US2521806A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential propeller control
Assignee: Individual
•
Filing: 1946-10-02
•
Granted: 1950-09-12
•
Expires: 1966-10-02
Abstract
No abstract record available.
Inventors
- 👤 Alfred I Roman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:43
CPC Classifications
B; B64; B64D; B64D31/00; B64D31/02; B64D31/06; B64D31/09; B64D31/10; B64C; B64C11/00; B64C11/30; B64C11/303; B64C9/00; Y; Y02; Y02T; Y02T50/00; Y02T50/30; Y02T50/40; Y10; Y10T; Y10T74/00; Y10T74/20; Y10T74/20207; Y10T74/20372; Y10T74/20384; Y10T74/2039
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1092365A
Cited
US1109891A
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GB191200483A
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GB148360A
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US1797669A
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US1993701A
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US1941616A
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US1976479A
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US2058161A
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US2079677A
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US2280654A
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US2334504A
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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) | 1953-09-11 | 1954-03-13 | 1954-09-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-11 | 1958-03-13 | 1958-09-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-11 | 1962-03-13 | 1962-09-12 | $7700.00 | Window Closed / Lapsed |