US2236987A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of cementing wells
Assignee: CalPortland Co
•
Filing: 1939-01-04
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Granted: 1941-04-01
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Expires: 1959-01-04
Abstract
No abstract record available.
Inventors
- 👤 Ira C Bechtold
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 18:54
CPC Classifications
C; C04; C04B; C04B24/00; C04B24/24; C04B24/34; C09; C09K; C09K8/00; C09K8/42; C09K8/46
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) | 1944-03-31 | 1944-09-30 | 1945-04-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-03-31 | 1948-09-30 | 1949-04-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-03-31 | 1952-09-30 | 1953-04-01 | $7700.00 | Window Closed / Lapsed |