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US2633929A
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Apparatus for filtering air
Assignee: Farr Co
•
Filing: 1948-08-24
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Granted: 1953-04-07
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Expires: 1968-08-24
Abstract
No abstract record available.
Inventors
- 👤 Richard S Farr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 12:01
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/10; B01D46/12; Y; Y10; Y10S; Y10S55/00; Y10S55/24; Y10S55/34
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2429265A
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1956-04-06 | 1956-10-06 | 1957-04-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-04-06 | 1960-10-06 | 1961-04-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-04-06 | 1964-10-06 | 1965-04-07 | $7700.00 | Window Closed / Lapsed |