US2996269A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helicopter with counter-rotating propeller
Assignee: JUSTIN G SHOLES
•
Filing: 1956-04-12
•
Granted: 1961-08-15
•
Expires: 1976-04-12
Abstract
No abstract record available.
Inventors
- 👤 Robert D Parry
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:58
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12; B64C27/20
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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CA449741A
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US1723479A
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US2461435A
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US2500860A
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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) | 1964-08-14 | 1965-02-13 | 1965-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-08-14 | 1969-02-13 | 1969-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-08-14 | 1973-02-13 | 1973-08-15 | $7700.00 | Window Closed / Lapsed |