Patent US2640543A successfully refreshed from Google Patents.
US2640543A
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Hydraulically operable valve controlled well tool
Assignee: Baker Hughes Oilfield Operations LLC
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Filing: 1947-08-18
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Granted: 1953-06-02
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Expires: 1967-08-18
Abstract
No abstract record available.
Inventors
- 👤 Roscoe O Childers
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 21:14
CPC Classifications
E; E21; E21B; E21B34/00; E21B34/06; E21B34/10
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2229635A
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US2196664A
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US2307983A
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US2246348A
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US2323321A
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US2368400A
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US2447827A
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US2458631A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-06-01 | 1956-12-01 | 1957-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-06-01 | 1960-12-01 | 1961-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-06-01 | 1964-12-01 | 1965-06-02 | $7700.00 | Window Closed / Lapsed |