US2639781A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Electrostatic filter
Assignee: Air Maze Corp
•
Filing: 1948-12-10
•
Granted: 1953-05-26
•
Expires: 1968-12-10
Abstract
No abstract record available.
Inventors
- 👤 Christian W Savitz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 15:58
CPC Classifications
B; B03; B03C; B03C3/00; B03C3/02; B03C3/04; B03C3/12
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2251451A
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US2215298A
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US2255677A
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US2333551A
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US2359149A
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US2386993A
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US2488712A
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US2427740A
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US2486520A
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US2476247A
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US2500572A
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US2504430A
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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) | 1956-05-25 | 1956-11-24 | 1957-05-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1960-05-25 | 1960-11-24 | 1961-05-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1964-05-25 | 1964-11-24 | 1965-05-26 | $7700.00 | Window Closed / Lapsed |