Abstract: A fluid servo network having a servo fluid pressure responsive movable output member controlled by a variable area orifice the effective area of which is established by a movable servo valve which is actuated by lever means in response to a variable force input applied thereto. The lever means includes a main input lever responsive to the variable force input and an opposing variable feedback force which varies in response to the reaction of the output member to establish a force balance on the main input lever. The main input lever is attached to a roller loaded by a constant reference force and movable along a secondary lever mounted for pivotal movement about a fixed axis to vary the effective lever arm of the secondary lever which is attached to the servo valve. The input torque tending to close the servo valve is opposed by the torque derived from a characteristic orifice force unbalance acting through the secondary lever.

Abstract: This invention relates to a hydraulic motor device comprising a cylinder and a piston reciprocating therein said piston being moved in one direction by means of a spring and in the other direction by means of fluid under pressure supplied against one side of the piston, said cylinder including an inlet for fluid at one end and an outlet for fluid at the other end, and said piston including an overflow aperture from one working side to the other, which aperture is controlled by a stop valve that is either completely open or completely closed depending upon its impact against two spaced apart points on the cylinder end walls.

Abstract: 1.

Abstract: A servo device for steering gears for vehicles and ships is adapted to be coupled in a mechanical connection between said gear or the like and the steering rod or the like operated thereby. The device comprises a pair of opposed cylinder-and-piston units each having a working chamber, defined by the respective piston and adapted to be supplied pressurized fluid from a suitable source during control by valve means responsive to a movement of the output member of said gear and the resistance thereagainst of the steering rod operated thereby so as to amplify the power for overcoming said resistance by means of the pressure fluid in one of said pair of working chambers.