Patent US2250100A successfully refreshed from Google Patents.
US2250100A
Expired / Lapsed
US
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Signaling system
Assignee: AT&T Inc
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Filing: 1939-11-14
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Granted: 1941-07-22
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Expires: 1959-11-14
Abstract
No abstract record available.
Inventors
- 👤 Francis A Hubbard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 21:35
CPC Classifications
H; H04; H04M; H04M1/00; H04M1/26; H04M1/30; H04M1/50; H04Q; H04Q3/00; H04Q3/42
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) | 1944-07-21 | 1945-01-20 | 1945-07-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-07-21 | 1949-01-20 | 1949-07-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-07-21 | 1953-01-20 | 1953-07-22 | $7700.00 | Window Closed / Lapsed |