US2471936A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making poppet valves
Assignee: Northrop Grumman Space and Mission Systems Corp
•
Filing: 1944-01-21
•
Granted: 1949-05-31
•
Expires: 1964-01-21
Abstract
No abstract record available.
Inventors
- 👤 Archie T Colwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 21:32
CPC Classifications
B; B23; B23K; B23K5/00; B23K5/006; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49298; Y10T29/49307; Y10T29/49309
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) | 1952-05-30 | 1952-11-29 | 1953-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-05-30 | 1956-11-29 | 1957-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-05-30 | 1960-11-29 | 1961-05-31 | $7700.00 | Window Closed / Lapsed |