Heave alleviation and control device for a surface effect ship

摘要

A heave alleviation and control device for a surface effect ship having a central plenum chamber pressurized from a source of pressure interconnected to a stern seal plenum chamber by a duct. The duct contains a first valve positioned between the inlet from the central plenum chamber and the outlet to said stern seal plenum chamber for controlling the flow of pressurized gas therethrough. The rear wall of the duct has an opening therethrough to the atmosphere. A second valve is positioned adjacent the opening within the duct to control the flow of gas under pressure therethrough. The two valves are interconnected by levers to a piston translatable within a cylinder for simultaneous movement with the piston. One side of the piston is exposed to the central plenum chamber pressure and the opposite side is exposed to a source of hydraulic fluid under a preselected pressure. Directional movement of the piston is provided by the pressure differential between the sides of the piston.