US2806662A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter with tiltable lift rotor and coaxial counter-torque rotor
Assignee: Individual
•
Filing: 1954-03-05
•
Granted: 1957-09-17
•
Expires: 1974-03-05
Abstract
No abstract record available.
Inventors
- 👤 Meredith L Yonkers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 10:58
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/52
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1023233A
Cited
FR377789A
Cited
US1819863A
Cited
US1788218A
Cited
US2265193A
Cited
GB531834A
Cited
US2404014A
Cited
US2684213A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1960-09-16 | 1961-03-18 | 1961-09-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1964-09-16 | 1965-03-18 | 1965-09-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1968-09-16 | 1969-03-18 | 1969-09-17 | $7700.00 | Window Closed / Lapsed |