US2765040A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Counter-rotating propeller drive
Assignee: Individual
•
Filing: 1953-09-28
•
Granted: 1956-10-02
•
Expires: 1973-09-28
Abstract
No abstract record available.
Inventors
- 👤 Kermit L Darrah
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:50
CPC Classifications
B; B64; B64D; B64D35/00; F; F42; F42B; F42B19/00; F42B19/12
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) | 1959-10-02 | 1960-04-02 | 1960-10-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-10-02 | 1964-04-02 | 1964-10-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-10-02 | 1968-04-02 | 1968-10-02 | $7700.00 | Window Closed / Lapsed |