US3428177A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fluid control means for filter backwashing and air scouring
Assignee: Union Tank Car Co
•
Filing: 1966-08-24
•
Granted: 1969-02-18
•
Expires: 1986-08-24
Abstract
No abstract record available.
Inventors
- 👤 Joseph H Duff
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 04:04
CPC Classifications
B; B01; B01D; B01D24/00; B01D24/46; B01D24/4631; B01D24/4636; B01D24/02; B01D24/10; B01D24/14
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
NL95596C
Cited
GB578811A
Cited
US2746605A
Cited
US3017247A
Cited
US2879891A
Cited
US2879893A
Cited
US3111486A
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US3260366A
Cited
US3342334A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1972-02-18 | 1972-08-19 | 1973-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1976-02-18 | 1976-08-19 | 1977-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1980-02-18 | 1980-08-19 | 1981-02-18 | $7700.00 | Window Closed / Lapsed |