Patent US2487809A successfully refreshed from Google Patents.
US2487809A
Expired / Lapsed
US
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Combined attitude and directional instrument for aircraft
Assignee: Individual
•
Filing: 1944-09-28
•
Granted: 1949-11-15
•
Expires: 1964-09-28
Abstract
No abstract record available.
Inventors
- 👤 George W Hoover
- 👤 Erving E Easton
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:38
CPC Classifications
G; G01; G01C; G01C21/00; G01C21/10; G01C21/12; G01C21/16; G01C21/166
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2038531A
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US2053182A
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US2018735A
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US2183133A
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US2283190A
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US2323897A
Cited
US2395250A
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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) | 1952-11-14 | 1953-05-16 | 1953-11-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-11-14 | 1957-05-16 | 1957-11-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-11-14 | 1961-05-16 | 1961-11-15 | $7700.00 | Window Closed / Lapsed |