / Lapsed | 1943-09-17 | 1947-12-16 | 0 | Details |
| US2432944A | Oscillograph system for testing electrical contact making d… | Expired / Lapsed | 1943-08-28 | 1947-12-16 | 0 | Details |
| US2432454A | Manual range gate for stroboscopic indicators | Expired / Lapsed | 1945-11-08 | 1947-12-09 | 0 | Details |
| US2432123A | Translation of visual symbols | Expired / Lapsed | 1945-04-05 | 1947-12-09 | 0 | Details |
| US2432134A | Directional radio system | Expired / Lapsed | 1944-06-28 | 1947-12-09 | 0 | Details |
| US2432120A | Electrical connector | Expired / Lapsed | 1943-08-25 | 1947-12-09 | 0 | Details |
| US2432116A | Crystal detector mounting | Expired / Lapsed | 1943-04-19 | 1947-12-09 | 0 | Details |
| US2432093A | Wave transmission network | Expired / Lapsed | 1942-07-30 | 1947-12-09 | 0 | Details |
| US2431692A | Alternate route telephone switching mechanism | Expired / Lapsed | 1945-05-15 | 1947-12-02 | 0 | Details |
| US2431696A | Relay desing calculator | Expired / Lapsed | 1944-08-23 | 1947-12-02 | 0 | Details |
| US2430447A | Printing telegraph automatic switching system | Expired / Lapsed | 1942-06-27 | 1947-11-11 | 0 | Details |
| US2430038A | Cathode-ray device for improving signal-to-noise ratio in r… | Expired / Lapsed | 1943-10-05 | 1947-11-04 | 0 | Details |
| US2430028A | Translating device and method of making it | Expired / Lapsed | 1943-03-16 | 1947-11-04 | 0 | Details |
| US2429933A | Image translating device | Expired / Lapsed | 1945-08-08 | 1947-10-28 | 0 | Details |
| US2429651A | Control system for two-phase induction motors | Expired / Lapsed | 1945-01-01 | 1947-10-28 | 0 | Details |
| US2429601A | Microwave radar directive antenna | Expired / Lapsed | 1943-11-22 | 1947-10-28 | 0 | Details |
| US2429236A | Analysis and representation of complex waves | Expired / Lapsed | 1945-04-05 | 1947-10-21 | 0 | Details |
| US2429229A | Analysis and representation of complex waves | Expired / Lapsed | 1945-04-04 | 1947-10-21 | 0 | Details |
| US2429216A | Electrical phase indicating apparatus | Expired / Lapsed | 1944-10-04 | 1947-10-21 | 0 | Details |
| US2429222A | Method of making contact wires | Expired / Lapsed | 1943-06-05 | 1947-10-21 | 0 | Details |
| US2428770A | Automatic dead-reckoning device | Expired / Lapsed | 1944-09-07 | 1947-10-14 | 0 | Details |
| US2428958A | Assembling apparatus | Expired / Lapsed | 1944-07-25 | 1947-10-14 | 0 | Details |
| US2428800A | Telemetric summation system | Expired / Lapsed | 1944-06-30 | 1947-10-14 | 0 | Details |
| US2428767A | Electric motor control circuits | Expired / Lapsed | 1943-09-15 | 1947-10-14 | 0 | Details |
| US2428366A | Pulse multiplex system | Expired / Lapsed | 1945-02-08 | 1947-10-07 | 0 | Details |
| US2428007A | Telephone call-indicating facilities | Expired / Lapsed | 1944-12-01 | 1947-09-30 | 0 | Details |
| US2428275A | Apparatus for molding articles | Expired / Lapsed | 1944-07-29 | 1947-09-30 | 0 | Details |
| US2428058A | Object locating and distance measuring systems of the pulse… | Expired / Lapsed | 1943-10-27 | 1947-09-30 | 0 | Details |
| US2427666A | Magnetic field strength indicator | Expired / Lapsed | 1943-04-20 | 1947-09-23 | 0 | Details |
| US2427417A | Method of manufacturing electrical resistors | Expired / Lapsed | 1945-07-14 | 1947-09-16 | 0 | Details |
| US2427348A | Piezoelectric vibrator | Expired / Lapsed | 1941-08-19 | 1947-09-16 | 0 | Details |
| US2426996A | Frequency modulation | Expired / Lapsed | 1944-08-17 | 1947-09-09 | 0 | Details |
| US2427005A | Directive microwave antenna | Expired / Lapsed | 1943-11-06 | 1947-09-09 | 0 | Details |
| US2427198A | Conductor insulated with rubber compound layers bonded toge… | Expired / Lapsed | 1942-08-18 | 1947-09-09 | 0 | Details |
| US2427196A | Bonding of vulcanizable compositions to metallic surfaces | Expired / Lapsed | 1942-08-18 | 1947-09-09 | 0 | Details |
| US2427197A | Bonding of rubber and rubberlike compositions | Expired / Lapsed | 1942-08-18 | 1947-09-09 | 0 | Details |
| US2426981A | Automatic toll ticketing alarm system | Expired / Lapsed | 1942-06-27 | 1947-09-09 | 0 | Details |
| US2426622A | Magnetic field detector | Expired / Lapsed | 1944-09-21 | 1947-09-02 | 0 | Details |
| US2426650A | Method of soldering a terminal to a piezoelectric crystal | Expired / Lapsed | 1943-12-27 | 1947-09-02 | 0 | Details |
| US2426658A | Radar tracking device | Expired / Lapsed | 1943-08-19 | 1947-09-02 | 0 | Details |
| US2426232A | Distance measuring system | Expired / Lapsed | 1944-02-05 | 1947-08-26 | 0 | Details |
| US2426182A | Time division radar ranging system | Expired / Lapsed | 1943-10-01 | 1947-08-26 | 0 | Details |
| US2426216A | Aperiodic pulse timing system | Expired / Lapsed | 1942-10-19 | 1947-08-26 | 0 | Details |
| US2426189A | Object locating system | Expired / Lapsed | 1941-10-04 | 1947-08-26 | 0 | Details |
| US2425820A | Selective system | Expired / Lapsed | 1944-02-17 | 1947-08-19 | 0 | Details |
| US2425346A | Automatic dead reckoning device | Expired / Lapsed | 1944-10-02 | 1947-08-12 | 0 | Details |
| US2425345A | Microwave transmission system | Expired / Lapsed | 1942-12-23 | 1947-08-12 | 0 | Details |
| US2425336A | Microwave directive antenna | Expired / Lapsed | 1942-12-17 | 1947-08-12 | 0 | Details |
| US2425361A | Magnetic testing apparatus | Expired / Lapsed | 1942-12-08 | 1947-08-12 | 0 | Details |
| US2425003A | Analysis and representation of complex waves | Expired / Lapsed | 1944-12-23 | 1947-08-05 | 0 | Details |
| US2424971A | Frequency-shift radio telegraph transmitting system | Expired / Lapsed | 1944-07-21 | 1947-08-05 | 0 | Details |
| US2425002A | Electrical apparatus | Expired / Lapsed | 1944-07-08 | 1947-08-05 | 0 | Details |
| US2424982A | Directional radio antenna lobe switching system | Expired / Lapsed | 1942-08-03 | 1947-08-05 | 0 | Details |
| US2424571A | Telegraph alarm system | Expired / Lapsed | 1943-09-01 | 1947-07-29 | 0 | Details |
| US2424549A | Submarine signal detector or receiver | Expired / Lapsed | 1943-07-14 | 1947-07-29 | 0 | Details |
| US2424273A | Crystal growing apparatus | Expired / Lapsed | 1945-04-13 | 1947-07-22 | 0 | Details |
| US2424246A | Frequency-modulated crystal oscillator | Expired / Lapsed | 1943-09-16 | 1947-07-22 | 0 | Details |
| US2423466A | Time division multiplex | Expired / Lapsed | 1944-08-01 | 1947-07-08 | 0 | Details |
| US2423459A | Frequency selective apparatus | Expired / Lapsed | 1942-09-15 | 1947-07-08 | 0 | Details |
| US2423437A | Direction finder | Expired / Lapsed | 1934-08-25 | 1947-07-08 | 0 | Details |
| US2423125A | Photoelectromotive force cell of the silicon-silicon oxide … | Expired / Lapsed | 1944-05-16 | 1947-07-01 | 0 | Details |
| US2423130A | Switching device in wave guide transmission system | Expired / Lapsed | 1944-03-25 | 1947-07-01 | 0 | Details |
| US2422697A | Viewing system | Expired / Lapsed | 1944-11-15 | 1947-06-24 | 0 | Details |
| US2422664A | Wobbled radio carrier communication system | Expired / Lapsed | 1944-07-12 | 1947-06-24 | 0 | Details |
| US2422655A | Time measuring system | Expired / Lapsed | 1943-09-16 | 1947-06-24 | 0 | Details |
| US2422654A | Time measuring system | Expired / Lapsed | 1943-08-19 | 1947-06-24 | 0 | Details |
| US2422698A | Time measuring system | Expired / Lapsed | 1942-11-05 | 1947-06-24 | 0 | Details |
| US2422191A | Impedance transformer for wave guides | Expired / Lapsed | 1945-08-25 | 1947-06-17 | 0 | Details |
| US2422184A | Directional microwave antenna | Expired / Lapsed | 1944-01-15 | 1947-06-17 | 0 | Details |
| US2422205A | Range indicator | Expired / Lapsed | 1943-10-05 | 1947-06-17 | 0 | Details |
| US2422212A | Adjustable step-by-step motor | Expired / Lapsed | 1943-10-02 | 1947-06-17 | 0 | Details |
| US2422204A | Range indicator | Expired / Lapsed | 1943-06-22 | 1947-06-17 | 0 | Details |
| US2421970A | Earth boring machine | Expired / Lapsed | 1944-07-11 | 1947-06-10 | 0 | Details |
| US2421919A | Telephone routing system | Expired / Lapsed | 1944-04-29 | 1947-06-10 | 0 | Details |
| US2421973A | Article assembling fixture | Expired / Lapsed | 1943-10-19 | 1947-06-10 | 0 | Details |
| US2421747A | Object locating system | Expired / Lapsed | 1943-07-14 | 1947-06-10 | 0 | Details |
| US2421026A | Delay device | Expired / Lapsed | 1943-07-08 | 1947-05-27 | 0 | Details |
| US2420671A | Magnetic recorder | Expired / Lapsed | 1944-10-27 | 1947-05-20 | 0 | Details |
| US2420342A | High frequency continuous amplifier | Expired / Lapsed | 1943-03-18 | 1947-05-13 | 0 | Details |
| US2419583A | Testing and indicating system | Expired / Lapsed | 1945-01-20 | 1947-04-29 | 0 | Details |
| US2419537A | Resistor | Expired / Lapsed | 1944-09-09 | 1947-04-29 | 0 | Details |
| US2419201A | Pulse generator | Expired / Lapsed | 1943-11-30 | 1947-04-22 | 0 | Details |
| US2419205A | Directive antenna system | Expired / Lapsed | 1942-11-04 | 1947-04-22 | 0 | Details |
| US2418809A | Wave transmission system | Expired / Lapsed | 1943-08-25 | 1947-04-15 | 0 | Details |
| US2418842A | Scanning oscillator | Expired / Lapsed | 1943-03-04 | 1947-04-15 | 0 | Details |
| US2418932A | Method of making enamel coated articles | Expired / Lapsed | 1940-11-13 | 1947-04-15 | 0 | Details |
| US2418469A | Tuner for multiresonators | Expired / Lapsed | 1944-05-04 | 1947-04-08 | 0 | Details |
| US2418460A | Resistor | Expired / Lapsed | 1943-12-31 | 1947-04-08 | 0 | Details |
| US2418117A | Electron discharge device | Expired / Lapsed | 1944-05-29 | 1947-04-01 | 0 | Details |
| US2418136A | Acoustic range finder | Expired / Lapsed | 1943-11-10 | 1947-04-01 | 0 | Details |
| US2418133A | Cathode-ray apparatus and method of controlling the ray | Expired / Lapsed | 1943-06-18 | 1947-04-01 | 0 | Details |
| US2417831A | Counting relay system | Expired / Lapsed | 1943-09-03 | 1947-03-25 | 0 | Details |
| US2417829A | Compressional wave signaling device | Expired / Lapsed | 1942-12-31 | 1947-03-25 | 0 | Details |
| US2417420A | Terminal block | Expired / Lapsed | 1944-11-29 | 1947-03-18 | 0 | Details |
| US2417427A | Counting circuit | Expired / Lapsed | 1943-08-21 | 1947-03-18 | 0 | Details |
| US2417446A | Stereotelevision and television range finding | Expired / Lapsed | 1941-08-01 | 1947-03-18 | 0 | Details |
| US2416692A | Impulse transmitter | Expired / Lapsed | 1945-09-11 | 1947-03-04 | 0 | Details |
| US2416683A | Wave transmission network | Expired / Lapsed | 1944-10-26 | 1947-03-04 | 0 | Details |
| US2416699A | Station selector system | Expired / Lapsed | 1942-12-08 | 1947-03-04 | 0 | Details |
| US2416718A | Pulse generator | Expired / Lapsed | 1942-10-01 | 1947-03-04 | 0 | Details |
| US2416698A | Radiation and reception of microwaves | Expired / Lapsed | 1942-05-25 | 1947-03-04 | 0 | Details |
| US2416675A | Horn antenna system | Expired / Lapsed | 1941-11-26 | 1947-03-04 | 0 | Details |
| US2416338A | Frequency selective system | Expired / Lapsed | 1945-04-11 | 1947-02-25 | 0 | Details |
| US2416297A | Wave transmission network | Expired / Lapsed | 1944-10-26 | 1947-02-25 | 0 | Details |
| US2416320A | Cathode-ray tube circuit | Expired / Lapsed | 1944-02-24 | 1947-02-25 | 0 | Details |
| US2416298A | Magnetron and control | Expired / Lapsed | 1942-11-02 | 1947-02-25 | 0 | Details |
| US2416290A | Cathode-ray oscilloscope circuit | Expired / Lapsed | 1942-10-02 | 1947-02-25 | 0 | Details |
| US2416283A | Ultra high frequency electronic device | Expired / Lapsed | 1942-07-03 | 1947-02-25 | 0 | Details |
| US2416346A | Visual reception of radio waves | Expired / Lapsed | 1942-04-14 | 1947-02-25 | 0 | Details |
| US2416351A | Position locating system | Expired / Lapsed | 1942-04-03 | 1947-02-25 | 0 | Details |
| US2415841A | Conducting material and device and method of making them | Expired / Lapsed | 1944-12-14 | 1947-02-18 | 0 | Details |
| US2415832A | Radiation absorber | Expired / Lapsed | 1942-12-31 | 1947-02-18 | 0 | Details |
| US2415405A | Stabilizing circuit for synchronous motors | Expired / Lapsed | 1944-04-12 | 1947-02-11 | 0 | Details |
| US2415089A | Microwave antennas | Expired / Lapsed | 1942-05-28 | 1947-02-04 | 0 | Details |
| US2414792A | Bolometric thermistor | Expired / Lapsed | 1945-06-29 | 1947-01-28 | 0 | Details |
| US2414819A | Computer for ballistic interactions | Expired / Lapsed | 1944-12-29 | 1947-01-28 | 0 | Details |
| US2414798A | Direction finder | Expired / Lapsed | 1941-06-28 | 1947-01-28 | 0 | Details |
| US2414443A | Time measuring device | Expired / Lapsed | 1945-03-02 | 1947-01-21 | 0 | Details |
| US2414486A | Sweep control circuits | Expired / Lapsed | 1943-11-30 | 1947-01-21 | 0 | Details |
| US2414477A | Indicating apparatus | Expired / Lapsed | 1943-10-05 | 1947-01-21 | 0 | Details |
| US2414624A | Apparatus for testing transmission lines | Expired / Lapsed | 1943-05-15 | 1947-01-21 | 0 | Details |
| US2414479A | Impulse generator | Expired / Lapsed | 1942-11-05 | 1947-01-21 | 0 | Details |
| US2414085A | Oscillator | Expired / Lapsed | 1944-12-14 | 1947-01-14 | 0 | Details |
| US2414242A | Voltage regulation | Expired / Lapsed | 1944-07-14 | 1947-01-14 | 0 | Details |
| US2414096A | Scanning system | Expired / Lapsed | 1944-02-04 | 1947-01-14 | 0 | Details |
| US2414115A | Wave filter | Expired / Lapsed | 1943-08-19 | 1947-01-14 | 0 | Details |
| US2414084A | Tunable resonator and oscillator | Expired / Lapsed | 1943-05-11 | 1947-01-14 | 0 | Details |
| US2414121A | Electron device of the magnetron type | Expired / Lapsed | 1941-01-17 | 1947-01-14 | 0 | Details |
| US2413715A | Retractile cord | Expired / Lapsed | 1943-10-15 | 1947-01-07 | 0 | Details |
| US2413689A | Electron discharge device | Expired / Lapsed | 1942-02-12 | 1947-01-07 | 0 | Details |
| US2413033A | Voltage regulated rectifying system | Expired / Lapsed | 1942-07-29 | 1946-12-24 | 0 | Details |
| US2412642A | Electronic telegraph transmitter distributor | Expired / Lapsed | 1943-08-25 | 1946-12-17 | 0 | Details |
| US2412231A | Electronic tube testing apparatus | Expired / Lapsed | 1942-10-28 | 1946-12-10 | 0 | Details |
| US2412210A | Cathode-ray sweep circuit | Expired / Lapsed | 1942-03-21 | 1946-12-10 | 0 | Details |
| US2412202A | Directive radio system | Expired / Lapsed | 1941-06-28 | 1946-12-10 | 0 | Details |
| US2412227A | Electrical differentiator | Expired / Lapsed | 1941-05-01 | 1946-12-10 | 0 | Details |
| US2411898A | Pulse generator | Expired / Lapsed | 1944-04-21 | 1946-12-03 | 0 | Details |
| US2411531A | Electro-optical control system | Expired / Lapsed | 1944-10-20 | 1946-11-26 | 0 | Details |
| US2411537A | Submarine signaling system | Expired / Lapsed | 1944-01-28 | 1946-11-26 | 0 | Details |
| US2411534A | Impedance transformer | Expired / Lapsed | 1943-03-30 | 1946-11-26 | 0 | Details |
| US2410825A | Piezoelectric crystal apparatus | Expired / Lapsed | 1943-03-04 | 1946-11-12 | 0 | Details |
| US2410840A | Electron beam modulator | Expired / Lapsed | 1942-05-06 | 1946-11-12 | 0 | Details |
| US2410434A | Telephone | Expired / Lapsed | 1942-11-25 | 1946-11-05 | 0 | Details |
| US2409620A | Oscillation generator | Expired / Lapsed | 1942-01-17 | 1946-10-22 | 0 | Details |
| US2409608A | Ultra high frequency detector | Expired / Lapsed | 1941-09-24 | 1946-10-22 | 0 | Details |
| US2409222A | Electron discharge device | Expired / Lapsed | 1941-07-19 | 1946-10-15 | 0 | Details |
| US2408843A | Electrical connector | Expired / Lapsed | 1943-12-01 | 1946-10-08 | 0 | Details |
| US2409151A | Electrical regulating device | Expired / Lapsed | 1943-02-02 | 1946-10-08 | 0 | Details |
| US2408794A | Carrier wave signal system | Expired / Lapsed | 1942-10-20 | 1946-10-08 | 0 | Details |
| US2408433A | Telephone system | Expired / Lapsed | 1943-02-13 | 1946-10-01 | 0 | Details |
| US2408437A | Harmonic generating system | Expired / Lapsed | 1941-10-11 | 1946-10-01 | 0 | Details |
| US2408409A | Ultra high frequency electronic device | Expired / Lapsed | 1941-04-08 | 1946-10-01 | 0 | Details |
| US2408435A | Pipe antenna and prism | Expired / Lapsed | 1941-03-01 | 1946-10-01 | 0 | Details |
| US2408423A | High frequency amplifying apparatus | Expired / Lapsed | 1941-02-05 | 1946-10-01 | 0 | Details |
| US2408093A | Method of making wire-wound cardtype resistance devices | Expired / Lapsed | 1944-01-24 | 1946-09-24 | 0 | Details |
| US2408085A | Communication system | Expired / Lapsed | 1943-07-23 | 1946-09-24 | 0 | Details |
| US2408108A | Television image production | Expired / Lapsed | 1943-05-11 | 1946-09-24 | 0 | Details |
| US2408033A | Coupling system | Expired / Lapsed | 1942-03-17 | 1946-09-24 | 0 | Details |
| US2408086A | Impulse system | Expired / Lapsed | 1941-06-05 | 1946-09-24 | 0 | Details |
| US2408081A | Artillery predictor | Expired / Lapsed | 1941-05-01 | 1946-09-24 | 0 | Details |
| US2407667A | Harmonic generator | Expired / Lapsed | 1941-09-30 | 1946-09-17 | 0 | Details |
| US2407649A | Direction finding system | Expired / Lapsed | 1941-07-23 | 1946-09-17 | 0 | Details |
| US2407690A | Wave guide electrotherapeutic system | Expired / Lapsed | 1941-05-16 | 1946-09-17 | 0 | Details |
| US2407293A | Frequency modulation | Expired / Lapsed | 1944-07-26 | 1946-09-10 | 0 | Details |
| US2407298A | Electron discharge apparatus | Expired / Lapsed | 1942-12-15 | 1946-09-10 | 0 | Details |
| US2407286A | Communication system | Expired / Lapsed | 1942-11-07 | 1946-09-10 | 0 | Details |
| US2407320A | Electronic counter | Expired / Lapsed | 1942-11-05 | 1946-09-10 | 0 | Details |
| US2407325A | Range converter | Expired / Lapsed | 1942-04-23 | 1946-09-10 | 0 | Details |
| US2407260A | Privacy system | Expired / Lapsed | 1941-07-19 | 1946-09-10 | 0 | Details |
| US2407259A | Transmission control in signaling systems | Expired / Lapsed | 1941-07-09 | 1946-09-10 | 0 | Details |
| US2407251A | Resistor | Expired / Lapsed | 1941-06-28 | 1946-09-10 | 0 | Details |
| US2407274A | Ultra high frequency electronic device | Expired / Lapsed | 1941-04-16 | 1946-09-10 | 0 | Details |
| US2406787A | Telegraph system | Expired / Lapsed | 1943-04-07 | 1946-09-03 | 0 | Details |
| US2406850A | Electron discharge apparatus | Expired / Lapsed | 1941-04-11 | 1946-09-03 | 0 | Details |
| US2406350A | Switching mechanism for signal systems | Expired / Lapsed | 1944-07-25 | 1946-08-27 | 0 | Details |
| US2406353A | Secret signaling | Expired / Lapsed | 1943-07-17 | 1946-08-27 | 0 | Details |
| US2406384A | Data transmission system | Expired / Lapsed | 1942-11-05 | 1946-08-27 | 0 | Details |
| US2406349A | Secret signaling | Expired / Lapsed | 1942-07-10 | 1946-08-27 | 0 | Details |
| US2406391A | Compressional wave directional, prismatic, and focusing sys… | Expired / Lapsed | 1942-01-06 | 1946-08-27 | 0 | Details |
| US2406402A | Frequency adjustment of resonant cavities | Expired / Lapsed | 1941-09-03 | 1946-08-27 | 0 | Details |
| US2406348A | Secret telephony | Expired / Lapsed | 1941-07-26 | 1946-08-27 | 0 | Details |
| US2406023A | Teletypewriter signal enciphering system | Expired / Lapsed | 1944-03-25 | 1946-08-20 | 0 | Details |
| US2405992A | Directive antenna system | Expired / Lapsed | 1944-01-19 | 1946-08-20 | 0 | Details |
| US2406032A | Telegraph signal enciphering mechanism | Expired / Lapsed | 1942-11-23 | 1946-08-20 | 0 | Details |
| US2406031A | Telegraph ciphering key tape machine | Expired / Lapsed | 1942-05-21 | 1946-08-20 | 0 | Details |
| US2406046A | Telegraph signal enciphering key tape producing device | Expired / Lapsed | 1942-05-21 | 1946-08-20 | 0 | Details |
| US2406021A | Sealed reed contact device | Expired / Lapsed | 1941-07-01 | 1946-08-20 | 0 | Details |
| US2405591A | Training device | Expired / Lapsed | 1943-12-27 | 1946-08-13 | 0 | Details |
| US2405604A | Compressional wave translating device | Expired / Lapsed | 1943-03-13 | 1946-08-13 | 0 | Details |
| US2405597A | Frequency measuring system | Expired / Lapsed | 1942-11-05 | 1946-08-13 | 0 | Details |
| US2405569A | Cryptographic telegraph system | Expired / Lapsed | 1942-03-18 | 1946-08-13 | 0 | Details |
| US2405599A | Privacy system | Expired / Lapsed | 1941-09-24 | 1946-08-13 | 0 | Details |
| US2405180A | Insulator | Expired / Lapsed | 1944-03-04 | 1946-08-06 | 0 | Details |
| US2405226A | Low frequency projector or hydrophone | Expired / Lapsed | 1942-12-28 | 1946-08-06 | 0 | Details |
| US2405225A | Submarine signal system | Expired / Lapsed | 1942-10-14 | 1946-08-06 | 0 | Details |
| US2405211A | Communication system | Expired / Lapsed | 1942-07-16 | 1946-08-06 | 0 | Details |
| US2405231A | Aircraft blind landing system | Expired / Lapsed | 1942-03-31 | 1946-08-06 | 0 | Details |
| US2405242A | Microwave radio transmission | Expired / Lapsed | 1941-11-28 | 1946-08-06 | 0 | Details |
| US2404786A | Moisture control in an electromechanical device | Expired / Lapsed | 1942-09-15 | 1946-07-30 | 0 | Details |
| US2404799A | Submarine signal device | Expired / Lapsed | 1942-07-03 | 1946-07-30 | 0 | Details |
| US2404387A | Electrical computing system | Expired / Lapsed | 1941-05-01 | 1946-07-23 | 0 | Details |
| US2403984A | Representation of complex waves | Expired / Lapsed | 1945-04-03 | 1946-07-16 | 0 | Details |
| US2403983A | Representation of complex waves | Expired / Lapsed | 1945-04-03 | 1946-07-16 | 0 | Details |
| US2403985A | Sound reproduction | Expired / Lapsed | 1945-04-03 | 1946-07-16 | 0 | Details |
| US2403982A | Analysis and representation of complex waves | Expired / Lapsed | 1944-12-19 | 1946-07-16 | 0 | Details |
| US2403990A | Compressional wave radiator | Expired / Lapsed | 1942-08-01 | 1946-07-16 | 0 | Details |
| US2403997A | Representation of complex waves | Expired / Lapsed | 1942-04-14 | 1946-07-16 | 0 | Details |
| US2403009A | Pulse generating system and its use in signal transmission … | Expired / Lapsed | 1943-07-31 | 1946-07-02 | 0 | Details |
| US2402985A | Magnetic recorder | Expired / Lapsed | 1942-07-07 | 1946-07-02 | 0 | Details |
| US2403023A | Television follower apparatus | Expired / Lapsed | 1941-08-28 | 1946-07-02 | 0 | Details |
| US2402663A | Thermoelectric device | Expired / Lapsed | 1942-04-11 | 1946-06-25 | 0 | Details |
| US2402662A | Light-sensitive electric device | Expired / Lapsed | 1941-05-27 | 1946-06-25 | 0 | Details |
| US2402839A | Electrical translating device utilizing silicon | Expired / Lapsed | 1941-03-27 | 1946-06-25 | 0 | Details |
| US2402661A | Alternating current rectifier | Expired / Lapsed | 1941-03-01 | 1946-06-25 | 0 | Details |
| US2402700A | Telephone system | Expired / Lapsed | 1940-05-22 | 1946-06-25 | 0 | Details |
| US2401759A | Directionally selective radio communication system | Expired / Lapsed | 1944-03-22 | 1946-06-11 | 0 | Details |
| US2401751A | Coupling system | Expired / Lapsed | 1942-03-17 | 1946-06-11 | 0 | Details |
| US2401779A | Summing amplifier | Expired / Lapsed | 1941-05-01 | 1946-06-11 | 0 | Details |
| US2400893A | Process of carbiding | Expired / Lapsed | 1944-04-24 | 1946-05-28 | 0 | Details |
| US2400574A | Start-stop receiving selector mechanism | Expired / Lapsed | 1943-12-11 | 1946-05-21 | 0 | Details |
| US2400148A | Telephone call transmitting device | Expired / Lapsed | 1943-06-23 | 1946-05-14 | 0 | Details |
| US2399754A | Cathode-ray apparatus | Expired / Lapsed | 1943-01-09 | 1946-05-07 | 0 | Details |
| US2399213A | Timing circuit | Expired / Lapsed | 1944-07-18 | 1946-04-30 | 0 | Details |
| US2398449A | Method of making hermetic seals | Expired / Lapsed | 1941-07-09 | 1946-04-16 | 0 | Details |
| US2397829A | Telephone system | Expired / Lapsed | 1944-09-26 | 1946-04-02 | 0 | Details |
| US2397830A | Harmonic control system | Expired / Lapsed | 1943-07-01 | 1946-04-02 | 0 | Details |
| US2397884A | Frequency diversity telegraph system | Expired / Lapsed | 1943-06-30 | 1946-04-02 | 0 | Details |
| US2396990A | Automatic line testing and switching circuits | Expired / Lapsed | 1943-12-09 | 1946-03-19 | 0 | Details |
| US2397052A | Soldering apparatus | Expired / Lapsed | 1943-09-02 | 1946-03-19 | 0 | Details |
| US2396211A | Selective calling signal device | Expired / Lapsed | 1942-09-16 | 1946-03-05 | 0 | Details |
| US2396044A | Switching device | Expired / Lapsed | 1941-12-10 | 1946-03-05 | 0 | Details |
| US2396187A | Electric recorder | Expired / Lapsed | 1939-09-29 | 1946-03-05 | 0 | Details |
| US2395477A | Motor-control circuit | Expired / Lapsed | 1944-06-30 | 1946-02-26 | 0 | Details |
| US2395539A | Telephone call transmitter | Expired / Lapsed | 1943-12-31 | 1946-02-26 | 0 | Details |
| US2395743A | Method of making dry rectifiers | Expired / Lapsed | 1942-12-22 | 1946-02-26 | 0 | Details |
| US2395515A | Frequency detecting network | Expired / Lapsed | 1942-11-21 | 1946-02-26 | 0 | Details |
| US2395517A | Speed control system for electric motors | Expired / Lapsed | 1942-11-21 | 1946-02-26 | 0 | Details |
| US2395575A | System for the transmission of motion | Expired / Lapsed | 1942-11-02 | 1946-02-26 | 0 | Details |
| US2395560A | Wave guide | Expired / Lapsed | 1940-10-19 | 1946-02-26 | 0 | Details |
| US2395299A | Electron discharge apparatus | Expired / Lapsed | 1944-06-29 | 1946-02-19 | 0 | Details |
| US2395259A | Method of making dry rectifiers | Expired / Lapsed | 1942-10-24 | 1946-02-19 | 0 | Details |
| US2394837A | Apparatus for assembling articles | Expired / Lapsed | 1943-02-24 | 1946-02-12 | 0 | Details |
| US2393236A | Subscribers' line testing system | Expired / Lapsed | 1944-09-15 | 1946-01-22 | 0 | Details |
| US2393548A | Winding machine | Expired / Lapsed | 1944-09-01 | 1946-01-22 | 0 | Details |
| US2393243A | Strand handling apparatus and a method of handling strands | Expired / Lapsed | 1943-10-06 | 1946-01-22 | 0 | Details |
| US2393355A | Method of forming solderless electrical conductor connectio… | Expired / Lapsed | 1942-10-10 | 1946-01-22 | 0 | Details |
| US2392429A | Piezoelectric crystal apparatus | Expired / Lapsed | 1944-03-28 | 1946-01-08 | 0 | Details |
| US2392434A | Voltage regulator | Expired / Lapsed | 1943-09-17 | 1946-01-08 | 0 | Details |
| US2392350A | Ultrasonic cell | Expired / Lapsed | 1942-12-02 | 1946-01-08 | 0 | Details |
| US2392311A | Sealing of metallic members in molded casings | Expired / Lapsed | 1942-09-26 | 1946-01-08 | 0 | Details |
| US2392356A | Telegraph system | Expired / Lapsed | 1941-05-31 | 1946-01-08 | 0 | Details |
| US2392089A | Switching system | Expired / Lapsed | 1944-06-23 | 1946-01-01 | 0 | Details |
| US2391967A | Wave generator | Expired / Lapsed | 1943-01-27 | 1946-01-01 | 0 | Details |
| US2391687A | Stabilization of electric condensers | Expired / Lapsed | 1941-01-09 | 1945-12-25 | 0 | Details |
| US2391280A | Method of forming layers for electronic cathodes | Expired / Lapsed | 1942-11-26 | 1945-12-18 | 0 | Details |
| US2390863A | Method of making electromagnetic cores | Expired / Lapsed | 1941-10-09 | 1945-12-11 | 0 | Details |
| US2389725A | Method of and apparatus for applying material to advancing … | Expired / Lapsed | 1941-05-31 | 1945-11-27 | 0 | Details |
| US2389082A | Code calling signal | Expired / Lapsed | 1943-10-14 | 1945-11-13 | 0 | Details |
| US2388662A | Liquid measuring apparatus | Expired / Lapsed | 1941-12-09 | 1945-11-13 | 0 | Details |
| US2388598A | Method of making coils | Expired / Lapsed | 1943-11-12 | 1945-11-06 | 0 | Details |
| US2387719A | Key-equipped telephone set | Expired / Lapsed | 1942-03-28 | 1945-10-30 | 0 | Details |
| US2387652A | Signal transmission system | Expired / Lapsed | 1942-10-01 | 1945-10-23 | 0 | Details |
| US2387017A | Electric switch | Expired / Lapsed | 1942-08-22 | 1945-10-16 | 0 | Details |
| US2386903A | Temperature control apparatus | Expired / Lapsed | 1941-07-31 | 1945-10-16 | 0 | Details |
| US2386763A | Record controlled system | Expired / Lapsed | 1940-08-07 | 1945-10-16 | 0 | Details |
| US2386515A | Two-way carrier wave signal transmission system | Expired / Lapsed | 1944-12-30 | 1945-10-09 | 0 | Details |
| US2386638A | Power plant | Expired / Lapsed | 1944-02-09 | 1945-10-09 | 0 | Details |
| US2385265A | Substation circuit | Expired / Lapsed | 1944-01-26 | 1945-09-18 | 0 | Details |
| US2385279A | Distant talking loud-speaker telephone system | Expired / Lapsed | 1943-01-27 | 1945-09-18 | 0 | Details |
| US2385061A | Communication system | Expired / Lapsed | 1943-01-01 | 1945-09-18 | 0 | Details |
| US2384456A | Radio receiving system | Expired / Lapsed | 1944-05-23 | 1945-09-11 | 0 | Details |
| US2384575A | Tape dispenser | Expired / Lapsed | 1943-12-04 | 1945-09-11 | 0 | Details |
| US2384379A | Electrical impulse counting circuits | Expired / Lapsed | 1943-03-13 | 1945-09-04 | 0 | Details |
| US2383826A | Line usage recorder circuit | Expired / Lapsed | 1944-03-21 | 1945-08-28 | 0 | Details |
| US2382994A | Electric maneuvering board | Expired / Lapsed | 1943-12-11 | 1945-08-21 | 0 | Details |
| US2382200A | Molding apparatus | Expired / Lapsed | 1944-02-22 | 1945-08-14 | 0 | Details |
| US2381920A | Telemetric device | Expired / Lapsed | 1944-02-17 | 1945-08-14 | 0 | Details |
| US2382251A | Telegraph perforator-transmitter | Expired / Lapsed | 1943-08-25 | 1945-08-14 | 0 | Details |
| US2381978A | Impulse transmitter | Expired / Lapsed | 1943-08-05 | 1945-08-14 | 0 | Details |
| US2382024A | Resistor and method of making it | Expired / Lapsed | 1943-04-24 | 1945-08-14 | 0 | Details |
| US2382863A | Article handling apparatus | Expired / Lapsed | 1943-03-02 | 1945-08-14 | 0 | Details |
| US2381871A | Communication system | Expired / Lapsed | 1941-03-15 | 1945-08-14 | 0 | Details |
| US2380982A | Electronic commutation of currents | Expired / Lapsed | 1942-11-12 | 1945-08-07 | 0 | Details |
| US2380422A | Strand coating apparatus | Expired / Lapsed | 1943-01-09 | 1945-07-31 | 0 | Details |
| US2379982A | Truck | Expired / Lapsed | 1943-11-12 | 1945-07-10 | 0 | Details |
| US2379942A | Cable terminating means | Expired / Lapsed | 1942-12-31 | 1945-07-10 | 0 | Details |
| US2379947A | Testing device | Expired / Lapsed | 1942-09-09 | 1945-07-10 | 0 | Details |
| US2379694A | Stabilized oscillator | Expired / Lapsed | 1943-10-07 | 1945-07-03 | 0 | Details |
| US2379457A | Variable inductive device | Expired / Lapsed | 1942-12-30 | 1945-07-03 | 0 | Details |
| US2379715A | Communication system | Expired / Lapsed | 1942-10-09 | 1945-07-03 | 0 | Details |
| US2379768A | Transmission control in two-way signaling system | Expired / Lapsed | 1942-10-01 | 1945-07-03 | 0 | Details |
| US2379744A | Electric circuit arrangement employing delay networks | Expired / Lapsed | 1942-03-31 | 1945-07-03 | 0 | Details |
| US2379069A | Automatic line testing and switching circuits | Expired / Lapsed | 1943-07-24 | 1945-06-26 | 0 | Details |
| US2379055A | Signal wave transmission system | Expired / Lapsed | 1943-05-12 | 1945-06-26 | 0 | Details |
| US2379262A | Electric control circuit | Expired / Lapsed | 1943-03-31 | 1945-06-26 | 0 | Details |
| US2379221A | Communication system | Expired / Lapsed | 1942-10-09 | 1945-06-26 | 0 | Details |
| US2379047A | Bridging conductor | Expired / Lapsed | 1942-05-01 | 1945-06-26 | 0 | Details |
| US2376395A | Electron switching means and circuit | Expired / Lapsed | 1943-03-05 | 1945-05-22 | 0 | Details |
| US2375791A | Telephone station circuit | Expired / Lapsed | 1943-03-09 | 1945-05-15 | 0 | Details |
| US2376232A | Testing device | Expired / Lapsed | 1942-09-09 | 1945-05-15 | 0 | Details |
| US2375273A | Electric oscillation generating circuit including a thermor… | Expired / Lapsed | 1941-07-31 | 1945-05-08 | 0 | Details |
| US2375272A | Electric cable | Expired / Lapsed | 1941-02-15 | 1945-05-08 | 0 | Details |
| US2373816A | Continuous vulcanization process and apparatus | Expired / Lapsed | 1942-02-12 | 1945-04-17 | 0 | Details |
| US2373208A | Voltage regulation | Expired / Lapsed | 1943-03-02 | 1945-04-10 | 0 | Details |
| US2373624A | Negative resistance loading | Expired / Lapsed | 1943-01-27 | 1945-04-10 | 0 | Details |
| US2373569A | Wave translating system | Expired / Lapsed | 1943-01-23 | 1945-04-10 | 0 | Details |
| US2373160A | Resistor having a high temperature coefficient of resistance | Expired / Lapsed | 1943-01-07 | 1945-04-10 | 0 | Details |
| US2373134A | Signaling system | Expired / Lapsed | 1942-08-06 | 1945-04-10 | 0 | Details |
| US2373396A | Electron discharge device | Expired / Lapsed | 1942-04-04 | 1945-04-10 | 0 | Details |
| US2373383A | Self-regulating rectifier | Expired / Lapsed | 1941-06-28 | 1945-04-10 | 0 | Details |
| US2372193A | Producing and transmitting electromagnetic waves | Expired / Lapsed | 1940-06-05 | 1945-03-27 | 0 | Details |
| US2371972A | Signaling system | Expired / Lapsed | 1944-02-22 | 1945-03-20 | 0 | Details |
| US2371613A | Piezoelectric crystal apparatus | Expired / Lapsed | 1942-12-31 | 1945-03-20 | 0 | Details |
| US2370712A | Automatic toll ticketing system | Expired / Lapsed | 1943-01-27 | 1945-03-06 | 0 | Details |
| US2370727A | Time measuring system | Expired / Lapsed | 1942-12-11 | 1945-03-06 | 0 | Details |
| US2370685A | Electrical timing circuit | Expired / Lapsed | 1942-02-28 | 1945-03-06 | 0 | Details |
| US2370736A | Telephone system | Expired / Lapsed | 1940-03-13 | 1945-03-06 | 0 | Details |
| US2370385A | Method of acoustic measurement and apparatus therefor | Expired / Lapsed | 1942-11-17 | 1945-02-27 | 0 | Details |
| US2370221A | Electric wave circuits | Expired / Lapsed | 1942-07-22 | 1945-02-27 | 0 | Details |
| US2370403A | Telephone system | Expired / Lapsed | 1941-10-15 | 1945-02-27 | 0 | Details |
| US2369935A | Automatic telegraph transmitter system | Expired / Lapsed | 1942-05-14 | 1945-02-20 | 0 | Details |
| US2369663A | Synchronizing system | Expired / Lapsed | 1942-02-28 | 1945-02-20 | 0 | Details |
| US2369808A | Short-wave radio transmission | Expired / Lapsed | 1940-06-08 | 1945-02-20 | 0 | Details |
| US2369561A | Coating apparatus | Expired / Lapsed | 1942-12-23 | 1945-02-13 | 0 | Details |
| US2369291A | Molding | Expired / Lapsed | 1942-09-29 | 1945-02-13 | 0 | Details |
| US2369619A | Relay testing system | Expired / Lapsed | 1942-05-07 | 1945-02-13 | 0 | Details |
| US2369070A | Signal for electric bridge measurements | Expired / Lapsed | 1943-12-14 | 1945-02-06 | 0 | Details |
| US2369030A | Amplifier circuit | Expired / Lapsed | 1942-07-07 | 1945-02-06 | 0 | Details |
| US2369062A | Automatic toll ticketing system | Expired / Lapsed | 1942-06-27 | 1945-02-06 | 0 | Details |
| US2369045A | Electric heating unit | Expired / Lapsed | 1942-01-01 | 1945-02-06 | 0 | Details |
| US2367728A | Balanced cathode ray sweep circuit | Expired / Lapsed | 1943-02-24 | 1945-01-23 | 0 | Details |
| US2368060A | Coating of electron discharge device parts | Expired / Lapsed | 1942-01-01 | 1945-01-23 | 0 | Details |
| US2368031A | Electron discharge device | Expired / Lapsed | 1940-03-15 | 1945-01-23 | 0 | Details |
| US2367509A | High or low voltage detector | Expired / Lapsed | 1943-02-20 | 1945-01-16 | 0 | Details |
| US2367522A | Signaling system | Expired / Lapsed | 1942-10-02 | 1945-01-16 | 0 | Details |
| US2367513A | Testing apparatus | Expired / Lapsed | 1942-05-30 | 1945-01-16 | 0 | Details |
| US2366954A | Method of making piezoelectric crystals | Expired / Lapsed | 1943-01-09 | 1945-01-09 | 0 | Details |
| US2367042A | Signaling apparatus | Expired / Lapsed | 1941-12-23 | 1945-01-09 | 0 | Details |
| US2366733A | Communication system | Expired / Lapsed | 1941-08-28 | 1945-01-09 | 0 | Details |
| US2365277A | Material handling apparatus | Expired / Lapsed | 1943-05-06 | 1944-12-19 | 0 | Details |
| US2364771A | Telephone signaling system | Expired / Lapsed | 1942-05-28 | 1944-12-12 | 0 | Details |
| US2364446A | Card translator | Expired / Lapsed | 1944-01-18 | 1944-12-05 | 0 | Details |
| US2364190A | Measuring system and circuit | Expired / Lapsed | 1941-10-29 | 1944-12-05 | 0 | Details |
| US2363671A | Telephone system | Expired / Lapsed | 1942-12-31 | 1944-11-28 | 0 | Details |
| US2363583A | Two-way radio communication | Expired / Lapsed | 1942-12-16 | 1944-11-28 | 0 | Details |
| US2363659A | Electric circuit | Expired / Lapsed | 1942-01-31 | 1944-11-28 | 0 | Details |
| US2363781A | Apparatus for and method of applying metallic coatings by t… | Expired / Lapsed | 1940-08-29 | 1944-11-28 | 0 | Details |
| US2363208A | Control device | Expired / Lapsed | 1942-11-12 | 1944-11-21 | 0 | Details |
| US2363062A | Signaling system | Expired / Lapsed | 1941-11-26 | 1944-11-21 | 0 | Details |
| US2362898A | Signal transmission system | Expired / Lapsed | 1942-03-18 | 1944-11-14 | 0 | Details |
| US2361990A | Vibration analyzer | Expired / Lapsed | 1943-04-15 | 1944-11-07 | 0 | Details |
| US2362079A | Conveyer apparatus | Expired / Lapsed | 1942-12-12 | 1944-11-07 | 0 | Details |
| US2362228A | Method of forming contacts on metal oxide-metal rectifiers | Expired / Lapsed | 1941-06-12 | 1944-11-07 | 0 | Details |
| US2361680A | Method of reducing edge leakage in metal oxide-metal rectif… | Expired / Lapsed | 1941-06-18 | 1944-10-31 | 0 | Details |
| US2361246A | Card translator | Expired / Lapsed | 1943-05-05 | 1944-10-24 | 0 | Details |
| US2360932A | Negative resistance loading | Expired / Lapsed | 1942-04-25 | 1944-10-24 | 0 | Details |
| US2360940A | Negative resistance loading | Expired / Lapsed | 1942-04-25 | 1944-10-24 | 0 | Details |
| US2360523A | Electrical measuring apparatus | Expired / Lapsed | 1943-05-15 | 1944-10-17 | 0 | Details |
| US2360063A | Composite article | Expired / Lapsed | 1942-03-13 | 1944-10-10 | 0 | Details |
| US2360233A | Thermistor as amplifier for low frequency signals | Expired / Lapsed | 1941-12-10 | 1944-10-10 | 0 | Details |
| US2358610A | Telegraph signaling system | Expired / Lapsed | 1943-03-12 | 1944-09-19 | 0 | Details |
| US2358237A | Telephone system | Expired / Lapsed | 1942-12-22 | 1944-09-12 | 0 | Details |
| US2358045A | Noise reduction in signal transmission systems | Expired / Lapsed | 1942-08-06 | 1944-09-12 | 0 | Details |
| US2357591A | Joint for metal sheath cables | Expired / Lapsed | 1942-05-01 | 1944-09-05 | 0 | Details |
| US2356956A | Process of carbonizing | Expired / Lapsed | 1942-01-01 | 1944-08-29 | 0 | Details |
| US2356519A | Communication system | Expired / Lapsed | 1942-10-09 | 1944-08-22 | 0 | Details |
| US2356583A | Process of preparing soldering coppers | Expired / Lapsed | 1941-08-20 | 1944-08-22 | 0 | Details |
| US2355908A | Telephone system | Expired / Lapsed | 1943-07-20 | 1944-08-15 | 0 | Details |
| US2355795A | Electrode system | Expired / Lapsed | 1942-08-17 | 1944-08-15 | 0 | Details |
| US2355903A | Signaling system | Expired / Lapsed | 1942-06-27 | 1944-08-15 | 0 | Details |
| US2353732A | Wire connector | Expired / Lapsed | 1942-06-30 | 1944-07-18 | 0 | Details |
| US2353638A | Conveyer system | Expired / Lapsed | 1942-04-10 | 1944-07-18 | 0 | Details |
| US2352451A | Frequency converter | Expired / Lapsed | 1942-02-07 | 1944-06-27 | 0 | Details |
| US2352072A | Conoscope | Expired / Lapsed | 1942-12-19 | 1944-06-20 | 0 | Details |
| US2352056A | Thermally controlled resistor | Expired / Lapsed | 1942-09-23 | 1944-06-20 | 0 | Details |
| US2351551A | Telephone system | Expired / Lapsed | 1943-05-29 | 1944-06-13 | 0 | Details |
| US2351446A | Sender load control | Expired / Lapsed | 1942-12-22 | 1944-06-13 | 0 | Details |
| US2351201A | Method of and means for measuring | Expired / Lapsed | 1942-07-16 | 1944-06-13 | 0 | Details |
| US2351435A | Plug cutting tool | Expired / Lapsed | 1942-05-30 | 1944-06-13 | 0 | Details |
| US2351321A | Apparatus for the manufacture of electrolytic condensers | Expired / Lapsed | 1941-09-27 | 1944-06-13 | 0 | Details |
| US2350466A | Telephone system trouble recorder | Expired / Lapsed | 1942-10-31 | 1944-06-06 | 0 | Details |
| US2350887A | Method of manufacturing parts for electrical apparatus | Expired / Lapsed | 1941-11-28 | 1944-06-06 | 0 | Details |
| US2350888A | Selecting system | Expired / Lapsed | 1941-11-21 | 1944-06-06 | 0 | Details |
| US2350916A | Ultra short wave antenna system | Expired / Lapsed | 1940-05-17 | 1944-06-06 | 0 | Details |
| US2350180A | Telegraph system | Expired / Lapsed | 1942-10-17 | 1944-05-30 | 0 | Details |
| US2349882A | Multiple unit apparatus | Expired / Lapsed | 1942-05-23 | 1944-05-30 | 0 | Details |
| US2349952A | Electrical conductor | Expired / Lapsed | 1939-04-22 | 1944-05-30 | 0 | Details |
| US2348932A | Knitting machine | Expired / Lapsed | 1943-03-17 | 1944-05-16 | 0 | Details |
| US2349129A | Dialing system | Expired / Lapsed | 1942-07-01 | 1944-05-16 | 0 | Details |
| US2349144A | Telephone booth | Expired / Lapsed | 1941-12-04 | 1944-05-16 | 0 | Details |
| US2348572A | Variable attenuation network | Expired / Lapsed | 1943-02-20 | 1944-05-09 | 0 | Details |
| US2348626A | Channel selecting circuit | Expired / Lapsed | 1942-11-14 | 1944-05-09 | 0 | Details |
| US2348592A | Telephone housing detail | Expired / Lapsed | 1942-09-26 | 1944-05-09 | 0 | Details |
| US2347738A | Switching mechanism | Expired / Lapsed | 1942-08-06 | 1944-05-02 | 0 | Details |
| US2348045A | Electron discharge device and method of manufacture | Expired / Lapsed | 1942-01-01 | 1944-05-02 | 0 | Details |
| US2347777A | Signaling circuit | Expired / Lapsed | 1941-12-23 | 1944-05-02 | 0 | Details |
| US2347831A | Communication system | Expired / Lapsed | 1941-08-28 | 1944-05-02 | 0 | Details |
| US2347733A | Switching device | Expired / Lapsed | 1941-06-06 | 1944-05-02 | 0 | Details |
| US2347347A | Vibration translating device | Expired / Lapsed | 1942-08-26 | 1944-04-25 | 0 | Details |
| US2347108A | Call transmitter for telephone signaling systems | Expired / Lapsed | 1943-02-05 | 1944-04-18 | 0 | Details |
| US2347098A | Electrical wave modulation | Expired / Lapsed | 1942-01-09 | 1944-04-18 | 0 | Details |
| US2345932A | Measuring apparatus | Expired / Lapsed | 1941-03-26 | 1944-04-04 | 0 | Details |
| US2345491A | Wave transmission network | Expired / Lapsed | 1941-11-25 | 1944-03-28 | 0 | Details |
| US2345048A | Communication system | Expired / Lapsed | 1941-11-13 | 1944-03-28 | 0 | Details |
| US2345115A | Wave transmission system | Expired / Lapsed | 1941-05-22 | 1944-03-28 | 0 | Details |
| US2345317A | Satellite telegraph switching system | Expired / Lapsed | 1941-05-17 | 1944-03-28 | 0 | Details |
| US2344612A | Electric signaling | Expired / Lapsed | 1942-06-27 | 1944-03-21 | 0 | Details |
| US2344792A | Motor control mechanism for printing telegraph apparatus | Expired / Lapsed | 1941-11-27 | 1944-03-21 | 0 | Details |
| US2344633A | Impulse repeater | Expired / Lapsed | 1941-11-13 | 1944-03-21 | 0 | Details |
| US2343988A | Cathode ray intensity control circuit | Expired / Lapsed | 1943-02-24 | 1944-03-14 | 0 | Details |
| US2344454A | Training device | Expired / Lapsed | 1942-12-07 | 1944-03-14 | 0 | Details |
| US2344340A | Apparatus for applying tape upon articles | Expired / Lapsed | 1942-05-29 | 1944-03-14 | 0 | Details |
| US2343753A | Receiving circuit for telegraph signaling systems | Expired / Lapsed | 1942-09-25 | 1944-03-07 | 0 | Details |
| US2343539A | Stabilized oscillator | Expired / Lapsed | 1942-01-16 | 1944-03-07 | 0 | Details |
| US2342813A | Mechanical wave filter | Expired / Lapsed | 1942-10-01 | 1944-02-29 | 0 | Details |
| US2342869A | Wave filter | Expired / Lapsed | 1942-09-11 | 1944-02-29 | 0 | Details |
| US2342886A | Printing telegraph apparatus and system | Expired / Lapsed | 1941-02-25 | 1944-02-29 | 0 | Details |
| US2343059A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-09-18 | 1944-02-29 | 0 | Details |
| US2342552A | Switching apparatus | Expired / Lapsed | 1943-02-20 | 1944-02-22 | 0 | Details |
| US2342245A | Electric signaling | Expired / Lapsed | 1942-06-27 | 1944-02-22 | 0 | Details |
| US2342238A | Variable attenuation circuits | Expired / Lapsed | 1941-12-31 | 1944-02-22 | 0 | Details |
| US2342395A | Control system for sound films | Expired / Lapsed | 1941-10-22 | 1944-02-22 | 0 | Details |
| US2340576A | Telegraph system | Expired / Lapsed | 1942-06-04 | 1944-02-01 | 0 | Details |
| US2339413A | Telephone handset hanger | Expired / Lapsed | 1943-02-03 | 1944-01-18 | 0 | Details |
| US2339465A | System for the artificial production of vocal or other soun… | Expired / Lapsed | 1942-07-10 | 1944-01-18 | 0 | Details |
| US2339633A | Variable selective system | Expired / Lapsed | 1942-03-23 | 1944-01-18 | 0 | Details |
| US2339613A | Selenium rectifier and method of making it | Expired / Lapsed | 1942-02-27 | 1944-01-18 | 0 | Details |
| US2339404A | Switching mechanism | Expired / Lapsed | 1941-09-17 | 1944-01-18 | 0 | Details |
| US2339662A | Television transmitter | Expired / Lapsed | 1941-07-31 | 1944-01-18 | 0 | Details |
| US2339406A | Electrical transmission system | Expired / Lapsed | 1941-05-31 | 1944-01-18 | 0 | Details |
| US2339683A | Method of making retractile cords | Expired / Lapsed | 1940-06-05 | 1944-01-18 | 0 | Details |
| US2339194A | Material handling apparatus | Expired / Lapsed | 1941-10-17 | 1944-01-11 | 0 | Details |
| US2338218A | Time-measuring device | Expired / Lapsed | 1942-12-11 | 1944-01-04 | 0 | Details |
| US2338245A | Fault-locating device | Expired / Lapsed | 1942-09-14 | 1944-01-04 | 0 | Details |
| US2338636A | Automatic billing system | Expired / Lapsed | 1937-12-08 | 1944-01-04 | 0 | Details |
| US2337886A | Telegraph system | Expired / Lapsed | 1942-06-20 | 1943-12-28 | 0 | Details |
| US2337953A | Telephone headset | Expired / Lapsed | 1942-01-28 | 1943-12-28 | 0 | Details |
| US2338036A | Cathode ray device | Expired / Lapsed | 1941-08-08 | 1943-12-28 | 0 | Details |
| US2337540A | Measurement of envelope delay of electric circuits | Expired / Lapsed | 1941-02-01 | 1943-12-28 | 0 | Details |
| US2337423A | Negative feed-back amplifier | Expired / Lapsed | 1942-10-01 | 1943-12-21 | 0 | Details |
| US2336888A | Two-way telephone system | Expired / Lapsed | 1942-10-01 | 1943-12-14 | 0 | Details |
| US2336543A | Digit signal translator | Expired / Lapsed | 1942-07-31 | 1943-12-14 | 0 | Details |
| US2336384A | Surface hardening of linear polyamide bodies | Expired / Lapsed | 1941-06-10 | 1943-12-07 | 0 | Details |
| US2336373A | Teletypewriter switching system | Expired / Lapsed | 1940-06-15 | 1943-12-07 | 0 | Details |
| US2334534A | Teletypewriter | Expired / Lapsed | 1942-12-02 | 1943-11-16 | 0 | Details |
| US2334575A | Selective signaling system | Expired / Lapsed | 1941-01-08 | 1943-11-16 | 0 | Details |
| US2334574A | Selective signaling system | Expired / Lapsed | 1941-01-08 | 1943-11-16 | 0 | Details |
| US2332912A | Telephone system | Expired / Lapsed | 1942-05-01 | 1943-10-26 | 0 | Details |
| US2332966A | Code call system | Expired / Lapsed | 1942-02-25 | 1943-10-26 | 0 | Details |
| US2332622A | Electron discharge device | Expired / Lapsed | 1941-10-11 | 1943-10-26 | 0 | Details |
| US2332596A | Resistor device | Expired / Lapsed | 1941-08-30 | 1943-10-26 | 0 | Details |
| US2332977A | Space discharge device and circuits | Expired / Lapsed | 1941-07-31 | 1943-10-26 | 0 | Details |
| US2332338A | Contact making device | Expired / Lapsed | 1942-12-03 | 1943-10-19 | 0 | Details |
| US2332430A | Two-way telephone system | Expired / Lapsed | 1942-07-16 | 1943-10-19 | 0 | Details |
| US2332102A | Negative transconductance tube oscillator | Expired / Lapsed | 1941-11-26 | 1943-10-19 | 0 | Details |
| US2332091A | Ventilating system for telephone booths | Expired / Lapsed | 1941-05-03 | 1943-10-19 | 0 | Details |
| US2332451A | Telegraph trouble indicator circuit | Expired / Lapsed | 1940-11-20 | 1943-10-19 | 0 | Details |
| US2332448A | Telephone system | Expired / Lapsed | 1940-10-22 | 1943-10-19 | 0 | Details |
| US2332073A | Electric circuit control | Expired / Lapsed | 1940-07-11 | 1943-10-19 | 0 | Details |
| US2331398A | Electronic discharge device | Expired / Lapsed | 1942-10-19 | 1943-10-12 | 0 | Details |
| US2331411A | Regulated rectifier | Expired / Lapsed | 1940-11-07 | 1943-10-12 | 0 | Details |
| US2329792A | Electron discharge device circuit | Expired / Lapsed | 1942-09-01 | 1943-09-21 | 0 | Details |
| US2329764A | Relay circuit | Expired / Lapsed | 1941-08-26 | 1943-09-21 | 0 | Details |
| US2329511A | Method of making resistors | Expired / Lapsed | 1942-09-19 | 1943-09-14 | 0 | Details |
| US2329471A | Electrical terminal | Expired / Lapsed | 1942-08-07 | 1943-09-14 | 0 | Details |
| US2329466A | Call transmitter | Expired / Lapsed | 1940-12-17 | 1943-09-14 | 0 | Details |
| US2329504A | Electric timing device | Expired / Lapsed | 1940-01-06 | 1943-09-14 | 0 | Details |
| US2329010A | Power supply system | Expired / Lapsed | 1942-07-22 | 1943-09-07 | 0 | Details |
| US2328951A | Two-way signal transmission system | Expired / Lapsed | 1942-07-17 | 1943-09-07 | 0 | Details |
| US2328750A | Test device | Expired / Lapsed | 1942-04-29 | 1943-09-07 | 0 | Details |
| US2328383A | Article handling apparatus | Expired / Lapsed | 1941-07-08 | 1943-08-31 | 0 | Details |
| US2328422A | Method for coating bodies with carbon | Expired / Lapsed | 1940-10-09 | 1943-08-31 | 0 | Details |
| US2328107A | Electrical connecting and conditioning apparatus | Expired / Lapsed | 1940-09-28 | 1943-08-31 | 0 | Details |
| US2328478A | Piezoelectric transducer | Expired / Lapsed | 1940-03-30 | 1943-08-31 | 0 | Details |
| US2327877A | Telephone call diverting system | Expired / Lapsed | 1942-03-31 | 1943-08-24 | 0 | Details |
| US2327792A | Selector | Expired / Lapsed | 1941-12-09 | 1943-08-24 | 0 | Details |
| US2327275A | Signaling system | Expired / Lapsed | 1941-08-28 | 1943-08-17 | 0 | Details |
| US2326572A | Holder for electrically heated tools | Expired / Lapsed | 1942-07-01 | 1943-08-10 | 0 | Details |
| US2326478A | Selection system | Expired / Lapsed | 1942-02-17 | 1943-08-10 | 0 | Details |
| US2326458A | Selection system | Expired / Lapsed | 1942-02-17 | 1943-08-10 | 0 | Details |
| US2326290A | Alarm and testing circuit | Expired / Lapsed | 1941-07-30 | 1943-08-10 | 0 | Details |
| US2326313A | Alarm circuit | Expired / Lapsed | 1941-02-27 | 1943-08-10 | 0 | Details |
| US2326296A | Machine for sealing receptacles | Expired / Lapsed | 1940-06-15 | 1943-08-10 | 0 | Details |
| US2325952A | Signaling device | Expired / Lapsed | 1941-12-11 | 1943-08-03 | 0 | Details |
| US2324809A | Soldering method | Expired / Lapsed | 1942-07-22 | 1943-07-20 | 0 | Details |
| US2324534A | Television transmitter | Expired / Lapsed | 1941-09-30 | 1943-07-20 | 0 | Details |
| US2324797A | Differentiating amplifier | Expired / Lapsed | 1941-09-17 | 1943-07-20 | 0 | Details |
| US2324215A | Measuring apparatus | Expired / Lapsed | 1941-04-25 | 1943-07-13 | 0 | Details |
| US2324394A | Signaling system | Expired / Lapsed | 1940-10-17 | 1943-07-13 | 0 | Details |
| US2323641A | Antenna system | Expired / Lapsed | 1940-01-26 | 1943-07-06 | 0 | Details |
| US2322756A | Method of impregnation | Expired / Lapsed | 1941-07-11 | 1943-06-29 | 0 | Details |
| US2322851A | Magnetic switch hook | Expired / Lapsed | 1941-01-24 | 1943-06-29 | 0 | Details |
| US2322292A | Bearing structure for relays and the like | Expired / Lapsed | 1941-07-17 | 1943-06-22 | 0 | Details |
| US2322653A | Telautographic device | Expired / Lapsed | 1940-01-05 | 1943-06-22 | 0 | Details |
| US2321731A | Method of making repairs and joints in cable sheaths | Expired / Lapsed | 1941-12-18 | 1943-06-15 | 0 | Details |
| US2321758A | Telephone system | Expired / Lapsed | 1941-09-26 | 1943-06-15 | 0 | Details |
| US2320175A | System for testing resonant networks | Expired / Lapsed | 1942-05-16 | 1943-05-25 | 0 | Details |
| US2320076A | Selecting system | Expired / Lapsed | 1941-11-21 | 1943-05-25 | 0 | Details |
| US2319965A | Variable frequency bridge stabilized oscillator | Expired / Lapsed | 1941-06-14 | 1943-05-25 | 0 | Details |
| US2319940A | Gravitational force measuring apparatus | Expired / Lapsed | 1939-09-12 | 1943-05-25 | 0 | Details |
| US2319306A | Signaling system | Expired / Lapsed | 1941-10-31 | 1943-05-18 | 0 | Details |
| US2319744A | Shielding for communication circuits | Expired / Lapsed | 1941-10-30 | 1943-05-18 | 0 | Details |
| US2319333A | Service observing system | Expired / Lapsed | 1941-06-14 | 1943-05-18 | 0 | Details |
| US2319339A | Signaling system | Expired / Lapsed | 1940-05-22 | 1943-05-18 | 0 | Details |
| US2319087A | Electric organ keying system | Expired / Lapsed | 1941-05-31 | 1943-05-11 | 0 | Details |
| US2318418A | Electron discharge device | Expired / Lapsed | 1941-10-28 | 1943-05-04 | 0 | Details |
| US2318168A | Printing telegraph apparatus | Expired / Lapsed | 1941-06-14 | 1943-05-04 | 0 | Details |
| US2318533A | Apparatus for heating material | Expired / Lapsed | 1940-12-06 | 1943-05-04 | 0 | Details |
| US2318508A | Material feeding apparatus | Expired / Lapsed | 1940-07-10 | 1943-05-04 | 0 | Details |
| US2317471A | Selection system | Expired / Lapsed | 1942-02-17 | 1943-04-27 | 0 | Details |
| US2317191A | Telephone system | Expired / Lapsed | 1941-01-24 | 1943-04-20 | 0 | Details |
| US2316609A | Article supporting rack | Expired / Lapsed | 1940-04-09 | 1943-04-13 | 0 | Details |
| US2315720A | Electrical connecting device | Expired / Lapsed | 1941-03-15 | 1943-04-06 | 0 | Details |
| US2315621A | Electron camera | Expired / Lapsed | 1940-09-24 | 1943-04-06 | 0 | Details |
| US2315445A | Regulated rectifier circuit | Expired / Lapsed | 1940-08-31 | 1943-03-30 | 0 | Details |
| US2315434A | Transmission system | Expired / Lapsed | 1940-07-03 | 1943-03-30 | 0 | Details |
| US2315456A | Call indicator | Expired / Lapsed | 1940-05-15 | 1943-03-30 | 0 | Details |
| US2315312A | Electron discharge device circuits | Expired / Lapsed | 1939-01-21 | 1943-03-30 | 0 | Details |
| US2314851A | Power factor measuring system | Expired / Lapsed | 1942-04-30 | 1943-03-23 | 0 | Details |
| US2314409A | Magnetic coil structure | Expired / Lapsed | 1940-09-28 | 1943-03-23 | 0 | Details |
| US2314471A | Two-way television and speech television | Expired / Lapsed | 1940-08-24 | 1943-03-23 | 0 | Details |
| US2313809A | Contact protection device | Expired / Lapsed | 1941-04-19 | 1943-03-16 | 0 | Details |
| US2312954A | Observer controlled television system | Expired / Lapsed | 1941-06-04 | 1943-03-02 | 0 | Details |
| US2312723A | Electron discharge device | Expired / Lapsed | 1939-08-16 | 1943-03-02 | 0 | Details |
| US2311801A | Thermal time delay relay | Expired / Lapsed | 1941-07-11 | 1943-02-23 | 0 | Details |
| US2311807A | Electron discharge device circuit | Expired / Lapsed | 1940-08-10 | 1943-02-23 | 0 | Details |
| US2312206A | Method of and apparatus for reducing halo from fluorescent … | Expired / Lapsed | 1940-06-12 | 1943-02-23 | 0 | Details |
| US2310749A | Singaling system | Expired / Lapsed | 1942-03-31 | 1943-02-09 | 0 | Details |
| US2310452A | Switching system | Expired / Lapsed | 1941-06-05 | 1943-02-09 | 0 | Details |
| US2309703A | Alternating current generator | Expired / Lapsed | 1941-05-21 | 1943-02-02 | 0 | Details |
| US2309081A | Electrically conductive device | Expired / Lapsed | 1941-10-01 | 1943-01-26 | 0 | Details |
| US2309467A | Rochelle salt piezoelectric crystal apparatus | Expired / Lapsed | 1941-07-25 | 1943-01-26 | 0 | Details |
| US2309525A | Electric signaling | Expired / Lapsed | 1941-01-21 | 1943-01-26 | 0 | Details |
| US2308800A | Electron discharge device | Expired / Lapsed | 1941-02-15 | 1943-01-19 | 0 | Details |
| US2307989A | Sound signal | Expired / Lapsed | 1942-03-24 | 1943-01-12 | 0 | Details |
| US2307868A | Binary counter | Expired / Lapsed | 1941-11-26 | 1943-01-12 | 0 | Details |
| US2308381A | Two-way television transmission | Expired / Lapsed | 1939-12-29 | 1943-01-12 | 0 | Details |
| US2308360A | Light modulating apparatus and method | Expired / Lapsed | 1939-11-15 | 1943-01-12 | 0 | Details |
| US2307728A | Signaling system | Expired / Lapsed | 1940-08-10 | 1943-01-05 | 0 | Details |
| US2306707A | Audiphone | Expired / Lapsed | 1941-05-09 | 1942-12-29 | 0 | Details |
| US2306732A | Molding fixture | Expired / Lapsed | 1941-05-08 | 1942-12-29 | 0 | Details |
| US2306435A | Frequency compression | Expired / Lapsed | 1941-01-17 | 1942-12-29 | 0 | Details |
| US2306909A | Piezoelectric crystal apparatus | Expired / Lapsed | 1939-06-09 | 1942-12-29 | 0 | Details |
| US2306282A | Tuning arrangement for cavity resonators | Expired / Lapsed | 1941-06-28 | 1942-12-22 | 0 | Details |
| US2306087A | Key pulsing register circuit | Expired / Lapsed | 1941-06-19 | 1942-12-22 | 0 | Details |
| US2306067A | Telephone system | Expired / Lapsed | 1940-10-16 | 1942-12-22 | 0 | Details |
| US2304856A | Electrical transmission system | Expired / Lapsed | 1941-10-15 | 1942-12-15 | 0 | Details |
| US2304135A | Modulating system | Expired / Lapsed | 1941-05-13 | 1942-12-08 | 0 | Details |
| US2304613A | Delayed operation circuit | Expired / Lapsed | 1941-04-12 | 1942-12-08 | 0 | Details |
| US2304061A | Switching device for telephone instruments | Expired / Lapsed | 1940-05-15 | 1942-12-08 | 0 | Details |
| US2303555A | Hot plate device | Expired / Lapsed | 1942-03-13 | 1942-12-01 | 0 | Details |
| US2304044A | Voltage regulation and rectification | Expired / Lapsed | 1941-08-15 | 1942-12-01 | 0 | Details |
| US2303377A | Communication system with voiceoperated switching mechanisms | Expired / Lapsed | 1941-07-23 | 1942-12-01 | 0 | Details |
| US2303497A | Duplex metal body | Expired / Lapsed | 1941-05-09 | 1942-12-01 | 0 | Details |
| US2303952A | Relay | Expired / Lapsed | 1940-10-05 | 1942-12-01 | 0 | Details |
| US2303930A | Electro-optical system | Expired / Lapsed | 1936-03-04 | 1942-12-01 | 0 | Details |
| US2303054A | Polar signal test transmitter | Expired / Lapsed | 1941-08-06 | 1942-11-24 | 0 | Details |
| US2303016A | Impulse counting circuit | Expired / Lapsed | 1941-06-20 | 1942-11-24 | 0 | Details |
| US2303166A | Electron discharge device | Expired / Lapsed | 1941-01-21 | 1942-11-24 | 0 | Details |
| US2302767A | Terminal for electrical conductors | Expired / Lapsed | 1940-12-21 | 1942-11-24 | 0 | Details |
| US2302024A | Method of cutting | Expired / Lapsed | 1941-05-23 | 1942-11-17 | 0 | Details |
| US2301929A | Radio distance and altitude indicating system | Expired / Lapsed | 1941-04-18 | 1942-11-17 | 0 | Details |
| US2302334A | Telephone system | Expired / Lapsed | 1940-03-30 | 1942-11-17 | 0 | Details |
| US2301223A | Transmission system | Expired / Lapsed | 1941-05-13 | 1942-11-10 | 0 | Details |
| US2301343A | Regulated rectifier | Expired / Lapsed | 1940-10-19 | 1942-11-10 | 0 | Details |
| US2301199A | Facsimile system | Expired / Lapsed | 1940-04-26 | 1942-11-10 | 0 | Details |
| US2300951A | Telephone system | Expired / Lapsed | 1941-07-26 | 1942-11-03 | 0 | Details |
| US2300638A | Alternating current generator | Expired / Lapsed | 1941-05-21 | 1942-11-03 | 0 | Details |
| US2300505A | Selective system | Expired / Lapsed | 1940-10-31 | 1942-11-03 | 0 | Details |
| US2301015A | Telephone system | Expired / Lapsed | 1940-03-22 | 1942-11-03 | 0 | Details |
| US2300007A | Telegraph system | Expired / Lapsed | 1941-12-03 | 1942-10-27 | 0 | Details |
| US2300320A | Device for reproducing tone frequencies | Expired / Lapsed | 1941-05-27 | 1942-10-27 | 0 | Details |
| US2300366A | Signal transmission system | Expired / Lapsed | 1940-11-28 | 1942-10-27 | 0 | Details |
| US2299815A | Gas detector | Expired / Lapsed | 1940-11-05 | 1942-10-27 | 0 | Details |
| US2300133A | Broad band amplifier | Expired / Lapsed | 1940-09-20 | 1942-10-27 | 0 | Details |
| US2300044A | Telephone subscriber's station | Expired / Lapsed | 1940-07-23 | 1942-10-27 | 0 | Details |
| US2299821A | Signaling system | Expired / Lapsed | 1940-04-05 | 1942-10-27 | 0 | Details |
| US2299867A | Calibrating apparatus for temperature reporating devices | Expired / Lapsed | 1939-01-10 | 1942-10-27 | 0 | Details |
| US2299229A | Selecting system | Expired / Lapsed | 1941-11-26 | 1942-10-20 | 0 | Details |
| US2299212A | Telephone system | Expired / Lapsed | 1941-07-03 | 1942-10-20 | 0 | Details |
| US2299252A | Frequency detector | Expired / Lapsed | 1941-05-29 | 1942-10-20 | 0 | Details |
| US2299487A | Electric wave transmission system | Expired / Lapsed | 1941-05-03 | 1942-10-20 | 0 | Details |
| US2299279A | Signaling system | Expired / Lapsed | 1941-04-19 | 1942-10-20 | 0 | Details |
| US2299689A | Manufacture of electrical conductors | Expired / Lapsed | 1941-03-05 | 1942-10-20 | 0 | Details |
| US2299203A | Telephone system | Expired / Lapsed | 1940-07-05 | 1942-10-20 | 0 | Details |
| US2298449A | Antenna | Expired / Lapsed | 1941-11-08 | 1942-10-13 | 0 | Details |
| US2298699A | Translation device | Expired / Lapsed | 1941-05-29 | 1942-10-13 | 0 | Details |
| US2298519A | Telephone system | Expired / Lapsed | 1940-06-21 | 1942-10-13 | 0 | Details |
| US2298722A | Impulse transmission system | Expired / Lapsed | 1939-06-30 | 1942-10-13 | 0 | Details |
| US2298324A | Electrical conductor | Expired / Lapsed | 1934-09-29 | 1942-10-13 | 0 | Details |
| US2298192A | Thermistor circuit | Expired / Lapsed | 1941-12-26 | 1942-10-06 | 0 | Details |
| US2298207A | Telephone substation apparatus | Expired / Lapsed | 1940-12-24 | 1942-10-06 | 0 | Details |
| US2297673A | Voltage regulator | Expired / Lapsed | 1940-08-31 | 1942-09-29 | 0 | Details |
| US2296353A | Signal system | Expired / Lapsed | 1940-10-19 | 1942-09-22 | 0 | Details |
| US2295602A | Switching device | Expired / Lapsed | 1941-07-17 | 1942-09-15 | 0 | Details |
| US2295953A | Material handling apparatus | Expired / Lapsed | 1939-02-11 | 1942-09-15 | 0 | Details |
| US2295153A | Two-way signal transmission system | Expired / Lapsed | 1941-06-10 | 1942-09-08 | 0 | Details |
| US2294907A | Telephone system | Expired / Lapsed | 1941-01-17 | 1942-09-08 | 0 | Details |
| US2294457A | Selective system | Expired / Lapsed | 1940-10-31 | 1942-09-01 | 0 | Details |
| US2294464A | Impulse transmitter | Expired / Lapsed | 1938-04-09 | 1942-09-01 | 0 | Details |
| US2294114A | Electrostatic scanning | Expired / Lapsed | 1941-05-31 | 1942-08-25 | 0 | Details |
| US2293869A | Signaling system | Expired / Lapsed | 1940-09-14 | 1942-08-25 | 0 | Details |
| US2293870A | Electro-optical image production | Expired / Lapsed | 1940-02-03 | 1942-08-25 | 0 | Details |
| US2293588A | Telephone system | Expired / Lapsed | 1941-04-18 | 1942-08-18 | 0 | Details |
| US2293628A | Modulating apparatus | Expired / Lapsed | 1940-11-16 | 1942-08-18 | 0 | Details |
| US2293567A | Electron dischrage apparatus | Expired / Lapsed | 1940-06-27 | 1942-08-18 | 0 | Details |
| US2293203A | Automatic telephone system | Expired / Lapsed | 1937-05-06 | 1942-08-18 | 0 | Details |
| US2292388A | Rochelle salt piezoelectric crystal apparatus | Expired / Lapsed | 1941-05-23 | 1942-08-11 | 0 | Details |
| US2292886A | Rochelle salt piezoelectric crystal apparatus | Expired / Lapsed | 1941-05-22 | 1942-08-11 | 0 | Details |
| US2292885A | Rochelle salt piezoelectric crystal apparatus | Expired / Lapsed | 1941-05-09 | 1942-08-11 | 0 | Details |
| US2292890A | Conveyer control | Expired / Lapsed | 1940-07-05 | 1942-08-11 | 0 | Details |
| US2291615A | Telephone system | Expired / Lapsed | 1941-07-19 | 1942-08-04 | 0 | Details |
| US2291752A | Selecting system | Expired / Lapsed | 1941-02-05 | 1942-08-04 | 0 | Details |
| US2291723A | Apparatus for and method of generating television signals | Expired / Lapsed | 1940-02-29 | 1942-08-04 | 0 | Details |
| US2291224A | Selecting system | Expired / Lapsed | 1941-02-08 | 1942-07-28 | 0 | Details |
| US2291040A | Switching system | Expired / Lapsed | 1941-02-08 | 1942-07-28 | 0 | Details |
| US2291555A | Wave transmission | Expired / Lapsed | 1940-06-05 | 1942-07-28 | 0 | Details |
| US2289564A | Phase modulating system | Expired / Lapsed | 1941-11-14 | 1942-07-14 | 0 | Details |
| US2289895A | Telephone system | Expired / Lapsed | 1941-03-29 | 1942-07-14 | 0 | Details |
| US2289746A | Teletypewriter "answer back" circuit | Expired / Lapsed | 1940-03-26 | 1942-07-14 | 0 | Details |
| US2289830A | Circuit closing device | Expired / Lapsed | 1938-03-29 | 1942-07-14 | 0 | Details |
| US2289048A | Power line carrier frequency telephone system | Expired / Lapsed | 1941-06-19 | 1942-07-07 | 0 | Details |
| US2288817A | Oscillation modulator | Expired / Lapsed | 1939-07-18 | 1942-07-07 | 0 | Details |
| US2288025A | Automatic frequency control system | Expired / Lapsed | 1940-08-03 | 1942-06-30 | 0 | Details |
| US2288452A | Electric switch | Expired / Lapsed | 1940-06-15 | 1942-06-30 | 0 | Details |
| US2287881A | Telephone system | Expired / Lapsed | 1939-02-24 | 1942-06-30 | 0 | Details |
| US2287077A | Volume range control in signal transmission systems | Expired / Lapsed | 1941-07-19 | 1942-06-23 | 0 | Details |
| US2287708A | Strand handling apparatus | Expired / Lapsed | 1941-05-09 | 1942-06-23 | 0 | Details |
| US2287413A | Facsimile system | Expired / Lapsed | 1940-10-31 | 1942-06-23 | 0 | Details |
| US2287587A | Light modulating apparatus | Expired / Lapsed | 1939-11-02 | 1942-06-23 | 0 | Details |
| US2287174A | Relative phase measuring circuit and method | Expired / Lapsed | 1939-09-16 | 1942-06-23 | 0 | Details |
| US2286839A | Directive antenna system | Expired / Lapsed | 1939-12-20 | 1942-06-16 | 0 | Details |
| US2285832A | Feedback amplifier | Expired / Lapsed | 1940-04-20 | 1942-06-09 | 0 | Details |
| US2285796A | Gaseous discharge device | Expired / Lapsed | 1939-10-19 | 1942-06-09 | 0 | Details |
| US2284870A | Telephone system | Expired / Lapsed | 1940-09-20 | 1942-06-02 | 0 | Details |
| US2284753A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-09-20 | 1942-06-02 | 0 | Details |
| US2285017A | Coating apparatus | Expired / Lapsed | 1940-02-08 | 1942-06-02 | 0 | Details |
| US2285166A | Tension gauge | Expired / Lapsed | 1940-01-11 | 1942-06-02 | 0 | Details |
| US2284402A | Modulation circuit | Expired / Lapsed | 1940-08-27 | 1942-05-26 | 0 | Details |
| US2284401A | Modulation circuit | Expired / Lapsed | 1940-08-27 | 1942-05-26 | 0 | Details |
| US2284444A | Demodulation circuit | Expired / Lapsed | 1940-08-27 | 1942-05-26 | 0 | Details |
| US2284612A | Phase control in electrical transmission | Expired / Lapsed | 1940-01-06 | 1942-05-26 | 0 | Details |
| US2284547A | Electrical device | Expired / Lapsed | 1938-08-06 | 1942-05-26 | 0 | Details |
| US2283935A | Transmission, radiation, and reception of electromagnetic w… | Expired / Lapsed | 1938-04-29 | 1942-05-26 | 0 | Details |
| US2283616A | Oscillographic method of frequency setting or measurement | Expired / Lapsed | 1940-08-03 | 1942-05-19 | 0 | Details |
| US2283568A | Ultra high frequency system | Expired / Lapsed | 1940-06-18 | 1942-05-19 | 0 | Details |
| US2283610A | Telephone system | Expired / Lapsed | 1940-02-02 | 1942-05-19 | 0 | Details |
| US2282465A | Speech transmission system | Expired / Lapsed | 1941-02-27 | 1942-05-12 | 0 | Details |
| US2283148A | Modulation of cathode ray devices | Expired / Lapsed | 1941-02-14 | 1942-05-12 | 0 | Details |
| US2282369A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-08-03 | 1942-05-12 | 0 | Details |
| US2281717A | Electron discharge apparatus | Expired / Lapsed | 1941-01-21 | 1942-05-05 | 0 | Details |
| US2281778A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-10-19 | 1942-05-05 | 0 | Details |
| US2281542A | Electrical conductor | Expired / Lapsed | 1939-03-03 | 1942-05-05 | 0 | Details |
| US2281891A | Picture transmission, television, and the like | Expired / Lapsed | 1938-09-08 | 1942-05-05 | 0 | Details |
| US2281461A | Temperature compensating means | Expired / Lapsed | 1941-09-24 | 1942-04-28 | 0 | Details |
| US2281035A | Repeatered transmission system | Expired / Lapsed | 1941-05-31 | 1942-04-28 | 0 | Details |
| US2281040A | Thermionic relay circuit | Expired / Lapsed | 1941-04-26 | 1942-04-28 | 0 | Details |
| US2281312A | Wave translation | Expired / Lapsed | 1941-02-25 | 1942-04-28 | 0 | Details |
| US2280949A | Electric signaling | Expired / Lapsed | 1941-01-21 | 1942-04-28 | 0 | Details |
| US2281441A | Electric signaling | Expired / Lapsed | 1941-01-21 | 1942-04-28 | 0 | Details |
| US2281238A | Feedback amplifier | Expired / Lapsed | 1940-05-01 | 1942-04-28 | 0 | Details |
| US2280939A | Luminescent screen | Expired / Lapsed | 1940-04-05 | 1942-04-28 | 0 | Details |
| US2280890A | Luminescent screen | Expired / Lapsed | 1940-04-05 | 1942-04-28 | 0 | Details |
| US2281396A | Relay selecting circuit | Expired / Lapsed | 1940-04-03 | 1942-04-28 | 0 | Details |
| US2281508A | Telephone system | Expired / Lapsed | 1940-02-02 | 1942-04-28 | 0 | Details |
| US2280981A | Fabrication of laminated metal objects | Expired / Lapsed | 1939-10-17 | 1942-04-28 | 0 | Details |
| US2280257A | Resistor device and method of making the same | Expired / Lapsed | 1939-07-25 | 1942-04-21 | 0 | Details |
| US2279319A | Electric wave circuit | Expired / Lapsed | 1941-05-28 | 1942-04-14 | 0 | Details |
| US2278504A | Telephone signaling system | Expired / Lapsed | 1941-03-08 | 1942-04-07 | 0 | Details |
| US2278410A | Telephone system | Expired / Lapsed | 1940-10-08 | 1942-04-07 | 0 | Details |
| US2278633A | Temperature control apparatus | Expired / Lapsed | 1940-08-15 | 1942-04-07 | 0 | Details |
| US2278940A | Picture reproduction | Expired / Lapsed | 1938-01-03 | 1942-04-07 | 0 | Details |
| US2277709A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-12-12 | 1942-03-31 | 0 | Details |
| US2277907A | Telephone set | Expired / Lapsed | 1940-08-15 | 1942-03-31 | 0 | Details |
| US2278280A | Electrical switching device | Expired / Lapsed | 1940-04-09 | 1942-03-31 | 0 | Details |
| US2277228A | Telephone system | Expired / Lapsed | 1940-11-29 | 1942-03-24 | 0 | Details |
| US2277586A | Telephone system | Expired / Lapsed | 1940-10-16 | 1942-03-24 | 0 | Details |
| US2277134A | Brake | Expired / Lapsed | 1940-06-28 | 1942-03-24 | 0 | Details |
| US2277206A | Key sender | Expired / Lapsed | 1940-06-22 | 1942-03-24 | 0 | Details |
| US2277470A | Automatic toll ticketing system | Expired / Lapsed | 1939-01-19 | 1942-03-24 | 0 | Details |
| US2277245A | Piezoelectric crystal apparatus | Expired / Lapsed | 1936-11-25 | 1942-03-24 | 0 | Details |
| US2276665A | Pulse regenerator | Expired / Lapsed | 1940-10-25 | 1942-03-17 | 0 | Details |
| US2276986A | Latex | Expired / Lapsed | 1939-09-09 | 1942-03-17 | 0 | Details |
| US2275452A | Stabilized vacuum tube oscillator | Expired / Lapsed | 1939-06-24 | 1942-03-10 | 0 | Details |
| US2275977A | Means for calibrating scales | Expired / Lapsed | 1938-09-28 | 1942-03-10 | 0 | Details |
| US2275122A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-06-05 | 1942-03-03 | 0 | Details |
| US2274845A | Resistance device | Expired / Lapsed | 1940-02-21 | 1942-03-03 | 0 | Details |
| US2274638A | Telautograph system | Expired / Lapsed | 1939-11-15 | 1942-03-03 | 0 | Details |
| US2274709A | Electro-optical image production | Expired / Lapsed | 1936-09-02 | 1942-03-03 | 0 | Details |
| US2274686A | Electro-optical system | Expired / Lapsed | 1931-09-16 | 1942-03-03 | 0 | Details |
| US2273945A | Two-way speech transmission | Expired / Lapsed | 1941-04-16 | 1942-02-24 | 0 | Details |
| US2274083A | Sender control system | Expired / Lapsed | 1940-09-11 | 1942-02-24 | 0 | Details |
| US2274592A | Resistance material and method of making the same | Expired / Lapsed | 1939-06-23 | 1942-02-24 | 0 | Details |
| US2274100A | Key pulsing sender for telephone systems | Expired / Lapsed | 1938-01-20 | 1942-02-24 | 0 | Details |
| US2273793A | Cathode ray tube | Expired / Lapsed | 1940-04-10 | 1942-02-17 | 0 | Details |
| US2273433A | Cathode ray tube | Expired / Lapsed | 1940-04-10 | 1942-02-17 | 0 | Details |
| US2273432A | Electron discharge device circuits | Expired / Lapsed | 1940-01-03 | 1942-02-17 | 0 | Details |
| US2273447A | Unidirective energy radiating system | Expired / Lapsed | 1939-09-07 | 1942-02-17 | 0 | Details |
| US2273165A | Tariff determining equipment for telephone systems | Expired / Lapsed | 1939-02-25 | 1942-02-17 | 0 | Details |
| US2273193A | Wave transmission and shaping | Expired / Lapsed | 1938-10-07 | 1942-02-17 | 0 | Details |
| US2273530A | Telephone set | Expired / Lapsed | 1938-03-30 | 1942-02-17 | 0 | Details |
| US2273704A | Electrical conducting material | Expired / Lapsed | 1935-10-10 | 1942-02-17 | 0 | Details |
| US2272452A | Transformer | Expired / Lapsed | 1941-05-08 | 1942-02-10 | 0 | Details |
| US2272994A | Piezoelectric crystal element | Expired / Lapsed | 1940-12-14 | 1942-02-10 | 0 | Details |
| US2272432A | Electrical connector | Expired / Lapsed | 1940-11-28 | 1942-02-10 | 0 | Details |
| US2272998A | Slow-operate electrical circuit | Expired / Lapsed | 1940-10-23 | 1942-02-10 | 0 | Details |
| US2272701A | Electric wave transmission system | Expired / Lapsed | 1940-10-05 | 1942-02-10 | 0 | Details |
| US2272718A | Die casting machine | Expired / Lapsed | 1940-06-05 | 1942-02-10 | 0 | Details |
| US2270906A | Piezoelectric crystal apparatus | Expired / Lapsed | 1940-11-16 | 1942-01-27 | 0 | Details |
| US2271200A | Wave filter | Expired / Lapsed | 1939-07-19 | 1942-01-27 | 0 | Details |
| US2270246A | Telephone system | Expired / Lapsed | 1940-09-20 | 1942-01-20 | 0 | Details |
| US2269565A | Communication system | Expired / Lapsed | 1940-09-28 | 1942-01-13 | 0 | Details |
| US2269692A | Alarm signaling system | Expired / Lapsed | 1937-08-31 | 1942-01-13 | 0 | Details |
| US2269408A | Gain control circuits | Expired / Lapsed | 1940-09-14 | 1942-01-06 | 0 | Details |
| US2269379A | Teletypewriter switching system | Expired / Lapsed | 1939-06-09 | 1942-01-06 | 0 | Details |
| US2267936A | Impulse code converter | Expired / Lapsed | 1940-07-27 | 1941-12-30 | 0 | Details |
| US2268194A | Electron discharge device | Expired / Lapsed | 1939-12-02 | 1941-12-30 | 0 | Details |
| US2267827A | Electric signaling system | Expired / Lapsed | 1939-07-26 | 1941-12-30 | 0 | Details |
| US2268203A | Calculating machine | Expired / Lapsed | 1937-11-06 | 1941-12-30 | 0 | Details |
| US2266925A | Electrical coil | Expired / Lapsed | 1940-08-17 | 1941-12-23 | 0 | Details |
| US2267622A | Voice-operated switching circuit for two-way telephony | Expired / Lapsed | 1940-05-07 | 1941-12-23 | 0 | Details |
| US2266933A | Article feeding apparatus | Expired / Lapsed | 1940-02-14 | 1941-12-23 | 0 | Details |
| US2267545A | Light valve | Expired / Lapsed | 1940-02-14 | 1941-12-23 | 0 | Details |
| US2267286A | Negative feedback amplifier | Expired / Lapsed | 1939-10-17 | 1941-12-23 | 0 | Details |
| US2266416A | Control apparatus | Expired / Lapsed | 1939-01-14 | 1941-12-16 | 0 | Details |
| US2266168A | Amplifier | Expired / Lapsed | 1938-11-22 | 1941-12-16 | 0 | Details |
| US2265831A | Method and apparatus for magnetic recording | Expired / Lapsed | 1940-11-28 | 1941-12-09 | 0 | Details |
| US2265846A | Swivel connector | Expired / Lapsed | 1940-11-15 | 1941-12-09 | 0 | Details |
| US2265844A | Calling line identification circuit | Expired / Lapsed | 1940-07-03 | 1941-12-09 | 0 | Details |
| US2265224A | Relay circuit | Expired / Lapsed | 1939-11-02 | 1941-12-09 | 0 | Details |
| US2265292A | Method and apparatus for testing telephone transmitters | Expired / Lapsed | 1938-06-18 | 1941-12-09 | 0 | Details |
| US2265056A | Radio telephone system | Expired / Lapsed | 1940-09-27 | 1941-12-02 | 0 | Details |
| US2264746A | Electromagnetic switch | Expired / Lapsed | 1940-06-27 | 1941-12-02 | 0 | Details |
| US2264735A | Vacuum tube grid | Expired / Lapsed | 1939-06-02 | 1941-12-02 | 0 | Details |
| US2264022A | Relay | Expired / Lapsed | 1940-06-27 | 1941-11-25 | 0 | Details |
| US2264124A | Relay | Expired / Lapsed | 1940-06-27 | 1941-11-25 | 0 | Details |
| US2263320A | Power supply circuit employing electrical converters | Expired / Lapsed | 1940-08-14 | 1941-11-18 | 0 | Details |
| US2262149A | Volume control circuit for oscillators | Expired / Lapsed | 1940-07-03 | 1941-11-11 | 0 | Details |
| US2262020A | Frequency stabilization at ultrahigh frequencies | Expired / Lapsed | 1938-01-15 | 1941-11-11 | 0 | Details |
| US2261272A | Radiant energy distance measuring system | Expired / Lapsed | 1940-08-07 | 1941-11-04 | 0 | Details |
| US2261628A | Stereophonic reproduction by carrier wave transmission | Expired / Lapsed | 1940-03-22 | 1941-11-04 | 0 | Details |
| US2261772A | Apparatus for measuring articles | Expired / Lapsed | 1940-01-11 | 1941-11-04 | 0 | Details |
| US2261412A | Fabrication of duplex metal bodies | Expired / Lapsed | 1938-10-27 | 1941-11-04 | 0 | Details |
| US2260709A | Television system | Expired / Lapsed | 1936-03-04 | 1941-10-28 | 0 | Details |
| US2260160A | Location and identification of faults in signaling transmis… | Expired / Lapsed | 1940-04-26 | 1941-10-21 | 0 | Details |
| US2260202A | Sound film recording or reproducing device | Expired / Lapsed | 1940-04-03 | 1941-10-21 | 0 | Details |
| US2258662A | Sound transmission system | Expired / Lapsed | 1940-04-05 | 1941-10-14 | 0 | Details |
| US2258651A | Telephone system | Expired / Lapsed | 1940-02-21 | 1941-10-14 | 0 | Details |
| US2258646A | Resistance material | Expired / Lapsed | 1939-05-17 | 1941-10-14 | 0 | Details |
| US2259000A | Transmission of frequency modulated waves | Expired / Lapsed | 1938-05-21 | 1941-10-14 | 0 | Details |
| US2259284A | Sweep circuits | Expired / Lapsed | 1937-08-26 | 1941-10-14 | 0 | Details |
| US2257783A | Guided wave transmission | Expired / Lapsed | 1939-09-21 | 1941-10-07 | 0 | Details |
| US2257795A | Electron discharge apparatus and circuits | Expired / Lapsed | 1939-05-27 | 1941-10-07 | 0 | Details |
| US2258128A | Wave translating system | Expired / Lapsed | 1938-12-20 | 1941-10-07 | 0 | Details |
| US2257894A | Telephone system | Expired / Lapsed | 1938-11-02 | 1941-10-07 | 0 | Details |
| US2257568A | Communication system | Expired / Lapsed | 1939-06-14 | 1941-09-30 | 0 | Details |
| US2257663A | Apparatus for producing interrupted alternating current | Expired / Lapsed | 1939-06-01 | 1941-09-30 | 0 | Details |
| US2254601A | Automatic measuring of cross talk | Expired / Lapsed | 1940-04-03 | 1941-09-02 | 0 | Details |
| US2254378A | Telephone system | Expired / Lapsed | 1940-02-02 | 1941-09-02 | 0 | Details |
| US2254852A | Oscillation generator | Expired / Lapsed | 1939-01-05 | 1941-09-02 | 0 | Details |
| US2254036A | Phase control | Expired / Lapsed | 1939-11-18 | 1941-08-26 | 0 | Details |
| US2253577A | Resistance device | Expired / Lapsed | 1939-04-07 | 1941-08-26 | 0 | Details |
| US2253503A | Generation and transmission of high frequency oscillations | Expired / Lapsed | 1938-08-06 | 1941-08-26 | 0 | Details |
| US2252766A | Signaling system | Expired / Lapsed | 1940-10-17 | 1941-08-19 | 0 | Details |
| US2252899A | Method of manufacturing contact springs | Expired / Lapsed | 1939-11-14 | 1941-08-19 | 0 | Details |
| US2252552A | Luminescent coating | Expired / Lapsed | 1940-07-05 | 1941-08-12 | 0 | Details |
| US2252293A | Modulation system | Expired / Lapsed | 1939-06-14 | 1941-08-12 | 0 | Details |
| US2251332A | Cathode ray device | Expired / Lapsed | 1938-03-31 | 1941-08-05 | 0 | Details |
| US2250528A | Signal translating system and apparatus | Expired / Lapsed | 1939-02-11 | 1941-07-29 | 0 | Details |
| US2250527A | Signal translating apparatus | Expired / Lapsed | 1939-02-11 | 1941-07-29 | 0 | Details |
| US2250529A | Signal translating apparatus | Expired / Lapsed | 1939-02-11 | 1941-07-29 | 0 | Details |
| US2250104A | Frequency regulation | Expired / Lapsed | 1940-03-30 | 1941-07-22 | 0 | Details |
| US2250101A | Telephone system | Expired / Lapsed | 1939-12-07 | 1941-07-22 | 0 | Details |
| US2250100A | Signaling system | Expired / Lapsed | 1939-11-14 | 1941-07-22 | 0 | Details |
| US2250156A | Electrical connection | Expired / Lapsed | 1939-06-02 | 1941-07-22 | 0 | Details |
| US2249950A | Method of preparing linear polyesters | Expired / Lapsed | 1938-05-28 | 1941-07-22 | 0 | Details |
| US2249164A | Electrical measuring system | Expired / Lapsed | 1940-05-01 | 1941-07-15 | 0 | Details |
| US2249160A | Acoustic device | Expired / Lapsed | 1939-05-19 | 1941-07-15 | 0 | Details |
| US2248923A | Communication system | Expired / Lapsed | 1939-05-09 | 1941-07-15 | 0 | Details |
| US2249153A | Testing device | Expired / Lapsed | 1939-05-02 | 1941-07-15 | 0 | Details |
| US2248985A | Electro-optical apparatus | Expired / Lapsed | 1938-08-25 | 1941-07-15 | 0 | Details |
| US2249323A | Testing apparatus | Expired / Lapsed | 1937-08-11 | 1941-07-15 | 0 | Details |
| US2248215A | Radio direction and distance indicating system | Expired / Lapsed | 1940-06-20 | 1941-07-08 | 0 | Details |
| US2248746A | Signal wave transmission system | Expired / Lapsed | 1940-03-22 | 1941-07-08 | 0 | Details |
| US2248250A | Single side-band modulation | Expired / Lapsed | 1939-09-21 | 1941-07-08 | 0 | Details |
| US2248057A | Electrical cutting device | Expired / Lapsed | 1939-01-25 | 1941-07-08 | 0 | Details |
| US2247442A | Neutralizing arrangement for amplifiers | Expired / Lapsed | 1940-02-02 | 1941-07-01 | 0 | Details |
| US2247737A | Inspection apparatus | Expired / Lapsed | 1940-01-11 | 1941-07-01 | 0 | Details |
| US2247666A | Directional antenna system | Expired / Lapsed | 1939-08-02 | 1941-07-01 | 0 | Details |
| US2247960A | Tuning fork | Expired / Lapsed | 1939-07-07 | 1941-07-01 | 0 | Details |
| US2247662A | Radiant energy distance measuring system | Expired / Lapsed | 1938-11-16 | 1941-07-01 | 0 | Details |
| US2247028A | Telephone booth cooling apparatus | Expired / Lapsed | 1940-10-29 | 1941-06-24 | 0 | Details |
| US2246534A | Alternating current wave production | Expired / Lapsed | 1940-06-26 | 1941-06-24 | 0 | Details |
| US2246655A | Tape splicer | Expired / Lapsed | 1940-02-20 | 1941-06-24 | 0 | Details |
| US2247214A | Oscillograph apparatus | Expired / Lapsed | 1939-05-13 | 1941-06-24 | 0 | Details |
| US2245732A | Stop mechanism | Expired / Lapsed | 1940-06-12 | 1941-06-17 | 0 | Details |
| US2245660A | Radio system | Expired / Lapsed | 1938-10-12 | 1941-06-17 | 0 | Details |
| US2245598A | Wave translation system | Expired / Lapsed | 1938-10-07 | 1941-06-17 | 0 | Details |
| US2244700A | Telephone system | Expired / Lapsed | 1939-09-21 | 1941-06-10 | 0 | Details |
| US2245364A | Cathode ray device | Expired / Lapsed | 1937-05-29 | 1941-06-10 | 0 | Details |
| US2244338A | Contact chatter indicator | Expired / Lapsed | 1940-08-30 | 1941-06-03 | 0 | Details |
| US2243851A | Wire line transmission | Expired / Lapsed | 1940-06-06 | 1941-06-03 | 0 | Details |
| US2244041A | Transmission measuring system | Expired / Lapsed | 1939-09-26 | 1941-06-03 | 0 | Details |
| US2243835A | Die casting machine | Expired / Lapsed | 1939-06-10 | 1941-06-03 | 0 | Details |
| US2244013A | Electric circuit | Expired / Lapsed | 1939-02-11 | 1941-06-03 | 0 | Details |
| US2244500A | Telephone system | Expired / Lapsed | 1938-09-30 | 1941-06-03 | 0 | Details |
| US2244004A | Telephone system | Expired / Lapsed | 1938-02-11 | 1941-06-03 | 0 | Details |
| US2244513A | Sweep circuit for cathode ray oscillograph | Expired / Lapsed | 1937-12-15 | 1941-06-03 | 0 | Details |
| US2243399A | Contact operating device | Expired / Lapsed | 1939-10-04 | 1941-05-27 | 0 | Details |
| US2242776A | Telephone system | Expired / Lapsed | 1939-04-25 | 1941-05-20 | 0 | Details |
| US2241591A | Calculating machine | Expired / Lapsed | 1939-05-24 | 1941-05-13 | 0 | Details |
| US2241761A | Electrical coil and a method of making the same | Expired / Lapsed | 1939-02-11 | 1941-05-13 | 0 | Details |
| US2241441A | Manufacture of magnetic bodies | Expired / Lapsed | 1938-07-15 | 1941-05-13 | 0 | Details |
| US2241031A | Telephone system | Expired / Lapsed | 1940-01-23 | 1941-05-06 | 0 | Details |
| US2240929A | Testing apparatus | Expired / Lapsed | 1939-11-22 | 1941-05-06 | 0 | Details |
| US2240941A | Oscillation source of the spark discharge gap type | Expired / Lapsed | 1939-06-20 | 1941-05-06 | 0 | Details |
| US2241228A | Coating machine | Expired / Lapsed | 1939-03-03 | 1941-05-06 | 0 | Details |
| US2241256A | Circuit for cathode ray tubes | Expired / Lapsed | 1937-12-31 | 1941-05-06 | 0 | Details |
| US2240286A | Amplifier | Expired / Lapsed | 1940-02-02 | 1941-04-29 | 0 | Details |
| US2240039A | Selector switch | Expired / Lapsed | 1938-07-09 | 1941-04-29 | 0 | Details |
| US2239771A | Electrically conductive device and its manufacture | Expired / Lapsed | 1938-05-14 | 1941-04-29 | 0 | Details |
| US2238142A | Teletypewriter switching system | Expired / Lapsed | 1939-07-14 | 1941-04-15 | 0 | Details |
| US2238555A | Voice operated mechanism | Expired / Lapsed | 1939-03-31 | 1941-04-15 | 0 | Details |
| US2237742A | Telephone system | Expired / Lapsed | 1939-11-28 | 1941-04-08 | 0 | Details |
| US2237906A | Telephone system | Expired / Lapsed | 1939-09-15 | 1941-04-08 | 0 | Details |
| US2237413A | Telephone system | Expired / Lapsed | 1939-04-04 | 1941-04-08 | 0 | Details |
| US2237326A | Apparatus for measuring acceleration | Expired / Lapsed | 1938-02-23 | 1941-04-08 | 0 | Details |
| US2236893A | Radiant energy distance determining system | Expired / Lapsed | 1939-12-30 | 1941-04-01 | 0 | Details |
| US2236690A | Negative impedance circuit | Expired / Lapsed | 1938-03-05 | 1941-04-01 | 0 | Details |
| US2236246A | Telephone system | Expired / Lapsed | 1939-09-15 | 1941-03-25 | 0 | Details |
| US2236393A | Directional antenna | Expired / Lapsed | 1939-03-01 | 1941-03-25 | 0 | Details |
| US2236374A | Remote indication and control | Expired / Lapsed | 1937-01-12 | 1941-03-25 | 0 | Details |
| US2236172A | Electro-optical system | Expired / Lapsed | 1936-03-04 | 1941-03-25 | 0 | Details |
| US2235132A | Magnetic telegraphone | Expired / Lapsed | 1939-07-29 | 1941-03-18 | 0 | Details |
| US2235126A | Magnetic telegraphone | Expired / Lapsed | 1939-07-13 | 1941-03-18 | 0 | Details |
| US2235153A | Chain start circuit | Expired / Lapsed | 1939-07-11 | 1941-03-18 | 0 | Details |
| US2235667A | Relaxation oscillator | Expired / Lapsed | 1938-12-16 | 1941-03-18 | 0 | Details |
| US2235803A | Telephone system | Expired / Lapsed | 1938-06-17 | 1941-03-18 | 0 | Details |
| US2234687A | Balanced vacuum tube circuit | Expired / Lapsed | 1939-11-25 | 1941-03-11 | 0 | Details |
| US2234353A | Electrical insulating material | Expired / Lapsed | 1939-04-12 | 1941-03-11 | 0 | Details |
| US2234587A | Radio direction finding system | Expired / Lapsed | 1938-09-23 | 1941-03-11 | 0 | Details |
| US2233621A | Pole-piece assembly for telegraphones | Expired / Lapsed | 1939-07-13 | 1941-03-04 | 0 | Details |
| US2233860A | Modulating system | Expired / Lapsed | 1939-04-27 | 1941-03-04 | 0 | Details |
| US2233848A | Audiphone | Expired / Lapsed | 1938-06-30 | 1941-03-04 | 0 | Details |
| US2233384A | Radio receiver | Expired / Lapsed | 1939-12-28 | 1941-02-25 | 0 | Details |
| US2232792A | Method of and apparatus for measuring impedances | Expired / Lapsed | 1939-12-15 | 1941-02-25 | 0 | Details |
| US2232866A | Signaling system | Expired / Lapsed | 1939-11-14 | 1941-02-25 | 0 | Details |
| US2232858A | Frequency meter | Expired / Lapsed | 1939-07-27 | 1941-02-25 | 0 | Details |
| US2232642A | Loading system | Expired / Lapsed | 1939-12-13 | 1941-02-18 | 0 | Details |
| US2231538A | Transmission control | Expired / Lapsed | 1939-06-21 | 1941-02-11 | 0 | Details |
| US2231542A | Transmission control circuit | Expired / Lapsed | 1939-06-21 | 1941-02-11 | 0 | Details |
| US2231085A | Method and apparatus for measuring force factors | Expired / Lapsed | 1939-06-03 | 1941-02-11 | 0 | Details |
| US2231634A | Variable frequency wave producing means | Expired / Lapsed | 1939-04-21 | 1941-02-11 | 0 | Details |
| US2231602A | Multiplex high frequency signaling | Expired / Lapsed | 1937-03-20 | 1941-02-11 | 0 | Details |
| US2230228A | Manufacture of magnetic cores | Expired / Lapsed | 1940-01-06 | 1941-02-04 | 0 | Details |
| US2230363A | Winding machine | Expired / Lapsed | 1939-03-03 | 1941-02-04 | 0 | Details |
| US2230649A | Variable electric capacity device | Expired / Lapsed | 1938-09-03 | 1941-02-04 | 0 | Details |
| US2229108A | Switching of spare repeater sections | Expired / Lapsed | 1939-09-28 | 1941-01-21 | 0 | Details |
| US2229158A | Switching of spare repeater sections | Expired / Lapsed | 1939-09-28 | 1941-01-21 | 0 | Details |
| US2229089A | Switching of spare channel | Expired / Lapsed | 1939-09-28 | 1941-01-21 | 0 | Details |
| US2228266A | Signal translating apparatus | Expired / Lapsed | 1939-07-01 | 1941-01-14 | 0 | Details |
| US2228113A | Selective system | Expired / Lapsed | 1937-11-05 | 1941-01-07 | 0 | Details |
| US2227268A | Piezoelectric apparatus | Expired / Lapsed | 1939-04-05 | 1940-12-31 | 0 | Details |
| US2226944A | Method of bonding dissimilar metals | Expired / Lapsed | 1938-10-27 | 1940-12-31 | 0 | Details |
| US2227048A | Negative feedback amplifier | Expired / Lapsed | 1938-07-09 | 1940-12-31 | 0 | Details |
| US2225653A | Compensation for variations in phase change | Expired / Lapsed | 1939-12-20 | 1940-12-24 | 0 | Details |
| US2226238A | Coupling circuit | Expired / Lapsed | 1939-11-10 | 1940-12-24 | 0 | Details |
| US2225688A | Telephone testing circuit | Expired / Lapsed | 1939-08-09 | 1940-12-24 | 0 | Details |
| US2225853A | Method of and apparatus for making grids | Expired / Lapsed | 1938-12-13 | 1940-12-24 | 0 | Details |
| US2226258A | Grid bias modulating system | Expired / Lapsed | 1938-09-22 | 1940-12-24 | 0 | Details |
| US2225312A | Acoustic device | Expired / Lapsed | 1939-10-05 | 1940-12-17 | 0 | Details |
| US2225057A | Light fixture for telephone booths | Expired / Lapsed | 1939-03-31 | 1940-12-17 | 0 | Details |
| US2224696A | Telephone system | Expired / Lapsed | 1939-05-13 | 1940-12-10 | 0 | Details |
| US2224677A | Signaling system | Expired / Lapsed | 1939-03-23 | 1940-12-10 | 0 | Details |
| US2223200A | Telephone repeater control circuit | Expired / Lapsed | 1939-07-11 | 1940-11-26 | 0 | Details |
| US2223224A | Radio speed and drift indicator | Expired / Lapsed | 1939-06-24 | 1940-11-26 | 0 | Details |
| US2222688A | Vibratory frequency controlling device | Expired / Lapsed | 1939-04-19 | 1940-11-26 | 0 | Details |
| US2222417A | Wave filter | Expired / Lapsed | 1938-09-24 | 1940-11-19 | 0 | Details |
| US2222425A | Magnetic structure | Expired / Lapsed | 1938-08-20 | 1940-11-19 | 0 | Details |
| US2220883A | Circuit controller | Expired / Lapsed | 1939-07-08 | 1940-11-12 | 0 | Details |
| US2220961A | Soldering alloy | Expired / Lapsed | 1937-11-06 | 1940-11-12 | 0 | Details |
| US2219749A | Single side band diversity radio receiving system | Expired / Lapsed | 1939-08-31 | 1940-10-29 | 0 | Details |
| US2219751A | Single side band diversity radio receiving system | Expired / Lapsed | 1939-08-23 | 1940-10-29 | 0 | Details |
| US2219365A | Electrical resistance device and method of manufacture ther… | Expired / Lapsed | 1939-05-17 | 1940-10-29 | 0 | Details |
| US2219888A | Extruding apparatus | Expired / Lapsed | 1938-09-15 | 1940-10-29 | 0 | Details |
| US2219021A | Frequency changing | Expired / Lapsed | 1939-06-30 | 1940-10-22 | 0 | Details |
| US2218711A | Electrical switching device | Expired / Lapsed | 1938-12-30 | 1940-10-22 | 0 | Details |
| US2217774A | Electron discharge apparatus | Expired / Lapsed | 1939-05-27 | 1940-10-15 | 0 | Details |
| US2218330A | Ventilator | Expired / Lapsed | 1939-01-10 | 1940-10-15 | 0 | Details |
| US2218225A | Piezoelectric apparatus | Expired / Lapsed | 1937-04-07 | 1940-10-15 | 0 | Details |
| US2217455A | Package | Expired / Lapsed | 1937-11-20 | 1940-10-08 | 0 | Details |
| US2216464A | Insulator | Expired / Lapsed | 1939-01-13 | 1940-10-01 | 0 | Details |
| US2216435A | Composition of matter and electrical conductor cable contai… | Expired / Lapsed | 1938-01-03 | 1940-10-01 | 0 | Details |
| US2214130A | Measurement of phase change and envelope delay of a transmi… | Expired / Lapsed | 1939-03-03 | 1940-09-10 | 0 | Details |
| US2214151A | Terminal and wire connection | Expired / Lapsed | 1938-06-28 | 1940-09-10 | 0 | Details |
| US2214019A | Electronic switching device | Expired / Lapsed | 1937-10-30 | 1940-09-10 | 0 | Details |
| US2213320A | Privacy system | Expired / Lapsed | 1938-09-10 | 1940-09-03 | 0 | Details |
| US2213938A | Multiplex signaling with phase discrimination | Expired / Lapsed | 1938-07-26 | 1940-09-03 | 0 | Details |
| US2213941A | Multiplex signaling by phase discrimination | Expired / Lapsed | 1938-07-26 | 1940-09-03 | 0 | Details |
| US2213398A | Vacuum tube circuit | Expired / Lapsed | 1938-07-22 | 1940-09-03 | 0 | Details |
| US2212337A | Electron discharge device circuit | Expired / Lapsed | 1939-01-27 | 1940-08-20 | 0 | Details |
| US2211020A | Telephone system | Expired / Lapsed | 1939-01-21 | 1940-08-13 | 0 | Details |
| US2210503A | Wave translation system | Expired / Lapsed | 1938-10-25 | 1940-08-06 | 0 | Details |
| US2210732A | Regulated rectifier system | Expired / Lapsed | 1938-04-21 | 1940-08-06 | 0 | Details |
| US2210028A | Amplifier | Expired / Lapsed | 1936-04-01 | 1940-08-06 | 0 | Details |
| US2209157A | Educational apparatus | Expired / Lapsed | 1939-06-02 | 1940-07-23 | 0 | Details |
| US2208923A | Volume limiter circuit | Expired / Lapsed | 1939-02-24 | 1940-07-23 | 0 | Details |
| US2208655A | Condenser storage equipment | Expired / Lapsed | 1938-11-19 | 1940-07-23 | 0 | Details |
| US2209064A | Measurement of phase shift | Expired / Lapsed | 1938-11-12 | 1940-07-23 | 0 | Details |
| US2208665A | Amplifier circuits with controlled gain | Expired / Lapsed | 1937-09-04 | 1940-07-23 | 0 | Details |
| US2207711A | Convoy current timing arrangement | Expired / Lapsed | 1939-07-08 | 1940-07-16 | 0 | Details |
| US2208398A | Radio receiver | Expired / Lapsed | 1939-02-23 | 1940-07-16 | 0 | Details |
| US2207720A | Communication system | Expired / Lapsed | 1938-07-19 | 1940-07-16 | 0 | Details |
| US2207940A | Biasing potential supply circuit | Expired / Lapsed | 1937-10-05 | 1940-07-16 | 0 | Details |
| US2207976A | Amplifier circuit | Expired / Lapsed | 1937-08-06 | 1940-07-16 | 0 | Details |
| US2206934A | Electrical conductor | Expired / Lapsed | 1939-03-03 | 1940-07-09 | 0 | Details |
| US2207355A | Electron discharge device | Expired / Lapsed | 1938-08-31 | 1940-07-09 | 0 | Details |
| US2207356A | Electron discharge apparatus | Expired / Lapsed | 1938-05-04 | 1940-07-09 | 0 | Details |
| US2207253A | Measuring and indicating circuits | Expired / Lapsed | 1937-12-31 | 1940-07-09 | 0 | Details |
| US2206080A | Transmission control and signaling system | Expired / Lapsed | 1939-04-27 | 1940-07-02 | 0 | Details |
| US2206538A | Telephone system | Expired / Lapsed | 1938-09-24 | 1940-07-02 | 0 | Details |
| US2206410A | Core for forming concrete conduits | Expired / Lapsed | 1937-11-17 | 1940-07-02 | 0 | Details |
| US2206224A | Telephone call transmitter | Expired / Lapsed | 1937-09-18 | 1940-07-02 | 0 | Details |
| US2204762A | Piezoelectric crystal apparatus | Expired / Lapsed | 1937-12-21 | 1940-06-18 | 0 | Details |
| US2204055A | Telephone system | Expired / Lapsed | 1938-11-25 | 1940-06-11 | 0 | Details |
| US2202921A | Trouble recorder | Expired / Lapsed | 1938-11-05 | 1940-06-04 | 0 | Details |
| US2203004A | Amplifying apparatus | Expired / Lapsed | 1938-05-05 | 1940-06-04 | 0 | Details |
| US2202172A | Control system | Expired / Lapsed | 1937-12-22 | 1940-05-28 | 0 | Details |
| US2202060A | Alarm system | Expired / Lapsed | 1936-12-12 | 1940-05-28 | 0 | Details |
| US2201344A | Mounting device | Expired / Lapsed | 1939-02-08 | 1940-05-21 | 0 | Details |
| US2201296A | Telephone system | Expired / Lapsed | 1938-10-18 | 1940-05-21 | 0 | Details |
| US2201879A | Delay type piezoelectric relay | Expired / Lapsed | 1938-09-03 | 1940-05-21 | 0 | Details |
| US2200933A | Strand handling apparatus | Expired / Lapsed | 1937-09-01 | 1940-05-14 | 0 | Details |
| US2200741A | Electrostatic recording and reproducing | Expired / Lapsed | 1937-05-01 | 1940-05-14 | 0 | Details |
| US2200819A | Measuring system | Expired / Lapsed | 1936-10-31 | 1940-05-14 | 0 | Details |
| US2200059A | Electrical terminal | Expired / Lapsed | 1938-06-11 | 1940-05-07 | 0 | Details |
| US2199824A | Signaling system | Expired / Lapsed | 1938-04-07 | 1940-05-07 | 0 | Details |
| US2199559A | Sound picture film | Expired / Lapsed | 1938-04-07 | 1940-05-07 | 0 | Details |
| US2199820A | Coupling circuits | Expired / Lapsed | 1937-10-30 | 1940-05-07 | 0 | Details |
| US2199219A | Terminal block | Expired / Lapsed | 1938-09-09 | 1940-04-30 | 0 | Details |
| US2199221A | Wave filter | Expired / Lapsed | 1938-08-20 | 1940-04-30 | 0 | Details |
| US2199083A | Transmission of guided waves | Expired / Lapsed | 1937-09-04 | 1940-04-30 | 0 | Details |
| US2197122A | Guided wave transmission | Expired / Lapsed | 1937-06-18 | 1940-04-16 | 0 | Details |
| US2196844A | Wave amplifying system | Expired / Lapsed | 1939-04-26 | 1940-04-09 | 0 | Details |
| US2196278A | Electron discharge apparatus | Expired / Lapsed | 1937-08-31 | 1940-04-09 | 0 | Details |
| US2195417A | Vibrating piezoelectric relay | Expired / Lapsed | 1937-11-10 | 1940-04-02 | 0 | Details |
| US2195081A | Sound printing mechanism | Expired / Lapsed | 1938-07-01 | 1940-03-26 | 0 | Details |
| US2194298A | System for the artificial production of vocal or other soun… | Expired / Lapsed | 1937-12-23 | 1940-03-19 | 0 | Details |
| US2192961A | Signaling system | Expired / Lapsed | 1939-02-11 | 1940-03-12 | 0 | Details |
| US2192529A | Projection apparatus | Expired / Lapsed | 1938-05-10 | 1940-03-05 | 0 | Details |
| US2190668A | Diode oscillator | Expired / Lapsed | 1937-07-31 | 1940-02-20 | 0 | Details |
| US2190546A | Control circuit for radio receivers | Expired / Lapsed | 1938-08-27 | 1940-02-13 | 0 | Details |
| US2190307A | Designation transmitter | Expired / Lapsed | 1937-08-31 | 1940-02-13 | 0 | Details |
| US2190552A | Gas tube circuit | Expired / Lapsed | 1936-07-03 | 1940-02-13 | 0 | Details |
| US2189898A | System of communication | Expired / Lapsed | 1933-08-23 | 1940-02-13 | 0 | Details |
| US2189395A | Insulated conductor and a method of making the same | Expired / Lapsed | 1937-04-14 | 1940-02-06 | 0 | Details |
| US2189110A | Voltage recording device | Expired / Lapsed | 1936-09-18 | 1940-02-06 | 0 | Details |
| US2188154A | Piezoelectric substance and process for producing it | Expired / Lapsed | 1938-08-04 | 1940-01-23 | 0 | Details |
| US2188159A | Gas-filled space discharge tube circuits | Expired / Lapsed | 1937-10-27 | 1940-01-23 | 0 | Details |
| US2187115A | Switching device | Expired / Lapsed | 1939-03-02 | 1940-01-16 | 0 | Details |
| US2187114A | Pneumatic device | Expired / Lapsed | 1938-03-31 | 1940-01-16 | 0 | Details |
| US2187158A | Telegraph system | Expired / Lapsed | 1936-08-22 | 1940-01-16 | 0 | Details |
| US2186217A | Control of electric generating apparatus | Expired / Lapsed | 1938-12-30 | 1940-01-09 | 0 | Details |
| US2185684A | Signal wave modulation | Expired / Lapsed | 1938-11-05 | 1940-01-02 | 0 | Details |
| US2185693A | Multiplex signaling system | Expired / Lapsed | 1938-02-25 | 1940-01-02 | 0 | Details |
| US2185283A | Cathode ray discharge device | Expired / Lapsed | 1936-08-20 | 1940-01-02 | 0 | Details |
| US2185300A | Telegraphone | Expired / Lapsed | 1936-02-21 | 1940-01-02 | 0 | Details |
| US2184978A | Carrier current telegraphy | Expired / Lapsed | 1938-05-19 | 1939-12-26 | 0 | Details |
| US2183708A | Signaling system | Expired / Lapsed | 1938-03-03 | 1939-12-19 | 0 | Details |
| US2183389A | Indicating circuit | Expired / Lapsed | 1939-01-14 | 1939-12-12 | 0 | Details |
| US2182841A | Reduction of distortion in signal transmission systems | Expired / Lapsed | 1938-05-19 | 1939-12-12 | 0 | Details |
| US2181265A | Signaling system | Expired / Lapsed | 1937-08-25 | 1939-11-28 | 0 | Details |
| US2181188A | Insulated cable | Expired / Lapsed | 1937-02-06 | 1939-11-28 | 0 | Details |
| US2180816A | Frequency conversion circuit | Expired / Lapsed | 1938-04-30 | 1939-11-21 | 0 | Details |
| US2180824A | Automatic call ticketing system | Expired / Lapsed | 1938-02-24 | 1939-11-21 | 0 | Details |
| US2180950A | Guided wave transmission | Expired / Lapsed | 1937-03-30 | 1939-11-21 | 0 | Details |
| US2179915A | Gain control circuits | Expired / Lapsed | 1938-09-08 | 1939-11-14 | 0 | Details |
| US2179971A | Means and method of sectionalizing coaxial cables | Expired / Lapsed | 1937-01-29 | 1939-11-14 | 0 | Details |
| US2179098A | Electro-optical apparatus | Expired / Lapsed | 1937-08-11 | 1939-11-07 | 0 | Details |
| US2179106A | Secrecy signaling system | Expired / Lapsed | 1937-08-11 | 1939-11-07 | 0 | Details |
| US2179261A | Method and apparatus for heating dielectric materials | Expired / Lapsed | 1937-08-11 | 1939-11-07 | 0 | Details |
| US2179243A | Cathode ray device | Expired / Lapsed | 1936-08-21 | 1939-11-07 | 0 | Details |
| US2178548A | Resistor | Expired / Lapsed | 1936-01-17 | 1939-11-07 | 0 | Details |
| US2178333A | Gain control circuits | Expired / Lapsed | 1938-09-08 | 1939-10-31 | 0 | Details |
| US2178365A | Electric conductor | Expired / Lapsed | 1936-02-19 | 1939-10-31 | 0 | Details |
| US2177260A | Apparatus for and a method of making coils | Expired / Lapsed | 1937-06-12 | 1939-10-24 | 0 | Details |
| US2175388A | Picture broadcasting system | Expired / Lapsed | 1936-12-28 | 1939-10-10 | 0 | Details |
| US2173858A | Radio system | Expired / Lapsed | 1937-06-23 | 1939-09-26 | 0 | Details |
| US2174003A | Optical device | Expired / Lapsed | 1935-11-29 | 1939-09-26 | 0 | Details |
| US2173170A | Teletypewriter apparatus | Expired / Lapsed | 1938-04-07 | 1939-09-19 | 0 | Details |
| US2173589A | Piezoelectric apparatus | Expired / Lapsed | 1933-12-14 | 1939-09-19 | 0 | Details |
| US2172847A | Assembling tool | Expired / Lapsed | 1936-06-20 | 1939-09-12 | 0 | Details |
| US2170944A | Multicathode ray discharge device | Expired / Lapsed | 1937-05-29 | 1939-08-29 | 0 | Details |
| US2170645A | High frequency amplifier | Expired / Lapsed | 1938-01-03 | 1939-08-22 | 0 | Details |
| US2170206A | Electrical and electromechanical system employing magnetost… | Expired / Lapsed | 1937-05-08 | 1939-08-22 | 0 | Details |
| US2170187A | Lacquer | Expired / Lapsed | 1936-09-29 | 1939-08-22 | 0 | Details |
| US2169732A | Method of making magnetic bodies | Expired / Lapsed | 1937-08-17 | 1939-08-15 | 0 | Details |
| US2169304A | Frequency selective system | Expired / Lapsed | 1937-06-23 | 1939-08-15 | 0 | Details |
| US2169553A | Directive radio system | Expired / Lapsed | 1936-09-11 | 1939-08-15 | 0 | Details |
| US2169396A | Signal-translating apparatus | Expired / Lapsed | 1936-05-08 | 1939-08-15 | 0 | Details |
| US2168769A | Protector | Expired / Lapsed | 1937-08-31 | 1939-08-08 | 0 | Details |
| US2168049A | Electro-optical system | Expired / Lapsed | 1936-12-24 | 1939-08-01 | 0 | Details |
| US2168047A | Electro-optical system | Expired / Lapsed | 1936-12-24 | 1939-08-01 | 0 | Details |
| US2167254A | Piezoelectric vibrator oscillator | Expired / Lapsed | 1938-04-23 | 1939-07-25 | 0 | Details |
| US2167007A | Transmission circuit | Expired / Lapsed | 1937-05-15 | 1939-07-25 | 0 | Details |
| US2167525A | Cabinet | Expired / Lapsed | 1935-08-08 | 1939-07-25 | 0 | Details |
| US2165509A | Oscillation generator | Expired / Lapsed | 1938-04-22 | 1939-07-11 | 0 | Details |
| US2165308A | Cathode ray device | Expired / Lapsed | 1937-03-31 | 1939-07-11 | 0 | Details |
| US2165307A | Means for translating magnetic variations into electric var… | Expired / Lapsed | 1937-03-31 | 1939-07-11 | 0 | Details |
| US2165510A | Electrical measuring, recording, and control system | Expired / Lapsed | 1936-03-27 | 1939-07-11 | 0 | Details |
| US2165892A | Multiplex telemetering system | Expired / Lapsed | 1935-05-10 | 1939-07-11 | 0 | Details |
| US2165925A | Automatic billing system | Expired / Lapsed | 1933-11-15 | 1939-07-11 | 0 | Details |
| US2165924A | Telephone system | Expired / Lapsed | 1933-10-31 | 1939-07-11 | 0 | Details |
| US2164335A | Telephone system | Expired / Lapsed | 1938-04-13 | 1939-07-04 | 0 | Details |
| US2164731A | Telephone system | Expired / Lapsed | 1937-04-07 | 1939-07-04 | 0 | Details |
| US2164383A | Magnetic device | Expired / Lapsed | 1934-12-29 | 1939-07-04 | 0 | Details |
| US2162874A | Electrical measuring circuit | Expired / Lapsed | 1937-09-02 | 1939-06-20 | 0 | Details |
| US2163403A | Stabilized oscillator | Expired / Lapsed | 1937-07-02 | 1939-06-20 | 0 | Details |
| US2163195A | Mechanical relay | Expired / Lapsed | 1936-10-08 | 1939-06-20 | 0 | Details |
| US2162362A | Asymmetrical conductor | Expired / Lapsed | 1938-10-11 | 1939-06-13 | 0 | Details |
| US2162268A | Signaling system | Expired / Lapsed | 1936-11-18 | 1939-06-13 | 0 | Details |
| US2161950A | Deposition furnace | Expired / Lapsed | 1936-05-27 | 1939-06-13 | 0 | Details |
| US2161570A | Cooling system | Expired / Lapsed | 1936-04-23 | 1939-06-06 | 0 | Details |
| US2160823A | Control of electromagnets | Expired / Lapsed | 1936-01-17 | 1939-06-06 | 0 | Details |
| US2159597A | Frequency conversion circuits | Expired / Lapsed | 1938-04-30 | 1939-05-23 | 0 | Details |
| US2159595A | Frequency conversion circuits | Expired / Lapsed | 1937-07-31 | 1939-05-23 | 0 | Details |
| US2159751A | Signaling system | Expired / Lapsed | 1935-06-22 | 1939-05-23 | 0 | Details |
| US2158630A | Testing apparatus | Expired / Lapsed | 1937-04-07 | 1939-05-16 | 0 | Details |
| US2157336A | Electron discharge apparatus | Expired / Lapsed | 1937-01-06 | 1939-05-09 | 0 | Details |
| US2156772A | Method of splicing a cable | Expired / Lapsed | 1936-03-25 | 1939-05-02 | 0 | Details |
| US2155508A | Wave guide impedance element and network | Expired / Lapsed | 1936-12-04 | 1939-04-25 | 0 | Details |
| US2155980A | Cable forming apparatus | Expired / Lapsed | 1934-05-26 | 1939-04-25 | 0 | Details |
| US2154886A | Selective signaling system | Expired / Lapsed | 1937-08-25 | 1939-04-18 | 0 | Details |
| US2154624A | Regenerative telegraph repeater | Expired / Lapsed | 1937-07-16 | 1939-04-18 | 0 | Details |
| US2155035A | Piezoelectric crystal apparatus | Expired / Lapsed | 1936-01-02 | 1939-04-18 | 0 | Details |
| US2154547A | Teletypewriter system | Expired / Lapsed | 1935-12-11 | 1939-04-18 | 0 | Details |
| US2153989A | Electrical testing apparatus | Expired / Lapsed | 1937-10-15 | 1939-04-11 | 0 | Details |
| US2153990A | Electrical testing apparatus | Expired / Lapsed | 1937-10-15 | 1939-04-11 | 0 | Details |
| US2153728A | Ultra high frequency signaling | Expired / Lapsed | 1936-10-07 | 1939-04-11 | 0 | Details |
| US2153638A | Amplifier | Expired / Lapsed | 1936-09-26 | 1939-04-11 | 0 | Details |
| US2151736A | Piezoelectric apparatus | Expired / Lapsed | 1936-09-23 | 1939-03-28 | 0 | Details |
| US2151726A | Signaling device | Expired / Lapsed | 1936-09-19 | 1939-03-28 | 0 | Details |
| US2151157A | Guided electromagnetic wave transmission | Expired / Lapsed | 1936-10-31 | 1939-03-21 | 0 | Details |
| US2151083A | Microphonic material | Expired / Lapsed | 1936-02-07 | 1939-03-21 | 0 | Details |
| US2151118A | Termination for dielectric guides | Expired / Lapsed | 1936-02-06 | 1939-03-21 | 0 | Details |
| US2150364A | Signaling system | Expired / Lapsed | 1937-07-31 | 1939-03-14 | 0 | Details |
| US2150376A | Electrical device | Expired / Lapsed | 1936-09-05 | 1939-03-14 | 0 | Details |
| US2150159A | Electro-optical system | Expired / Lapsed | 1936-03-04 | 1939-03-14 | 0 | Details |
| US2149356A | Wave transmission network | Expired / Lapsed | 1936-09-12 | 1939-03-07 | 0 | Details |
| US2149343A | Signaling system | Expired / Lapsed | 1936-03-14 | 1939-03-07 | 0 | Details |
| US2148532A | Radio repeater | Expired / Lapsed | 1938-04-28 | 1939-02-28 | 0 | Details |
| US2148578A | Signaling system | Expired / Lapsed | 1935-07-11 | 1939-02-28 | 0 | Details |
| US2147689A | Method and apparatus for heating dielectric materials | Expired / Lapsed | 1937-08-11 | 1939-02-21 | 0 | Details |
| US2147712A | Wave filter | Expired / Lapsed | 1936-02-19 | 1939-02-21 | 0 | Details |
| US2147717A | Guided wave transmission | Expired / Lapsed | 1935-12-31 | 1939-02-21 | 0 | Details |
| US2146869A | Tension control apparatus | Expired / Lapsed | 1936-07-30 | 1939-02-14 | 0 | Details |
| US2144844A | Magnetic telegraphone | Expired / Lapsed | 1936-08-06 | 1939-01-24 | 0 | Details |
| US2144873A | Time measuring system | Expired / Lapsed | 1934-05-04 | 1939-01-24 | 0 | Details |
| US2143971A | Telephone system | Expired / Lapsed | 1937-03-27 | 1939-01-17 | 0 | Details |
| US2143056A | Transmission system | Expired / Lapsed | 1937-11-17 | 1939-01-10 | 0 | Details |
| US2143407A | Gain control circuits | Expired / Lapsed | 1937-08-05 | 1939-01-10 | 0 | Details |
| US2143414A | Electrical device | Expired / Lapsed | 1934-08-25 | 1939-01-10 | 0 | Details |
| US2142138A | Guided wave transmission | Expired / Lapsed | 1935-10-03 | 1939-01-03 | 0 | Details |
| US2142339A | Picture broadcasting system | Expired / Lapsed | 1934-07-07 | 1939-01-03 | 0 | Details |
| US2141281A | Wave transmission | Expired / Lapsed | 1936-07-22 | 1938-12-27 | 0 | Details |
| US2141282A | Wave transmission | Expired / Lapsed | 1936-07-22 | 1938-12-27 | 0 | Details |
| US2141372A | Telephone system | Expired / Lapsed | 1935-10-16 | 1938-12-27 | 0 | Details |
| US2141388A | Facsimile telegraph system | Expired / Lapsed | 1935-05-22 | 1938-12-27 | 0 | Details |
| US2140492A | Distortion correction in wave transmission | Expired / Lapsed | 1937-08-10 | 1938-12-20 | 0 | Details |
| US2140138A | Impulse transmitter | Expired / Lapsed | 1937-02-18 | 1938-12-13 | 0 | Details |
| US2139685A | Electron discharge device | Expired / Lapsed | 1937-01-05 | 1938-12-13 | 0 | Details |
| US2139249A | Telephone system | Expired / Lapsed | 1937-05-01 | 1938-12-06 | 0 | Details |
| US2138966A | Radio compass system | Expired / Lapsed | 1937-04-12 | 1938-12-06 | 0 | Details |
| US2139232A | Transmission system | Expired / Lapsed | 1936-06-01 | 1938-12-06 | 0 | Details |
| US2139247A | Telephone system | Expired / Lapsed | 1935-06-11 | 1938-12-06 | 0 | Details |
| US2138594A | Telephone system | Expired / Lapsed | 1936-01-07 | 1938-11-29 | 0 | Details |
| US2138577A | Electro-optical transmission | Expired / Lapsed | 1934-04-06 | 1938-11-29 | 0 | Details |
| US2137852A | Piezoelectric oscillating and stress-measuring means | Expired / Lapsed | 1924-01-08 | 1938-11-22 | 0 | Details |
| US2137036A | Transmission system | Expired / Lapsed | 1936-10-31 | 1938-11-15 | 0 | Details |
| US2137032A | Sound reproducing system | Expired / Lapsed | 1936-09-30 | 1938-11-15 | 0 | Details |
| US2136621A | Antenna selector system | Expired / Lapsed | 1936-06-20 | 1938-11-15 | 0 | Details |
| US2136609A | Electrical device and a method of making the same | Expired / Lapsed | 1936-04-10 | 1938-11-15 | 0 | Details |
| US2137023A | Carrier communicating system | Expired / Lapsed | 1935-12-20 | 1938-11-15 | 0 | Details |
| US2133814A | Telephone system | Expired / Lapsed | 1937-12-22 | 1938-10-18 | 0 | Details |
| US2133384A | System and method for identification of conductors in cables | Expired / Lapsed | 1937-09-03 | 1938-10-18 | 0 | Details |
| US2133456A | Regenerative telegraph repeater | Expired / Lapsed | 1936-02-15 | 1938-10-18 | 0 | Details |
| US2132684A | Printing telegraph automatic exchange system | Expired / Lapsed | 1937-05-22 | 1938-10-11 | 0 | Details |
| US2132214A | Measuring system | Expired / Lapsed | 1937-01-27 | 1938-10-04 | 0 | Details |
| US2132213A | Recorder of liquid level heights | Expired / Lapsed | 1936-03-12 | 1938-10-04 | 0 | Details |
| US2132225A | Timing apparatus | Expired / Lapsed | 1935-06-26 | 1938-10-04 | 0 | Details |
| US2131578A | Monitoring circuit for telephone systems | Expired / Lapsed | 1937-08-25 | 1938-09-27 | 0 | Details |
| US2131366A | Electric wave amplifying system | Expired / Lapsed | 1936-12-05 | 1938-09-27 | 0 | Details |
| US2131173A | Cable sheath extruding press | Expired / Lapsed | 1936-02-15 | 1938-09-27 | 0 | Details |
| US2131202A | Simplified teleprinter and system | Expired / Lapsed | 1934-11-23 | 1938-09-27 | 0 | Details |
| US2129669A | Guided wave transmission | Expired / Lapsed | 1937-05-19 | 1938-09-13 | 0 | Details |
| US2129712A | Transmission of energy effects by guided electric waves in … | Expired / Lapsed | 1933-12-09 | 1938-09-13 | 0 | Details |
| US2129711A | Guided transmission of ultra high frequency waves | Expired / Lapsed | 1933-03-16 | 1938-09-13 | 0 | Details |
| US2129004A | Radio signaling | Expired / Lapsed | 1937-05-08 | 1938-09-06 | 0 | Details |
| US2129011A | Telephone system | Expired / Lapsed | 1936-09-09 | 1938-09-06 | 0 | Details |
| US2129008A | Condenser | Expired / Lapsed | 1936-05-20 | 1938-09-06 | 0 | Details |
| US2128412A | Cable plug | Expired / Lapsed | 1936-11-28 | 1938-08-30 | 0 | Details |
| US2128257A | Electrical network system | Expired / Lapsed | 1936-07-07 | 1938-08-30 | 0 | Details |
| US2127640A | Method of chromium plating | Expired / Lapsed | 1936-01-07 | 1938-08-23 | 0 | Details |
| US2126915A | Wave transmission network | Expired / Lapsed | 1937-03-12 | 1938-08-16 | 0 | Details |
| US2126929A | Sound reproducing system | Expired / Lapsed | 1936-05-15 | 1938-08-16 | 0 | Details |
| US2125280A | Electron discharge apparatus | Expired / Lapsed | 1936-11-20 | 1938-08-02 | 0 | Details |
| US2125279A | Electron discharge device | Expired / Lapsed | 1936-11-13 | 1938-08-02 | 0 | Details |
| US2124599A | Electrical network system | Expired / Lapsed | 1936-07-18 | 1938-07-26 | 0 | Details |
| US2123241A | Electric wave amplifier | Expired / Lapsed | 1937-08-05 | 1938-07-12 | 0 | Details |
| US2123227A | Piezoelectric device | Expired / Lapsed | 1935-06-26 | 1938-07-12 | 0 | Details |
| US2122538A | Wave amplifier | Expired / Lapsed | 1935-01-22 | 1938-07-05 | 0 | Details |
| US2122468A | Apparatus control system | Expired / Lapsed | 1934-03-23 | 1938-07-05 | 0 | Details |
| US2121142A | System for the artificial production of vocal or other soun… | Expired / Lapsed | 1937-04-07 | 1938-06-21 | 0 | Details |
| US2121287A | Composite set | Expired / Lapsed | 1937-03-03 | 1938-06-21 | 0 | Details |
| US2121282A | Combined telephone and fire alarm system | Expired / Lapsed | 1936-12-12 | 1938-06-21 | 0 | Details |
| US2120971A | System and method of determining distance | Expired / Lapsed | 1935-12-21 | 1938-06-21 | 0 | Details |
| US2120396A | Electrical contact member | Expired / Lapsed | 1936-06-04 | 1938-06-14 | 0 | Details |
| US2119607A | Radio communicating system | Expired / Lapsed | 1934-08-25 | 1938-06-07 | 0 | Details |
| US2118957A | Article supporting apparatus | Expired / Lapsed | 1936-06-27 | 1938-05-31 | 0 | Details |
| US2118944A | Control mechanism | Expired / Lapsed | 1934-03-13 | 1938-05-31 | 0 | Details |
| US2118161A | Receiving system for frequency modulated waves | Expired / Lapsed | 1935-12-24 | 1938-05-24 | 0 | Details |
| US2118471A | Electrical transmission system | Expired / Lapsed | 1932-09-01 | 1938-05-24 | 0 | Details |
| US2117752A | Harmonic producer | Expired / Lapsed | 1936-05-05 | 1938-05-17 | 0 | Details |
| US2117692A | Battery box | Expired / Lapsed | 1936-01-23 | 1938-05-17 | 0 | Details |
| US2116586A | Strip feeding mechanism | Expired / Lapsed | 1936-05-20 | 1938-05-10 | 0 | Details |
| US2116562A | Soldering iron | Expired / Lapsed | 1935-07-02 | 1938-05-10 | 0 | Details |
| US2116996A | Variable tuned circuits | Expired / Lapsed | 1935-05-17 | 1938-05-10 | 0 | Details |
| US2116600A | Electrical transmission control | Expired / Lapsed | 1935-04-25 | 1938-05-10 | 0 | Details |
| US2116593A | Cutting or milling machine | Expired / Lapsed | 1934-04-13 | 1938-05-10 | 0 | Details |
| US2115827A | Electric system and control apparatus therefor | Expired / Lapsed | 1935-10-08 | 1938-05-03 | 0 | Details |
| US2115917A | Picture transmitting system | Expired / Lapsed | 1925-03-12 | 1938-05-03 | 0 | Details |
| US2115894A | Apparatus and method for the electrical transmission of pic… | Expired / Lapsed | 1923-12-15 | 1938-05-03 | 0 | Details |
| US2115133A | Telephone system | Expired / Lapsed | 1935-08-30 | 1938-04-26 | 0 | Details |
| US2115138A | Wave transmission network | Expired / Lapsed | 1935-03-20 | 1938-04-26 | 0 | Details |
| US2115141A | Transmission regulating system | Expired / Lapsed | 1935-02-09 | 1938-04-26 | 0 | Details |
| US2114471A | Sound recording and reproducing system | Expired / Lapsed | 1936-06-20 | 1938-04-19 | 0 | Details |
| US2114036A | Frequency stabilization system | Expired / Lapsed | 1936-10-17 | 1938-04-12 | 0 | Details |
| US2114019A | Sound reproducing system | Expired / Lapsed | 1934-04-26 | 1938-04-12 | 0 | Details |
| US2114016A | Electrical counting system | Expired / Lapsed | 1934-01-20 | 1938-04-12 | 0 | Details |
| US2113210A | Frequency stable electric discharge oscillator | Expired / Lapsed | 1936-09-12 | 1938-04-05 | 0 | Details |
| US2113220A | Rectifier system | Expired / Lapsed | 1936-06-01 | 1938-04-05 | 0 | Details |
| US2113253A | Therapeutic apparatus | Expired / Lapsed | 1935-12-24 | 1938-04-05 | 0 | Details |
| US2113221A | Signaling system | Expired / Lapsed | 1935-10-31 | 1938-04-05 | 0 | Details |
| US2112951A | Telephone system | Expired / Lapsed | 1934-04-28 | 1938-04-05 | 0 | Details |
| US2112542A | Electromagnet and controlling circuits therefor | Expired / Lapsed | 1936-01-17 | 1938-03-29 | 0 | Details |
| US2111632A | Relay circuit | Expired / Lapsed | 1936-12-19 | 1938-03-22 | 0 | Details |
| US2111626A | Ultrahigh frequency generator | Expired / Lapsed | 1936-05-13 | 1938-03-22 | 0 | Details |
| US2111607A | Repeatered line system | Expired / Lapsed | 1935-11-30 | 1938-03-22 | 0 | Details |
| US2111598A | Frequency indicating and controlling apparatus | Expired / Lapsed | 1935-01-26 | 1938-03-22 | 0 | Details |
| US2111023A | Noise and cross-talk reduction in telephone communication c… | Expired / Lapsed | 1935-11-05 | 1938-03-15 | 0 | Details |
| US2110260A | Telegraph system | Expired / Lapsed | 1935-12-17 | 1938-03-08 | 0 | Details |
| US2109562A | Transmission system | Expired / Lapsed | 1935-01-02 | 1938-03-01 | 0 | Details |
| US2108219A | Gas tube circuits | Expired / Lapsed | 1936-07-03 | 1938-02-15 | 0 | Details |
| US2108637A | Testing apparatus | Expired / Lapsed | 1936-05-01 | 1938-02-15 | 0 | Details |
| US2108618A | Hard alloy | Expired / Lapsed | 1934-11-10 | 1938-02-15 | 0 | Details |
| US2107746A | Relay circuit | Expired / Lapsed | 1936-03-11 | 1938-02-08 | 0 | Details |
| US2107752A | Electrical device | Expired / Lapsed | 1934-10-20 | 1938-02-08 | 0 | Details |
| US2107168A | Carrier communicating system | Expired / Lapsed | 1936-02-12 | 1938-02-01 | 0 | Details |
| US2106805A | Teletypewriter | Expired / Lapsed | 1935-09-28 | 1938-02-01 | 0 | Details |
| US2106769A | Transmission of guided waves | Expired / Lapsed | 1935-08-23 | 1938-02-01 | 0 | Details |
| US2106793A | Filter including space discharge device | Expired / Lapsed | 1934-12-26 | 1938-02-01 | 0 | Details |
| US2106768A | Filter system for high frequency electric waves | Expired / Lapsed | 1934-09-25 | 1938-02-01 | 0 | Details |
| US2106344A | Electrical device | Expired / Lapsed | 1936-05-19 | 1938-01-25 | 0 | Details |
| US2105921A | Number checking system | Expired / Lapsed | 1936-03-11 | 1938-01-18 | 0 | Details |
| US2105083A | Temperature control means for extrusion apparatus | Expired / Lapsed | 1936-09-25 | 1938-01-11 | 0 | Details |
| US2104441A | Testing apparatus | Expired / Lapsed | 1936-08-19 | 1938-01-04 | 0 | Details |
| US2104142A | Gas-filled tube circuits | Expired / Lapsed | 1935-12-27 | 1938-01-04 | 0 | Details |
| US2104433A | Acoustic device | Expired / Lapsed | 1934-04-25 | 1938-01-04 | 0 | Details |
| US2103481A | Signaling system and method | Expired / Lapsed | 1928-07-24 | 1937-12-28 | 0 | Details |
| US2102708A | Signal testing apparatus | Expired / Lapsed | 1936-12-28 | 1937-12-21 | 0 | Details |
| US2102760A | Photoelectric tube | Expired / Lapsed | 1930-08-11 | 1937-12-21 | 0 | Details |
| US2102670A | Wave translation system | Expired / Lapsed | 1929-12-03 | 1937-12-21 | 0 | Details |
| US2102138A | Transmission system | Expired / Lapsed | 1936-02-21 | 1937-12-14 | 0 | Details |
| US2102141A | Battery charging system | Expired / Lapsed | 1935-03-23 | 1937-12-14 | 0 | Details |
| US2101976A | Television system | Expired / Lapsed | 1929-09-18 | 1937-12-14 | 0 | Details |
| US2101272A | Combined magnetostriction and piezoelectric selective device | Expired / Lapsed | 1934-07-18 | 1937-12-07 | 0 | Details |
| US2100400A | Telephone system | Expired / Lapsed | 1936-06-30 | 1937-11-30 | 0 | Details |
| US2100375A | Gain control | Expired / Lapsed | 1936-05-01 | 1937-11-30 | 0 | Details |
| US2100394A | Reception of frequency modulated waves and circuits therefor | Expired / Lapsed | 1936-01-23 | 1937-11-30 | 0 | Details |
| US2100412A | Temperature-compensated device | Expired / Lapsed | 1935-02-09 | 1937-11-30 | 0 | Details |
| US2099876A | Strand handling apparatus | Expired / Lapsed | 1934-06-09 | 1937-11-23 | 0 | Details |
| US2099889A | Television system | Expired / Lapsed | 1933-08-18 | 1937-11-23 | 0 | Details |
| US2098956A | Signaling system | Expired / Lapsed | 1936-12-02 | 1937-11-16 | 0 | Details |
| US2099065A | Distributor device | Expired / Lapsed | 1935-03-15 | 1937-11-16 | 0 | Details |
| US2099115A | Communication system | Expired / Lapsed | 1930-04-08 | 1937-11-16 | 0 | Details |
| US2098286A | Transmission control in signaling systems | Expired / Lapsed | 1936-07-31 | 1937-11-09 | 0 | Details |
| US2098326A | Calculating device | Expired / Lapsed | 1935-04-10 | 1937-11-09 | 0 | Details |
| US2097518A | Apparatus for winding material | Expired / Lapsed | 1935-12-11 | 1937-11-02 | 0 | Details |
| US2097578A | Apparatus for recording steep wave front voltages of short … | Expired / Lapsed | 1935-11-05 | 1937-11-02 | 0 | Details |
| US2097501A | Electrical cable and a method of making the same | Expired / Lapsed | 1933-07-12 | 1937-11-02 | 0 | Details |
| US2096824A | Power supply circuit | Expired / Lapsed | 1937-01-12 | 1937-10-26 | 0 | Details |
| US2096805A | Phonograph | Expired / Lapsed | 1935-09-18 | 1937-10-26 | 0 | Details |
| US2096460A | Space discharge apparatus | Expired / Lapsed | 1936-01-23 | 1937-10-19 | 0 | Details |
| US2096436A | Telephone system | Expired / Lapsed | 1935-07-11 | 1937-10-19 | 0 | Details |
| US2096046A | Support for telephones | Expired / Lapsed | 1935-03-27 | 1937-10-19 | 0 | Details |
| US2096416A | Method of coating hollow receptacles | Expired / Lapsed | 1934-08-22 | 1937-10-19 | 0 | Details |
| US2096429A | Accounting device | Expired / Lapsed | 1932-11-17 | 1937-10-19 | 0 | Details |
| US2095537A | Coating material | Expired / Lapsed | 1934-08-11 | 1937-10-12 | 0 | Details |
| US2094113A | Wave transmission | Expired / Lapsed | 1936-07-10 | 1937-09-28 | 0 | Details |
| US2094044A | Wave filter | Expired / Lapsed | 1935-07-02 | 1937-09-28 | 0 | Details |
| US2094068A | Telautograph | Expired / Lapsed | 1935-05-22 | 1937-09-28 | 0 | Details |
| US2093854A | Measuring device | Expired / Lapsed | 1936-12-12 | 1937-09-21 | 0 | Details |
| US2093512A | Electrical measuring system | Expired / Lapsed | 1936-08-25 | 1937-09-21 | 0 | Details |
| US2093855A | Radio telephone monitoring system | Expired / Lapsed | 1936-05-19 | 1937-09-21 | 0 | Details |
| US2092861A | Oscillation generating circuits including gas-filled tube | Expired / Lapsed | 1936-07-22 | 1937-09-14 | 0 | Details |
| US2092851A | Resetting circuits for gas-filled tubes | Expired / Lapsed | 1935-06-21 | 1937-09-14 | 0 | Details |
| US2093117A | Telephone system | Expired / Lapsed | 1935-06-19 | 1937-09-14 | 0 | Details |
| US2093103A | Testing apparatus | Expired / Lapsed | 1932-04-13 | 1937-09-14 | 0 | Details |
| US2092509A | Telephone booth | Expired / Lapsed | 1935-08-09 | 1937-09-07 | 0 | Details |
| US2092465A | Telephone system | Expired / Lapsed | 1935-06-22 | 1937-09-07 | 0 | Details |
| US2092493A | Automatic stock quotation system | Expired / Lapsed | 1934-12-08 | 1937-09-07 | 0 | Details |
| US2092489A | Treatment of fibrous insulating materials | Expired / Lapsed | 1927-11-26 | 1937-09-07 | 0 | Details |
| US2091533A | Automatic measuring device | Expired / Lapsed | 1936-11-07 | 1937-08-31 | 0 | Details |
| US2091554A | Composite refractory body | Expired / Lapsed | 1935-10-03 | 1937-08-31 | 0 | Details |
| US2090744A | Method of and apparatus for manufacturing an electrical cab… | Expired / Lapsed | 1933-10-11 | 1937-08-24 | 0 | Details |
| US2089409A | Phase correcting means and method | Expired / Lapsed | 1936-04-14 | 1937-08-10 | 0 | Details |
| US2089179A | Coaxial transmission system | Expired / Lapsed | 1936-04-07 | 1937-08-10 | 0 | Details |
| US2089338A | Telephone system | Expired / Lapsed | 1936-03-11 | 1937-08-10 | 0 | Details |
| US2089438A | Telephone system | Expired / Lapsed | 1936-03-10 | 1937-08-10 | 0 | Details |
| US2089264A | Electrical terminal | Expired / Lapsed | 1933-06-30 | 1937-08-10 | 0 | Details |
| US2088722A | Vacuum tube with tank circuits | Expired / Lapsed | 1936-06-12 | 1937-08-03 | 0 | Details |
| US2088750A | Answer-back device for machine switching printing telegraph… | Expired / Lapsed | 1936-01-18 | 1937-08-03 | 0 | Details |
| US2088749A | Reception of guided waves | Expired / Lapsed | 1935-10-30 | 1937-08-03 | 0 | Details |
| US2088297A | Harmonic analyzer | Expired / Lapsed | 1936-01-11 | 1937-07-27 | 0 | Details |
| US2087950A | Electrical attenuator | Expired / Lapsed | 1935-04-27 | 1937-07-27 | 0 | Details |
| US2087949A | Electrical attenuator | Expired / Lapsed | 1932-09-23 | 1937-07-27 | 0 | Details |
| US2087316A | Volume control system | Expired / Lapsed | 1935-12-11 | 1937-07-20 | 0 | Details |
| US2086683A | Gas tube circuits for measuring short-lived impulses | Expired / Lapsed | 1936-04-16 | 1937-07-13 | 0 | Details |
| US2086602A | Modulating system | Expired / Lapsed | 1935-08-08 | 1937-07-13 | 0 | Details |
| US2086601A | Modulating system | Expired / Lapsed | 1934-05-03 | 1937-07-13 | 0 | Details |
| US2086136A | Method of manufacturing switches | Expired / Lapsed | 1934-09-20 | 1937-07-06 | 0 | Details |
| US2085637A | Teletypewriter exchange system | Expired / Lapsed | 1936-11-14 | 1937-06-29 | 0 | Details |
| US2085125A | Radio transmitter | Expired / Lapsed | 1935-06-26 | 1937-06-29 | 0 | Details |
| US2085639A | Transmission regulation system | Expired / Lapsed | 1931-11-02 | 1937-06-29 | 0 | Details |
| US2084105A | Telephone control system | Expired / Lapsed | 1936-03-11 | 1937-06-15 | 0 | Details |
| US2084135A | Amplifier circuits | Expired / Lapsed | 1935-11-21 | 1937-06-15 | 0 | Details |
| US2084119A | Compensating network | Expired / Lapsed | 1935-06-22 | 1937-06-15 | 0 | Details |
| US2083666A | High frequency signaling system | Expired / Lapsed | 1933-09-30 | 1937-06-15 | 0 | Details |
| US2084149A | Apparatus for extruding matter | Expired / Lapsed | 1932-10-12 | 1937-06-15 | 0 | Details |
| US2082911A | Switch | Expired / Lapsed | 1935-11-08 | 1937-06-08 | 0 | Details |
| US2083495A | Electrical indicating or measuring system | Expired / Lapsed | 1935-10-30 | 1937-06-08 | 0 | Details |
| US2083344A | System and method of determining distances | Expired / Lapsed | 1934-04-06 | 1937-06-08 | 0 | Details |
| US2082877A | Multiplex communication signaling system | Expired / Lapsed | 1932-10-21 | 1937-06-08 | 0 | Details |
| US2082104A | Testing system | Expired / Lapsed | 1936-01-09 | 1937-06-01 | 0 | Details |
| US2082123A | Circuit control arrangements | Expired / Lapsed | 1935-05-11 | 1937-06-01 | 0 | Details |
| US2082102A | Resistance element | Expired / Lapsed | 1935-04-25 | 1937-06-01 | 0 | Details |
| US2081411A | Synchronous motor | Expired / Lapsed | 1935-09-21 | 1937-05-25 | 0 | Details |
| US2081405A | Wave filter | Expired / Lapsed | 1935-07-27 | 1937-05-25 | 0 | Details |
| US2081427A | Electric communication cable | Expired / Lapsed | 1935-02-16 | 1937-05-25 | 0 | Details |
| US2080494A | Method of and apparatus for coating strands | Expired / Lapsed | 1933-06-01 | 1937-05-18 | 0 | Details |
| US2079690A | Method of making resistance devices | Expired / Lapsed | 1936-01-02 | 1937-05-11 | 0 | Details |
| US2077172A | Telegraph signal distortion measuring device | Expired / Lapsed | 1934-12-19 | 1937-04-13 | 0 | Details |
| US2077160A | Radio transmitter | Expired / Lapsed | 1934-07-14 | 1937-04-13 | 0 | Details |
| US2075956A | Electric wave translating system | Expired / Lapsed | 1935-05-11 | 1937-04-06 | 0 | Details |
| US2075898A | Synchronizing system | Expired / Lapsed | 1925-06-11 | 1937-04-06 | 0 | Details |
| US2075527A | Telephone system | Expired / Lapsed | 1936-03-11 | 1937-03-30 | 0 | Details |
| US2073756A | Timing mechanism | Expired / Lapsed | 1936-03-10 | 1937-03-16 | 0 | Details |
| US2073679A | Electroplating apparatus | Expired / Lapsed | 1935-02-05 | 1937-03-16 | 0 | Details |
| US2073459A | Temperature control system and method | Expired / Lapsed | 1934-02-27 | 1937-03-09 | 0 | Details |
| US2073477A | Electric wave amplification | Expired / Lapsed | 1925-01-26 | 1937-03-09 | 0 | Details |
| US2072455A | Electrooptical system | Expired / Lapsed | 1929-12-04 | 1937-03-02 | 0 | Details |
| US2070668A | Wave transmission network | Expired / Lapsed | 1935-10-04 | 1937-02-16 | 0 | Details |
| US2070671A | Repeater testing | Expired / Lapsed | 1933-10-04 | 1937-02-16 | 0 | Details |
| US2069915A | Signaling system | Expired / Lapsed | 1935-05-01 | 1937-02-09 | 0 | Details |
| US2069841A | Safety device for phonographs | Expired / Lapsed | 1935-02-09 | 1937-02-09 | 0 | Details |
| US2069251A | Interconnecting telegraph repeater system | Expired / Lapsed | 1935-07-24 | 1937-02-02 | 0 | Details |
| US2069000A | Telegraph system | Expired / Lapsed | 1936-07-02 | 1937-01-26 | 0 | Details |
| US2068352A | Tungsten wire reducing machine | Expired / Lapsed | 1931-06-15 | 1937-01-19 | 0 | Details |
| US2066522A | Protective system and method | Expired / Lapsed | 1934-12-19 | 1937-01-05 | 0 | Details |
| US2066332A | Carrier wave transmission system | Expired / Lapsed | 1934-12-14 | 1937-01-05 | 0 | Details |
| US2066333A | Wave amplification and generation | Expired / Lapsed | 1934-12-14 | 1937-01-05 | 0 | Details |
| US2066525A | Conductor | Expired / Lapsed | 1929-03-29 | 1937-01-05 | 0 | Details |
| US2064907A | Common medium multichannel exchange system | Expired / Lapsed | 1934-05-26 | 1936-12-22 | 0 | Details |
| US2064894A | Common medium multichannel exchange system | Expired / Lapsed | 1934-05-26 | 1936-12-22 | 0 | Details |
| US2064906A | Common medium multichannel exchange system | Expired / Lapsed | 1934-05-26 | 1936-12-22 | 0 | Details |
| US2064958A | Signaling system for radiotelephones | Expired / Lapsed | 1934-05-26 | 1936-12-22 | 0 | Details |
| US2064905A | Common medium multichannel exchange system | Expired / Lapsed | 1934-05-26 | 1936-12-22 | 0 | Details |
| US2064896A | Common medium multichannel exchange system | Expired / Lapsed | 1934-05-26 | 1936-12-22 | 0 | Details |
| US2063998A | Electro-optical system | Expired / Lapsed | 1930-12-13 | 1936-12-15 | 0 | Details |
| US2064295A | Power transmission mechanism | Expired / Lapsed | 1930-12-10 | 1936-12-15 | 0 | Details |
| US2063342A | Electron discharge device | Expired / Lapsed | 1934-12-08 | 1936-12-08 | 0 | Details |
| US2061555A | Transmission control in two-way signaling systems | Expired / Lapsed | 1935-11-27 | 1936-11-24 | 0 | Details |
| US2060905A | Asymmetrical conductor | Expired / Lapsed | 1935-03-30 | 1936-11-17 | 0 | Details |
| US2060913A | Electrical conductor | Expired / Lapsed | 1934-07-07 | 1936-11-17 | 0 | Details |
| US2060849A | Electrical measuring device | Expired / Lapsed | 1933-11-24 | 1936-11-17 | 0 | Details |
| US2061027A | Communication with moving trains | Expired / Lapsed | 1931-09-10 | 1936-11-17 | 0 | Details |
| US2060184A | Telephone system | Expired / Lapsed | 1935-11-21 | 1936-11-10 | 0 | Details |
| US2060042A | Regulation of transmission lines | Expired / Lapsed | 1934-11-03 | 1936-11-10 | 0 | Details |
| US2060250A | Combined teleprinter and telephone system | Expired / Lapsed | 1932-04-23 | 1936-11-10 | 0 | Details |
| US2059596A | Telephone call distributing system | Expired / Lapsed | 1934-11-30 | 1936-11-03 | 0 | Details |
| US2058263A | Cabinet | Expired / Lapsed | 1935-07-11 | 1936-10-20 | 0 | Details |
| US2058170A | Marginal control of gas-filled tubes | Expired / Lapsed | 1932-08-26 | 1936-10-20 | 0 | Details |
| US2055181A | Photoelectric tube | Expired / Lapsed | 1930-11-26 | 1936-09-22 | 0 | Details |
| US2053645A | Strand handling apparatus | Expired / Lapsed | 1934-12-08 | 1936-09-08 | 0 | Details |
| US2050703A | Transmission system regulation | Expired / Lapsed | 1934-06-09 | 1936-08-11 | 0 | Details |
| US2050265A | Iterative telegraph system | Expired / Lapsed | 1933-07-14 | 1936-08-11 | 0 | Details |
| US2050633A | Constant temperature device | Expired / Lapsed | 1931-06-09 | 1936-08-11 | 0 | Details |
| US2048506A | Telephone system | Expired / Lapsed | 1935-03-07 | 1936-07-21 | 0 | Details |
| US2048080A | Signaling with high frequency waves | Expired / Lapsed | 1934-02-10 | 1936-07-21 | 0 | Details |
| US2047782A | Electrical measuring system | Expired / Lapsed | 1935-05-14 | 1936-07-14 | 0 | Details |
| US2047312A | Signaling system | Expired / Lapsed | 1926-12-01 | 1936-07-14 | 0 | Details |
| US2047817A | Picture transmitting system | Expired / Lapsed | 1924-12-24 | 1936-07-14 | 0 | Details |
| US2046422A | Motor generator regulator system | Expired / Lapsed | 1936-03-10 | 1936-07-07 | 0 | Details |
| US2046436A | Ground impedance measurement | Expired / Lapsed | 1935-06-12 | 1936-07-07 | 0 | Details |
| US2046704A | Owen bridge | Expired / Lapsed | 1935-04-10 | 1936-07-07 | 0 | Details |
| US2046686A | Asymmetrical electrical conductor | Expired / Lapsed | 1934-05-22 | 1936-07-07 | 0 | Details |
| US2045735A | Radio receiving circuits | Expired / Lapsed | 1934-05-26 | 1936-06-30 | 0 | Details |
| US2045072A | Method and means for measuring altitude of aircraft | Expired / Lapsed | 1936-01-30 | 1936-06-23 | 0 | Details |
| US2045409A | Electromagnet | Expired / Lapsed | 1935-03-15 | 1936-06-23 | 0 | Details |
| US2045438A | Control apparatus | Expired / Lapsed | 1934-12-19 | 1936-06-23 | 0 | Details |
| US2045071A | Altimeter for aircraft | Expired / Lapsed | 1930-04-29 | 1936-06-23 | 0 | Details |
| US2044470A | Impulse sender | Expired / Lapsed | 1933-04-12 | 1936-06-16 | 0 | Details |
| US2044424A | Insulation testing system | Expired / Lapsed | 1932-07-13 | 1936-06-16 | 0 | Details |
| US2043403A | Telephone transmission circuits | Expired / Lapsed | 1934-11-08 | 1936-06-09 | 0 | Details |
| US2043347A | Directional radio transmission system | Expired / Lapsed | 1932-01-02 | 1936-06-09 | 0 | Details |
| US2042869A | Code calling system | Expired / Lapsed | 1935-01-23 | 1936-06-02 | 0 | Details |
| US2042848A | Cabinet | Expired / Lapsed | 1934-07-28 | 1936-06-02 | 0 | Details |
| US2041964A | Telephone system | Expired / Lapsed | 1934-08-16 | 1936-05-26 | 0 | Details |
| US2041822A | Electrooptical system | Expired / Lapsed | 1934-03-06 | 1936-05-26 | 0 | Details |
| US2041084A | Telephone system | Expired / Lapsed | 1934-12-29 | 1936-05-19 | 0 | Details |
| US2041600A | Radio system | Expired / Lapsed | 1934-04-05 | 1936-05-19 | 0 | Details |
| US2040462A | Selective signaling system | Expired / Lapsed | 1934-05-26 | 1936-05-12 | 0 | Details |
| US2040285A | Method of measuring fluid pressure | Expired / Lapsed | 1933-01-13 | 1936-05-12 | 0 | Details |
| US2039625A | Acoustic device | Expired / Lapsed | 1934-07-13 | 1936-05-05 | 0 | Details |
| US2039404A | Remote metering system | Expired / Lapsed | 1933-03-21 | 1936-05-05 | 0 | Details |
| US2038647A | Signaling system | Expired / Lapsed | 1934-09-14 | 1936-04-28 | 0 | Details |
| US2038992A | Modulating system for ultra short waves | Expired / Lapsed | 1933-12-15 | 1936-04-28 | 0 | Details |
| US2038649A | Selective signaling system | Expired / Lapsed | 1932-10-13 | 1936-04-28 | 0 | Details |
| US2038216A | Support for vibration translating devices | Expired / Lapsed | 1934-12-29 | 1936-04-21 | 0 | Details |
| US2038240A | Transmission system | Expired / Lapsed | 1934-11-14 | 1936-04-21 | 0 | Details |
| US2038215A | Lubricating and protective coating | Expired / Lapsed | 1934-01-10 | 1936-04-21 | 0 | Details |
| US2038202A | Carrier wave system | Expired / Lapsed | 1933-11-02 | 1936-04-21 | 0 | Details |
| US2037166A | Electrooptical system | Expired / Lapsed | 1935-05-31 | 1936-04-14 | 0 | Details |
| US2037191A | Registering device | Expired / Lapsed | 1932-09-30 | 1936-04-14 | 0 | Details |
| US2036010A | Mounting for acoustic devices | Expired / Lapsed | 1934-07-25 | 1936-03-31 | 0 | Details |
| US2035536A | Interconnection of transmission lines | Expired / Lapsed | 1934-06-09 | 1936-03-31 | 0 | Details |
| US2035545A | Coaxial conductor transmission system | Expired / Lapsed | 1932-06-18 | 1936-03-31 | 0 | Details |
| US2034872A | Phonograph reproducer | Expired / Lapsed | 1934-10-20 | 1936-03-24 | 0 | Details |
| US2034708A | Remote control apparatus | Expired / Lapsed | 1934-04-28 | 1936-03-24 | 0 | Details |
| US2034881A | Electromagnetic relay circuits | Expired / Lapsed | 1933-05-26 | 1936-03-24 | 0 | Details |
| US2035263A | Volume control system | Expired / Lapsed | 1933-05-26 | 1936-03-24 | 0 | Details |
| US2034047A | Coaxial circuit with stranded inner conductor | Expired / Lapsed | 1933-06-07 | 1936-03-17 | 0 | Details |
| US2034032A | Shielded pair of wires | Expired / Lapsed | 1933-06-07 | 1936-03-17 | 0 | Details |
| US2034034A | Circuits with noncircular shields | Expired / Lapsed | 1933-06-07 | 1936-03-17 | 0 | Details |
| US2034260A | Accounting system | Expired / Lapsed | 1932-11-17 | 1936-03-17 | 0 | Details |
| US2033237A | Frequency control system | Expired / Lapsed | 1934-08-15 | 1936-03-10 | 0 | Details |
| US2032514A | Gas-filled tube and circuit therefor | Expired / Lapsed | 1935-06-01 | 1936-03-03 | 0 | Details |
| US2032360A | Power line carrier system | Expired / Lapsed | 1930-12-12 | 1936-03-03 | 0 | Details |
| US2031692A | Telephone system | Expired / Lapsed | 1935-03-28 | 1936-02-25 | 0 | Details |
| US2031951A | Burglar alarm system | Expired / Lapsed | 1932-02-25 | 1936-02-25 | 0 | Details |
| US2031952A | Electrooptical system | Expired / Lapsed | 1930-08-11 | 1936-02-25 | 0 | Details |
| US2030412A | Telephone exchange system | Expired / Lapsed | 1934-10-24 | 1936-02-11 | 0 | Details |
| US2030443A | Solid rectifying element | Expired / Lapsed | 1934-07-19 | 1936-02-11 | 0 | Details |
| US2030179A | Electrical circuit arrangement | Expired / Lapsed | 1933-08-18 | 1936-02-11 | 0 | Details |
| US2030178A | Electrical circuit arrangement | Expired / Lapsed | 1933-01-19 | 1936-02-11 | 0 | Details |
| US2029730A | Combined recorder and reproducer | Expired / Lapsed | 1933-02-15 | 1936-02-04 | 0 | Details |
| US2028212A | Radio transmitting system | Expired / Lapsed | 1933-12-22 | 1936-01-21 | 0 | Details |
| US2027169A | Vibration translating device | Expired / Lapsed | 1934-09-29 | 1936-01-07 | 0 | Details |
| US2025158A | Modulating system | Expired / Lapsed | 1934-06-07 | 1935-12-24 | 0 | Details |
| US2025400A | Volume control circuits | Expired / Lapsed | 1934-05-26 | 1935-12-24 | 0 | Details |
| US2025407A | Electrical recorder | Expired / Lapsed | 1933-04-21 | 1935-12-24 | 0 | Details |
| US2024609A | Sound picture system | Expired / Lapsed | 1933-11-14 | 1935-12-17 | 0 | Details |
| US2022972A | Variable gain amplifier | Expired / Lapsed | 1934-08-21 | 1935-12-03 | 0 | Details |
| US2022969A | Electrical wave production | Expired / Lapsed | 1934-07-07 | 1935-12-03 | 0 | Details |
| US2023011A | Telephone system | Expired / Lapsed | 1934-05-22 | 1935-12-03 | 0 | Details |
| US2022991A | Alarm transmitting system | Expired / Lapsed | 1933-12-01 | 1935-12-03 | 0 | Details |
| US2022790A | Frequency indicating system | Expired / Lapsed | 1933-08-24 | 1935-12-03 | 0 | Details |
| US2021920A | Control circuits | Expired / Lapsed | 1935-01-15 | 1935-11-26 | 0 | Details |
| US2021329A | Switching mechanism | Expired / Lapsed | 1933-12-15 | 1935-11-19 | 0 | Details |
| US2021276A | Spring winding machine | Expired / Lapsed | 1933-04-04 | 1935-11-19 | 0 | Details |
| US2021302A | Perforating apparatus | Expired / Lapsed | 1932-05-13 | 1935-11-19 | 0 | Details |
| US2020477A | Ceramic article | Expired / Lapsed | 1933-10-27 | 1935-11-12 | 0 | Details |
| US2020297A | Submarine cable transmission | Expired / Lapsed | 1933-10-06 | 1935-11-12 | 0 | Details |
| US2020409A | Band separation system | Expired / Lapsed | 1933-08-15 | 1935-11-12 | 0 | Details |
| US2020476A | Ceramic article | Expired / Lapsed | 1933-02-17 | 1935-11-12 | 0 | Details |
| US2019594A | Signal transmission system | Expired / Lapsed | 1933-07-21 | 1935-11-05 | 0 | Details |
| US2018851A | Unattended repeater system | Expired / Lapsed | 1934-06-09 | 1935-10-29 | 0 | Details |
| US2018859A | Unattended repeater system | Expired / Lapsed | 1934-06-09 | 1935-10-29 | 0 | Details |
| US2018384A | Gauge | Expired / Lapsed | 1933-09-14 | 1935-10-22 | 0 | Details |
| US2018464A | Voice operated transmission circuit | Expired / Lapsed | 1930-06-07 | 1935-10-22 | 0 | Details |
| US2017653A | Velocity comparing system for film driving apparatus | Expired / Lapsed | 1933-04-06 | 1935-10-15 | 0 | Details |
| US2016420A | Gauge | Expired / Lapsed | 1933-11-02 | 1935-10-08 | 0 | Details |
| US2016452A | Carrier current channel separation system | Expired / Lapsed | 1931-12-17 | 1935-10-08 | 0 | Details |
| US2016455A | Apparatus for processing electrical devices | Expired / Lapsed | 1930-01-09 | 1935-10-08 | 0 | Details |
| US2014524A | Article | Expired / Lapsed | 1933-04-28 | 1935-09-17 | 0 | Details |
| US2014228A | Variable attenuator | Expired / Lapsed | 1933-02-24 | 1935-09-10 | 0 | Details |
| US2014179A | Electrical discharge registering system | Expired / Lapsed | 1931-03-21 | 1935-09-10 | 0 | Details |
| US2012995A | Stereoscopic motion picture | Expired / Lapsed | 1929-02-09 | 1935-09-03 | 0 | Details |
| US2012286A | Wave translation system | Expired / Lapsed | 1932-01-29 | 1935-08-27 | 0 | Details |
| US2011932A | Projection of motion pictures | Expired / Lapsed | 1932-01-23 | 1935-08-20 | 0 | Details |
| US2010644A | Signal transmission line | Expired / Lapsed | 1933-08-23 | 1935-08-06 | 0 | Details |
| US2010543A | Electrooptical system | Expired / Lapsed | 1931-01-10 | 1935-08-06 | 0 | Details |
| US2009438A | Carrier wave transmission system | Expired / Lapsed | 1931-07-31 | 1935-07-30 | 0 | Details |
| US2008857A | Mechanical impedance meter | Expired / Lapsed | 1933-04-04 | 1935-07-23 | 0 | Details |
| US2008874A | Photo-electric tube | Expired / Lapsed | 1929-04-06 | 1935-07-23 | 0 | Details |
| US2008288A | Wire wound electrical device | Expired / Lapsed | 1934-01-31 | 1935-07-16 | 0 | Details |
| US2007172A | Wave translation system | Expired / Lapsed | 1933-03-29 | 1935-07-09 | 0 | Details |
| US2006438A | Telephone exchange system | Expired / Lapsed | 1934-10-20 | 1935-07-02 | 0 | Details |
| US2006354A | Telephone system | Expired / Lapsed | 1934-06-20 | 1935-07-02 | 0 | Details |
| US2006698A | Electrical measuring system | Expired / Lapsed | 1934-05-26 | 1935-07-02 | 0 | Details |
| US2005588A | Stylus feed mechanism for phonographs | Expired / Lapsed | 1931-08-28 | 1935-06-18 | 0 | Details |
| US2004248A | Time announcing system | Expired / Lapsed | 1933-12-22 | 1935-06-11 | 0 | Details |
| US2004599A | Telephone system | Expired / Lapsed | 1933-07-19 | 1935-06-11 | 0 | Details |
| US2003428A | Volume control for transmission circuits | Expired / Lapsed | 1932-09-20 | 1935-06-04 | 0 | Details |
| US2003282A | Wave translation system | Expired / Lapsed | 1929-12-03 | 1935-06-04 | 0 | Details |
| US2003294A | Television system | Expired / Lapsed | 1927-11-02 | 1935-06-04 | 0 | Details |
| US2001730A | Electrooptical system | Expired / Lapsed | 1930-10-11 | 1935-05-21 | 0 | Details |
| US2000990A | Electron discharge device | Expired / Lapsed | 1933-10-27 | 1935-05-14 | 0 | Details |
| US2000441A | Filter | Expired / Lapsed | 1934-07-06 | 1935-05-07 | 0 | Details |
| US2000130A | Wide band transmission system | Expired / Lapsed | 1932-12-16 | 1935-05-07 | 0 | Details |
| US1998827A | Composite articles and their method of manufacture | Expired / Lapsed | 1932-03-10 | 1935-04-23 | 0 | Details |
| US1998119A | Frequency changer and circuits therefor | Expired / Lapsed | 1932-08-19 | 1935-04-16 | 0 | Details |
| US1998072A | Signal and contact device | Expired / Lapsed | 1930-06-07 | 1935-04-16 | 0 | Details |
| US1998110A | Flowmeter | Expired / Lapsed | 1928-03-07 | 1935-04-16 | 0 | Details |
| US1997195A | Telephone exchange system | Expired / Lapsed | 1933-12-29 | 1935-04-09 | 0 | Details |
| US1997198A | Terminal mounting for resistances | Expired / Lapsed | 1931-01-31 | 1935-04-09 | 0 | Details |
| US1996511A | Phonograph reproducing system | Expired / Lapsed | 1933-08-02 | 1935-04-02 | 0 | Details |
| US1996504A | Wave filter | Expired / Lapsed | 1933-04-12 | 1935-04-02 | 0 | Details |
| US1996186A | Transmission line conductor | Expired / Lapsed | 1932-10-05 | 1935-04-02 | 0 | Details |
| US1995404A | Rectifier system | Expired / Lapsed | 1932-09-01 | 1935-03-26 | 0 | Details |
| US1995356A | Submarine communication conductor | Expired / Lapsed | 1929-03-19 | 1935-03-26 | 0 | Details |
| US1994632A | Asymmetric conductor | Expired / Lapsed | 1933-05-11 | 1935-03-19 | 0 | Details |
| US1994624A | Control system | Expired / Lapsed | 1933-01-07 | 1935-03-19 | 0 | Details |
| US1993781A | Electrically heated tool | Expired / Lapsed | 1931-08-05 | 1935-03-12 | 0 | Details |
| US1993793A | Timing mechanism | Expired / Lapsed | 1930-04-30 | 1935-03-12 | 0 | Details |
| US1992268A | Acoustic device | Expired / Lapsed | 1933-04-11 | 1935-02-26 | 0 | Details |
| US1992271A | Automatic stock quotation system | Expired / Lapsed | 1931-09-17 | 1935-02-26 | 0 | Details |
| US1990544A | Electrooptical system | Expired / Lapsed | 1930-03-25 | 1935-02-12 | 0 | Details |
| US1990437A | Telephone system | Expired / Lapsed | 1933-09-01 | 1935-02-05 | 0 | Details |
| US1988609A | Synchronizing system | Expired / Lapsed | 1931-07-21 | 1935-01-22 | 0 | Details |
| US1986583A | Phonograph reproducer | Expired / Lapsed | 1933-01-12 | 1935-01-01 | 0 | Details |
| US1984036A | Electrical insulating device having a terminal thereon and … | Expired / Lapsed | 1932-10-12 | 1934-12-11 | 0 | Details |
| US1984066A | Signal transmission system | Expired / Lapsed | 1931-03-27 | 1934-12-11 | 0 | Details |
| US1984031A | Apparatus for testing and sorting articles | Expired / Lapsed | 1930-11-08 | 1934-12-11 | 0 | Details |
| US1981999A | Optical telephone system | Expired / Lapsed | 1932-08-20 | 1934-11-27 | 0 | Details |
| US1981689A | Program distributing system | Expired / Lapsed | 1933-08-16 | 1934-11-20 | 0 | Details |
| US1981669A | Electric discharge device | Expired / Lapsed | 1932-08-12 | 1934-11-20 | 0 | Details |
| US1981652A | Method of coating electrodes | Expired / Lapsed | 1931-04-28 | 1934-11-20 | 0 | Details |
| US1980190A | Impulse transmitter | Expired / Lapsed | 1932-03-04 | 1934-11-13 | 0 | Details |
| US1980176A | Unidirectional current passing device | Expired / Lapsed | 1931-06-25 | 1934-11-13 | 0 | Details |
| US1979414A | Differential mechanism | Expired / Lapsed | 1933-11-22 | 1934-11-06 | 0 | Details |
| US1978418A | Concentric return multiconductor cable | Expired / Lapsed | 1930-10-08 | 1934-10-30 | 0 | Details |
| US1979101A | Transmission system | Expired / Lapsed | 1929-02-06 | 1934-10-30 | 0 | Details |
| US1977703A | Method of and apparatus for electrical testing | Expired / Lapsed | 1932-01-07 | 1934-10-23 | 0 | Details |
| US1977677A | Electrical connecter | Expired / Lapsed | 1930-09-27 | 1934-10-23 | 0 | Details |
| US1978200A | Electrostatic acoustic device | Expired / Lapsed | 1930-03-24 | 1934-10-23 | 0 | Details |
| US1977697A | Control apparatus | Expired / Lapsed | 1929-10-23 | 1934-10-23 | 0 | Details |
| US1976935A | Control apparatus | Expired / Lapsed | 1932-05-13 | 1934-10-16 | 0 | Details |
| US1976481A | Wave analysis | Expired / Lapsed | 1931-08-20 | 1934-10-09 | 0 | Details |
| US1976570A | Constant frequency oscillator | Expired / Lapsed | 1930-08-28 | 1934-10-09 | 0 | Details |
| US1976548A | Electrical communication system | Expired / Lapsed | 1930-07-15 | 1934-10-09 | 0 | Details |
| US1974067A | Electrooptical system | Expired / Lapsed | 1931-08-12 | 1934-09-18 | 0 | Details |
| US1972985A | Electric switching device | Expired / Lapsed | 1930-09-23 | 1934-09-11 | 0 | Details |
| US1971686A | Telegraph signal transmitting circuits | Expired / Lapsed | 1932-02-03 | 1934-08-28 | 0 | Details |
| US1970337A | Telephone system | Expired / Lapsed | 1932-11-10 | 1934-08-14 | 0 | Details |
| US1969488A | Circuit controller | Expired / Lapsed | 1930-09-23 | 1934-08-07 | 0 | Details |
| US1968420A | Telephone system | Expired / Lapsed | 1933-02-16 | 1934-07-31 | 0 | Details |
| US1967250A | Wave filter | Expired / Lapsed | 1933-01-26 | 1934-07-24 | 0 | Details |
| US1966491A | Antenna system | Expired / Lapsed | 1930-12-01 | 1934-07-17 | 0 | Details |
| US1966509A | Insulated conductor | Expired / Lapsed | 1928-11-21 | 1934-07-17 | 0 | Details |
| US1965439A | Regulated rectifier circuit | Expired / Lapsed | 1933-02-03 | 1934-07-03 | 0 | Details |
| US1964526A | Testing system and apparatus therefor | Expired / Lapsed | 1933-03-31 | 1934-06-26 | 0 | Details |
| US1964141A | Impedance measuring circuits | Expired / Lapsed | 1932-09-20 | 1934-06-26 | 0 | Details |
| US1964110A | Control system | Expired / Lapsed | 1931-11-10 | 1934-06-26 | 0 | Details |
| US1963751A | Negative resistance device | Expired / Lapsed | 1930-08-04 | 1934-06-19 | 0 | Details |
| US1962745A | Conveyer system | Expired / Lapsed | 1932-05-13 | 1934-06-12 | 0 | Details |
| US1959494A | System for voltage transformation of currents of wide frequ… | Expired / Lapsed | 1932-04-09 | 1934-05-22 | 0 | Details |
| US1959429A | Crystal filter | Expired / Lapsed | 1931-04-01 | 1934-05-22 | 0 | Details |
| US1960011A | Apparatus for making stereoscopic parallax panoramagrams | Expired / Lapsed | 1931-02-26 | 1934-05-22 | 0 | Details |
| US1958620A | Piezo-electric crystals having low temperature coefficients… | Expired / Lapsed | 1929-04-02 | 1934-05-15 | 0 | Details |
| US1957519A | Multiple radio receiving system | Expired / Lapsed | 1931-12-18 | 1934-05-08 | 0 | Details |
| US1957565A | Alarm system | Expired / Lapsed | 1931-10-31 | 1934-05-08 | 0 | Details |
| US1957538A | Electrical network | Expired / Lapsed | 1931-06-13 | 1934-05-08 | 0 | Details |
| US1957487A | Multicore cable with thermoplastic insulation | Expired / Lapsed | 1930-11-12 | 1934-05-08 | 0 | Details |
| US1956670A | Selective signaling system | Expired / Lapsed | 1932-11-01 | 1934-05-01 | 0 | Details |
| US1955828A | Wave translating system | Expired / Lapsed | 1932-08-11 | 1934-04-24 | 0 | Details |
| US1955788A | Transmission network | Expired / Lapsed | 1931-11-28 | 1934-04-24 | 0 | Details |
| US1954950A | Apparatus for metallically coating phonograph records | Expired / Lapsed | 1931-05-29 | 1934-04-17 | 0 | Details |
| US1954995A | Process for metal-coating phonograph records | Expired / Lapsed | 1931-05-29 | 1934-04-17 | 0 | Details |
| US1954898A | Radio receiving system | Expired / Lapsed | 1930-06-10 | 1934-04-17 | 0 | Details |
| US1953474A | Telephone exchange system | Expired / Lapsed | 1930-05-07 | 1934-04-03 | 0 | Details |
| US1952578A | Voice-operated circuits | Expired / Lapsed | 1932-06-16 | 1934-03-27 | 0 | Details |
| US1952879A | Direction finding system | Expired / Lapsed | 1931-11-27 | 1934-03-27 | 0 | Details |
| US1952592A | Electrooptical system | Expired / Lapsed | 1931-01-22 | 1934-03-27 | 0 | Details |
| US1951457A | Universal framework | Expired / Lapsed | 1932-03-02 | 1934-03-20 | 0 | Details |
| US1951461A | Apparatus for measuring electrical quantities | Expired / Lapsed | 1931-12-05 | 1934-03-20 | 0 | Details |
| US1951482A | Alternating current power reserve system | Expired / Lapsed | 1931-08-20 | 1934-03-20 | 0 | Details |
| US1948973A | Wave transmission with narrowed band | Expired / Lapsed | 1932-06-10 | 1934-02-27 | 0 | Details |
| US1948238A | Apparatus for testing electrical conductors | Expired / Lapsed | 1933-04-07 | 1934-02-20 | 0 | Details |
| US1947588A | Fuse and mounting therefor | Expired / Lapsed | 1932-11-19 | 1934-02-20 | 0 | Details |
| US1947621A | Reverberation circuit | Expired / Lapsed | 1932-06-14 | 1934-02-20 | 0 | Details |
| US1948308A | Method of making magnetic bodies | Expired / Lapsed | 1931-12-11 | 1934-02-20 | 0 | Details |
| US1946223A | Translating device | Expired / Lapsed | 1930-08-16 | 1934-02-06 | 0 | Details |
| US1944238A | Telegraphone | Expired / Lapsed | 1931-04-15 | 1934-01-23 | 0 | Details |
| US1944211A | Method of and means for testing the electrical characterist… | Expired / Lapsed | 1931-01-13 | 1934-01-23 | 0 | Details |
| US1944273A | Lubricating compound | Expired / Lapsed | 1929-06-06 | 1934-01-23 | 0 | Details |
| US1943475A | System for selective calling of telegraph stations | Expired / Lapsed | 1932-06-14 | 1934-01-16 | 0 | Details |
| US1941121A | Ribbon cable | Expired / Lapsed | 1929-10-11 | 1933-12-26 | 0 | Details |
| US1940088A | Sound picture record container | Expired / Lapsed | 1929-10-31 | 1933-12-19 | 0 | Details |
| US1940599A | Temperature controlling device | Expired / Lapsed | 1928-05-17 | 1933-12-19 | 0 | Details |
| US1938742A | Gas-filled discharge tube | Expired / Lapsed | 1932-11-16 | 1933-12-12 | 0 | Details |
| US1938684A | Testing apparatus | Expired / Lapsed | 1931-09-25 | 1933-12-12 | 0 | Details |
| US1936706A | Directionally selective sound receiver | Expired / Lapsed | 1931-12-24 | 1933-11-28 | 0 | Details |
| US1936683A | Frequency measurement | Expired / Lapsed | 1931-09-04 | 1933-11-28 | 0 | Details |
| US1936153A | Electric wave transmission system | Expired / Lapsed | 1928-05-26 | 1933-11-21 | 0 | Details |
| US1934879A | Frequency measuring system | Expired / Lapsed | 1931-06-18 | 1933-11-14 | 0 | Details |
| US1934897A | Manifold typewriting machine | Expired / Lapsed | 1930-10-03 | 1933-11-14 | 0 | Details |
| US1934377A | Conveyer system | Expired / Lapsed | 1932-03-10 | 1933-11-07 | 0 | Details |
| US1933669A | Selective antenna circuits | Expired / Lapsed | 1931-10-19 | 1933-11-07 | 0 | Details |
| US1934400A | Frequency control system | Expired / Lapsed | 1931-09-30 | 1933-11-07 | 0 | Details |
| US1933650A | Signaling system | Expired / Lapsed | 1927-04-06 | 1933-11-07 | 0 | Details |
| US1932589A | Frequency translating device | Expired / Lapsed | 1932-11-03 | 1933-10-31 | 0 | Details |
| US1933274A | Testing device | Expired / Lapsed | 1932-03-30 | 1933-10-31 | 0 | Details |
| US1933248A | Radio direction finding | Expired / Lapsed | 1929-05-14 | 1933-10-31 | 0 | Details |
| US1931866A | Gain control circuits | Expired / Lapsed | 1932-06-16 | 1933-10-24 | 0 | Details |
| US1932253A | Television system | Expired / Lapsed | 1926-10-01 | 1933-10-24 | 0 | Details |
| US1930609A | Signaling system | Expired / Lapsed | 1932-04-21 | 1933-10-17 | 0 | Details |
| US1930631A | Signaling system | Expired / Lapsed | 1932-03-18 | 1933-10-17 | 0 | Details |
| US1930905A | Piezo-electric apparatus | Expired / Lapsed | 1931-10-31 | 1933-10-17 | 0 | Details |
| US1931054A | Measuring apparatus | Expired / Lapsed | 1930-10-09 | 1933-10-17 | 0 | Details |
| US1930932A | Resistance unit | Expired / Lapsed | 1930-08-29 | 1933-10-17 | 0 | Details |
| US1929925A | Multiple terminal bank | Expired / Lapsed | 1931-11-11 | 1933-10-10 | 0 | Details |
| US1930269A | Inductance device | Expired / Lapsed | 1931-01-30 | 1933-10-10 | 0 | Details |
| US1930278A | Oscillation generator | Expired / Lapsed | 1928-05-11 | 1933-10-10 | 0 | Details |
| US1928610A | High frequency signaling system | Expired / Lapsed | 1925-12-24 | 1933-10-03 | 0 | Details |
| US1927989A | System for replacement of alpha defective circuit | Expired / Lapsed | 1931-12-17 | 1933-09-26 | 0 | Details |
| US1927400A | Method of applying and vulcanizing an insulating compound | Expired / Lapsed | 1932-10-29 | 1933-09-19 | 0 | Details |
| US1927045A | Testing instrument | Expired / Lapsed | 1929-04-16 | 1933-09-19 | 0 | Details |
| US1926169A | Phase and frequency control | Expired / Lapsed | 1931-03-11 | 1933-09-12 | 0 | Details |
| US1925681A | Telephone system | Expired / Lapsed | 1932-04-20 | 1933-09-05 | 0 | Details |
| US1922677A | Radio direction finding system | Expired / Lapsed | 1931-10-15 | 1933-08-15 | 0 | Details |
| US1922059A | Radio receiving system | Expired / Lapsed | 1930-11-01 | 1933-08-15 | 0 | Details |
| US1922115A | Antenna array | Expired / Lapsed | 1930-04-12 | 1933-08-15 | 0 | Details |
| US1921022A | Submarine cable signaling system | Expired / Lapsed | 1931-07-25 | 1933-08-08 | 0 | Details |
| US1921432A | Constant temperature apparatus | Expired / Lapsed | 1930-05-05 | 1933-08-08 | 0 | Details |
| US1919803A | Measuring and indicating system | Expired / Lapsed | 1931-03-17 | 1933-07-25 | 0 | Details |
| US1918252A | High speed telegraphy | Expired / Lapsed | 1931-05-25 | 1933-07-18 | 0 | Details |
| US1919046A | Selective calling circuits | Expired / Lapsed | 1931-03-05 | 1933-07-18 | 0 | Details |
| US1917884A | Call charging telephone system | Expired / Lapsed | 1932-03-30 | 1933-07-11 | 0 | Details |
| US1917418A | Electric delay circuits | Expired / Lapsed | 1931-06-18 | 1933-07-11 | 0 | Details |
| US1916320A | Stereoscopic picture with exaggerated or diminished relief | Expired / Lapsed | 1931-08-12 | 1933-07-04 | 0 | Details |
| US1917009A | Electrical connecter | Expired / Lapsed | 1931-03-17 | 1933-07-04 | 0 | Details |
| US1916358A | Radio direction finder | Expired / Lapsed | 1930-10-17 | 1933-07-04 | 0 | Details |
| US1915358A | Electrodynamic device | Expired / Lapsed | 1930-04-11 | 1933-06-27 | 0 | Details |
| US1915368A | Oscillator | Expired / Lapsed | 1928-08-08 | 1933-06-27 | 0 | Details |
| US1914407A | Signaling system | Expired / Lapsed | 1932-10-01 | 1933-06-20 | 0 | Details |
| US1913495A | Multifrequency transmission measuring system | Expired / Lapsed | 1930-12-18 | 1933-06-13 | 0 | Details |
| US1913428A | Radio receiver circuit | Expired / Lapsed | 1929-03-14 | 1933-06-13 | 0 | Details |
| US1910957A | Reactive element having stable temperature-reactance charac… | Expired / Lapsed | 1932-01-13 | 1933-05-23 | 0 | Details |
| US1910977A | Wave transmission system | Expired / Lapsed | 1931-08-14 | 1933-05-23 | 0 | Details |
| US1910254A | Sound recording | Expired / Lapsed | 1929-10-30 | 1933-05-23 | 0 | Details |
| US1910960A | Power line carrier current system | Expired / Lapsed | 1929-08-10 | 1933-05-23 | 0 | Details |
| US1907109A | Radio signaling system | Expired / Lapsed | 1930-12-12 | 1933-05-02 | 0 | Details |
| US1905359A | Channel selection | Expired / Lapsed | 1931-11-14 | 1933-04-25 | 0 | Details |
| US1905353A | Attenuation unit | Expired / Lapsed | 1931-06-18 | 1933-04-25 | 0 | Details |
| US1904261A | Indirectly heated cathode | Expired / Lapsed | 1931-03-16 | 1933-04-18 | 0 | Details |
| US1904845A | Method of forming molded articles | Expired / Lapsed | 1929-01-02 | 1933-04-18 | 0 | Details |
| US1901921A | Electrical meter | Expired / Lapsed | 1930-05-24 | 1933-03-21 | 0 | Details |
| US1901929A | Voltage limiting system | Expired / Lapsed | 1930-03-06 | 1933-03-21 | 0 | Details |
| US1901400A | Harmonic analyzer | Expired / Lapsed | 1931-08-27 | 1933-03-14 | 0 | Details |
| US1898118A | Signaling system | Expired / Lapsed | 1931-11-10 | 1933-02-21 | 0 | Details |
| US1898921A | Remote control system | Expired / Lapsed | 1930-09-24 | 1933-02-21 | 0 | Details |
| US1897040A | Inductive device | Expired / Lapsed | 1932-03-08 | 1933-02-14 | 0 | Details |
| US1897048A | Telephone system | Expired / Lapsed | 1931-09-01 | 1933-02-14 | 0 | Details |
| US1896480A | Balanced inductance device | Expired / Lapsed | 1931-06-29 | 1933-02-07 | 0 | Details |
| US1896762A | Coil | Expired / Lapsed | 1930-12-31 | 1933-02-07 | 0 | Details |
| US1896513A | Piezo-electric crystal | Expired / Lapsed | 1930-10-08 | 1933-02-07 | 0 | Details |
| US1895774A | Signal shaping circuit | Expired / Lapsed | 1932-01-12 | 1933-01-31 | 0 | Details |
| US1895531A | Electrooptical system | Expired / Lapsed | 1930-06-18 | 1933-01-31 | 0 | Details |
| US1895542A | Pilot channel indicating system | Expired / Lapsed | 1928-09-25 | 1933-01-31 | 0 | Details |
| US1895498A | Electric regulator | Expired / Lapsed | 1919-06-11 | 1933-01-31 | 0 | Details |
| US1894644A | Method of coating metallic bodies | Expired / Lapsed | 1929-06-08 | 1933-01-17 | 0 | Details |
| US1894023A | Circuits for photo-electric cells | Expired / Lapsed | 1931-12-30 | 1933-01-10 | 0 | Details |
| US1894025A | Gauging apparatus | Expired / Lapsed | 1927-12-15 | 1933-01-10 | 0 | Details |
| US1891299A | Radio telephone system | Expired / Lapsed | 1929-09-20 | 1932-12-20 | 0 | Details |
| US1890543A | Current-suppressor | Expired / Lapsed | 1930-04-17 | 1932-12-13 | 0 | Details |
| US1888275A | Electrical apparatus and alpha method of manufacturing it | Expired / Lapsed | 1931-07-07 | 1932-11-22 | 0 | Details |
| US1888288A | Container and its method of manufacture | Expired / Lapsed | 1931-02-27 | 1932-11-22 | 0 | Details |
| US1887172A | Combined earth boring machine and derrick apparatus | Expired / Lapsed | 1932-07-02 | 1932-11-08 | 0 | Details |
| US1885214A | Signaling system | Expired / Lapsed | 1932-03-18 | 1932-11-01 | 0 | Details |
| US1885728A | Harmonic generating and selecting system | Expired / Lapsed | 1930-06-19 | 1932-11-01 | 0 | Details |
| US1884675A | Electric wave transmission system | Expired / Lapsed | 1928-10-24 | 1932-10-25 | 0 | Details |
| US1882854A | Mounting frame for electrical apparatus | Expired / Lapsed | 1931-12-10 | 1932-10-18 | 0 | Details |
| US1883291A | Projection of stereoscopic pictures | Expired / Lapsed | 1930-10-29 | 1932-10-18 | 0 | Details |
| US1882849A | Frequency control system | Expired / Lapsed | 1929-07-31 | 1932-10-18 | 0 | Details |
| US1883116A | Device for determining the condition of alpha gas | Expired / Lapsed | 1929-02-16 | 1932-10-18 | 0 | Details |
| US1882925A | Method of sealing materials | Expired / Lapsed | 1927-10-03 | 1932-10-18 | 0 | Details |
| US1881503A | Mounting frame for electrical apparatus | Expired / Lapsed | 1931-12-04 | 1932-10-11 | 0 | Details |
| US1881711A | Magnetic structure | Expired / Lapsed | 1931-08-14 | 1932-10-11 | 0 | Details |
| US1881642A | Transmission control circuits | Expired / Lapsed | 1931-07-15 | 1932-10-11 | 0 | Details |
| US1881483A | Radio transmission systems | Expired / Lapsed | 1930-06-10 | 1932-10-11 | 0 | Details |
| US1881640A | Tabulating system | Expired / Lapsed | 1928-08-28 | 1932-10-11 | 0 | Details |
| US1880805A | Inductive device | Expired / Lapsed | 1932-03-16 | 1932-10-04 | 0 | Details |
| US1881273A | Telephone system | Expired / Lapsed | 1932-02-12 | 1932-10-04 | 0 | Details |
| US1880425A | Measurement of mechanical impedance | Expired / Lapsed | 1931-11-27 | 1932-10-04 | 0 | Details |
| US1880764A | Submarine signaling cable | Expired / Lapsed | 1931-06-29 | 1932-10-04 | 0 | Details |
| US1880806A | Heat treating furnace | Expired / Lapsed | 1931-04-10 | 1932-10-04 | 0 | Details |
| US1880942A | Photographic recorder | Expired / Lapsed | 1930-07-07 | 1932-10-04 | 0 | Details |
| US1880917A | Method of and apparatus for testing coating materials | Expired / Lapsed | 1929-10-17 | 1932-10-04 | 0 | Details |
| US1878147A | Electrooptical transmission | Expired / Lapsed | 1927-09-10 | 1932-09-20 | 0 | Details |
| US1874271A | Resilient mounting for electrical devices | Expired / Lapsed | 1931-02-10 | 1932-08-30 | 0 | Details |
| US1875157A | Compression and expansion of range of energy level | Expired / Lapsed | 1929-06-29 | 1932-08-30 | 0 | Details |
| US1871944A | Transmission measuring system | Expired / Lapsed | 1932-01-14 | 1932-08-16 | 0 | Details |
| US1871933A | Telegraph printer | Expired / Lapsed | 1931-09-01 | 1932-08-16 | 0 | Details |
| US1870352A | Telegraph system | Expired / Lapsed | 1930-08-13 | 1932-08-09 | 0 | Details |
| US1869870A | Filtering circuits | Expired / Lapsed | 1930-04-17 | 1932-08-02 | 0 | Details |
| US1869178A | Sound translating device | Expired / Lapsed | 1930-08-15 | 1932-07-26 | 0 | Details |
| US1869181A | Electric test connecter | Expired / Lapsed | 1929-09-06 | 1932-07-26 | 0 | Details |
| US1869160A | Piezo-electric resonator | Expired / Lapsed | 1928-05-11 | 1932-07-26 | 0 | Details |
| US1866631A | Magneto-optical device | Expired / Lapsed | 1928-06-28 | 1932-07-12 | 0 | Details |
| US1866097A | Electrical heating device | Expired / Lapsed | 1929-05-14 | 1932-07-05 | 0 | Details |
| US1864646A | Telephone signaling arrangement | Expired / Lapsed | 1931-06-27 | 1932-06-28 | 0 | Details |
| US1864553A | Telephone system | Expired / Lapsed | 1930-12-06 | 1932-06-28 | 0 | Details |
| US1864543A | Frequency measuring circuits | Expired / Lapsed | 1927-03-02 | 1932-06-28 | 0 | Details |
| US1863307A | Telephone exchange system | Expired / Lapsed | 1931-01-27 | 1932-06-14 | 0 | Details |
| US1863292A | Telephone system | Expired / Lapsed | 1930-12-31 | 1932-06-14 | 0 | Details |
| US1862556A | Tool | Expired / Lapsed | 1930-08-09 | 1932-06-14 | 0 | Details |
| US1863309A | Motion picture projector | Expired / Lapsed | 1930-04-05 | 1932-06-14 | 0 | Details |
| US1862595A | Voltage regulator | Expired / Lapsed | 1930-03-17 | 1932-06-14 | 0 | Details |
| US1862571A | Terminal strip | Expired / Lapsed | 1929-04-13 | 1932-06-14 | 0 | Details |
| US1863089A | Remote control system | Expired / Lapsed | 1927-12-28 | 1932-06-14 | 0 | Details |
| US1859930A | Recording and reproduction of intelligence | Expired / Lapsed | 1930-09-26 | 1932-05-24 | 0 | Details |
| US1859924A | Call charging telephone exchange system | Expired / Lapsed | 1930-06-28 | 1932-05-24 | 0 | Details |
| US1859901A | Extruding apparatus | Expired / Lapsed | 1930-04-05 | 1932-05-24 | 0 | Details |
| US1859885A | Telephone system | Expired / Lapsed | 1930-02-24 | 1932-05-24 | 0 | Details |
| US1859390A | Concentric conductor system | Expired / Lapsed | 1929-05-23 | 1932-05-24 | 0 | Details |
| US1859423A | Sound recording | Expired / Lapsed | 1929-05-07 | 1932-05-24 | 0 | Details |
| US1858364A | Multiple slide wire potentiometer | Expired / Lapsed | 1929-05-14 | 1932-05-17 | 0 | Details |
| US1858339A | Piezo electric oscillator | Expired / Lapsed | 1926-06-24 | 1932-05-17 | 0 | Details |
| US1856676A | Telephone cable | Expired / Lapsed | 1929-02-09 | 1932-05-03 | 0 | Details |
| US1856707A | Frequency measuring circuits | Expired / Lapsed | 1928-03-28 | 1932-05-03 | 0 | Details |
| US1855288A | Coaxial construction for power line carrier systems | Expired / Lapsed | 1931-04-21 | 1932-04-26 | 0 | Details |
| US1855855A | Molding die | Expired / Lapsed | 1929-07-29 | 1932-04-26 | 0 | Details |
| US1855869A | Method of and apparatus for coating articles | Expired / Lapsed | 1928-12-31 | 1932-04-26 | 0 | Details |
| US1854828A | Transmission system | Expired / Lapsed | 1930-04-12 | 1932-04-19 | 0 | Details |
| US1854255A | Triple concentric conductor system | Expired / Lapsed | 1930-01-30 | 1932-04-19 | 0 | Details |
| US1854432A | Generation of electric waves | Expired / Lapsed | 1927-08-18 | 1932-04-19 | 0 | Details |
| US1853548A | Coil | Expired / Lapsed | 1928-11-10 | 1932-04-12 | 0 | Details |
| US1854106A | Automatic telephone system | Expired / Lapsed | 1922-12-22 | 1932-04-12 | 0 | Details |
| US1852045A | Signaling arrangement for telephone lines | Expired / Lapsed | 1931-04-10 | 1932-04-05 | 0 | Details |
| US1852795A | Wave transmission device | Expired / Lapsed | 1928-10-24 | 1932-04-05 | 0 | Details |
| US1851092A | Transmission delay circuits | Expired / Lapsed | 1928-02-08 | 1932-03-29 | 0 | Details |
| US1851072A | Apparatus and method for electrical transmission of pictures | Expired / Lapsed | 1923-12-15 | 1932-03-29 | 0 | Details |
| US1848174A | Trouble recording system | Expired / Lapsed | 1931-02-28 | 1932-03-08 | 0 | Details |
| US1848222A | Producing musical sounds | Expired / Lapsed | 1929-05-29 | 1932-03-08 | 0 | Details |
| US1847151A | Transmitter of variably biased impulses | Expired / Lapsed | 1930-08-13 | 1932-03-01 | 0 | Details |
| US1847079A | Wave modulation and application thereof | Expired / Lapsed | 1926-12-21 | 1932-03-01 | 0 | Details |
| US1847086A | Fluid operated switch | Expired / Lapsed | 1925-06-09 | 1932-03-01 | 0 | Details |
| US1846261A | Telephone system | Expired / Lapsed | 1931-04-11 | 1932-02-23 | 0 | Details |
| US1844110A | Determination of telephone quality | Expired / Lapsed | 1930-04-17 | 1932-02-09 | 0 | Details |
| US1844886A | Means for measuring time of propagation of wave fronts over… | Expired / Lapsed | 1927-12-02 | 1932-02-09 | 0 | Details |
| US1841084A | Telephone system | Expired / Lapsed | 1930-04-19 | 1932-01-12 | 0 | Details |
| US1839490A | Apparatus for distributing parts | Expired / Lapsed | 1928-12-04 | 1932-01-05 | 0 | Details |
| US1839290A | Direction finder for radiowaves | Expired / Lapsed | 1928-04-25 | 1932-01-05 | 0 | Details |
| US1840112A | Artificial larynx | Expired / Lapsed | 1927-12-17 | 1932-01-05 | 0 | Details |
| US1837337A | Means for producing current of reduced frequency | Expired / Lapsed | 1928-06-02 | 1931-12-22 | 0 | Details |
| US1837245A | Inductance device | Expired / Lapsed | 1928-05-05 | 1931-12-22 | 0 | Details |
| US1837355A | Electrodeposition of alloys | Expired / Lapsed | 1926-09-08 | 1931-12-22 | 0 | Details |
| US1837364A | Signaling apparatus | Expired / Lapsed | 1925-08-20 | 1931-12-22 | 0 | Details |
| US1836594A | Radio signaling system | Expired / Lapsed | 1925-10-16 | 1931-12-15 | 0 | Details |
| US1836556A | Regulating device for high frequency power amplifiers | Expired / Lapsed | 1924-11-04 | 1931-12-15 | 0 | Details |
| US1835099A | Valve commutator and its use in multiplex signaling | Expired / Lapsed | 1929-12-28 | 1931-12-08 | 0 | Details |
| US1835031A | Concentric conducting system | Expired / Lapsed | 1929-05-23 | 1931-12-08 | 0 | Details |
| US1833656A | Material forming apparatus | Expired / Lapsed | 1928-02-10 | 1931-11-24 | 0 | Details |
| US1832901A | Measurement of mechanical impedance | Expired / Lapsed | 1928-02-10 | 1931-11-24 | 0 | Details |
| US1831881A | Radio signal measuring device | Expired / Lapsed | 1929-09-12 | 1931-11-17 | 0 | Details |
| US1832292A | Electrical circuits | Expired / Lapsed | 1928-08-28 | 1931-11-17 | 0 | Details |
| US1829799A | Zone metering telephone exchange system | Expired / Lapsed | 1930-03-08 | 1931-11-03 | 0 | Details |
| US1829783A | Method and system of secret signaling | Expired / Lapsed | 1929-11-08 | 1931-11-03 | 0 | Details |
| US1829836A | Signaling system | Expired / Lapsed | 1928-03-05 | 1931-11-03 | 0 | Details |
| US1828454A | Transmission network | Expired / Lapsed | 1930-07-03 | 1931-10-20 | 0 | Details |
| US1827860A | Carrier telegraph system | Expired / Lapsed | 1929-10-22 | 1931-10-20 | 0 | Details |
| US1828498A | Oscillation circuits | Expired / Lapsed | 1928-05-26 | 1931-10-20 | 0 | Details |
| US1828507A | Circuit controlling device | Expired / Lapsed | 1927-06-14 | 1931-10-20 | 0 | Details |
| US1827297A | Method of joining wires by means of sleeves | Expired / Lapsed | 1930-01-03 | 1931-10-13 | 0 | Details |
| US1827187A | Recording apparatus | Expired / Lapsed | 1927-11-30 | 1931-10-13 | 0 | Details |
| US1825723A | Telephone system | Expired / Lapsed | 1929-04-03 | 1931-10-06 | 0 | Details |
| US1824801A | Electrical potentiometer | Expired / Lapsed | 1926-07-08 | 1931-09-29 | 0 | Details |
| US1824827A | Radio signaling system | Expired / Lapsed | 1925-09-25 | 1931-09-29 | 0 | Details |
| US1823885A | Method of and apparatus for handling strand material | Expired / Lapsed | 1929-04-06 | 1931-09-22 | 0 | Details |
| US1823354A | High speed submarine cable telegraph system | Expired / Lapsed | 1929-08-19 | 1931-09-15 | 0 | Details |
| US1823739A | System operating on a marginal current basis | Expired / Lapsed | 1928-03-31 | 1931-09-15 | 0 | Details |
| US1820088A | Recording apparatus | Expired / Lapsed | 1927-09-07 | 1931-08-25 | 0 | Details |
| US1819083A | Phonograph reproducer | Expired / Lapsed | 1929-05-14 | 1931-08-18 | 0 | Details |
| US1819612A | Electrical connecting cord and method of producing it | Expired / Lapsed | 1927-11-26 | 1931-08-18 | 0 | Details |
| US1819054A | Carrier signaling system | Expired / Lapsed | 1927-05-24 | 1931-08-18 | 0 | Details |
| US1818018A | Control circuit | Expired / Lapsed | 1930-07-11 | 1931-08-11 | 0 | Details |
| US1818070A | Magnetic body | Expired / Lapsed | 1930-06-06 | 1931-08-11 | 0 | Details |
| US1816887A | Automatic article selecting and distributing system | Expired / Lapsed | 1929-06-28 | 1931-08-04 | 0 | Details |
| US1816905A | Communication system | Expired / Lapsed | 1929-02-21 | 1931-08-04 | 0 | Details |
| US1815986A | Telegraph reading machine | Expired / Lapsed | 1929-06-29 | 1931-07-28 | 0 | Details |
| US1815996A | Telegraph reading machine | Expired / Lapsed | 1929-06-29 | 1931-07-28 | 0 | Details |
| US1815212A | Terminal connecter | Expired / Lapsed | 1930-09-18 | 1931-07-21 | 0 | Details |
| US1815710A | Apparatus for detecting a difference in the thickness of ma… | Expired / Lapsed | 1929-06-29 | 1931-07-21 | 0 | Details |
| US1815250A | Apparatus for rewinding rolls of material | Expired / Lapsed | 1928-03-10 | 1931-07-21 | 0 | Details |
| US1815717A | Apparatus for measuring variations in thickness of metallic… | Expired / Lapsed | 1926-01-12 | 1931-07-21 | 0 | Details |
| US1813913A | Rotary distributor | Expired / Lapsed | 1928-12-07 | 1931-07-14 | 0 | Details |
| US1813969A | Method and apparatus for measuring small time intervals | Expired / Lapsed | 1927-06-29 | 1931-07-14 | 0 | Details |
| US1814158A | Signaling system | Expired / Lapsed | 1926-04-22 | 1931-07-14 | 0 | Details |
| US1814956A | Radio signaling system | Expired / Lapsed | 1925-08-26 | 1931-07-14 | 0 | Details |
| US1813197A | Cable forming apparatus | Expired / Lapsed | 1929-08-30 | 1931-07-07 | 0 | Details |
| US1812977A | Oscillation generator | Expired / Lapsed | 1925-11-25 | 1931-07-07 | 0 | Details |
| US1811839A | Sound transmission | Expired / Lapsed | 1929-06-14 | 1931-06-30 | 0 | Details |
| US1811858A | Control system for transmission of signals | Expired / Lapsed | 1929-04-30 | 1931-06-30 | 0 | Details |
| US1812828A | Switch or commutating means | Expired / Lapsed | 1928-10-18 | 1931-06-30 | 0 | Details |
| US1811857A | Railway traffic controlling system | Expired / Lapsed | 1926-11-30 | 1931-06-30 | 0 | Details |
| US1811102A | Signal transmission by guided and unguided waves | Expired / Lapsed | 1924-09-10 | 1931-06-23 | 0 | Details |
| US1809925A | Variable resistance device | Expired / Lapsed | 1929-05-14 | 1931-06-16 | 0 | Details |
| US1810225A | Method of and apparatus for welding | Expired / Lapsed | 1927-10-11 | 1931-06-16 | 0 | Details |
| US1809039A | Telephone exchange system | Expired / Lapsed | 1929-06-28 | 1931-06-09 | 0 | Details |
| US1808137A | Electrooptical system | Expired / Lapsed | 1928-08-28 | 1931-06-02 | 0 | Details |
| US1805591A | Signaling system | Expired / Lapsed | 1926-12-18 | 1931-05-19 | 0 | Details |
| US1804526A | Radio receiving circuit | Expired / Lapsed | 1926-09-01 | 1931-05-12 | 0 | Details |
| US1802605A | Method and machine for insulating cables | Expired / Lapsed | 1927-05-18 | 1931-04-28 | 0 | Details |
| US1801342A | Electrical network | Expired / Lapsed | 1927-07-02 | 1931-04-21 | 0 | Details |
| US1799627A | Signal-interpolating system | Expired / Lapsed | 1929-02-28 | 1931-04-07 | 0 | Details |
| US1799795A | Sound recording and reproducing | Expired / Lapsed | 1928-05-05 | 1931-04-07 | 0 | Details |
| US1797317A | Binaural phase-discrimination radio system | Expired / Lapsed | 1928-12-20 | 1931-03-24 | 0 | Details |
| US1796497A | Rectifying arrangement | Expired / Lapsed | 1929-04-18 | 1931-03-17 | 0 | Details |
| US1795647A | Method and apparatus for measuring acoustical impedances | Expired / Lapsed | 1929-02-19 | 1931-03-10 | 0 | Details |
| US1794393A | Transmission-measuring apparatus | Expired / Lapsed | 1929-10-22 | 1931-03-03 | 0 | Details |
| US1794418A | Radio receiving circuit | Expired / Lapsed | 1928-09-20 | 1931-03-03 | 0 | Details |
| US1794847A | Frequency eliminator | Expired / Lapsed | 1927-03-18 | 1931-03-03 | 0 | Details |
| US1791587A | Printing-telegraph system | Expired / Lapsed | 1928-12-01 | 1931-02-10 | 0 | Details |
| US1789451A | Method of and apparatus for manufacturing electrostatic con… | Expired / Lapsed | 1926-06-05 | 1931-01-20 | 0 | Details |
| US1788733A | Regulator system | Expired / Lapsed | 1929-04-24 | 1931-01-13 | 0 | Details |
| US1788533A | Frequency-control system | Expired / Lapsed | 1927-03-28 | 1931-01-13 | 0 | Details |
| US1788519A | Mechanical transmission system | Expired / Lapsed | 1926-05-26 | 1931-01-13 | 0 | Details |
| US1784867A | Signaling system | Expired / Lapsed | 1927-06-13 | 1930-12-16 | 0 | Details |
| US1784176A | Equalization for carrier systems | Expired / Lapsed | 1929-07-02 | 1930-12-09 | 0 | Details |
| US1782438A | Clamping device | Expired / Lapsed | 1929-04-30 | 1930-11-25 | 0 | Details |
| US1782907A | Remote control system | Expired / Lapsed | 1925-01-26 | 1930-11-25 | 0 | Details |
| US1781093A | Concentric conductor system | Expired / Lapsed | 1929-05-23 | 1930-11-11 | 0 | Details |
| US1780921A | Communication system | Expired / Lapsed | 1928-11-24 | 1930-11-11 | 0 | Details |
| US1781363A | Electrical testing system | Expired / Lapsed | 1927-07-08 | 1930-11-11 | 0 | Details |
| US1781469A | Wave filter | Expired / Lapsed | 1927-06-25 | 1930-11-11 | 0 | Details |
| US1780962A | Radio signaling system | Expired / Lapsed | 1927-04-13 | 1930-11-11 | 0 | Details |
| US1778761A | Remote control system | Expired / Lapsed | 1924-03-03 | 1930-10-21 | 0 | Details |
| US1778378A | Telephone system | Expired / Lapsed | 1929-04-27 | 1930-10-14 | 0 | Details |
| US1778377A | Telegraph repeating device | Expired / Lapsed | 1928-07-18 | 1930-10-14 | 0 | Details |
| US1778085A | Distortionless amplifying system | Expired / Lapsed | 1926-11-24 | 1930-10-14 | 0 | Details |
| US1778077A | Remote-control system | Expired / Lapsed | 1924-10-11 | 1930-10-14 | 0 | Details |
| US1777118A | Acoustic device | Expired / Lapsed | 1928-10-04 | 1930-09-30 | 0 | Details |
| US1776822A | Automatic volume-control system | Expired / Lapsed | 1927-05-21 | 1930-09-30 | 0 | Details |
| US1775775A | Method of and means for wave retardation | Expired / Lapsed | 1926-08-07 | 1930-09-16 | 0 | Details |
| US1775241A | Electrooptical system | Expired / Lapsed | 1929-05-25 | 1930-09-09 | 0 | Details |
| US1773772A | Harmonic suppressor | Expired / Lapsed | 1926-12-30 | 1930-08-26 | 0 | Details |
| US1773116A | Single-side-band system | Expired / Lapsed | 1928-01-24 | 1930-08-19 | 0 | Details |
| US1772506A | Wave filter | Expired / Lapsed | 1923-04-02 | 1930-08-12 | 0 | Details |
| US1772167A | Signaling system | Expired / Lapsed | 1926-12-31 | 1930-08-05 | 0 | Details |
| US1771446A | Regenerative telegraph repeater | Expired / Lapsed | 1928-06-09 | 1930-07-29 | 0 | Details |
| US1771445A | Regenerative telegraph repeater | Expired / Lapsed | 1928-06-09 | 1930-07-29 | 0 | Details |
| US1770969A | Method of and apparatus for sheathing cores | Expired / Lapsed | 1928-12-19 | 1930-07-22 | 0 | Details |
| US1770985A | Apparatus for continuously sheathing cores of material | Expired / Lapsed | 1926-05-29 | 1930-07-22 | 0 | Details |
| US1771148A | Central energy wave signaling system | Expired / Lapsed | 1923-06-29 | 1930-07-22 | 0 | Details |
| US1769920A | Electrooptical transmission system | Expired / Lapsed | 1929-04-30 | 1930-07-08 | 0 | Details |
| US1765413A | Vibratory element and method of producing the same | Expired / Lapsed | 1928-12-31 | 1930-06-24 | 0 | Details |
| US1765607A | Amplifying device | Expired / Lapsed | 1928-04-26 | 1930-06-24 | 0 | Details |
| US1768262A | Phase measuring system and method | Expired / Lapsed | 1928-02-07 | 1930-06-24 | 0 | Details |
| US1765585A | Set for measuring operating time of relays | Expired / Lapsed | 1926-09-21 | 1930-06-24 | 0 | Details |
| US1763880A | Signaling system | Expired / Lapsed | 1928-06-02 | 1930-06-17 | 0 | Details |
| US1763909A | Speed regulator | Expired / Lapsed | 1927-06-23 | 1930-06-17 | 0 | Details |
| US1764665A | Power-driven apparatus | Expired / Lapsed | 1926-11-26 | 1930-06-17 | 0 | Details |
| US1763138A | Signaling system | Expired / Lapsed | 1929-07-24 | 1930-06-10 | 0 | Details |
| US1763003A | Electromagnetic device | Expired / Lapsed | 1929-05-06 | 1930-06-10 | 0 | Details |
| US1762984A | Secret-communicating system | Expired / Lapsed | 1928-10-08 | 1930-06-10 | 0 | Details |
| US1762981A | Acoustic device | Expired / Lapsed | 1928-06-06 | 1930-06-10 | 0 | Details |
| US1762725A | Method of and means for indicating synchronism | Expired / Lapsed | 1928-03-24 | 1930-06-10 | 0 | Details |
| US1763006A | Telephone-exchange equipment | Expired / Lapsed | 1927-09-12 | 1930-06-10 | 0 | Details |
| US1762969A | High-frequency attenuating network | Expired / Lapsed | 1925-04-10 | 1930-06-10 | 0 | Details |
| US1759938A | Coordination of direction-finder observations | Expired / Lapsed | 1929-04-20 | 1930-05-27 | 0 | Details |
| US1759952A | Electrical transmission system | Expired / Lapsed | 1926-03-01 | 1930-05-27 | 0 | Details |
| US1759610A | Radio receiving set | Expired / Lapsed | 1925-04-16 | 1930-05-20 | 0 | Details |
| US1756097A | Electrical delay-circuit arrangement | Expired / Lapsed | 1928-09-24 | 1930-04-29 | 0 | Details |
| US1756131A | High-frequency-oscillation generator | Expired / Lapsed | 1925-08-14 | 1930-04-29 | 0 | Details |
| US1755244A | Device for measuring level differences | Expired / Lapsed | 1928-12-20 | 1930-04-22 | 0 | Details |
| US1754240A | Composite telephone and telegraph system | Expired / Lapsed | 1926-09-08 | 1930-04-15 | 0 | Details |
| US1753444A | Signaling system | Expired / Lapsed | 1926-10-08 | 1930-04-08 | 0 | Details |
| US1752303A | Interference neutralizer for alternating-current telegraph … | Expired / Lapsed | 1930-01-24 | 1930-04-01 | 0 | Details |
| US1752346A | Interference neutralizer for alternating-current telegraph … | Expired / Lapsed | 1929-02-01 | 1930-04-01 | 0 | Details |
| US1752474A | Method of treating metals | Expired / Lapsed | 1927-03-31 | 1930-04-01 | 0 | Details |
| US1751516A | Common-frequency broadcasting system | Expired / Lapsed | 1927-08-08 | 1930-03-25 | 0 | Details |
| US1750668A | Determining movement and position of moving objects | Expired / Lapsed | 1927-12-08 | 1930-03-18 | 0 | Details |
| US1751263A | Electrical switching system | Expired / Lapsed | 1927-04-30 | 1930-03-18 | 0 | Details |
| US1750310A | Apparatus for arranging articles | Expired / Lapsed | 1926-06-16 | 1930-03-11 | 0 | Details |
| US1749015A | Meter | Expired / Lapsed | 1927-12-14 | 1930-03-04 | 0 | Details |
| US1747160A | Single-side band-carrier system | Expired / Lapsed | 1926-09-22 | 1930-02-18 | 0 | Details |
| US1746808A | Power-line signaling | Expired / Lapsed | 1927-02-08 | 1930-02-11 | 0 | Details |
| US1746829A | Radio signaling system | Expired / Lapsed | 1925-07-14 | 1930-02-11 | 0 | Details |
| US1745419A | Apparatus for testing open-wire joints | Expired / Lapsed | 1927-09-28 | 1930-02-04 | 0 | Details |
| US1744836A | Carrier-amplitude control in radio systems | Expired / Lapsed | 1925-12-31 | 1930-01-28 | 0 | Details |
| US1744840A | Voltage-indicating and translating device | Expired / Lapsed | 1925-12-30 | 1930-01-28 | 0 | Details |
| US1744835A | Constant-frequency oscillator | Expired / Lapsed | 1925-09-22 | 1930-01-28 | 0 | Details |
| US1744044A | Single-side-band carrier system | Expired / Lapsed | 1926-09-20 | 1930-01-21 | 0 | Details |
| US1743478A | Magnetic device | Expired / Lapsed | 1927-10-21 | 1930-01-14 | 0 | Details |
| US1743386A | Electrical testing apparatus | Expired / Lapsed | 1927-07-12 | 1930-01-14 | 0 | Details |
| US1743414A | Method and apparatus for determining the properties of acou… | Expired / Lapsed | 1926-07-13 | 1930-01-14 | 0 | Details |
| US1743711A | Supervisory system | Expired / Lapsed | 1925-11-21 | 1930-01-14 | 0 | Details |
| US1742902A | Multichannel radio communication system | Expired / Lapsed | 1925-02-14 | 1930-01-07 | 0 | Details |
| US1741375A | Current-equalizing device | Expired / Lapsed | 1928-09-24 | 1929-12-31 | 0 | Details |
| US1739520A | Radioreceiving circuits | Expired / Lapsed | 1926-12-04 | 1929-12-17 | 0 | Details |
| US1738522A | Electromagnetic wave signaling system | Expired / Lapsed | 1919-09-30 | 1929-12-10 | 0 | Details |
| US1738307A | Metallic element | Expired / Lapsed | 1927-04-11 | 1929-12-03 | 0 | Details |
| US1738299A | Intermittently-operated signaling device | Expired / Lapsed | 1926-11-30 | 1929-12-03 | 0 | Details |
| US1737671A | Multichannel radio printing-telegraph system | Expired / Lapsed | 1924-12-24 | 1929-12-03 | 0 | Details |
| US1734745A | Apparatus for removing insulation | Expired / Lapsed | 1926-06-30 | 1929-11-05 | 0 | Details |
| US1734038A | Electrical transmission of energy | Expired / Lapsed | 1918-08-12 | 1929-11-05 | 0 | Details |
| US1733614A | Subharmonic frequency producer | Expired / Lapsed | 1927-08-20 | 1929-10-29 | 0 | Details |
| US1733609A | Transmission system | Expired / Lapsed | 1923-07-02 | 1929-10-29 | 0 | Details |
| US1731264A | Apparatus for controlling the output of alternating-current… | Expired / Lapsed | 1928-03-01 | 1929-10-15 | 0 | Details |
| US1728986A | Picture-transmission system | Expired / Lapsed | 1926-07-08 | 1929-09-24 | 0 | Details |
| US1728311A | Electrical converting and measuring system | Expired / Lapsed | 1927-08-17 | 1929-09-17 | 0 | Details |
| US1727328A | High-frequency measuring system | Expired / Lapsed | 1927-09-17 | 1929-09-10 | 0 | Details |
| US1727971A | Electrical cable | Expired / Lapsed | 1923-11-30 | 1929-09-10 | 0 | Details |
| US1726359A | Apparatus for applying material to cores | Expired / Lapsed | 1927-06-08 | 1929-08-27 | 0 | Details |
| US1725022A | Alarm | Expired / Lapsed | 1927-09-10 | 1929-08-20 | 0 | Details |
| US1724924A | Telephone system | Expired / Lapsed | 1926-03-26 | 1929-08-20 | 0 | Details |
| US1724973A | Testing device | Expired / Lapsed | 1925-07-24 | 1929-08-20 | 0 | Details |
| US1722262A | Telephone-exchange system | Expired / Lapsed | 1927-12-15 | 1929-07-30 | 0 | Details |
| US1722751A | Optical inspection system | Expired / Lapsed | 1927-11-19 | 1929-07-30 | 0 | Details |
| US1722347A | Acoustic apparatus | Expired / Lapsed | 1926-10-20 | 1929-07-30 | 0 | Details |
| US1722353A | Connecting terminal for electrical conductors | Expired / Lapsed | 1925-12-07 | 1929-07-30 | 0 | Details |
| US1722121A | Electron-discharge device | Expired / Lapsed | 1925-06-25 | 1929-07-23 | 0 | Details |
| US1720738A | Signaling system | Expired / Lapsed | 1926-12-16 | 1929-07-16 | 0 | Details |
| US1719474A | Current-controlling device | Expired / Lapsed | 1928-04-18 | 1929-07-02 | 0 | Details |
| US1719492A | Regulator system | Expired / Lapsed | 1928-01-25 | 1929-07-02 | 0 | Details |
| US1719456A | System of space discharge devices | Expired / Lapsed | 1924-02-25 | 1929-07-02 | 0 | Details |
| US1717400A | Phase-shifting network | Expired / Lapsed | 1926-08-25 | 1929-06-18 | 0 | Details |
| US1717049A | Synchronous telegraph system | Expired / Lapsed | 1927-07-14 | 1929-06-11 | 0 | Details |
| US1717070A | Rectifying system | Expired / Lapsed | 1921-11-01 | 1929-06-11 | 0 | Details |
| US1715415A | Volume-control system | Expired / Lapsed | 1925-12-19 | 1929-06-04 | 0 | Details |
| US1713039A | Phonograph recording and reproducing | Expired / Lapsed | 1919-11-15 | 1929-05-14 | 0 | Details |
| US1712993A | Signaling system | Expired / Lapsed | 1916-08-14 | 1929-05-14 | 0 | Details |
| US1711651A | Signaling system | Expired / Lapsed | 1927-01-29 | 1929-05-07 | 0 | Details |
| US1711658A | Current-controlling and static-reducing system | Expired / Lapsed | 1923-11-21 | 1929-05-07 | 0 | Details |
| US1711101A | Means for indicating frequency changes | Expired / Lapsed | 1923-08-21 | 1929-04-30 | 0 | Details |
| US1708949A | Telephone system | Expired / Lapsed | 1926-11-29 | 1929-04-16 | 0 | Details |
| US1709067A | Indicating system | Expired / Lapsed | 1924-10-22 | 1929-04-16 | 0 | Details |
| US1709076A | Multiplex signaling system | Expired / Lapsed | 1924-09-24 | 1929-04-16 | 0 | Details |
| US1707260A | Recording and reproducing of sound waves | Expired / Lapsed | 1927-11-10 | 1929-04-02 | 0 | Details |
| US1707544A | Electrodynamic device | Expired / Lapsed | 1926-08-04 | 1929-04-02 | 0 | Details |
| US1706538A | Testing television and like system | Expired / Lapsed | 1927-06-22 | 1929-03-26 | 0 | Details |
| US1705903A | Power line signaling | Expired / Lapsed | 1927-02-09 | 1929-03-19 | 0 | Details |
| US1705993A | Voltage-limiting device | Expired / Lapsed | 1925-11-25 | 1929-03-19 | 0 | Details |
| US1706005A | Method of making cord tips | Expired / Lapsed | 1922-01-26 | 1929-03-19 | 0 | Details |
| US1702568A | Constant frequency wave source | Expired / Lapsed | 1927-11-26 | 1929-02-19 | 0 | Details |
| US1700833A | Sound-recording system | Expired / Lapsed | 1928-01-30 | 1929-02-05 | 0 | Details |
| US1700454A | Electron emitter and process of making the same | Expired / Lapsed | 1924-07-08 | 1929-01-29 | 0 | Details |
| US1699570A | Carrier suppression modulation | Expired / Lapsed | 1927-09-23 | 1929-01-22 | 0 | Details |
| US1699567A | Radio signaling system | Expired / Lapsed | 1924-12-13 | 1929-01-22 | 0 | Details |
| US1697933A | Signaling circuits for repeaters | Expired / Lapsed | 1926-10-26 | 1929-01-08 | 0 | Details |
| US1696415A | Voltage-balance regulator | Expired / Lapsed | 1927-08-09 | 1928-12-25 | 0 | Details |
| US1695048A | Picture transmission | Expired / Lapsed | 1925-12-24 | 1928-12-11 | 0 | Details |
| US1695042A | High-efficiency discharge-device system | Expired / Lapsed | 1923-08-15 | 1928-12-11 | 0 | Details |
| US1691962A | Selective signaling system | Expired / Lapsed | 1923-05-25 | 1928-11-20 | 0 | Details |
| US1691986A | Apparatus and method for generating pure sine waves of elec… | Expired / Lapsed | 1922-03-30 | 1928-11-20 | 0 | Details |
| US1691076A | Two-way radio signaling system | Expired / Lapsed | 1924-03-11 | 1928-11-13 | 0 | Details |
| US1690206A | Telephone system | Expired / Lapsed | 1927-06-04 | 1928-11-06 | 0 | Details |
| US1690373A | Method of and apparatus for twisting strands | Expired / Lapsed | 1924-11-14 | 1928-11-06 | 0 | Details |
| US1690299A | Generation and control of electric waves | Expired / Lapsed | 1922-03-21 | 1928-11-06 | 0 | Details |
| US1689206A | Apparatus for treating vulcanizable material | Expired / Lapsed | 1926-12-16 | 1928-10-30 | 0 | Details |
| US1689205A | Method of and apparatus for continuously sheathing cores | Expired / Lapsed | 1926-05-29 | 1928-10-30 | 0 | Details |
| US1689294A | Remote control and indicating system | Expired / Lapsed | 1925-11-27 | 1928-10-30 | 0 | Details |
| US1689348A | Combined jack and selecting switch | Expired / Lapsed | 1924-12-29 | 1928-10-30 | 0 | Details |
| US1689292A | Navigation-directing system | Expired / Lapsed | 1923-06-25 | 1928-10-30 | 0 | Details |
| US1689030A | Acoustic diaphragm | Expired / Lapsed | 1926-06-12 | 1928-10-23 | 0 | Details |
| US1688451A | Telephone signaling system | Expired / Lapsed | 1926-05-19 | 1928-10-23 | 0 | Details |
| US1688452A | Telephone signaling system | Expired / Lapsed | 1926-05-19 | 1928-10-23 | 0 | Details |
| US1688453A | Telephone signaling system | Expired / Lapsed | 1926-05-19 | 1928-10-23 | 0 | Details |
| US1688976A | Audiphone | Expired / Lapsed | 1924-06-21 | 1928-10-23 | 0 | Details |
| US1688991A | Electron-discharge device | Expired / Lapsed | 1923-10-29 | 1928-10-23 | 0 | Details |
| US1687524A | Material-feeding device | Expired / Lapsed | 1926-11-30 | 1928-10-16 | 0 | Details |
| US1687574A | Article-forming apparatus | Expired / Lapsed | 1926-11-30 | 1928-10-16 | 0 | Details |
| US1688038A | Protective device | Expired / Lapsed | 1926-04-30 | 1928-10-16 | 0 | Details |
| US1687933A | Electrical signaling system | Expired / Lapsed | 1923-10-25 | 1928-10-16 | 0 | Details |
| US1687882A | Oscillation generator and modulator | Expired / Lapsed | 1923-03-31 | 1928-10-16 | 0 | Details |
| US1686585A | Telegraph cipher system | Expired / Lapsed | 1925-10-31 | 1928-10-09 | 0 | Details |
| US1685357A | Transmission system | Expired / Lapsed | 1925-10-16 | 1928-09-25 | 0 | Details |
| US1684403A | Electrical testing system and method | Expired / Lapsed | 1926-05-29 | 1928-09-18 | 0 | Details |
| US1681252A | Distortion correction for transmission lines | Expired / Lapsed | 1926-09-11 | 1928-08-21 | 0 | Details |
| US1681566A | Manufacture of cables | Expired / Lapsed | 1924-08-26 | 1928-08-21 | 0 | Details |
| US1680367A | Repeater circuits | Expired / Lapsed | 1922-07-07 | 1928-08-14 | 0 | Details |
| US1678872A | Method and apparatus for producing musical sounds | Expired / Lapsed | 1926-01-02 | 1928-07-31 | 0 | Details |
| US1678672A | Two-way radio telephone system | Expired / Lapsed | 1924-04-19 | 1928-07-31 | 0 | Details |
| US1677966A | Carrier signaling system | Expired / Lapsed | 1925-12-30 | 1928-07-24 | 0 | Details |
| US1677967A | Radio signaling system | Expired / Lapsed | 1924-05-29 | 1928-07-24 | 0 | Details |
| US1678163A | Modulation | Expired / Lapsed | 1923-12-29 | 1928-07-24 | 0 | Details |
| US1678116A | Device for the transmission of mechanical vibratory energy | Expired / Lapsed | 1923-10-16 | 1928-07-24 | 0 | Details |
| US1678101A | Air-conditioning system | Expired / Lapsed | 1923-06-29 | 1928-07-24 | 0 | Details |
| US1678203A | Communicating and switching system | Expired / Lapsed | 1923-02-27 | 1928-07-24 | 0 | Details |
| US1677224A | Carrier-receiving system | Expired / Lapsed | 1926-03-23 | 1928-07-17 | 0 | Details |
| US1677205A | Device for welding parts | Expired / Lapsed | 1925-05-25 | 1928-07-17 | 0 | Details |
| US1677157A | System for measuring contact rebounding | Expired / Lapsed | 1925-02-25 | 1928-07-17 | 0 | Details |
| US1677133A | Method of and machine for feeding and working articles | Expired / Lapsed | 1924-12-29 | 1928-07-17 | 0 | Details |
| US1677191A | Modulating arrangement | Expired / Lapsed | 1923-05-26 | 1928-07-17 | 0 | Details |
| US1675894A | Method and apparatus for recording and reproducing sound | Expired / Lapsed | 1924-06-20 | 1928-07-03 | 0 | Details |
| US1673023A | Carrier-wave repeater | Expired / Lapsed | 1926-05-01 | 1928-06-12 | 0 | Details |
| US1672979A | Loaded conductor | Expired / Lapsed | 1924-10-01 | 1928-06-12 | 0 | Details |
| US1673002A | Control of electric waves | Expired / Lapsed | 1923-02-23 | 1928-06-12 | 0 | Details |
| US1672049A | Alternating-current relay | Expired / Lapsed | 1926-03-29 | 1928-06-05 | 0 | Details |
| US1672215A | Wave varying and transmitting | Expired / Lapsed | 1923-08-15 | 1928-06-05 | 0 | Details |
| US1671151A | Method of and apparatus for reducing width of transmission … | Expired / Lapsed | 1924-12-10 | 1928-05-29 | 0 | Details |
| US1671143A | Wave translator | Expired / Lapsed | 1924-09-24 | 1928-05-29 | 0 | Details |
| US1669644A | Magnetic material | Expired / Lapsed | 1926-04-24 | 1928-05-15 | 0 | Details |
| US1669646A | Magnetic material | Expired / Lapsed | 1926-04-17 | 1928-05-15 | 0 | Details |
| US1667792A | Radio signaling system | Expired / Lapsed | 1923-01-11 | 1928-05-01 | 0 | Details |
| US1666158A | System for binaural transmission of signals | Expired / Lapsed | 1925-12-31 | 1928-04-17 | 0 | Details |
| US1666206A | Modulation system | Expired / Lapsed | 1925-01-15 | 1928-04-17 | 0 | Details |
| US1666681A | Mechanical wave filter | Expired / Lapsed | 1924-04-22 | 1928-04-17 | 0 | Details |
| US1666680A | Dynamometer | Expired / Lapsed | 1922-12-30 | 1928-04-17 | 0 | Details |
| US1663747A | Telephone-exchange system | Expired / Lapsed | 1927-08-05 | 1928-03-27 | 0 | Details |
| US1663890A | Electrical control system | Expired / Lapsed | 1924-11-19 | 1928-03-27 | 0 | Details |
| US1663086A | Means for indicating frequency changes | Expired / Lapsed | 1924-03-04 | 1928-03-20 | 0 | Details |
| US1662084A | Electric regulator | Expired / Lapsed | 1926-08-04 | 1928-03-13 | 0 | Details |
| US1661167A | System of picture transmission | Expired / Lapsed | 1925-01-23 | 1928-03-06 | 0 | Details |
| US1661535A | Electric shielding | Expired / Lapsed | 1924-10-23 | 1928-03-06 | 0 | Details |
| US1660979A | Current-control device | Expired / Lapsed | 1926-06-30 | 1928-02-28 | 0 | Details |
| US1659083A | Telephone-exchange system | Expired / Lapsed | 1925-06-27 | 1928-02-14 | 0 | Details |
| US1658095A | Feeding device for belt conveyers | Expired / Lapsed | 1925-12-14 | 1928-02-07 | 0 | Details |
| US1658094A | Paper-conveying system | Expired / Lapsed | 1925-12-05 | 1928-02-07 | 0 | Details |
| US1658337A | Carrier-wave signaling system | Expired / Lapsed | 1924-06-21 | 1928-02-07 | 0 | Details |
| US1657462A | Nonsinging reamplifying circuits | Expired / Lapsed | 1923-05-15 | 1928-01-31 | 0 | Details |
| US1656987A | Ultrahigh-frequency generator | Expired / Lapsed | 1924-12-24 | 1928-01-24 | 0 | Details |
| US1656956A | Electric vacuum valve tubb | Expired / Lapsed | 1921-03-30 | 1928-01-24 | 0 | Details |
| US1655557A | Amplifier circuits | Expired / Lapsed | 1919-11-07 | 1928-01-10 | 0 | Details |
| US1655061A | Telephone-exchange system | Expired / Lapsed | 1926-08-28 | 1928-01-03 | 0 | Details |
| US1654633A | Recording system | Expired / Lapsed | 1925-01-30 | 1928-01-03 | 0 | Details |
| US1654645A | Recording system | Expired / Lapsed | 1925-01-30 | 1928-01-03 | 0 | Details |
| US1654902A | Modulating system | Expired / Lapsed | 1924-05-24 | 1928-01-03 | 0 | Details |
| US1654123A | Frequency selective transmission system | Expired / Lapsed | 1924-09-30 | 1927-12-27 | 0 | Details |
| US1653736A | Impulse-registering device | Expired / Lapsed | 1924-07-11 | 1927-12-27 | 0 | Details |
| US1653694A | Apparatus and method for measuring transmitted light | Expired / Lapsed | 1923-12-15 | 1927-12-27 | 0 | Details |
| US1649819A | System of television | Expired / Lapsed | 1926-01-30 | 1927-11-22 | 0 | Details |
| US1648944A | Nut-tightening apparatus | Expired / Lapsed | 1925-11-27 | 1927-11-15 | 0 | Details |
| US1648058A | Electrovision | Expired / Lapsed | 1925-11-25 | 1927-11-08 | 0 | Details |
| US1647737A | Magnetic core | Expired / Lapsed | 1927-01-03 | 1927-11-01 | 0 | Details |
| US1647270A | System for indicating frequency changes | Expired / Lapsed | 1924-03-07 | 1927-11-01 | 0 | Details |
| US1647192A | Apparatus for controlling the frequency of an alternating c… | Expired / Lapsed | 1923-12-19 | 1927-11-01 | 0 | Details |
| US1645573A | Telephone-exchange system | Expired / Lapsed | 1926-01-27 | 1927-10-18 | 0 | Details |
| US1645607A | System of synchronizing signaling apparatus | Expired / Lapsed | 1925-02-26 | 1927-10-18 | 0 | Details |
| US1645810A | Direction finding and indicating system | Expired / Lapsed | 1921-01-08 | 1927-10-18 | 0 | Details |
| US1645139A | Mechanical vibratory system | Expired / Lapsed | 1923-11-16 | 1927-10-11 | 0 | Details |
| US1642040A | Public-address system | Expired / Lapsed | 1925-12-12 | 1927-09-13 | 0 | Details |
| US1640524A | Means for detecting metal particles in nonmetallic material | Expired / Lapsed | 1921-02-24 | 1927-08-30 | 0 | Details |
| US1639000A | Wave modulation | Expired / Lapsed | 1924-01-04 | 1927-08-16 | 0 | Details |
| US1638925A | High-frequency signaling system | Expired / Lapsed | 1922-08-16 | 1927-08-16 | 0 | Details |
| US1637404A | Signaling system | Expired / Lapsed | 1921-03-12 | 1927-08-02 | 0 | Details |
| US1636031A | Voice-operated relay equipment | Expired / Lapsed | 1925-11-06 | 1927-07-19 | 0 | Details |
| US1633577A | Electrical coil | Expired / Lapsed | 1925-12-22 | 1927-06-28 | 0 | Details |
| US1633082A | Distribution of intelligence | Expired / Lapsed | 1922-01-25 | 1927-06-21 | 0 | Details |
| US1633100A | Plural channel signaling | Expired / Lapsed | 1916-03-03 | 1927-06-21 | 0 | Details |
| US1632076A | Method of determining inequalities in wall thickness of tub… | Expired / Lapsed | 1925-04-22 | 1927-06-14 | 0 | Details |
| US1631963A | Transmission of pictures by electricity | Expired / Lapsed | 1923-12-31 | 1927-06-14 | 0 | Details |
| US1631958A | Pneumatic relay | Expired / Lapsed | 1923-12-12 | 1927-06-14 | 0 | Details |
| US1632054A | Oscillation generator | Expired / Lapsed | 1923-12-03 | 1927-06-14 | 0 | Details |
| US1632106A | Signaling system | Expired / Lapsed | 1923-11-24 | 1927-06-14 | 0 | Details |
| US1630451A | Method of producing coated cores | Expired / Lapsed | 1925-02-14 | 1927-05-31 | 0 | Details |
| US1629100A | Transmission system | Expired / Lapsed | 1923-12-21 | 1927-05-17 | 0 | Details |
| US1629009A | Low-impedance electric discharge device | Expired / Lapsed | 1920-08-07 | 1927-05-17 | 0 | Details |
| US1628398A | Magnetic coil | Expired / Lapsed | 1922-06-06 | 1927-05-10 | 0 | Details |
| US1625449A | Method of molding phenol plastic or like compounds | Expired / Lapsed | 1921-08-05 | 1927-04-19 | 0 | Details |
| US1624422A | Dial-testing circuit | Expired / Lapsed | 1926-06-30 | 1927-04-12 | 0 | Details |
| US1624672A | Communication system | Expired / Lapsed | 1924-12-17 | 1927-04-12 | 0 | Details |
| US1624601A | Secret communication | Expired / Lapsed | 1923-07-02 | 1927-04-12 | 0 | Details |
| US1624596A | Signaling method and system | Expired / Lapsed | 1920-12-24 | 1927-04-12 | 0 | Details |
| US1624412A | Submarine signaling | Expired / Lapsed | 1919-10-31 | 1927-04-12 | 0 | Details |
| US1624537A | Oscillation generator | Expired / Lapsed | 1918-02-01 | 1927-04-12 | 0 | Details |
| US1621480A | Testing system | Expired / Lapsed | 1926-08-31 | 1927-03-15 | 0 | Details |
| US1620204A | Frequency indication and control | Expired / Lapsed | 1924-12-29 | 1927-03-08 | 0 | Details |
| US1619085A | Carrier-current signaling system | Expired / Lapsed | 1924-02-29 | 1927-03-01 | 0 | Details |
| US1618242A | Time-announcing system | Expired / Lapsed | 1925-02-09 | 1927-02-22 | 0 | Details |
| US1617392A | Carrier-wave-transmission system | Expired / Lapsed | 1924-03-04 | 1927-02-15 | 0 | Details |
| US1617991A | Synchronizing system | Expired / Lapsed | 1923-12-24 | 1927-02-15 | 0 | Details |
| US1616622A | Oscillation generator with automatic frequency control | Expired / Lapsed | 1923-05-21 | 1927-02-08 | 0 | Details |
| US1616186A | Control and supervisory system | Expired / Lapsed | 1921-06-30 | 1927-02-01 | 0 | Details |
| US1615219A | Telephone switchboard cord terminal test connecter | Expired / Lapsed | 1925-03-25 | 1927-01-25 | 0 | Details |
| US1613686A | Method of and apparatus for secret electrical transmission … | Expired / Lapsed | 1924-12-05 | 1927-01-11 | 0 | Details |
| US1613626A | Space discharge system | Expired / Lapsed | 1918-09-30 | 1927-01-11 | 0 | Details |
| US1612952A | Radio receiving apparatus | Expired / Lapsed | 1921-08-24 | 1927-01-04 | 0 | Details |
| US1611932A | Frequency selective-current transmission | Expired / Lapsed | 1921-12-17 | 1926-12-28 | 0 | Details |
| US1611223A | Apparatus for controlling the frequency of an alternating c… | Expired / Lapsed | 1923-12-19 | 1926-12-21 | 0 | Details |
| US1611224A | Method and apparatus for measuring frequency | Expired / Lapsed | 1923-12-19 | 1926-12-21 | 0 | Details |
| US1611716A | Measuring electrical quantities | Expired / Lapsed | 1921-07-09 | 1926-12-21 | 0 | Details |
| US1610910A | Composite article and method of forming it | Expired / Lapsed | 1924-10-16 | 1926-12-14 | 0 | Details |
| US1608551A | Radio signaling system | Expired / Lapsed | 1925-12-30 | 1926-11-30 | 0 | Details |
| US1608527A | Facsimile telegraph system | Expired / Lapsed | 1921-07-20 | 1926-11-30 | 0 | Details |
| US1607837A | Radio repeater system | Expired / Lapsed | 1924-03-22 | 1926-11-23 | 0 | Details |
| US1607074A | Forming mechanism | Expired / Lapsed | 1923-08-27 | 1926-11-16 | 0 | Details |
| US1606777A | Inductance device | Expired / Lapsed | 1923-05-08 | 1926-11-16 | 0 | Details |
| US1606764A | Speed regulation | Expired / Lapsed | 1922-09-07 | 1926-11-16 | 0 | Details |
| US1606792A | Oscillation generator for current of continuously varying f… | Expired / Lapsed | 1919-10-06 | 1926-11-16 | 0 | Details |
| US1606131A | Carrier-wave signaling system | Expired / Lapsed | 1925-10-07 | 1926-11-09 | 0 | Details |
| US1606164A | Circuit-controlling device | Expired / Lapsed | 1923-05-09 | 1926-11-09 | 0 | Details |
| US1605930A | Television system | Expired / Lapsed | 1920-08-24 | 1926-11-09 | 0 | Details |
| US1604163A | Means for regulating motors | Expired / Lapsed | 1923-09-05 | 1926-10-26 | 0 | Details |
| US1604610A | Modulation indicator | Expired / Lapsed | 1923-02-28 | 1926-10-26 | 0 | Details |
| US1602469A | Electrical transmission of pictures | Expired / Lapsed | 1923-12-20 | 1926-10-12 | 0 | Details |
| US1601940A | Telegraph system | Expired / Lapsed | 1922-10-03 | 1926-10-05 | 0 | Details |
| US1601066A | Electron-discharge device | Expired / Lapsed | 1922-12-08 | 1926-09-28 | 0 | Details |
| US1601070A | Wave meter | Expired / Lapsed | 1922-04-18 | 1926-09-28 | 0 | Details |
| US1598673A | Secrecy communication system | Expired / Lapsed | 1920-12-18 | 1926-09-07 | 0 | Details |
| US1596942A | Measuring transmission phase shift | Expired / Lapsed | 1925-09-01 | 1926-08-24 | 0 | Details |
| US1596102A | High-frequency translating circuits | Expired / Lapsed | 1924-12-24 | 1926-08-17 | 0 | Details |
| US1595799A | Heated element | Expired / Lapsed | 1924-08-16 | 1926-08-10 | 0 | Details |
| US1595072A | Telephone-exchange system | Expired / Lapsed | 1923-03-09 | 1926-08-10 | 0 | Details |
| US1595135A | Carrier-current signal system | Expired / Lapsed | 1922-01-27 | 1926-08-10 | 0 | Details |
| US1594003A | Telephone-exchange system | Expired / Lapsed | 1924-06-30 | 1926-07-27 | 0 | Details |
| US1593640A | Neutralization of inductive interference | Expired / Lapsed | 1924-05-13 | 1926-07-27 | 0 | Details |
| US1593993A | Selective system | Expired / Lapsed | 1921-11-10 | 1926-07-27 | 0 | Details |
| US1593387A | Telephone-exchange system | Expired / Lapsed | 1924-07-05 | 1926-07-20 | 0 | Details |
| US1592940A | Secret signaling | Expired / Lapsed | 1920-09-09 | 1926-07-20 | 0 | Details |
| US1592274A | Employment of cathode ray oscillographs | Expired / Lapsed | 1924-06-28 | 1926-07-13 | 0 | Details |
| US1589405A | Ringing arrangement for carrier circuits | Expired / Lapsed | 1924-04-01 | 1926-06-22 | 0 | Details |
| US1589398A | System for guiding vessels | Expired / Lapsed | 1922-12-11 | 1926-06-22 | 0 | Details |
| US1588186A | Transmitting electrical energy | Expired / Lapsed | 1922-11-20 | 1926-06-08 | 0 | Details |
| US1587520A | Nonresonant system | Expired / Lapsed | 1919-02-03 | 1926-06-08 | 0 | Details |
| US1586533A | Thermionic meter | Expired / Lapsed | 1922-04-27 | 1926-06-01 | 0 | Details |
| US1587122A | Electrical switching and indicating system | Expired / Lapsed | 1921-12-31 | 1926-06-01 | 0 | Details |
| US1587121A | Remote control and supervisory system | Expired / Lapsed | 1921-12-01 | 1926-06-01 | 0 | Details |
| US1586884A | Magnetic material | Expired / Lapsed | 1921-05-31 | 1926-06-01 | 0 | Details |
| US1585729A | Emergency switching mechanism | Expired / Lapsed | 1922-10-12 | 1926-05-25 | 0 | Details |
| US1579709A | Method of and apparatus for serving material upon alpha core | Expired / Lapsed | 1925-09-04 | 1926-04-06 | 0 | Details |
| US1579769A | Material-handling apparatus | Expired / Lapsed | 1924-08-05 | 1926-04-06 | 0 | Details |
| US1579263A | Electrical transmission of pictures | Expired / Lapsed | 1924-03-26 | 1926-04-06 | 0 | Details |
| US1579256A | Carrier-wave communicating and switching system | Expired / Lapsed | 1923-11-09 | 1926-04-06 | 0 | Details |
| US1578634A | Clamping and supporting device | Expired / Lapsed | 1925-07-31 | 1926-03-30 | 0 | Details |
| US1578646A | Telephone device for aiding the deaf | Expired / Lapsed | 1923-11-02 | 1926-03-30 | 0 | Details |
| US1577722A | Generation and control of electric waves | Expired / Lapsed | 1922-04-24 | 1926-03-23 | 0 | Details |
| US1574780A | Means for and method of modulation | Expired / Lapsed | 1921-10-05 | 1926-03-02 | 0 | Details |
| US1573801A | Trouble-alarm system for radio receiving sets | Expired / Lapsed | 1923-10-05 | 1926-02-23 | 0 | Details |
| US1574350A | Electrical testing | Expired / Lapsed | 1923-08-14 | 1926-02-23 | 0 | Details |
| US1573983A | Secret signaling | Expired / Lapsed | 1923-08-08 | 1926-02-23 | 0 | Details |
| US1572869A | Electromagnet | Expired / Lapsed | 1923-12-15 | 1926-02-16 | 0 | Details |
| US1573282A | Thermionic modulator | Expired / Lapsed | 1923-11-23 | 1926-02-16 | 0 | Details |
| US1573303A | Carrier-wave transmission | Expired / Lapsed | 1922-10-21 | 1926-02-16 | 0 | Details |
| US1572756A | High-frequency-wave signaling and communicating system | Expired / Lapsed | 1921-05-14 | 1926-02-09 | 0 | Details |
| US1570948A | Test fixture | Expired / Lapsed | 1923-08-27 | 1926-01-26 | 0 | Details |
| US1571010A | Secret signaling | Expired / Lapsed | 1920-12-23 | 1926-01-26 | 0 | Details |
| US1568979A | Oscillation generator | Expired / Lapsed | 1921-09-03 | 1926-01-12 | 0 | Details |
| US1567265A | Telephone-exchange system | Expired / Lapsed | 1923-12-03 | 1925-12-29 | 0 | Details |
| US1568039A | Telephone-exchange system | Expired / Lapsed | 1922-11-06 | 1925-12-29 | 0 | Details |
| US1565869A | Etching | Expired / Lapsed | 1923-12-20 | 1925-12-15 | 0 | Details |
| US1565596A | Signal system | Expired / Lapsed | 1923-11-15 | 1925-12-15 | 0 | Details |
| US1565566A | Translating device | Expired / Lapsed | 1923-06-25 | 1925-12-15 | 0 | Details |
| US1565613A | Electrical measuring apparatus | Expired / Lapsed | 1923-02-10 | 1925-12-15 | 0 | Details |
| US1564274A | Method of and means for casting articles | Expired / Lapsed | 1923-10-08 | 1925-12-08 | 0 | Details |
| US1565151A | Electric discharge device | Expired / Lapsed | 1919-12-27 | 1925-12-08 | 0 | Details |
| US1563658A | Line switch | Expired / Lapsed | 1922-06-01 | 1925-12-01 | 0 | Details |
| US1563326A | Secret-communication system | Expired / Lapsed | 1921-11-08 | 1925-12-01 | 0 | Details |
| US1562485A | Movement and position indicator | Expired / Lapsed | 1923-05-05 | 1925-11-24 | 0 | Details |
| US1561782A | Inductance coil | Expired / Lapsed | 1923-06-30 | 1925-11-17 | 0 | Details |
| US1561204A | Transformer | Expired / Lapsed | 1923-07-26 | 1925-11-10 | 0 | Details |
| US1559642A | Signaling with phase reversals | Expired / Lapsed | 1923-08-28 | 1925-11-03 | 0 | Details |
| US1560056A | Source of waves of constant frequency | Expired / Lapsed | 1923-05-01 | 1925-11-03 | 0 | Details |
| US1559656A | Method of and means for increasing voltages | Expired / Lapsed | 1921-04-26 | 1925-11-03 | 0 | Details |
| US1559867A | Wave-transmission system | Expired / Lapsed | 1919-08-29 | 1925-11-03 | 0 | Details |
| US1559251A | Private-branch exchange sender circuit | Expired / Lapsed | 1924-06-13 | 1925-10-27 | 0 | Details |
| US1559325A | Means for analyzing or synthesizing electric waves | Expired / Lapsed | 1919-12-20 | 1925-10-27 | 0 | Details |
| US1557562A | Frequency selective device | Expired / Lapsed | 1919-10-16 | 1925-10-20 | 0 | Details |
| US1557079A | Telephone signaling equipment | Expired / Lapsed | 1919-09-16 | 1925-10-13 | 0 | Details |
| US1552590A | Acoustical and for deaf persons | Expired / Lapsed | 1921-12-21 | 1925-09-08 | 0 | Details |
| US1550660A | Prevention of overloading in speech circuits | Expired / Lapsed | 1924-09-19 | 1925-08-25 | 0 | Details |
| US1551033A | Automatic switch | Expired / Lapsed | 1923-07-09 | 1925-08-25 | 0 | Details |
| US1549907A | Telegraphy | Expired / Lapsed | 1920-11-11 | 1925-08-18 | 0 | Details |
| US1548895A | Electrical transmission of pictures | Expired / Lapsed | 1923-01-26 | 1925-08-11 | 0 | Details |
| US1548952A | Electric control circuits | Expired / Lapsed | 1921-11-04 | 1925-08-11 | 0 | Details |
| US1548022A | Inductance device | Expired / Lapsed | 1923-04-23 | 1925-08-04 | 0 | Details |
| US1548028A | Transmission system | Expired / Lapsed | 1918-10-07 | 1925-08-04 | 0 | Details |
| US1547242A | Carrier transmission over power circuits | Expired / Lapsed | 1924-04-29 | 1925-07-28 | 0 | Details |
| US1543836A | Signaling system | Expired / Lapsed | 1920-11-26 | 1925-06-30 | 0 | Details |
| US1543671A | Telephone system | Expired / Lapsed | 1920-04-23 | 1925-06-30 | 0 | Details |
| US1542385A | Thermionic cathode and method of making the same | Expired / Lapsed | 1920-10-12 | 1925-06-16 | 0 | Details |
| US1541311A | Vacuum-tube circuits | Expired / Lapsed | 1923-02-07 | 1925-06-09 | 0 | Details |
| US1541387A | Telephone system | Expired / Lapsed | 1923-01-05 | 1925-06-09 | 0 | Details |
| US1540322A | Humidity-control apparatus | Expired / Lapsed | 1920-12-13 | 1925-06-02 | 0 | Details |
| US1535538A | Vibratory system | Expired / Lapsed | 1923-01-03 | 1925-04-28 | 0 | Details |
| US1533311A | Secret signaling | Expired / Lapsed | 1923-12-18 | 1925-04-14 | 0 | Details |
| US1533178A | Artificial electric line | Expired / Lapsed | 1922-05-19 | 1925-04-14 | 0 | Details |
| US1532207A | Signaling system | Expired / Lapsed | 1921-09-15 | 1925-04-07 | 0 | Details |
| US1531633A | Oscillation generator | Expired / Lapsed | 1920-12-22 | 1925-03-31 | 0 | Details |
| US1530648A | Electric circuits | Expired / Lapsed | 1920-03-17 | 1925-03-24 | 0 | Details |
| US1528011A | Radio signaling system | Expired / Lapsed | 1923-12-31 | 1925-03-03 | 0 | Details |
| US1526337A | Method and apparatus for measuring time intervals | Expired / Lapsed | 1919-11-11 | 1925-02-17 | 0 | Details |
| US1523430A | Mounting for vacuum tubes | Expired / Lapsed | 1923-11-30 | 1925-01-20 | 0 | Details |
| US1523398A | Method of and apparatus for locating faults | Expired / Lapsed | 1922-11-20 | 1925-01-20 | 0 | Details |
| US1522581A | Radio broadcasting system | Expired / Lapsed | 1922-08-16 | 1925-01-13 | 0 | Details |
| US1522713A | Circuit-controlling switch | Expired / Lapsed | 1922-04-13 | 1925-01-13 | 0 | Details |
| US1523109A | Magnetic material | Expired / Lapsed | 1920-12-21 | 1925-01-13 | 0 | Details |
| US1521824A | Regulator | Expired / Lapsed | 1921-05-17 | 1925-01-06 | 0 | Details |
| US1520097A | Selective signaling system | Expired / Lapsed | 1923-12-03 | 1924-12-23 | 0 | Details |
| US1519477A | Signaling system | Expired / Lapsed | 1921-09-20 | 1924-12-16 | 0 | Details |
| US1518543A | Electrical measuring apparatus | Expired / Lapsed | 1921-10-28 | 1924-12-09 | 0 | Details |
| US1515669A | Switching device | Expired / Lapsed | 1921-11-15 | 1924-11-18 | 0 | Details |
| US1515735A | Machine-switching telephone system | Expired / Lapsed | 1921-07-21 | 1924-11-18 | 0 | Details |
| US1514753A | Signal-receiving system | Expired / Lapsed | 1920-11-19 | 1924-11-11 | 0 | Details |
| US1514751A | Vacuum-tube oscillator chronometer | Expired / Lapsed | 1920-08-24 | 1924-11-11 | 0 | Details |
| US1514735A | Method of and means for producing harmonics of alternating … | Expired / Lapsed | 1918-07-16 | 1924-11-11 | 0 | Details |
| US1505158A | Frequency-control system | Expired / Lapsed | 1921-11-23 | 1924-08-19 | 0 | Details |
| US1504275A | Automatic telephone-exchange system | Expired / Lapsed | 1921-06-23 | 1924-08-12 | 0 | Details |
| US1504882A | Method and apparatus for transmitting signals | Expired / Lapsed | 1920-01-16 | 1924-08-12 | 0 | Details |
| US1502813A | High-frequency multiplex signaling system | Expired / Lapsed | 1921-04-16 | 1924-07-29 | 0 | Details |
| US1502243A | System for determining the direction of propagation of wave… | Expired / Lapsed | 1920-11-13 | 1924-07-22 | 0 | Details |
| US1501649A | Transformer | Expired / Lapsed | 1919-12-26 | 1924-07-15 | 0 | Details |
| US1498544A | Electrical selective system | Expired / Lapsed | 1920-03-09 | 1924-06-24 | 0 | Details |
| US1496818A | Electrical switching circuit | Expired / Lapsed | 1920-12-21 | 1924-06-10 | 0 | Details |
| US1496817A | Electrical connecter | Expired / Lapsed | 1918-12-28 | 1924-06-10 | 0 | Details |
| US1496768A | Vibration-reducing mounting device for signaling systems | Expired / Lapsed | 1918-03-27 | 1924-06-10 | 0 | Details |
| US1497299A | System of wave transmission | Expired / Lapsed | 1917-06-29 | 1924-06-10 | 0 | Details |
| US1495429A | Piezophony | Expired / Lapsed | 1918-04-10 | 1924-05-27 | 0 | Details |
| US1494908A | Amplification of modulated waves | Expired / Lapsed | 1923-02-23 | 1924-05-20 | 0 | Details |
| US1493586A | Measuring and recording device | Expired / Lapsed | 1922-12-30 | 1924-05-13 | 0 | Details |
| US1487115A | Intelligence system | Expired / Lapsed | 1921-09-15 | 1924-03-18 | 0 | Details |
| US1486132A | Telephone-transmitter button | Expired / Lapsed | 1920-09-14 | 1924-03-11 | 0 | Details |
| US1485773A | Radio calling or signaling | Expired / Lapsed | 1921-09-12 | 1924-03-04 | 0 | Details |
| US1484967A | Amplifying system | Expired / Lapsed | 1920-12-24 | 1924-02-26 | 0 | Details |
| US1484731A | Manufacture of sponge-rubber articles | Expired / Lapsed | 1919-02-25 | 1924-02-26 | 0 | Details |
| US1483172A | Signaling system | Expired / Lapsed | 1920-04-19 | 1924-02-12 | 0 | Details |
| US1481284A | Means for and method of amplitude selection | Expired / Lapsed | 1921-10-05 | 1924-01-22 | 0 | Details |
| US1480217A | Method and means for signaling | Expired / Lapsed | 1922-01-20 | 1924-01-08 | 0 | Details |
| US1479779A | Electron-discharge device | Expired / Lapsed | 1920-07-20 | 1924-01-01 | 0 | Details |
| US1479051A | Artificial line | Expired / Lapsed | 1920-05-14 | 1924-01-01 | 0 | Details |
| US1477017A | Current-controlling and static-reducing system | Expired / Lapsed | 1919-05-02 | 1923-12-11 | 0 | Details |
| US1476003A | Radiosignaling call system | Expired / Lapsed | 1922-08-18 | 1923-12-04 | 0 | Details |
| US1474426A | Secret-communication system | Expired / Lapsed | 1922-07-19 | 1923-11-20 | 0 | Details |
| US1472503A | Switching device | Expired / Lapsed | 1922-06-20 | 1923-10-30 | 0 | Details |
| US1472505A | Method of making electrodes | Expired / Lapsed | 1920-04-16 | 1923-10-30 | 0 | Details |
| US1470696A | Television | Expired / Lapsed | 1917-12-07 | 1923-10-16 | 0 | Details |
| US1466284A | Detecting system | Expired / Lapsed | 1919-06-24 | 1923-08-28 | 0 | Details |
| US1465352A | Electrical testing system | Expired / Lapsed | 1920-09-27 | 1923-08-21 | 0 | Details |
| US1464565A | Call system for radiotelephony | Expired / Lapsed | 1921-04-13 | 1923-08-14 | 0 | Details |
| US1464096A | Secret signaling | Expired / Lapsed | 1920-08-28 | 1923-08-07 | 0 | Details |
| US1463795A | Translating circuit | Expired / Lapsed | 1918-10-10 | 1923-08-07 | 0 | Details |
| US1464104A | Selective apparatus for signaling circuits | Expired / Lapsed | 1917-07-26 | 1923-08-07 | 0 | Details |
| US1462050A | Switching device | Expired / Lapsed | 1921-12-27 | 1923-07-17 | 0 | Details |
| US1462053A | Electrical testing system | Expired / Lapsed | 1920-11-13 | 1923-07-17 | 0 | Details |
| US1462035A | Treatment of magnetic material | Expired / Lapsed | 1920-08-10 | 1923-07-17 | 0 | Details |
| US1461783A | Secret-communication system | Expired / Lapsed | 1919-12-27 | 1923-07-17 | 0 | Details |
| US1461064A | Multiplex transmission circuit | Expired / Lapsed | 1921-02-10 | 1923-07-10 | 0 | Details |
| US1458949A | Carrier radiotelephone system | Expired / Lapsed | 1922-01-07 | 1923-06-19 | 0 | Details |
| US1454157A | Phonographic recording and reproducing system | Expired / Lapsed | 1918-07-19 | 1923-05-08 | 0 | Details |
| US1452957A | High-frequency signaling | Expired / Lapsed | 1916-08-23 | 1923-04-24 | 0 | Details |
| US1449372A | System of telephony | Expired / Lapsed | 1915-12-01 | 1923-03-27 | 0 | Details |
| US1447773A | Radio transmission control system | Expired / Lapsed | 1921-09-15 | 1923-03-06 | 0 | Details |
| US1445242A | Variable inductance element | Expired / Lapsed | 1920-12-24 | 1923-02-13 | 0 | Details |
| US1441270A | Transmission system | Expired / Lapsed | 1919-09-26 | 1923-01-09 | 0 | Details |
| US1438976A | Electric regulator | Expired / Lapsed | 1918-06-08 | 1922-12-19 | 0 | Details |
| US1433599A | Radiocircuit | Expired / Lapsed | 1921-07-02 | 1922-10-31 | 0 | Details |
| US1432864A | Heating device | Expired / Lapsed | 1919-11-11 | 1922-10-24 | 0 | Details |
| US1428156A | Low-frequency amplifier | Expired / Lapsed | 1919-09-26 | 1922-09-05 | 0 | Details |
| US1426826A | Electron-discharge-device circuits | Expired / Lapsed | 1917-07-19 | 1922-08-22 | 0 | Details |
| US1419090A | Covering machine | Expired / Lapsed | 1921-08-12 | 1922-06-06 | 0 | Details |
| US1415980A | Glass composition | Expired / Lapsed | 1920-03-20 | 1922-05-16 | 0 | Details |
| US1412853A | Synchronizing system | Expired / Lapsed | 1919-09-30 | 1922-04-18 | 0 | Details |
| US1412405A | Method for testing transmitters | Expired / Lapsed | 1920-11-02 | 1922-04-11 | 0 | Details |
| US1412458A | Message-registering system | Expired / Lapsed | 1918-12-23 | 1922-04-11 | 0 | Details |
| US1410890A | Method of and means for modulating carrier oscillations | Expired / Lapsed | 1918-08-08 | 1922-03-28 | 0 | Details |
| US1406996A | Electric-wave-ranging system | Expired / Lapsed | 1920-09-30 | 1922-02-21 | 0 | Details |
| US1404311A | Electrical testing system | Expired / Lapsed | 1920-12-17 | 1922-01-24 | 0 | Details |
| US1403841A | Frequency-control system | Expired / Lapsed | 1919-09-30 | 1922-01-17 | 0 | Details |
| US1399728A | Automatic switch for telephone-exchange systems | Expired / Lapsed | 1919-07-26 | 1921-12-13 | 0 | Details |
| US1400039A | Signaling system | Expired / Lapsed | 1918-12-27 | 1921-12-13 | 0 | Details |
| US1399997A | Telegraph system | Expired / Lapsed | 1918-01-03 | 1921-12-13 | 0 | Details |
| US1397228A | Electrical measuring apparatus | Expired / Lapsed | 1920-09-03 | 1921-11-15 | 0 | Details |
| US1397093A | Radiorepeating system | Expired / Lapsed | 1919-09-27 | 1921-11-15 | 0 | Details |
| US1394642A | Electric signaling system | Expired / Lapsed | 1919-11-12 | 1921-10-25 | 0 | Details |
| US1393471A | Submarine signaling | Expired / Lapsed | 1919-10-09 | 1921-10-11 | 0 | Details |
| US1387240A | Stroboscopic system | Expired / Lapsed | 1918-02-14 | 1921-08-09 | 0 | Details |
| US1387252A | Test-connector | Expired / Lapsed | 1918-02-14 | 1921-08-09 | 0 | Details |
| US1386748A | Signaling system | Expired / Lapsed | 1918-01-14 | 1921-08-09 | 0 | Details |
| US1383703A | Method of insulating metal particles | Expired / Lapsed | 1920-01-21 | 1921-07-05 | 0 | Details |
| US1383750A | Alternating-current signaling system | Expired / Lapsed | 1918-06-26 | 1921-07-05 | 0 | Details |
| US1381640A | Detecting underwater vibrations | Expired / Lapsed | 1919-06-24 | 1921-06-14 | 0 | Details |
| US1381451A | Switching system | Expired / Lapsed | 1919-06-24 | 1921-06-14 | 0 | Details |
| US1380752A | Electrical relay | Expired / Lapsed | 1919-07-09 | 1921-06-07 | 0 | Details |
| US1378960A | Method of and apparatus for detecting under-water vibrations | Expired / Lapsed | 1919-06-24 | 1921-05-24 | 0 | Details |
| US1378950A | Recording-key | Expired / Lapsed | 1918-12-04 | 1921-05-24 | 0 | Details |
| US1374201A | Selector | Expired / Lapsed | 1919-09-19 | 1921-04-12 | 0 | Details |
| US1370669A | Machine-telegraph | Expired / Lapsed | 1915-12-14 | 1921-03-08 | 0 | Details |
| US1369764A | Photo-electric translating device | Expired / Lapsed | 1916-11-07 | 1921-02-22 | 0 | Details |
| US1367734A | Construction of reactance-coils | Expired / Lapsed | 1917-08-16 | 1921-02-08 | 0 | Details |
| US1366617A | Telegraphone | Expired / Lapsed | 1916-10-28 | 1921-01-25 | 0 | Details |
| US1362138A | Induction-coil | Expired / Lapsed | 1917-11-15 | 1920-12-14 | 0 | Details |
| US1361488A | Plural modulation system | Expired / Lapsed | 1920-03-31 | 1920-12-07 | 0 | Details |
| US1345717A | Acoustic device | Expired / Lapsed | 1918-08-09 | 1920-07-06 | 0 | Details |
| US1340955A | Telephone set | Expired / Lapsed | 1918-03-25 | 1920-05-25 | 0 | Details |
| US1338086A | Reversing mechanism | Expired / Lapsed | 1917-02-12 | 1920-04-27 | 0 | Details |
| US1337737A | Producing currents of desired wave form | Expired / Lapsed | 1918-09-30 | 1920-04-20 | 0 | Details |
| US1337681A | Telephone-exchange system | Expired / Lapsed | 1917-03-29 | 1920-04-20 | 0 | Details |
| US1334276A | Contact-terminal bank | Expired / Lapsed | 1916-03-31 | 1920-03-23 | 0 | Details |
| US1333744A | Telephone-transmitter | Expired / Lapsed | 1916-12-20 | 1920-03-16 | 0 | Details |
| US1332961A | Signaling system | Expired / Lapsed | 1918-06-06 | 1920-03-09 | 0 | Details |
| US1320980A | Transformer. | Expired / Lapsed | 1918-09-21 | 1919-11-04 | 0 | Details |
| US1302767A | Telephone-exchange system. | Expired / Lapsed | 1918-12-17 | 1919-05-06 | 0 | Details |
| US1301644A | Directive sending system. | Expired / Lapsed | 1915-09-13 | 1919-04-22 | 0 | Details |
| US1296653A | Container for electrical apparatus. | Expired / Lapsed | 1916-12-18 | 1919-03-11 | 0 | Details |
| US1295454A | Transmission-circuit. | Expired / Lapsed | 1916-08-30 | 1919-02-25 | 0 | Details |
| US1292206A | Magnet-core. | Expired / Lapsed | 1918-06-28 | 1919-01-21 | 0 | Details |
| US1291861A | Selective signaling system. | Expired / Lapsed | 1917-05-25 | 1919-01-21 | 0 | Details |
| US1289418A | High-frequency detector. | Expired / Lapsed | 1915-11-23 | 1918-12-31 | 0 | Details |
| US1287982A | Modulating system. | Expired / Lapsed | 1917-02-16 | 1918-12-17 | 0 | Details |
| US1287100A | Terminal strip. | Expired / Lapsed | 1916-11-09 | 1918-12-10 | 0 | Details |
| US1283563A | Contact-bank. | Expired / Lapsed | 1917-11-03 | 1918-11-05 | 0 | Details |
| US1279882A | Signaling system. | Expired / Lapsed | 1917-08-27 | 1918-09-24 | 0 | Details |
| US1271320A | Electric conductor. | Expired / Lapsed | 1916-09-11 | 1918-07-02 | 0 | Details |
| US1262323A | Telephone-exchange system. | Expired / Lapsed | 1917-10-29 | 1918-04-09 | 0 | Details |
| US1262359A | Impulse-transmitting device. | Expired / Lapsed | 1916-10-11 | 1918-04-09 | 0 | Details |
| US1254658A | Impulse-transmitting device or sender. | Expired / Lapsed | 1916-10-26 | 1918-01-29 | 0 | Details |
| US1254118A | Signaling-circuit. | Expired / Lapsed | 1917-08-18 | 1918-01-22 | 0 | Details |
| US1252502A | Protective circuit. | Expired / Lapsed | 1915-02-09 | 1918-01-08 | 0 | Details |
| US1251750A | Testing arrangement. | Expired / Lapsed | 1916-07-24 | 1918-01-01 | 0 | Details |
| US1251440A | Condenser-switch. | Expired / Lapsed | 1915-12-20 | 1917-12-25 | 0 | Details |
| US1250856A | Electric soldering-iron. | Expired / Lapsed | 1916-01-03 | 1917-12-18 | 0 | Details |
| US1246964A | Electric cable. | Expired / Lapsed | 1917-02-17 | 1917-11-20 | 0 | Details |
| US1221773A | Telephone-exchange system. | Expired / Lapsed | 1916-05-01 | 1917-04-03 | 0 | Details |
| US1221166A | Telephone-exchange system. | Expired / Lapsed | 1916-04-26 | 1917-04-03 | 0 | Details |
| US1202952A | Controlling system. | Expired / Lapsed | 1915-07-28 | 1916-10-31 | 0 | Details |
| US1200796A | Power-limiting device. | Expired / Lapsed | 1915-09-03 | 1916-10-10 | 0 | Details |
| US1200788A | Telephone-exchange system. | Expired / Lapsed | 1915-05-22 | 1916-10-10 | 0 | Details |
| US1200041A | Method of insulating conductors. | Expired / Lapsed | 1915-03-11 | 1916-10-03 | 0 | Details |
| US1196761A | Telephone system. | Expired / Lapsed | 1915-05-11 | 1916-09-05 | 0 | Details |
| US1167677A | System for measuring capacities. | Expired / Lapsed | 1912-04-11 | 1916-01-11 | 0 | Details |
| US1158991A | Spring-motor. | Expired / Lapsed | — | 1915-11-02 | 0 | Details |
| US1132094A | Contact member. | Expired / Lapsed | 1911-09-08 | 1915-03-16 | 0 | Details |
| US1127466A | Selective controlling apparatus. | Expired / Lapsed | 1909-09-02 | 1915-02-09 | 0 | Details |
| US1126009A | Selective signaling device. | Expired / Lapsed | — | 1915-01-26 | 0 | Details |
| US1104054A | Manufacture of non-oxidizing conductors. | Expired / Lapsed | 1914-01-03 | 1914-07-21 | 0 | Details |
| US1100178A | Spool-head. | Expired / Lapsed | 1909-12-18 | 1914-06-16 | 0 | Details |
| US1093147A | Electrical controlling mechanism. | Expired / Lapsed | 1912-08-20 | 1914-04-14 | 0 | Details |
| US1046823A | Electrical switch-contact. | Expired / Lapsed | 1908-02-27 | 1912-12-10 | 0 | Details |
| US1039988A | Controlling apparatus. | Expired / Lapsed | — | 1912-10-01 | 0 | Details |
| US1026196A | Watchcase-receiver. | Expired / Lapsed | 1910-08-10 | 1912-05-14 | 0 | Details |
| US1023482A | Party-line selective signaling system. | Expired / Lapsed | 1908-04-18 | 1912-04-16 | 0 | Details |
| US1019166A | Electrical contact-bank and process of making same. | Expired / Lapsed | 1907-04-24 | 1912-03-05 | 0 | Details |
| US944537A | Semi-mechanical telephone system. | Expired / Lapsed | 1908-02-19 | 1909-12-28 | 0 | Details |
| US911081A | Collector-ring and clamping-plate. | Expired / Lapsed | 1906-01-02 | 1909-02-02 | 0 | Details |
| US896700A | Electrical conducting-cord. | Expired / Lapsed | 1906-01-22 | 1908-08-25 | 0 | Details |
| US880871A | Holder for soldering-irons. | Expired / Lapsed | 1907-05-27 | 1908-03-03 | 0 | Details |
| US847555A | Adjusting device for relays. | Expired / Lapsed | 1906-02-05 | 1907-03-19 | 0 | Details |
| US794112A | Service-meter for party telephone-lines. | Expired / Lapsed | 1903-01-29 | 1905-07-04 | 0 | Details |
| US792248A | Induction-coil. | Expired / Lapsed | 1904-10-08 | 1905-06-13 | 0 | Details |
| US740547A | Speed and direction indicator. | Expired / Lapsed | 1902-01-15 | 1903-10-06 | 0 | Details |
| US649046A | Conning-tower for war-ships. | Expired / Lapsed | 1899-09-07 | 1900-05-08 | 0 | Details |