US3109893A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Proximity operated loudspeaking telephone
Assignee: Automatic Electric Laboratories Inc
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Filing: 1961-01-03
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Granted: 1963-11-05
•
Expires: 1981-01-03
Abstract
No abstract record available.
Inventors
- 👤 Robert V Burns
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:15
CPC Classifications
H; H03; H03K; H03K17/00; H03K17/94; H03K17/945; H03K17/955; H04; H04M; H04M1/00; H04M1/60; H04M1/6033
Claims Analysis
Total Claims: 1
Claim 1
Independent Claim
83 words
IN A TELEPHONE SYSTEM INCLUDING A CENTRAL OFFICE, A SUBSCRIBER SUBSTATION AND A TELEPHONE LINE EXTENDING BETWEEN SAID CENTRAL OFFICE AND SAID SUBSTATION; SAID SUBSTATION INCLUDING: SIGNAL RECEIVING MEANS CONNECTED TO SAID TELEPHONE LINE OPERATED IN RESPONSE TO THE APPLICATION OF RINGING CURRENT TO SAID TELEPHONE LINE AT SAID CENTRAL OFFICE TO SIGNAL THE SUBSCRIBER; A LOUDSPEAKING TELEPHONE; A PROXIMITY SWITCH COMPRISING AN OSCILLATOR, A TRIGGER CIRCUIT, A CAPACITANCE BRIDGE COUPLING SAID OSCILLATOR TO SAID TRIGGER CIRCUIT OPERATED IN RESPONSE TO THE INTRODUC-
References Cited (Backward Citations)
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US2490238A
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Cited
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1966-11-04 | 1967-05-06 | 1967-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1970-11-04 | 1971-05-06 | 1971-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1974-11-04 | 1975-05-06 | 1975-11-05 | $7700.00 | Window Closed / Lapsed |