Patent US2794972A successfully refreshed from Google Patents.
US2794972A
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US
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Selective signalling system
Assignee: General Telephone Laboratories Inc
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Filing: 1952-11-05
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Granted: 1957-06-04
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Expires: 1972-11-05
Abstract
No abstract record available.
Inventors
- 👤 Robert P Dimmer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:42
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/02; H04W88/022
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR778571A
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US1496875A
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US2063354A
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US2309174A
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US2321662A
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US2534299A
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US2591937A
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US2617024A
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US2607907A
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US2625597A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-06-03 | 1960-12-03 | 1961-06-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-06-03 | 1964-12-03 | 1965-06-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-06-03 | 1968-12-03 | 1969-06-04 | $7700.00 | Window Closed / Lapsed |