US2678561A
Expired / Lapsed
US
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Aircraft altimeter
Assignee: Kelvin Hughes Ltd
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Filing: 1950-03-09
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Granted: 1954-05-18
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Expires: 1970-03-09
Abstract
No abstract record available.
Inventors
- 👤 Grandidge John Everard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 06:40
CPC Classifications
G; G01; G01L; G01L7/00; G01L7/02; G01L7/10; G01L7/104
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1957-05-17 | 1957-11-16 | 1958-05-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-05-17 | 1961-11-16 | 1962-05-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-05-17 | 1965-11-16 | 1966-05-18 | $7700.00 | Window Closed / Lapsed |