Abstract: A low breakout power transfer unit for transferring power between first and second hydraulic systems includes first and second pump/motor units to allow fluid flow between the first and second pump/motor units and the first and second hydraulic systems, respectively. The transfer unit includes a detection device for sensing fluid flow demand in the hydraulic systems and values for automatically isolating the pump/motor units from the hydraulic systems when the detection means senses substantially no fluid flow demands in a hydraulic system. The transfer unit includes a bypass device for each pump/motor unit for recirculating pumped fluid in excess of fluid flow demand.

Abstract: A method of manufacturing a moving coil force motor particularly adapted for utilization with a hydraulic servovalve. The method includes aligning a flexure spring with respect to the permanent magnet structure and thereafter securing the permanent magnet structure and flexure spring within a case for the force motor. Subsequently, the coil structure is aligned with respect to the gap provided in the permanent magnet pole pieces by relatively moving the motorcase with respect to the coil until the appropriate position is attained and thereafter securing the case against further movements.

Abstract: An electrohydraulic servovalve which includes as an integral part thereof a monitor valve which senses the absence or lack of system pressure in the first or second stages of the valve and translates in the absence thereof to deactivate load control. The torque motor of the electrohydraulic servovalve is biased, electrically or magnetically, to provide a failure indication in the first stage of the valve in the absence of or excess of applied electrical signals to the torque motor.

Abstract: A non-conventional electric power source including a reciprocating hydraulically powered ram coupled to an electric generator. A pair of matched nozzles coupling a hydraulic fluid supply to the ram. Reciprocation of the ram is effected by a flapper disposed between the nozzles which alternatingly cuts off hydraulic fluid flow through the nozzles responsive to the ram approaching its travel limit.