US2452628A
Expired / Lapsed
US
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Method of making hollow poppet valves
Assignee: Northrop Grumman Space and Mission Systems Corp
•
Filing: 1944-08-25
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Granted: 1948-11-02
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Expires: 1964-08-25
Abstract
No abstract record available.
Inventors
- 👤 Kenneth M Bartlett
- 👤 Edward G Pekarek
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 01:53
CPC Classifications
B; B21; B21C; B21C23/00; B21C23/02; B21C23/18; B21C23/183; B21K; B21K1/00; B21K1/20; B21K1/22; F; F01; F01L; F01L3/00; F01L3/12; F01L3/14; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49298; Y10T29/49307; Y10T29/49311
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1294416A
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US1724426A
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US1683077A
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US1786285A
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US2093771A
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US2093776A
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US2029508A
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US2354947A
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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) | 1951-11-02 | 1952-05-03 | 1952-11-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-11-02 | 1956-05-03 | 1956-11-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-11-02 | 1960-05-03 | 1960-11-02 | $7700.00 | Window Closed / Lapsed |