Displacement control for a hydraulic pump or motor with failure override

Abstract From the Canadian patent

Abstract A displacement control for a pump or motor having a swash plate for setting displacement includes a control device operatively connected to the swash plate and a control valve having connections to a source of pressure and drain for operating said control cylinder. The control valve has a neutral position wherein the swash plate is at or near a minimum displacement position. The control valve is operable to other positions for setting the displacement of the pump or motor and, additionally is movable to a, control position other than the neutral position or normal displacement-setting positions in response to an operative failure of the control valve positioning system which …