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US2667227A
Expired / Lapsed
US
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Variable speed counter-rotating rotor system for helicopters and control means therefor
Assignee: Individual
•
Filing: 1948-01-12
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Granted: 1954-01-26
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Expires: 1968-01-12
Abstract
No abstract record available.
Inventors
- 👤 Isidor B Laskowitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:06
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1524309A
Cited
DE610434C
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US2434276A
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US2427936A
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US2410533A
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US2437165A
Cited
US2448073A
Cited
US2394346A
Cited
US2493042A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-01-25 | 1957-07-27 | 1958-01-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-01-25 | 1961-07-27 | 1962-01-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-01-25 | 1965-07-27 | 1966-01-26 | $7700.00 | Window Closed / Lapsed |