US2852037A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Diesel exhaust check valve
Assignee: Individual
•
Filing: 1956-06-21
•
Granted: 1958-09-16
•
Expires: 1976-06-21
Abstract
No abstract record available.
Inventors
- 👤 Willis T Downing
- 👤 Browning Harold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 17:10
CPC Classifications
F; F16; F16K; F16K15/00; F16K15/02; F16K15/03; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7734
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US660400A
Cited
US787565A
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US881544A
Cited
US1156326A
Cited
US1516000A
Cited
US1935329A
Cited
US2246802A
Cited
US2363943A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-09-15 | 1962-03-17 | 1962-09-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-09-15 | 1966-03-17 | 1966-09-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-09-15 | 1970-03-17 | 1970-09-16 | $7700.00 | Window Closed / Lapsed |