US2758819A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulically expansible drill bits
Assignee: Rotary Oil Tool Co
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Filing: 1954-08-25
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Granted: 1956-08-14
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Expires: 1974-08-25
Abstract
No abstract record available.
Inventors
- 👤 Jr Archer W Kammerer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 13:31
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/26; E21B10/32; E21B10/34; E21B10/345; E21B10/08; E21B10/18
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) | 1959-08-14 | 1960-02-13 | 1960-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1963-08-14 | 1964-02-13 | 1964-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1967-08-14 | 1968-02-13 | 1968-08-14 | $7700.00 | Window Closed / Lapsed |