Patent US2631679A successfully refreshed from Google Patents.
US2631679A
Expired / Lapsed
US
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Rotor head for rotary wing aircraft
Assignee: HILLER HELICOPTERS
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Filing: 1951-06-25
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Granted: 1953-03-17
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Expires: 1971-06-25
Abstract
No abstract record available.
Inventors
- 👤 Jr Stanley Hiller
- 👤 Harold H Sigler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 20:12
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/32; B64C27/37; B64C27/41; B64C27/43; B64C27/54
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) | 1956-03-16 | 1956-09-15 | 1957-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-03-16 | 1960-09-15 | 1961-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-03-16 | 1964-09-15 | 1965-03-17 | $7700.00 | Window Closed / Lapsed |