US2818223A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Jet propulsion of helicopters
Assignee: Fairey Aviation Co Ltd
•
Filing: 1953-01-27
•
Granted: 1957-12-31
•
Expires: 1973-01-27
Abstract
No abstract record available.
Inventors
- 👤 Doblhoff Friedrich List
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:31
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12; B64C27/16; B64C27/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2077471A
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GB538092A
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US2434134A
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US2380989A
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US2458600A
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GB556866A
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US2443717A
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US2477184A
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US2465099A
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US2433251A
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US2464724A
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US2518498A
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US2618470A
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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) | 1960-12-30 | 1961-07-01 | 1961-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-12-30 | 1965-07-01 | 1965-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-12-30 | 1969-07-01 | 1969-12-31 | $7700.00 | Window Closed / Lapsed |