Patent US3231687A successfully refreshed from Google Patents.
US3231687A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Echo suppressor with improved break-in
Assignee: AT&T Inc
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Filing: 1961-12-29
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Granted: 1966-01-25
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Expires: 1981-12-29
Abstract
No abstract record available.
Inventors
- 👤 Robert R Riesz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:02
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
51 words
IN A TRANSMISSION SYSTEM INCLUDING AT LEAST TWO TERMINALS INTERCONNECTED BY TRANSMITTING AND RECEIVING PATHS, AN ECHO SUPPRESSOR CONNECTED TO SAID PATHS AT EACH TERMINAL FOR INSERTING ATTENUATION IN SAID TRANSMITTING PATH WHEN SIGNALS ARE RECEIVED IN SAID RECEIVING PATH FROM THE OTHER OF SAID TERMINALS, MEANS FOR COMPARING THE VARIATION
Claim 2
Dependent Claim
51 words
IN A TRANSMISSION SYSTEM INCLUDING AT LEAST TWO TERMINALS INTERCONNECTED BY TRANSMITTING AND RECEIVING PATHS, AN ECHO SUPPRESSOR CONNECTED TO SAID PATHS AT EACH TERMINAL FOR INSERTING ATTENUATION IN SAID TRANSMITTING PATH WHEN SIGNALS ARE RECEIVED IN SAID RECEIVING PATH FROM THE OTHER OF SAID TERMINALS, MEANS FOR COMPARING THE VARIATION
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) | 1969-01-24 | 1969-07-26 | 1970-01-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-01-24 | 1973-07-26 | 1974-01-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-01-24 | 1977-07-26 | 1978-01-25 | $7700.00 | Window Closed / Lapsed |