Patent US2826638A successfully refreshed from Google Patents.
US2826638A
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Signaling system
Assignee: AT&T Inc
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Filing: 1952-04-26
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Granted: 1958-03-11
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Expires: 1972-04-26
Abstract
No abstract record available.
Inventors
- 👤 Wayne V K Large
- 👤 Robert O Soffel
- 👤 Bernard J Yokelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 06:51
CPC Classifications
H; H04; H04Q; H04Q1/00; H04Q1/18; H04Q1/30; H04Q1/44; H04Q1/444; H04Q1/45; H04Q1/453; H04Q3/00; H04Q3/42
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2282271A
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US2250100A
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US2535102A
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US2519763A
Cited
US2666809A
Cited
US2654002A
Cited
US2630525A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-03-10 | 1961-09-09 | 1962-03-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-03-10 | 1965-09-09 | 1966-03-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-03-10 | 1969-09-09 | 1970-03-11 | $7700.00 | Window Closed / Lapsed |