US2431559A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Helical chute concentrator and the method of concentration practiced thereby
Assignee: HUMPHREYS INVEST Co
•
Filing: 1943-04-10
•
Granted: 1947-11-25
•
Expires: 1963-04-10
Abstract
No abstract record available.
Inventors
- 👤 Ira B Humphreys
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:14
CPC Classifications
B; B03; B03B; B03B5/00; B03B5/62; B03B5/626
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US750281A
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US629596A
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US629595A
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US912766A
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US1032281A
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US1520451A
Cited
US1959736A
Cited
US2145315A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1950-11-24 | 1951-05-26 | 1951-11-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1954-11-24 | 1955-05-26 | 1955-11-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1958-11-24 | 1959-05-26 | 1959-11-25 | $7700.00 | Window Closed / Lapsed |