Patent US2912504A successfully refreshed from Google Patents.
US2912504A
Expired / Lapsed
US
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Disconnect control of telephone answering and message recording devices
Assignee: AT&T Inc
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Filing: 1955-06-16
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Granted: 1959-11-10
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Expires: 1975-06-16
Abstract
No abstract record available.
Inventors
- 👤 Jr Clarence H Dagnall
- 👤 Charles G Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:58
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/64; H04M1/65; H04M1/654
Claims Analysis
Total Claims: 0
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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) | 1962-11-09 | 1963-05-11 | 1963-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-09 | 1967-05-11 | 1967-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-09 | 1971-05-11 | 1971-11-10 | $7700.00 | Window Closed / Lapsed |