US2644537A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Spar type rotor blade
Assignee: Boeing Helicopters Co
•
Filing: 1947-05-02
•
Granted: 1953-07-07
•
Expires: 1967-05-02
Abstract
No abstract record available.
Inventors
- 👤 Donald N Meyers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 14:11
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/46; B64C27/473
Claims Analysis
Total Claims: 0
No claims parsed yet. Click Sync Now above to re-index claims from Google Patents.
References Cited (Backward Citations)
US1682399A
Cited
GB132849A
Cited
US1785543A
Cited
DE588997C
Cited
US2121052A
Cited
US2152861A
Cited
US2056592A
Cited
US2183158A
Cited
US2394445A
Cited
US2303707A
Cited
US2467031A
Cited
US2470056A
Cited
US2484141A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-07-06 | 1957-01-05 | 1957-07-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-07-06 | 1961-01-05 | 1961-07-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-07-06 | 1965-01-05 | 1965-07-07 | $7700.00 | Window Closed / Lapsed |