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US2019554A
Expired / Lapsed
US
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Production of alumina
Assignee: Alcoa Corp
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Filing: 1932-07-19
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Granted: 1935-11-05
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Expires: 1952-07-19
Abstract
No abstract record available.
Inventors
- 👤 Ralph B Derr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 20:55
CPC Classifications
C; C01; C01F; C01F7/00; C01F7/02; C01F7/20; C01F7/24
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) | 1938-11-04 | 1939-05-06 | 1939-11-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-11-04 | 1943-05-06 | 1943-11-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-11-04 | 1947-05-06 | 1947-11-05 | $7700.00 | Window Closed / Lapsed |