Patent US2291040A successfully refreshed from Google Patents.
US2291040A
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Assignee: AT&T Inc
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Filing: 1941-02-08
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Granted: 1942-07-28
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Expires: 1961-02-08
Abstract
No abstract record available.
Inventors
- 👤 William H T Holden
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:08
CPC Classifications
H; H04; H04Q; H04Q3/00; H04Q3/0004; G; G08; G08B; G08B21/00
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) | 1945-07-27 | 1946-01-26 | 1946-07-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-07-27 | 1950-01-26 | 1950-07-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-07-27 | 1954-01-26 | 1954-07-28 | $7700.00 | Window Closed / Lapsed |