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Patent US3567254A successfully refreshed from Google Patents.
US3567254A
Expired / Lapsed
US
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Drill steel
Assignee: Sullivan Machinery Co
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Filing: 1968-12-03
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Granted: 1971-03-02
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Expires: 1988-12-03
Abstract
Abstract A DRILL STEEL HAVING AN IMPROVED THREADING ARRANGEMENT THEREON WHEREIN A PLURALITY OF SPACED THREADED PORTIONS ARE PROVIDED ON THE DRILL STEEL ELEMENT AND SEPARATED BY UNTHREADED PORTIONS SO AS TO ALLOW REMOVING A WORN SECTION OF THE ELEMENT AND RECOUPLING THE ELEMENT WITH ANOTHER OF SAID THREADED PORTIONS.
Inventors
- 👤 Toimi A Parssinen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 23:34
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/02; E21B17/04; E21B17/042; E21B17/0426; Y; Y10; Y10T; Y10T403/00; Y10T403/57; Y10T403/5746
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) | 1974-03-01 | 1974-08-31 | 1975-03-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-03-01 | 1978-08-31 | 1979-03-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-03-01 | 1982-08-31 | 1983-03-02 | $7700.00 | Window Closed / Lapsed |