Patent US4493950A successfully refreshed from Google Patents.
US4493950A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Loudspeaker telephone
Assignee: Individual
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Filing: 1982-12-17
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Granted: 1985-01-15
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Expires: 2002-12-17
Abstract
Abstract A line powered loudspeaker telephone is provided with a lightweight headset and microphone as well as a loudspeaker and second microphone. A first switch is employed to go from the loudspeaker to the headphone and their respective microphones while a second switch is used as a listen-talk switch, preventing acoustical feedback.
Inventors
- 👤 Thomas M. Lott
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 22:02
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/60; H04M1/6033; H04M9/00; H04M9/08
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
153 words
A line powered telephone receiver and transmitter which is capable of being operated in a handset mode and in a loudspeaker mode comprising in combination: (a) a lightweight headphone and first microphone, (b) a loud speaker and second microphone, (c) an amplifier for said loudspeaker, (d) an amplifier for said second microphone, (e) a hybrid circuit for separating incoming from outgoing signals, (f) a power supply operated by telephone line current, (g) a three pole double throw switch, (h) a single pole double throw switch (i) said three pole switch having one position connecting said headset and said first microphone to said hybrid circuit and a second position connecting said power supply to the center pole of the single pole switch and said hybrid circuit to the loudspeaker and second microphone, and (j) said second switch having a listen position activating said loudspeaker amplifier and a talk switch actuating said second microphone amplifier.
Claim 2
Dependent Claim
153 words
A line powered telephone receiver and transmitter which is capable of being operated in a handset mode and in a loudspeaker mode comprising in combination: (a) a lightweight headphone and first microphone, (b) a loud speaker and second microphone, (c) an amplifier for said loudspeaker, (d) an amplifier for said second microphone, (e) a hybrid circuit for separating incoming from outgoing signals, (f) a power supply operated by telephone line current, (g) a three pole double throw switch, (h) a single pole double throw switch (i) said three pole switch having one position connecting said headset and said first microphone to said hybrid circuit and a second position connecting said power supply to the center pole of the single pole switch and said hybrid circuit to the loudspeaker and second microphone, and (j) said second switch having a listen position activating said loudspeaker amplifier and a talk switch actuating said second microphone amplifier.
References Cited (Backward Citations)
US3772472A
Cited
US4115659A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-01-15 | 1988-07-16 | 1989-01-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-01-15 | 1992-07-16 | 1993-01-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-01-15 | 1996-07-16 | 1997-01-15 | $7700.00 | Window Closed / Lapsed |