US2661931A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Hydraulic rotary rock bit
Assignee: SECURITY ENGINEERING DIVISION
•
Filing: 1950-12-04
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Granted: 1953-12-08
•
Expires: 1970-12-04
Abstract
No abstract record available.
Inventors
- 👤 Kenneth H Swart
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 18:18
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/08; E21B10/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1850358A
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US1992992A
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US2047110A
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US2058750A
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US2068327A
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US2135024A
Cited
US2244537A
Cited
US2320136A
Cited
US2320137A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-12-07 | 1957-06-08 | 1957-12-08 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-12-07 | 1961-06-08 | 1961-12-08 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-12-07 | 1965-06-08 | 1965-12-08 | $7700.00 | Window Closed / Lapsed |