Patent US2479920A successfully refreshed from Google Patents.
US2479920A
Expired / Lapsed
US
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Electric motor control system
Assignee: AT&T Inc
•
Filing: 1946-01-17
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Granted: 1949-08-23
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Expires: 1966-01-17
Abstract
No abstract record available.
Inventors
- 👤 Richard D Gambrill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:42
CPC Classifications
H; H02; H02G; H02G1/00; H02G1/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US889993A
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US999947A
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US1435314A
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US1436323A
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CH95885A
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US1785690A
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US1882815A
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US1853960A
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US2290198A
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US2362690A
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US2393177A
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US2413137A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1952-08-22 | 1953-02-21 | 1953-08-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-08-22 | 1957-02-21 | 1957-08-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-08-22 | 1961-02-21 | 1961-08-23 | $7700.00 | Window Closed / Lapsed |