Patent US2354947A successfully refreshed from Google Patents.
US2354947A
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Hollow head poppet valve
Assignee: Northrop Grumman Space and Mission Systems Corp
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Filing: 1940-08-30
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Granted: 1944-08-01
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Expires: 1960-08-30
Abstract
No abstract record available.
Inventors
- 👤 Archie T Colwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 16:09
CPC Classifications
B; B23; B23P; B23P15/00; B23P15/001; B23P15/002; F; F01; F01L; F01L3/00; F01L3/12; F01L3/14; F01L2303/00; F01L2820/00; F01L2820/01; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49298; Y10T29/49307; Y10T29/49314
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) | 1947-08-01 | 1948-01-31 | 1948-08-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1951-08-01 | 1952-01-31 | 1952-08-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1955-08-01 | 1956-01-31 | 1956-08-01 | $7700.00 | Window Closed / Lapsed |