Patent US2557338A successfully refreshed from Google Patents.
US2557338A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pitch control mechanism for helicopter rotors
Assignee: RTX Corp
•
Filing: 1946-03-30
•
Granted: 1951-06-19
•
Expires: 1966-03-30
Abstract
No abstract record available.
Inventors
- 👤 Frank W Caldwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:09
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/54
Claims Analysis
Total Claims: 0
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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) | 1954-06-18 | 1954-12-18 | 1955-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-06-18 | 1958-12-18 | 1959-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-06-18 | 1962-12-18 | 1963-06-19 | $7700.00 | Window Closed / Lapsed |