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US2161284A
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Apparatus for cementing wells
Assignee: Individual
•
Filing: 1938-03-28
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Granted: 1939-06-06
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Expires: 1958-03-28
Abstract
No abstract record available.
Inventors
- 👤 Erd V Crowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 04:22
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/14; E21B33/16; E21B21/00; E21B21/10; Y; Y10; Y10T; Y10T137/00; Y10T137/6851; Y10T137/7036; Y10T137/7722; Y10T137/7837; Y10T137/7854; Y10T137/7856; Y10T137/7904; Y10T137/7922; Y10T137/7929; Y10T137/7934; Y10T137/8593; Y10T137/86493; Y10T137/86574; Y10T137/8667
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) | 1942-06-05 | 1942-12-05 | 1943-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-06-05 | 1946-12-05 | 1947-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-06-05 | 1950-12-05 | 1951-06-06 | $7700.00 | Window Closed / Lapsed |