US2990897A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Abrading element inset bit having improved circulating characteristics
Assignee: Drilling and Service Inc
•
Filing: 1957-03-08
•
Granted: 1961-07-04
•
Expires: 1977-03-08
Abstract
No abstract record available.
Inventors
- 👤 Short Lot William
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 02:16
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/60; E21B10/46
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US671429A
Cited
US2264617A
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US2283510A
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US2381415A
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US2497144A
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US2612348A
Cited
US2607562A
Cited
US2614809A
Cited
US2838284A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-07-03 | 1965-01-02 | 1965-07-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-03 | 1969-01-02 | 1969-07-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-03 | 1973-01-02 | 1973-07-04 | $7700.00 | Window Closed / Lapsed |