James M Ellis
ABSTRACT
The invention relates to a self-propelled shark-proof cage which is provided with at least one access opening and a propeller mounting frame having pivot means coupling it to the cage so that the propeller mounting frame is pivotal about two axes at right angles to each other, and the propeller mounting frame carries on it an air motor and a propeller. The frame is provided with buoyancy means so that it can be made to be of approximately the same gravity as sea-water, and the air motor is driven by compressed air so that the cage can be propelled through the water, thereby enabling abalone divers to collect abalone without fear of predators and, beacause of less exertion, for longer periods of time.
Notes
Claims
What is claimed is:1. A self-propelled shark-proof cage comprising:an elongated frame, and wall means mounted on said frame for preventing sharks from entering the cage,said wall means including an upper wall and a base wall, a first access opening in said upper wall and a second access opening in said base wall, and a hatch door hinged to said upper wall and adapted to releasably overlie said first access opening and, when closed, to be retained in that state by the effects of gravity,a propell...