Patent US2691272A successfully refreshed from Google Patents.
US2691272A
Expired / Lapsed
US
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Submersible oil well drilling rig
Assignee: Individual
•
Filing: 1950-09-23
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Granted: 1954-10-12
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Expires: 1970-09-23
Abstract
No abstract record available.
Inventors
- 👤 Townsend Rex
- 👤 Frank L Davis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:47
CPC Classifications
E; E02; E02B; E02B17/00; E02B17/02; E02B17/021; E21; E21B; E21B7/00; E21B7/12; E21B7/136; E02B2017/0056; E02B2017/006
Claims Analysis
Total Claims: 0
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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) | 1957-10-11 | 1958-04-12 | 1958-10-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1961-10-11 | 1962-04-12 | 1962-10-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1965-10-11 | 1966-04-12 | 1966-10-12 | $7700.00 | Window Closed / Lapsed |