US1837896A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of promoting propeller efficiency and means thereof
Assignee: Individual
•
Filing: 1929-01-05
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Granted: 1931-12-22
•
Expires: 1949-01-05
Abstract
No abstract record available.
Inventors
- 👤 Costanievich Leone
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 21:20
CPC Classifications
B; B63; B63H; B63H1/00; B63H1/02; B63H1/12; B63H1/14; B63H1/28; B63B; B63B3/00; B63B3/14; B63B3/40; B63H25/00; B63H25/06; B63H25/38; B63H5/00; B63H5/07; B63H5/08; B63H5/16
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1934-12-21 | 1935-06-22 | 1935-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1938-12-21 | 1939-06-22 | 1939-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1942-12-21 | 1943-06-22 | 1943-12-22 | $7700.00 | Window Closed / Lapsed |