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Patent US2883156A successfully refreshed from Google Patents.
US2883156A
Expired / Lapsed
US
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Well drilling apparatus
Assignee: Individual
•
Filing: 1956-10-08
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Granted: 1959-04-21
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Expires: 1976-10-08
Abstract
No abstract record available.
Inventors
- 👤 Howard D Davenport
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:07
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1489282A
Cited
US1482702A
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US1860214A
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US2340738A
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US2591488A
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US2684835A
Cited
US2663541A
Cited
US2776817A
Cited
GB755207A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1962-04-20 | 1962-10-20 | 1963-04-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1966-04-20 | 1966-10-20 | 1967-04-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1970-04-20 | 1970-10-20 | 1971-04-21 | $7700.00 | Window Closed / Lapsed |