US3738491A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Under-gravel aquarium filter
Assignee: Individual
•
Filing: 1971-09-29
•
Granted: 1973-06-12
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Expires: 1991-09-29
Abstract
Abstract An improved means of filtering and circulating the water in an aquarium wherein gravel at the bottom of the aquarium is effectively employed to trap the waste material and debris so that it can be eliminated by natural decay or by backwashing of the gravel.
Inventors
- 👤 D Dockery
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 15:08
CPC Classifications
A; A01; A01K; A01K63/00; A01K63/04; A01K63/045
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
155 words
A circulating system for an aquarium having water and a material such as gravel on the bottom of the aquarium said system comprising: a grid disposed upwardly from the bottom of the aquarium to form a chamber between the bottom of said aquarium and the underside of said grid, said material being disposed on said grid; said chamber communicating with the water in said aquarium through said grid and through said material; means collecting water from the upper surface of said material and directing it into said chamber; said collecting means comprising a collector head having a flat inlet disposed above the material on said grid in close proximity thereto, said flat inlet being disposed generally parallel to the upper surface of the grid; and said collecting means further comprising means for conducting water through said grid and from the upper surface of said material, through said inlet, and into said chamber under said grid.
Claim 2
Dependent Claim
155 words
A circulating system for an aquarium having water and a material such as gravel on the bottom of the aquarium said system comprising: a grid disposed upwardly from the bottom of the aquarium to form a chamber between the bottom of said aquarium and the underside of said grid, said material being disposed on said grid; said chamber communicating with the water in said aquarium through said grid and through said material; means collecting water from the upper surface of said material and directing it into said chamber; said collecting means comprising a collector head having a flat inlet disposed above the material on said grid in close proximity thereto, said flat inlet being disposed generally parallel to the upper surface of the grid; and said collecting means further comprising means for conducting water through said grid and from the upper surface of said material, through said inlet, and into said chamber under said grid.
Claim 3
Dependent Claim
26 words
The system as defined in claim 1 and in which said grid is slanted downwardly from a horizontal plane in a direction toward said collector device.
Claim 4
Dependent Claim
76 words
The system as defined in claim 1 and in which said conducting means comprises an air pump and means for connecting said air pump to said collector head, generally vertically extending tubes with one of said tubes connected with said collector head and means mounting the other of said tubes to said grid and opening to said chamber, a removable U-shaped tube connecting the upper ends of said tubes, and vent openings in said U-shaped tube.
Claim 5
Dependent Claim
42 words
The system as defined in claim 3 and in which said mounting means comprises circumferentially spaced flange portions connected with said tube and spaced clamping means spaced upwardly from said grid for receiving said flange portions upon rotation of said flange portions.
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) | 1976-06-11 | 1976-12-11 | 1977-06-12 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-06-11 | 1980-12-11 | 1981-06-12 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-06-11 | 1984-12-11 | 1985-06-12 | $7700.00 | Window Closed / Lapsed |