Patent US1990359A successfully refreshed from Google Patents.
US1990359A
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Method of purifying lubricating oils
Assignee: Sharples Specialty Co
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Filing: 1933-01-19
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Granted: 1935-02-05
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Expires: 1953-01-19
Abstract
No abstract record available.
Inventors
- 👤 Jr Charles M Ambler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 19:14
CPC Classifications
C; C10; C10M; C10M175/00; C10M175/005
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) | 1938-02-04 | 1938-08-06 | 1939-02-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-02-04 | 1942-08-06 | 1943-02-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-02-04 | 1946-08-06 | 1947-02-05 | $7700.00 | Window Closed / Lapsed |