US3639692A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Subscriber terminal unit for telephone carrier system
Assignee: Superior Continental Corp
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Filing: 1969-12-22
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Granted: 1972-02-01
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Expires: 1989-12-22
Abstract
Abstract The disclosure relates to a subscriber terminal for a telephone communication system which is adapted for connection to a cable transmission pair from a central office to supply an additional facility without affecting the original system. The subscriber terminal utilizes a rechargeable battery which furnishes power to its receiver and transmitter sections which operate at frequencies different from those of the physical communication system. The battery is controlled by a charging circuit so as to be charged by the central office power supply during nonoperation of the physical system.
Inventors
- 👤 Lester Q Krasin
- 👤 Clifford E Greene
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 03:58
CPC Classifications
H; H04; H04M; H04M19/00; H04M19/08; H04M19/02; H04M19/04; H04Q; H04Q5/00; H04Q5/24; H04Q5/245
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
175 words
In a telephone system for providing service via a carrier derived circuit to an additional telephone set at a subscriber station without increasing the number of dual conductor signaling transmission lines of a physical circuit connected between a central office and its talking battery power supply and the subscriber''s station, having a first telephone set for the physical circuit, a subscriber terminal unit comprising receiver and transmitter sections having a pair of input terminals adapted to be connected to said transmission line, a pair of output terminals connected to the additional telephone set, said subscriber terminal unit also containing an electrical rechargeable battery for supplying power to its receiver and transmitter sections, and battery control means fully contained within said subscriber terminal unit and connected to said battery as well as to said physical circuit for charging said battery by power from the central office talking battery supply, said central means including means responsive to activation of the physical circuit for stopping the flow of current from the dual conductor transmission line to said battery.
Claim 2
Dependent Claim
175 words
In a telephone system for providing service via a carrier derived circuit to an additional telephone set at a subscriber station without increasing the number of dual conductor signaling transmission lines of a physical circuit connected between a central office and its talking battery power supply and the subscriber''s station, having a first telephone set for the physical circuit, a subscriber terminal unit comprising receiver and transmitter sections having a pair of input terminals adapted to be connected to said transmission line, a pair of output terminals connected to the additional telephone set, said subscriber terminal unit also containing an electrical rechargeable battery for supplying power to its receiver and transmitter sections, and battery control means fully contained within said subscriber terminal unit and connected to said battery as well as to said physical circuit for charging said battery by power from the central office talking battery supply, said central means including means responsive to activation of the physical circuit for stopping the flow of current from the dual conductor transmission line to said battery.
Claim 3
Dependent Claim
47 words
The subscriber terminal unit as described in claim 1 wherein said control means includes a transistor and a network connected to said cable transmission pair and said transistor and responsive to a reduced current flow in said transmission pair to bring said transistor to A nonconducting level.
Claim 4
Dependent Claim
40 words
The subscriber terminal unit as described in claim 2 wherein said control means includes a capacitor in said network having a predetermined time constant and operable to prevent activation of said transistor during a dialing of said first telephone set.
Claim 5
Dependent Claim
84 words
The subscriber terminal unit as described in claim 1 wherein said control means includes a ringing control circuit for applying power to the bell of the additional telephone set when a ringing signal is received by the subscriber terminal unit from the central office terminal unit and the additional telephone set is in the ''''on-hook'''' condition, and means for deactivating the ringing control circuit and applying power to the subscriber terminal unit transmitter when said additional telephone set is placed in the ''''off-hook'''' condition.
Claim 6
Dependent Claim
34 words
The subscriber terminal unit as described in claim 4 wherein said ringing control circuit includes a ringing inverter for providing an AC voltage output and a standard AC bell ringer connected to said inverter.
Claim 7
Dependent Claim
59 words
The apparatus as described in claim 5 wherein said ringing inverter comprises: a transformer having first and second portions of a primary winding: a pair of transistors connected to said portions of said primary winding so as to produce a multivibrator action and thus an AC output on the secondary of said transformer connected to said AC bell ringer.
Claim 8
Dependent Claim
52 words
The subscriber terminal unit as described in claim 1 wherein said control means comprises: a charging circuit; a diode bridge means between said charging circuit and said carrier transmission line which will conduct current only when the voltage apparent across the conductors of said transmission line exceeds the voltage of the battery.
Claim 9
Dependent Claim
119 words
The subscriber terminal unit as described in claim 1 wherein said control means comprises: a diode bridge circuit; a high frequency oscillator circuit connected to said bridge circuit and including a transistor and a transformer having first and second portions of a primary winding, said first portion being connected to the collector of said transistor in said oscillator circuit to provide a resonant circuit while said second portion is connected through a bias network to provide a feedback to the base of said transistor; and an inductively coupled secondary winding on said transformer connected as a full-wave rectifier, said oscillator circuit being operable at its resonant frequency to provide power to said rectifier which is connected to said battery.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-01-31 | 1975-08-02 | 1976-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-01-31 | 1979-08-02 | 1980-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-01-31 | 1983-08-02 | 1984-02-01 | $7700.00 | Window Closed / Lapsed |