US2590691A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for the separation of solid substances of different specific gravity and grain size
Assignee: Directie van de Staatsmijnen in Limburg
•
Filing: 1946-04-23
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Granted: 1952-03-25
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Expires: 1966-04-23
Abstract
No abstract record available.
Inventors
- 👤 Fontein Freerk Jan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:51
CPC Classifications
C; C03; C03B; C03B5/00; C03B5/16; C03B5/225; B; B03; B03B; B03B5/00; B03B5/28; B03B5/30; B03B5/32; B03B5/34; B04; B04C; B04C5/00; B04C5/02; B04C5/04; B04C5/14; B04C5/185; B04C5/187; B04C7/00
Claims Analysis
Total Claims: 0
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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) | 1955-03-25 | 1955-09-24 | 1956-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1959-03-25 | 1959-09-24 | 1960-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1963-03-25 | 1963-09-24 | 1964-03-25 | $7700.00 | Window Closed / Lapsed |