US2287274A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process of separating lead and zinc sulphides
Assignee: Armour and Co
•
Filing: 1939-11-09
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Granted: 1942-06-23
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Expires: 1959-11-09
Abstract
No abstract record available.
Inventors
- 👤 Anderson W Ralston
- 👤 Ervin W Segebrecht
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:52
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/001; B03D1/004; B03D1/01; C; C01; C01G; C01G9/00; C01G9/08; B03D2203/00; B03D2203/02
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) | 1945-06-22 | 1945-12-22 | 1946-06-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-06-22 | 1949-12-22 | 1950-06-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-06-22 | 1953-12-22 | 1954-06-23 | $7700.00 | Window Closed / Lapsed |