Patent US2261371A successfully refreshed from Google Patents.
US2261371A
Expired / Lapsed
US
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Recovery of tungstic acid from its ores
Assignee: Chemical Foundation Inc
•
Filing: 1938-02-16
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Granted: 1941-11-04
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Expires: 1958-02-16
Abstract
No abstract record available.
Inventors
- 👤 Arthur W Hixson
- 👤 Miller Ralph
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 17:13
CPC Classifications
C; C22; C22B; C22B34/00; C22B34/30; C22B34/36; C01; C01G; C01G41/00
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) | 1944-11-03 | 1945-05-05 | 1945-11-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1948-11-03 | 1949-05-05 | 1949-11-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1952-11-03 | 1953-05-05 | 1953-11-04 | $7700.00 | Window Closed / Lapsed |