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US2576872A
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Rotary drilling rig
Assignee: National Supply Co
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Filing: 1946-10-28
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Granted: 1951-11-27
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Expires: 1966-10-28
Abstract
No abstract record available.
Inventors
- 👤 Forrest J Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 05:13
CPC Classifications
E; E21; E21B; E21B3/00; E21B3/02; E21B3/04; E21B3/06; Y; Y10; Y10T; Y10T74/00; Y10T74/19; Y10T74/19014
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1526976A
Cited
US2026709A
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US2282597A
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US2405546A
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US2249873A
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US2344681A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1954-11-26 | 1955-05-28 | 1955-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1958-11-26 | 1959-05-28 | 1959-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1962-11-26 | 1963-05-28 | 1963-11-27 | $7700.00 | Window Closed / Lapsed |