US2991837A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Turbo drill thrust bearings
Assignee: California Research LLC
•
Filing: 1957-05-29
•
Granted: 1961-07-11
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Expires: 1977-05-29
Abstract
No abstract record available.
Inventors
- 👤 William R Postlewaite
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 18:56
CPC Classifications
E; E21; E21B; E21B4/00; E21B4/02
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) | 1964-07-10 | 1965-01-09 | 1965-07-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-07-10 | 1969-01-09 | 1969-07-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-07-10 | 1973-01-09 | 1973-07-11 | $7700.00 | Window Closed / Lapsed |