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US2669961A
Expired / Lapsed
US
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Apparatus for reducing the friction of water on the hull of a ship
Assignee: —
•
Filing: 1951-07-03
•
Granted: 1954-02-23
•
Expires: 1971-07-03
Abstract
No abstract record available.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 20:34
CPC Classifications
B; B63; B63B; B63B1/00; B63B1/32; B63B1/34; B63B1/38; B63B2001/387; Y; Y02; Y02T; Y02T70/00; Y02T70/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US725137A
Cited
US1398246A
Cited
US1445839A
Cited
US1697257A
Cited
US1875629A
Cited
US2062384A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-02-22 | 1957-08-24 | 1958-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-02-22 | 1961-08-24 | 1962-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-02-22 | 1965-08-24 | 1966-02-23 | $7700.00 | Window Closed / Lapsed |