Patent US2992687A successfully refreshed from Google Patents.
US2992687A
Expired / Lapsed
US
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Variable pitch propeller control system
Assignee: De Havilland Aircraft Co Ltd
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Filing: 1957-07-05
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Granted: 1961-07-18
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Expires: 1977-07-05
Abstract
No abstract record available.
Inventors
- 👤 Brett Peter
- 👤 Emerson Denis John Milner
- 👤 Keerie Donald
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 12:11
CPC Classifications
B; B64; B64C; B64C11/00; B64C11/30; B64C11/38; B64C11/385
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-17 | 1965-01-16 | 1965-07-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-17 | 1969-01-16 | 1969-07-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-17 | 1973-01-16 | 1973-07-18 | $7700.00 | Window Closed / Lapsed |