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US3405771A
Expired / Lapsed
US
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Deep well motor impact tool and drilling apparatus
Assignee: MR DUDLEY HUGHES
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Filing: 1966-04-12
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Granted: 1968-10-15
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Expires: 1986-04-12
Abstract
No abstract record available.
Inventors
- 👤 Charles J Carr
- 👤 Hughes Marion Dudley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:48
CPC Classifications
E; E21; E21B; E21B7/00; E21B7/04; E21B7/06; E21B6/00
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1971-10-15 | 1972-04-15 | 1972-10-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-15 | 1976-04-15 | 1976-10-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-15 | 1980-04-15 | 1980-10-15 | $7700.00 | Window Closed / Lapsed |