Patent US2742972A successfully refreshed from Google Patents.
US2742972A
Expired / Lapsed
US
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Turbo jet helicopter
Assignee: Individual
•
Filing: 1952-05-17
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Granted: 1956-04-24
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Expires: 1972-05-17
Abstract
No abstract record available.
Inventors
- 👤 Apostolescu Stefan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 17:04
CPC Classifications
B; B64; B64C; B64C27/00; B64C27/04; B64C27/12; B64C27/16; B64C27/18
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB191303379A
Cited
US1813877A
Cited
US1869867A
Cited
US2273303A
Cited
US2344266A
Cited
US2488018A
Cited
FR915917A
Cited
GB636653A
Cited
GB614696A
Cited
GB625176A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1959-04-24 | 1959-10-24 | 1960-04-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-04-24 | 1963-10-24 | 1964-04-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-04-24 | 1967-10-24 | 1968-04-24 | $7700.00 | Window Closed / Lapsed |