Patent US3270143A successfully refreshed from Google Patents.
US3270143A
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Call-progress signal detector
Assignee: AT&T Inc
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Filing: 1963-05-24
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Granted: 1966-08-30
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Expires: 1983-05-24
Abstract
No abstract record available.
Inventors
- 👤 Paul J Germond
- 👤 Jesse C Laswell
- 👤 Douglas T Seward
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 17:58
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
152 words
IN A CIRCUIT FOR DETECTING TELEPHONE CALL-PROGRESS SIGNALS WHICH CAN BE EITHER A STEADY TONE OF A FIRST FREQUENCY OR A TONE INTERVAL OF ALTERNATING PULSES OF THE FIRST FREQUENCY AND A SECOND FREQUENCY AND A NO-TONE INTERVAL LONGER THAN A CYCLE IN THE ALTERNATING TONE INTERVAL, THE COMBINATION OF A TUNED DETECTOR RESPONSIVE TO SAID FIRST FREQUENCY, FIRST MEANS DRIVEN BY SAID TUNED DETECTOR GENERATING AN OUTPUT SIGNAL RESPONSIVE TO THE STEADY PERSISTENCE OF SAID FIRST FREQUENCY FOR A PREDETERMINED MINIMUM TIME INTERVAL, SECOND MEANS DRIVEN BY SAID TUNED DETECTOR RESPONSIVE FIRST TO THE END OF AN INITIAL ALTERNATING TONE INTERVAL AND THEN TO THE BEGINNING OF A SECOND ALTERNATING TONE INTERVAL THEREBY FURNISHING OUTPUT SIGNALS CORRESPONDING TO THE BEGINNING AND END OF A NO-TONE INTERVAL, AND TIMING MEANS RESPONSIVE TO THE RESPECTIVE OUTPUT SIGNALS FROM SAID SECOND MEANS PRODUCING DISCRETE OUTPUTS ACCORDING TO THE LENGTH OF A GIVEN TONE-OFF INTERVAL.
Claim 2
Dependent Claim
152 words
IN A CIRCUIT FOR DETECTING TELEPHONE CALL-PROGRESS SIGNALS WHICH CAN BE EITHER A STEADY TONE OF A FIRST FREQUENCY OR A TONE INTERVAL OF ALTERNATING PULSES OF THE FIRST FREQUENCY AND A SECOND FREQUENCY AND A NO-TONE INTERVAL LONGER THAN A CYCLE IN THE ALTERNATING TONE INTERVAL, THE COMBINATION OF A TUNED DETECTOR RESPONSIVE TO SAID FIRST FREQUENCY, FIRST MEANS DRIVEN BY SAID TUNED DETECTOR GENERATING AN OUTPUT SIGNAL RESPONSIVE TO THE STEADY PERSISTENCE OF SAID FIRST FREQUENCY FOR A PREDETERMINED MINIMUM TIME INTERVAL, SECOND MEANS DRIVEN BY SAID TUNED DETECTOR RESPONSIVE FIRST TO THE END OF AN INITIAL ALTERNATING TONE INTERVAL AND THEN TO THE BEGINNING OF A SECOND ALTERNATING TONE INTERVAL THEREBY FURNISHING OUTPUT SIGNALS CORRESPONDING TO THE BEGINNING AND END OF A NO-TONE INTERVAL, AND TIMING MEANS RESPONSIVE TO THE RESPECTIVE OUTPUT SIGNALS FROM SAID SECOND MEANS PRODUCING DISCRETE OUTPUTS ACCORDING TO THE LENGTH OF A GIVEN TONE-OFF INTERVAL.
References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1969-08-29 | 1970-02-28 | 1970-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-08-29 | 1974-02-28 | 1974-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-08-29 | 1978-02-28 | 1978-08-30 | $7700.00 | Window Closed / Lapsed |