USRE28116E
Expired / Lapsed
US
⏱️ 0.0 years remaining
Filter and water recirculation system
Assignee: —
•
Filing: 1973-11-23
•
Granted: 1974-08-13
•
Expires: 1993-11-23
Abstract
Abstract AN AQUARIUM FILTER WATER RECIRCULATION SYSTEM COMPRISES A WATER-CARRYING AND AN INNER AIR-CARRYING MEMBER ATTACHED TO A BASE MEMBER WHICH IS SUPPORTED ABOVE THE FLOOR OF AN AQUARIUM. AIR IS PASSED THROUGH THE INNER CYLINDRICAL TUBE, DIFFUSED, AND MIXED WITH THE WATER IN THE WATER-CARRYING MEMBER. THE BASE MEMBER IS MADE OF POLYVINYL CHLORIDE AND IS PROVIDED WITH A CORRUGATED REGULAR CONTOUR ABOVE WHICH RESTS THE GRAVEL BED OF THE AQUARIUM.
Inventors
No inventors recorded.
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 22:13
CPC Classifications
A; A01; A01K; A01K63/00; A01K63/04; A01K63/045
Claims Analysis
Total Claims: 0
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References Cited (Backward Citations)
No citation records indexed.
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-08-12 | 1978-02-11 | 1978-08-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-08-12 | 1982-02-11 | 1982-08-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-08-12 | 1986-02-11 | 1986-08-13 | $7700.00 | Window Closed / Lapsed |