Patent US2921601A successfully refreshed from Google Patents.
US2921601A
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Tubular string control valve
Assignee: Baker Hughes Oilfield Operations LLC
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Filing: 1955-12-05
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Granted: 1960-01-19
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Expires: 1975-12-05
Abstract
No abstract record available.
Inventors
- 👤 Jr Hiram H Fisher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:39
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/10; E21B34/00; E21B34/06; E21B34/08; E21B2200/00; E21B2200/05; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7781; Y10T137/7783; Y10T137/7784; Y10T137/7792; Y10T137/7837; Y10T137/7854; Y10T137/7857
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1916767A
Cited
US1814549A
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US1818508A
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US2154768A
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US2162578A
Cited
US2676611A
Cited
US2797705A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1963-01-18 | 1963-07-20 | 1964-01-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1967-01-18 | 1967-07-20 | 1968-01-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1971-01-18 | 1971-07-20 | 1972-01-19 | $7700.00 | Window Closed / Lapsed |