Patent US5669927A successfully refreshed from Google Patents.
US2923871A
Expired / Lapsed
US
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Two-phase variable frequency power supply for motor
Assignee: Individual
•
Filing: 1954-03-08
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Granted: 1960-02-02
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Expires: 1974-03-08
Abstract
No abstract record available.
Inventors
- 👤 Nathaniel L Cohen
- 👤 Edgar W Van Winkle
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:29
CPC Classifications
H; H02; H02P; H02P27/00; H02P27/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US2392476A
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US2340875A
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US2341232A
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US2454426A
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US2668238A
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US2585573A
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US2570651A
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US2623203A
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US2576499A
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US2648773A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-02-01 | 1963-08-03 | 1964-02-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-02-01 | 1967-08-03 | 1968-02-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-02-01 | 1971-08-03 | 1972-02-02 | $7700.00 | Window Closed / Lapsed |