US3241791A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Compound helicopter with shrouded tail propeller
Assignee: Individual
•
Filing: 1964-04-03
•
Granted: 1966-03-22
•
Expires: 1984-04-03
Abstract
No abstract record available.
Inventors
- 👤 Frank N Piasecki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:49
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/82; B64C2027/8236; B64C2027/8254; B64C2027/8263; B64C2027/8272
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) | 1969-03-21 | 1969-09-20 | 1970-03-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1973-03-21 | 1973-09-20 | 1974-03-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1977-03-21 | 1977-09-20 | 1978-03-22 | $7700.00 | Window Closed / Lapsed |