Patent US1998774A successfully refreshed from Google Patents.
US1998774A
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US
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Process for purification of fluids
Assignee: CHESTER F HOCKLEY
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Filing: 1931-01-19
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Granted: 1935-04-23
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Expires: 1951-01-19
Abstract
No abstract record available.
Inventors
- 👤 Claude A Bulkeley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 15:30
CPC Classifications
B; B01; B01D; B01D53/00; B01D53/14; B01D53/18; C; C01; C01B; C01B32/00; C01B32/50
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) | 1938-04-22 | 1938-10-22 | 1939-04-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1942-04-22 | 1942-10-22 | 1943-04-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1946-04-22 | 1946-10-22 | 1947-04-23 | $7700.00 | Window Closed / Lapsed |