US2927748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Direct lift airfoils
Assignee: ELIZABETH M GRISWOLD
•
Filing: 1954-04-30
•
Granted: 1960-03-08
•
Expires: 1974-04-30
Abstract
No abstract record available.
Inventors
- 👤 Ii Roger W Griswold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 22:40
CPC Classifications
B; B64; B64C; B64C3/00; B64C3/10; B64C3/14; B64C3/141; Y; Y02; Y02T; Y02T50/00; Y02T50/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2477461A
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US2447100A
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GB634332A
Cited
US2589732A
Cited
US2759548A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-03-08 | 1963-09-07 | 1964-03-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-03-08 | 1967-09-07 | 1968-03-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-03-08 | 1971-09-07 | 1972-03-08 | $7700.00 | Window Closed / Lapsed |