Patent US2820474A successfully refreshed from Google Patents.
US2820474A
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US
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Relief valve with high-pressure seal
Assignee: Anderson Greenwood and Co
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Filing: 1954-09-10
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Granted: 1958-01-21
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Expires: 1974-09-10
Abstract
No abstract record available.
Inventors
- 👤 Marvin H Greenwood
- 👤 Jr Walter C Francis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 13:01
CPC Classifications
F; F16; F16K; F16K17/00; F16K17/02; F16K17/04; F16K17/0433; F16K1/00; F16K1/32; F16K1/34; F16K1/36; F16K15/00; F16K15/02; F16K15/06; F16K15/063; F16K17/0466; F16K2200/00; F16K2200/30; F16K2200/303; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7904; Y10T137/7922; Y10T137/7923; Y10T137/7925; Y10T137/7929; Y10T137/7934
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1000799A
Cited
US2568026A
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US2522913A
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US2595012A
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US2505613A
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US2610021A
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US2593740A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-01-20 | 1961-07-22 | 1962-01-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-01-20 | 1965-07-22 | 1966-01-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-01-20 | 1969-07-22 | 1970-01-21 | $7700.00 | Window Closed / Lapsed |