Abstract: Pressure accumulator consisting of an open-ended cylinder containing a tensioned elastic sleeve fastened to the open-end of the cylinder in which lies an open-ended vessel, the vessel being slideably carried on a post whose free end carries a piston which is slideable on the inside of the vessel.

Abstract: A wind vane and rudder combination, the vane composed of twin fins which are spaced apart and disposed at opposed angles to each other. The twin fins are supported by a beam which is gear connected to the rudder post. The pivot point of the driving gear is thus substantially inboard of the twin fins which considerably enhances the leverage required to turn the rudder as compared with that attainable by placing the vane in line with the pivot point. As a consequence increased efficiency is provided by the spaced fins; suction and turbulence is eliminated allowing a smoother flowing wind stream with minimal drag.