Patent US2981531A successfully refreshed from Google Patents.
US2981531A
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US
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Particle size control
Assignee: Individual
•
Filing: 1958-05-20
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Granted: 1961-04-25
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Expires: 1978-05-20
Abstract
No abstract record available.
Inventors
- 👤 Pyzel Robert
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 12:04
CPC Classifications
B; B01; B01J; B01J8/00; B01J8/18; B01J8/1809; C; C04; C04B; C04B7/00; C04B7/36; C04B7/43; C04B7/44; C04B7/45; B01J2208/00; B01J2208/00008; B01J2208/00017; B01J2208/00106; B01J2208/00168; B01J2208/00256; B01J2208/00265; B01J2208/00274; B01J2208/00504
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1964-04-24 | 1964-10-24 | 1965-04-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1968-04-24 | 1968-10-24 | 1969-04-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1972-04-24 | 1972-10-24 | 1973-04-25 | $7700.00 | Window Closed / Lapsed |