Patent US2158689A successfully refreshed from Google Patents.
US2158689A
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US
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Apparatus for treating complex ores
Assignee: METALS RECOVERY CO Inc
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Filing: 1937-03-23
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Granted: 1939-05-16
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Expires: 1957-03-23
Abstract
No abstract record available.
Inventors
- 👤 George W Buchanan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 15:41
CPC Classifications
C; C22; C22B; C22B11/00; C22B1/00; C22B1/02; C22B1/08; C22B1/11
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) | 1942-05-15 | 1942-11-14 | 1943-05-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1946-05-15 | 1946-11-14 | 1947-05-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1950-05-15 | 1950-11-14 | 1951-05-16 | $7700.00 | Window Closed / Lapsed |