Patent US4558874A successfully refreshed from Google Patents.
US2158356A
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US
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Apparatus for oil well drilling
Assignee: ConocoPhillips Co
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Filing: 1937-11-22
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Granted: 1939-05-16
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Expires: 1957-11-22
Abstract
No abstract record available.
Inventors
- 👤 Joseph G Dyer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 14:24
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/10; E21B21/106; E21B21/01; E21B21/019; Y; Y10; Y10T; Y10T137/00; Y10T137/7722; Y10T137/7837; Y10T137/7854; Y10T137/7856
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) | 1942-05-15 | 1942-11-14 | 1943-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-05-15 | 1946-11-14 | 1947-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-05-15 | 1950-11-14 | 1951-05-16 | $7700.00 | Window Closed / Lapsed |