Patent US3516414A successfully refreshed from Google Patents.
Patent US2183708A successfully refreshed from Google Patents.
US2183708A
Expired / Lapsed
US
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Signaling system
Assignee: AT&T Inc
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Filing: 1938-03-03
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Granted: 1939-12-19
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Expires: 1958-03-03
Abstract
No abstract record available.
Inventors
- 👤 George C Cummings
- 👤 Richard B Hearn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:53
CPC Classifications
H; H04; H04L; H04L5/00; H04L5/02; H04L5/12; H04L5/14; H04L5/1423
Claims Analysis
Total Claims: 0
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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) | 1942-12-18 | 1943-06-19 | 1943-12-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-12-18 | 1947-06-19 | 1947-12-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-12-18 | 1951-06-19 | 1951-12-19 | $7700.00 | Window Closed / Lapsed |