Patent US2911921A successfully refreshed from Google Patents.
US2911921A
Expired / Lapsed
US
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Valve seat washing pump and chemical injector
Assignee: TREX Corp
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Filing: 1957-02-25
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Granted: 1959-11-10
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Expires: 1977-02-25
Abstract
No abstract record available.
Inventors
- 👤 Mozel A Adams
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-22 22:18
CPC Classifications
E; E21; E21B; E21B37/00; Y; Y10; Y10T; Y10T137/00; Y10T137/4238; Y10T137/4245; Y10T137/4252
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1247113A
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US1535651A
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US1726804A
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US1741913A
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US2019969A
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US2111176A
Cited
US2231820A
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US2715368A
Cited
US2729171A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-11-09 | 1963-05-11 | 1963-11-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-11-09 | 1967-05-11 | 1967-11-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-11-09 | 1971-05-11 | 1971-11-10 | $7700.00 | Window Closed / Lapsed |