Patent US2712436A successfully refreshed from Google Patents.
US2712436A
Expired / Lapsed
US
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Flexible well drill collar
Assignee: OILWELL DRAIN HOLE DRILLING CO
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Filing: 1952-03-31
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Granted: 1955-07-05
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Expires: 1972-03-31
Abstract
No abstract record available.
Inventors
- 👤 John S Mccune
- 👤 William E Hanks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:18
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/20; E21B17/16; E21B17/22
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1958-07-04 | 1959-01-03 | 1959-07-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1962-07-04 | 1963-01-03 | 1963-07-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1966-07-04 | 1967-01-03 | 1967-07-05 | $7700.00 | Window Closed / Lapsed |