US2071391A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for cementing wells
Assignee: Individual
•
Filing: 1935-09-20
•
Granted: 1937-02-23
•
Expires: 1955-09-20
Abstract
No abstract record available.
Inventors
- 👤 Erd V Crowell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 12:59
CPC Classifications
E; E21; E21B; E21B33/00; E21B33/10; E21B33/13; E21B33/14; E21B33/16; E21B21/00; E21B21/10; F; F16; F16K; F16K15/00; F16K15/02; F16K15/06; F16K15/063; F16K15/14; F16K15/1401; Y; Y10; Y10T; Y10T137/00; Y10T137/6851; Y10T137/7036; Y10T137/7722; Y10T137/7837; Y10T137/7838; Y10T137/7842; Y10T137/7904; Y10T137/7922; Y10T137/7929
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) | 1940-02-23 | 1940-08-24 | 1941-02-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1944-02-23 | 1944-08-24 | 1945-02-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1948-02-23 | 1948-08-24 | 1949-02-23 | $7700.00 | Window Closed / Lapsed |