US3409249A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coaxial rigid rotor helicopter and method of flying same
Assignee: RTX Corp
•
Filing: 1966-06-29
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Granted: 1968-11-05
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Expires: 1986-06-29
Abstract
No abstract record available.
Inventors
- 👤 Bergquist Russell Raymond
- 👤 Philip L Michel
- 👤 Evan A Fradenburgh
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 11:47
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12; B64C27/08; B64C27/10; B64C27/14; B64C27/32; B64C27/37; B64C27/45; B64C27/54; B64C27/58
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3126966A
Cited
US2473331A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-11-05 | 1972-05-06 | 1972-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-11-05 | 1976-05-06 | 1976-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-11-05 | 1980-05-06 | 1980-11-05 | $7700.00 | Window Closed / Lapsed |