Patent US2581320A successfully refreshed from Google Patents.
US2581320A
Expired / Lapsed
US
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Multiengine contra-rotating propeller drive transmission
Assignee: Douglas Aircraft Co Inc
•
Filing: 1945-07-20
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Granted: 1952-01-01
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Expires: 1965-07-20
Abstract
No abstract record available.
Inventors
- 👤 Edward F Burton
- 👤 Jr Charles S Glasgow
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:23
CPC Classifications
F; F16; F16H; F16H37/00; F16H37/02; F16H37/06; F16H37/08; F16H37/0806; B; B64; B64D; B64D35/00; B64D35/04; B64D35/06; B64D35/08; F16H2700/00; F16H2700/02
Claims Analysis
Total Claims: 0
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-12-31 | 1955-07-02 | 1956-01-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-12-31 | 1959-07-02 | 1960-01-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-12-31 | 1963-07-02 | 1964-01-01 | $7700.00 | Window Closed / Lapsed |