Patent US2391622A successfully refreshed from Google Patents.
US2391622A
Expired / Lapsed
US
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Drilling mud
Assignee: Stanolind Oil and Gas Co
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Filing: 1944-02-29
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Granted: 1945-12-25
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Expires: 1964-02-29
Abstract
No abstract record available.
Inventors
- 👤 Thomas H Dunn
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:11
CPC Classifications
C; C09; C09K; C09K8/00; C09K8/02; C09K8/04; C09K8/14; C09K8/18; C09K8/22; C09K8/16
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) | 1948-12-24 | 1949-06-25 | 1949-12-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1952-12-24 | 1953-06-25 | 1953-12-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1956-12-24 | 1957-06-25 | 1957-12-25 | $7700.00 | Window Closed / Lapsed |