US2305633A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filtering device
Assignee: Individual
•
Filing: 1939-05-17
•
Granted: 1942-12-22
•
Expires: 1959-05-17
Abstract
No abstract record available.
Inventors
- 👤 Elmer J Pratt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 20:22
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/14; B01D35/147; Y; Y10; Y10T; Y10T137/00; Y10T137/1624; Y10T137/1797; Y10T137/1812; Y10T137/7722; Y10T137/7737
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) | 1945-12-21 | 1946-06-22 | 1946-12-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1949-12-21 | 1950-06-22 | 1950-12-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1953-12-21 | 1954-06-22 | 1954-12-22 | $7700.00 | Window Closed / Lapsed |