US3406501A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Automobile engine exhaust filter
Assignee: DAVID R WATKINS
•
Filing: 1967-07-06
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Granted: 1968-10-22
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Expires: 1987-07-06
Abstract
No abstract record available.
Inventors
- 👤 David R Watkins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:24
CPC Classifications
F; F01; F01N; F01N3/00; F01N3/08; F01N3/0807; F01N13/00; F01N13/18; F01N13/1888; F01N13/1894; F01N3/02; F01N3/021; F01N3/033; F01N2450/00; F01N2450/30; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10S; Y10S55/00; Y10S55/30
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) | 1971-10-22 | 1972-04-22 | 1972-10-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1975-10-22 | 1976-04-22 | 1976-10-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1979-10-22 | 1980-04-22 | 1980-10-22 | $7700.00 | Window Closed / Lapsed |