US2280686A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making engine poppet valves
Assignee: Northrop Grumman Space and Mission Systems Corp
•
Filing: 1938-04-06
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Granted: 1942-04-21
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Expires: 1958-04-06
Abstract
No abstract record available.
Inventors
- 👤 Archie T Colwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 22:16
CPC Classifications
B; B21; B21H; B21H7/00; B21H7/18; B21H7/182; Y; Y10; Y10S; Y10S29/00; Y10S29/049; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49298
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1945-04-20 | 1945-10-20 | 1946-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-04-20 | 1949-10-20 | 1950-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-04-20 | 1953-10-20 | 1954-04-21 | $7700.00 | Window Closed / Lapsed |