Patent US3435152A successfully refreshed from Google Patents.
US3435152A
Expired / Lapsed
US
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Ringing signal detector which distinguishes ringing signal from periodic noise
Assignee: AT&T Inc
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Filing: 1966-05-13
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Granted: 1969-03-25
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Expires: 1986-05-13
Abstract
No abstract record available.
Inventors
- 👤 Ernest M Gunter
- 👤 James L Simon
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 16:24
CPC Classifications
H; H04; H04M; H04M9/00; H04M9/002; H04M9/005; H04M9/006
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3192323A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-03-24 | 1972-09-23 | 1973-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-03-24 | 1976-09-23 | 1977-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-03-24 | 1980-09-23 | 1981-03-25 | $7700.00 | Window Closed / Lapsed |