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US2421582A
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Process for refining copper
Assignee: American Smelting and Refining Co
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Filing: 1942-10-16
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Granted: 1947-06-03
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Expires: 1962-10-16
Abstract
No abstract record available.
Inventors
- 👤 Hugh M Shepard
- 👤 Bryan James Howard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 14:58
CPC Classifications
C; C25; C25C; C25C7/00; C25C7/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US202027A
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US377487A
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US494231A
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US1163337A
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US1698486A
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US1836368A
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US1817707A
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US2059993A
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US2048854A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-06-02 | 1950-12-02 | 1951-06-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-06-02 | 1954-12-02 | 1955-06-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-06-02 | 1958-12-02 | 1959-06-03 | $7700.00 | Window Closed / Lapsed |