Propulsion air stream deflecting apparatus for air cushion vehicle

Abstract

A propulsion air stream deflecting apparatus for an air cushion vehicle having a hull, an air duct mounted on the hull and a propeller fan, includes a plurality of rudders, each mounted on the hull adjacent to the rear open end of the duct for pivotal movement about a vertical axis. The rudders are adapted to close the rear open end of the air duct. A rudder control mechanism is operatively connected to the rudders for controlling the pivotal movement of the rudders to selectively provide a propulsion thrust and a steering thrust to the hull and to provide a closed position in which the rear open end of the air duct is closed by the rudders. A flap is pivotably mounted at the rear end thereof to the duct such that the flap closes an opening, formed at the rear end of the air duct, at a closed position thereof where the inner face of the flap is substantially flush with the inner surface of the air duct. The flap turns outwardly to open the opening due to an increase in pressure in the duct in the closed position of the rudders, for deflecting the air stream, passing out the opening, forwards to provide a forward thrust to the hull for braking, stopping or rearwardly moving the hull. A flap urging spring urges the flap to close the opening.