US2471548A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Zigzag filter construction
Assignee: Air Maze Corp
•
Filing: 1945-12-14
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Granted: 1949-05-31
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Expires: 1965-12-14
Abstract
No abstract record available.
Inventors
- 👤 Oliver H Schaaf
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 04:13
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/52; B01D46/521; B01D46/522; B01D29/00; B01D29/11; B01D29/13; B01D29/15; B01D29/21; B01D46/10; B01D2201/00; B01D2201/12
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) | 1952-05-30 | 1952-11-29 | 1953-05-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1956-05-30 | 1956-11-29 | 1957-05-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1960-05-30 | 1960-11-29 | 1961-05-31 | $7700.00 | Window Closed / Lapsed |