Patent US2575574A successfully refreshed from Google Patents.
US2575574A
Expired / Lapsed
US
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Low-pressure and vacuum relief valve
Assignee: Individual
•
Filing: 1946-11-02
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Granted: 1951-11-20
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Expires: 1966-11-02
Abstract
No abstract record available.
Inventors
- 👤 Ralph A Withrow
- 👤 Robert E Colvard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:39
CPC Classifications
F; F16; F16K; F16K13/00; F16K13/08; F16K13/10; Y; Y10; Y10T; Y10T137/00; Y10T137/4456; Y10T137/4643; Y10T137/8158; Y10T137/8359
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US270034A
Cited
US2191458A
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US824442A
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US1371866A
Cited
US1977039A
Cited
US2125910A
Cited
GB502434A
Cited
US2252174A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-11-19 | 1955-05-21 | 1955-11-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-19 | 1959-05-21 | 1959-11-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-19 | 1963-05-21 | 1963-11-20 | $7700.00 | Window Closed / Lapsed |