US3189690A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Two-way telephone systems with talk-listen switching
Assignee: Modern Telephones Great Britain Ltd
•
Filing: 1961-04-26
•
Granted: 1965-06-15
•
Expires: 1981-04-26
Abstract
No abstract record available.
Inventors
- 👤 Millett Michael
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:30
CPC Classifications
H; H04; H04M; H04M9/00; H04M9/001
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
68 words
A TELEPHONE SYSTEM FOR TWO-WAY SPEECH COMMUNICATION OVER AN INTERCONNECTING CIRCUIT BETWEEN STATIONS WHICH CIRCUIT IS COMMON TO SPEECH SIGNALS IN BOTH DIRECTIONS WHEREIN THERE ARE PROVIDED AT ONE OF THE STATIONS SEPARATE SPEECH CHANNELS WITH AMPLIFIERS FOR INCOMING AND OUTGOING SPEECH SIGNALS, CONTROL MEANS AT THAT STATION ADAPTED TO PROVIDE A CONTROL SIGNAL WHEN THERE IS A SPEECH SIGNAL IN EITHER DIRECTION PRESENT IN SAID INTERCONNECTING CIRCUIT,
Claim 2
Dependent Claim
68 words
A TELEPHONE SYSTEM FOR TWO-WAY SPEECH COMMUNICATION OVER AN INTERCONNECTING CIRCUIT BETWEEN STATIONS WHICH CIRCUIT IS COMMON TO SPEECH SIGNALS IN BOTH DIRECTIONS WHEREIN THERE ARE PROVIDED AT ONE OF THE STATIONS SEPARATE SPEECH CHANNELS WITH AMPLIFIERS FOR INCOMING AND OUTGOING SPEECH SIGNALS, CONTROL MEANS AT THAT STATION ADAPTED TO PROVIDE A CONTROL SIGNAL WHEN THERE IS A SPEECH SIGNAL IN EITHER DIRECTION PRESENT IN SAID INTERCONNECTING CIRCUIT,
References Cited (Backward Citations)
US1924131A
Cited
US2129990A
Cited
US2093525A
Cited
US2267622A
Cited
US2356943A
Cited
US2424069A
Cited
US2468553A
Cited
US2819340A
Cited
US3066201A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-06-14 | 1968-12-14 | 1969-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-06-14 | 1972-12-14 | 1973-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-06-14 | 1976-12-14 | 1977-06-15 | $7700.00 | Window Closed / Lapsed |