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.
Claims6
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, said cage being substantially coincident with an imaginary rectangular box having four long corner edges, a plurality of water-tight control devices disposed along the said four long corner edges which are coincident with the perforated walls of said cage and secured relative to said walls with at least one said control device being wholly immersed in the ambient water at any given moment, each said control device having inlet and outlet valve means for allowing ingress and egress of air and/or water to provide in situ control of the overall buoyancy and/or the flotation attitude of the cage thereby to allow buoyancy-controlled rotation of the cage.
Dependencies are inferred from the claim text.