Rotatable fish cage
AssigneeNational Research Development Corporation
InventorsAlbert Blair, Patrick T. Grant
Life of this patent
Estimating the term…
Abstract
The perforated walls of conventional fish cages become partially blocked after prolonged use and the cage of the present invention offers a relatively simple means of preventing or remedying this defect by periodically rotating the cage to expose each wall in turn for cleaning or replacement. In the embodiment of FIG. 1, the cage (8) is provided with four control devices (A-D) which can be filled with air or water (via rotation valves 18 A-D) as appropriate to effect the desired rotation. These same devices can also be used to control the buoyancy of the cage and hence the level at which it floats in the ambient water preferably just on or under the surface.
Claims8
A fish cage comprising perforated walls for the flow into or out of the cage of ambient water in which the cage will be located in use, a plurality of water-tight control devices secured relative to said walls with at least one said control device being wholly immersed in said ambient water at any given moment, each said control device including first, inlet and outlet, rotation valves for use in rotating the cage and second, inlet and outlet, buoyancy valves for use in controlling the buoyancy of the cage, said control devices having external walls which are apertured to allow the ingress or egress of ambient water and each device including a water-tight and inflatable core member, the interior volume of each said core member communicating both with said respective rotation valve and said buoyancy valve.
Dependencies are inferred from the claim text.