Patent US1991791A successfully refreshed from Google Patents.
US1991791A
Expired / Lapsed
US
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Method of distilling heavy lubricating oils
Assignee: Lummus Technology LLC
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Filing: 1933-03-20
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Granted: 1935-02-19
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Expires: 1953-03-20
Abstract
No abstract record available.
Inventors
- 👤 George B Coubrough
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 17:25
CPC Classifications
C; C10; C10G; C10G7/00
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) | 1938-02-18 | 1938-08-20 | 1939-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-02-18 | 1942-08-20 | 1943-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-02-18 | 1946-08-20 | 1947-02-19 | $7700.00 | Window Closed / Lapsed |