US2306739A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Locking mechanism for well drilling rotary
Assignee: Oil Well Supply Co
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Filing: 1941-04-24
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Granted: 1942-12-29
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Expires: 1961-04-24
Abstract
No abstract record available.
Inventors
- 👤 August R Maier
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 04:47
CPC Classifications
E; E21; E21B; E21B3/00; E21B3/02; E21B3/04
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1945-12-28 | 1946-06-29 | 1946-12-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-12-28 | 1950-06-29 | 1950-12-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-12-28 | 1954-06-29 | 1954-12-29 | $7700.00 | Window Closed / Lapsed |