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Patent US2990894A successfully refreshed from Google Patents.
US2990894A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Turbodrill
Assignee: Individual
•
Filing: 1958-10-20
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Granted: 1961-07-04
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Expires: 1978-10-20
Abstract
No abstract record available.
Inventors
- 👤 Joseph A Mitchell
- 👤 William M Sanders
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 13:05
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB191126451A
Cited
US1663025A
Cited
US1786173A
Cited
US1999662A
Cited
US2095725A
Cited
US2588311A
Cited
US2710741A
Cited
US2828945A
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 |