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US1729423A
Expired / Lapsed
US
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Extraction of copper-nickel matte
Assignee: Harshaw Chemical Co
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Filing: 1926-04-28
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Granted: 1929-09-24
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Expires: 1946-04-28
Abstract
No abstract record available.
Inventors
- 👤 William J Harshaw
- 👤 George L Homer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:29
CPC Classifications
C; C22; C22B; C22B15/00; C22B15/0063; C22B15/0065; C22B15/0067; C22B15/0071; Y; Y02; Y02P; Y02P10/00; Y02P10/20
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) | 1932-09-23 | 1933-03-25 | 1933-09-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1936-09-23 | 1937-03-25 | 1937-09-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1940-09-23 | 1941-03-25 | 1941-09-24 | $7700.00 | Window Closed / Lapsed |