Patent US1022547A successfully refreshed from Google Patents.
Patent US2520804A successfully refreshed from Google Patents.
US2520804A
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Watercraft with pivoted flappers
Assignee: Individual
•
Filing: 1947-12-24
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Granted: 1950-08-29
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Expires: 1967-12-24
Abstract
No abstract record available.
Inventors
- 👤 Oliver A Hollar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 19:05
CPC Classifications
B; B63; B63H; B63H1/00; B63H1/30; B63H1/36; B63H16/00; B63H16/08; B63B; B63B1/00; B63B1/02; B63B1/10; B63B1/12; B63B1/125; B63H19/00; B63H19/02; Y; Y02; Y02T; Y02T70/00; Y02T70/50; Y02T70/5218; Y02T70/5236
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US22097A
Cited
US603469A
Cited
GB190300746A
Cited
US1006118A
Cited
US1093196A
Cited
US1723213A
Cited
US2021815A
Cited
US2226911A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-08-28 | 1954-02-27 | 1954-08-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-08-28 | 1958-02-27 | 1958-08-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-08-28 | 1962-02-27 | 1962-08-29 | $7700.00 | Window Closed / Lapsed |