Patent US1420138A successfully refreshed from Google Patents.
US1420138A
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US
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Process of separating mixed mineral particles of different degrees of specific gravity
Assignee: Individual
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Filing: 1921-07-20
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Granted: 1922-06-20
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Expires: 1941-07-20
Abstract
No abstract record available.
Inventors
- 👤 Wilbur H Peck
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:46
CPC Classifications
B; B03; B03D; B03D1/00; B03D1/14; B03D1/1418; B03D1/02; B03D1/06; B03D1/1443; B03D1/1456; B03D1/24; B03D1/245
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) | 1925-06-19 | 1925-12-19 | 1926-06-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1929-06-19 | 1929-12-19 | 1930-06-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1933-06-19 | 1933-12-19 | 1934-06-20 | $7700.00 | Window Closed / Lapsed |