US2509889A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Differential altimeter
Assignee: AT&T Inc
•
Filing: 1948-01-13
•
Granted: 1950-05-30
•
Expires: 1968-01-13
Abstract
No abstract record available.
Inventors
- 👤 Shockley William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 05:27
CPC Classifications
G; G01; G01P; G01P3/00; G01P3/62; G01P5/00; G01P5/10; G01P5/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1769358A
Cited
US2214181A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1953-05-29 | 1953-11-28 | 1954-05-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-05-29 | 1957-11-28 | 1958-05-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-05-29 | 1961-11-28 | 1962-05-30 | $7700.00 | Window Closed / Lapsed |