US3515280A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stacked element filter apparatus
Assignee: WATSON H PARKER
•
Filing: 1968-12-03
•
Granted: 1970-06-02
•
Expires: 1988-12-03
Abstract
No abstract record available.
Inventors
- 👤 Watson H Parker
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:06
CPC Classifications
B; B01; B01D; B01D36/00; B01D36/02; B01D29/00; B01D29/11; B01D29/13; B01D29/15; B01D29/21; B01D29/39; B01D29/41; B01D29/50; B01D29/52; B01D29/54; B01D29/56; B01D29/58; B01D2201/00; B01D2201/02; B01D2201/04; B01D2201/043; B01D2201/0446
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
US1906417A
Cited
US1932117A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1973-06-01 | 1973-12-01 | 1974-06-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1977-06-01 | 1977-12-01 | 1978-06-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1981-06-01 | 1981-12-01 | 1982-06-02 | $7700.00 | Window Closed / Lapsed |