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US2678409A
Expired / Lapsed
US
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Signaling system
Assignee: AT&T Inc
•
Filing: 1950-08-31
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Granted: 1954-05-11
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Expires: 1970-08-31
Abstract
No abstract record available.
Inventors
- 👤 William H T Holden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 23:14
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2088793A
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US2404739A
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US2373134A
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US2549769A
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US2503127A
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US2438492A
Cited
US2460789A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-05-10 | 1957-11-09 | 1958-05-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-10 | 1961-11-09 | 1962-05-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-10 | 1965-11-09 | 1966-05-11 | $7700.00 | Window Closed / Lapsed |