US2833520A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Annular mill for use in oil wells
Assignee: Individual
•
Filing: 1957-01-07
•
Granted: 1958-05-06
•
Expires: 1977-01-07
Abstract
No abstract record available.
Inventors
- 👤 Robert G Owen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 10:49
CPC Classifications
E; E21; E21B; E21B10/00; E21B10/46; E21B10/56; E21B10/567; E21B10/5676; E21B10/006; E21B29/00; E21B29/002
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1163867A
Cited
US1471526A
Cited
US1519135A
Cited
US2121202A
Cited
US2268775A
Cited
US2371488A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1961-05-05 | 1961-11-04 | 1962-05-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1965-05-05 | 1965-11-04 | 1966-05-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1969-05-05 | 1969-11-04 | 1970-05-06 | $7700.00 | Window Closed / Lapsed |