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US2521380A
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Centrifugal separator
Assignee: Columbian Carbon Co
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Filing: 1948-02-05
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Granted: 1950-09-05
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Expires: 1968-02-05
Abstract
No abstract record available.
Inventors
- 👤 Merle F Lichtenfels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:05
CPC Classifications
B; B04; B04C; B04C5/00; B04C5/22; B04C5/24; B04C5/28
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) | 1953-09-04 | 1954-03-06 | 1954-09-05 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1957-09-04 | 1958-03-06 | 1958-09-05 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1961-09-04 | 1962-03-06 | 1962-09-05 | $7700.00 | Window Closed / Lapsed |