Patent US2442594A successfully refreshed from Google Patents.
US2442594A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Pneumatic cleaner for sand filters
Assignee: Individual
•
Filing: 1938-04-27
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Granted: 1948-06-01
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Expires: 1958-04-27
Abstract
No abstract record available.
Inventors
- 👤 Charles E Fraser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 19:25
CPC Classifications
B; B01; B01D; B01D24/00; B01D24/02; B01D24/20; B01D24/22; B01D24/46; B01D24/4605; B01D24/461; B01D24/4621; B01D24/4631; B01D24/4636
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) | 1951-06-01 | 1951-12-01 | 1952-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1955-06-01 | 1955-12-01 | 1956-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1959-06-01 | 1959-12-01 | 1960-06-01 | $7700.00 | Window Closed / Lapsed |