US3474906A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Valve controlled filter change indicator
Assignee: Husco International Inc
•
Filing: 1967-03-28
•
Granted: 1969-10-28
•
Expires: 1987-03-28
Abstract
No abstract record available.
Inventors
- 👤 Francis H Tennis
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 20:06
CPC Classifications
B; B01; B01D; B01D35/00; B01D35/14; B01D35/143; B01D35/147; Y; Y10; Y10T; Y10T137/00; Y10T137/8158; Y10T137/8326
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
GB450104A
Cited
US2776056A
Cited
US2678134A
Cited
US3080972A
Cited
US3229816A
Cited
US3150633A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-10-27 | 1973-04-28 | 1973-10-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-10-27 | 1977-04-28 | 1977-10-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-10-27 | 1981-04-28 | 1981-10-28 | $7700.00 | Window Closed / Lapsed |