Patent US2397472A successfully refreshed from Google Patents.
US2397472A
Expired / Lapsed
US
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Oil well device
Assignee: Individual
•
Filing: 1937-12-17
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Granted: 1946-04-02
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Expires: 1957-12-17
Abstract
No abstract record available.
Inventors
- 👤 Erd V Crowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:03
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1949-04-01 | 1949-10-01 | 1950-04-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1953-04-01 | 1953-10-01 | 1954-04-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1957-04-01 | 1957-10-01 | 1958-04-02 | $7700.00 | Window Closed / Lapsed |