US3353680A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Dual element parallel flow filter assembly
Assignee: Walker Manufacturing Co
•
Filing: 1964-07-06
•
Granted: 1967-11-21
•
Expires: 1984-07-06
Abstract
No abstract record available.
Inventors
- 👤 Louis F Niebergall
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 20:22
CPC Classifications
B; B01; B01D; B01D27/00; B01D27/02; B01D27/04; B01D27/06; B01D27/10; B01D27/106; B01D27/14; B01D27/142; B01D27/144; Y; Y10; Y10S; Y10S210/00; Y10S210/17
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
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US2203668A
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GB588224A
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US2888141A
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US2936891A
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GB894916A
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FR1300086A
Cited
FR1338141A
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US3229817A
Cited
FR1368602A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1970-11-20 | 1971-05-22 | 1971-11-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1974-11-20 | 1975-05-22 | 1975-11-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1978-11-20 | 1979-05-22 | 1979-11-21 | $7700.00 | Window Closed / Lapsed |