Abstract: In a control valve assembly of the kind set forth for vehicle braking systesm a valve-operating member for operating first and second valves is guided to slide in a bore in a piston. The valve-operating member is adapted to permit the second valve to close and the first valve subsequently to open when the first piston is returned to an inoperative retracted position in response to the pressure of fluid remaining the pressure space when the applying force is relieved, the pressure space being defined between the first piston and a second piston.

Abstract: A valve piston in an automotive power-steering system has a pair of inner peripheral grooves, defined by confronting lands of adjoining piston heads, normally communicating with the high-pressure side of an oil pump via symmetrical branch channels and with the low-pressure side of that pump via a common return channel. The piston also has a pair of outer peripheral grooves, normally cut off from the adjoining inner grooves, connected to opposite cylinder chambers of a hydraulic servomotor. The inner grooves communicate with a pair of axial piston bores receiving fixed or spring-loaded plungers for exerting a counteracting hydraulic pressure upon the piston upon a displacement thereof from its centered position, such displacement also opening the path from one branch channel via the corresponding inner groove and the adjoining outer groove to a corresponding servomotor chamber.

Abstract: A control circuit for an actuator having an operation valve for selectively distributing hydraulic oil from a pump to plural actuators which has a plurality of conduits, a plurality of pilot-operated valves for controlling the flow direction of oil to the actuator side or the tank side, and a pilot spool valve, whereby the operating force of the operation valve can be greatly reduced in simple operation.

Abstract: A diaphragm valve has a relatively long seating formed by a plurality of ribs which engage with one air operated diaphragm. An annular valve is provided by slotting the outer surface of an annular seating member which engages an endless diaphragm, alternate slots communicating with the inlet or outlet of the valve. A pneumatic actuator for a vehicle braking system is provided with internal valve means for controlling the flow of air through the movable wall carrying the actuating member. An anti-skid braking system employs such a pneumatic brake actuator, the internal valve means being operated by skid sensing means.

Abstract: A method and apparatus for controlling speed and torque of hand held air driven vane type motors is available in several embodiments. For example, one embodiment is used in tool and die work and another embodiment is used in dental work. In reference to the latter, a foot operated control regulates the speed of an air driven handpiece, driving in turn various tools such as cutters and drills as they are generally used in a dental laboratory, by regulating the flow of compressed air both to and from the handpiece. Application of an operator's foot pressure on a floor level foot control, simultaneously depresses two valves which control the flow of compressed air. One valve controls the flow of compressed air from its source to the handpiece, and one valve controls the release into the atmosphere of compressed air from the handpiece.

Abstract: The valve arrangement includes four main control valves connected in a bridge circuit connected, at one end of a first diagonal, to a source of fluid under pressure and, at the other end of the first diagonal, to a fluid reservoir. Opposite ends of a second diagonal of the bridge are connected to inlet and outlet ports of the operated device. The arrangement includes two pressure adjusting valves, each connected to a respective pair of main control valves. In one bridge circuit, the main control valves are pressure limiting valves and each pair of main control valves includes one main control valve in one branch of the bridge circuit and another main control valve in the other branch of the bridge circuit.

Abstract: A servo mechanism for a prime mover interconnected to a hydrostatic transmission includes a source of pressurized fluid, a fluid reservoir, an actuator having a piston operatively connected to the hydrostatic transmission and being provided with large and small hydraulic receiving areas which are exposed to first and second hydraulic chambers, respectively within the actuator housing, a first passage for connecting the pressurized fluid source to the second chamber, a second passage for connecting the pressurized fluid source to the first chamber, a third passage for connecting the first chamber to the reservoir, and a pair of spool valve means disposed, respectively, within the second and third passages and responsive to a signal indicative of the power required of the prime mover and an actual speed or feedback signal of the prime mover.