Patent US2991618A successfully refreshed from Google Patents.
US2991618A
Expired / Lapsed
US
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Helicopter rotor speed control system
Assignee: General Electric Co
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Filing: 1959-07-03
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Granted: 1961-07-11
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Expires: 1979-07-03
Abstract
No abstract record available.
Inventors
- 👤 Marscher William Frederick
- 👤 Owens Robert Frank
- 👤 Fraser Robert Gerard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 21:59
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12; B64C27/32
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) | 1964-07-10 | 1965-01-09 | 1965-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-10 | 1969-01-09 | 1969-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-10 | 1973-01-09 | 1973-07-11 | $7700.00 | Window Closed / Lapsed |