US2657016A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid circulation head for drill strings
Assignee: Individual
•
Filing: 1950-01-20
•
Granted: 1953-10-27
•
Expires: 1970-01-20
Abstract
No abstract record available.
Inventors
- 👤 Donovan B Grable
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:58
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/12; E21B10/00; E21B10/02; E21B10/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
FR407051A
Cited
US1071199A
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US1280159A
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US1547461A
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US1703390A
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US1909075A
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US2054859A
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US2120132A
Cited
US2373323A
Cited
US2507122A
Cited
US2514585A
Cited
US2537605A
Cited
US2528955A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-10-26 | 1957-04-27 | 1957-10-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-10-26 | 1961-04-27 | 1961-10-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-10-26 | 1965-04-27 | 1965-10-27 | $7700.00 | Window Closed / Lapsed |