Patent US5517537A successfully refreshed from Google Patents.
US3208205A
Expired / Lapsed
US
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Multi-layer filter arrangement
Assignee: American Air Filter Co Inc
•
Filing: 1962-06-06
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Granted: 1965-09-28
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Expires: 1982-06-06
Abstract
No abstract record available.
Inventors
- 👤 John D Harms
- 👤 Karl L Westlin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 11:21
CPC Classifications
B; B01; B01D; B01D46/00; B01D46/02
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US3124441A
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US2607436A
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US2771153A
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GB800195A
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US2853154A
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US3057138A
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US2959247A
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US2964127A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1968-09-27 | 1969-03-29 | 1969-09-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1972-09-27 | 1973-03-29 | 1973-09-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1976-09-27 | 1977-03-29 | 1977-09-28 | $7700.00 | Window Closed / Lapsed |