Abstract: A method for producing a worm shaft for use in a rotation control valve of a power steering mechanism. The worm shaft is formed with grooves which receive a control body and form therewith a fail safe structure. The grooves are formed evenly so that the permitted range of movement on either side of a neutral position is uniform. A cylindrical member is plastically deformed in two steps to form the outer side of the control valve. Then, while in a die having in inner shape corresponding to the desired outer shape of the worm shaft, a punch, having an outer shape corresponding to the desired shape of the grooves on the inner surface of the worm shaft and an enlarged-diameter portion, is pressed into a hole in the interior of one end of the member to thereby plastically deform the member to the desired final inner and outer configurations.

Abstract: A power steering device having a fluid pressure cylinder of a single rod type providing like output characteristics for steering both rightwardly and leftwardly. A rod-side chamber and a head-side chamber of the fluid pressure cylinder have different pressure receiving areas. A control valve controls the changeover of a flow path among a pump, a tank and the rod-side and head-side chambers in accordance with the movement of a steering wheel such that the rod-side chamber is connected to the pump and the tank is connected to the head-side chamber when the piston is to be moved toward the head-side chamber, and the pump is connected to both the head-side chamber and the rod-side chamber when the piston is to be moved toward the rod-side chamber.

Abstract: A power steering apparatus includes a control valve of disc type which controls the delivery to or displacement from a power cylinder of a hydraulic fluid. A pair of mating parts are formed on the input and the output side for integral rotation therewith. A substantially C-shaped spring is engageable with the mating parts, which are maintained in position by the resilience of the spring.

Abstract: A power steering apparatus includes a pair of projections formed on the input and the output side, respectively, and also includes a substantially C-shaped spring disposed in surrounding relationship with the input shaft so that the both projections are maintained in their neutral position. In the neutral position, a circumferential clearance between the end faces of a notch formed in the spring and the projections is maintained substantially zero. The projection formed on the input side engages the lateral side of an inner race of a bearing which rotatably carries the input shaft, thereby preventing a withdrawal of the input shaft. Hydraulic fluid used in the control valve is utilized to define a hydraulic bearing between the input and the output shaft.

Abstract: In an oil pump of the type comprising a cartridge having an elliptical cam ring in which a rotor having a plurality of vanes is rotated to form a pair of pump chambers symmetric with respect to an axis of rotor, and a pair of suction passages and two pairs of discharge passages are provided for the pair of pump chambers. A valve opening is formed coaxially with the rotor in a pump body secured to one side of the cartridge to contain the spool valve. A metering orifice is provided in a discharge passage to actuate the spool valve in response to a pressure differential such that when the pump speed is low all outputs of both pump chambers are supplied to a load, whereas when the pump speed is high a portion of the outputs is supplied the suction side. According to this construction it is possible to decrease power consumption and to decrease the size and weight of the oil pump.

Abstract: A power steering apparatus is provided including a control valve or rotary type which controls the supply to or discharge from a power cylinder of a hydraulic fluid. A valve rotor is integrally formed with a projection within the region of a valve sleeve, which is formed with an opening therein to permit the free end of the projection to extend therethrough to the exterior thereof, with the projection being disposed in the opening to leave a given spacing therebetween, as viewed in the direction of rotation of the valve sleeve. Another projection is integrally provided on the valve sleeve, and the both projections are maintained at given positions by the resilience of a spring which is disposed in surrounding relationship with the valve sleeve. As a result, the both projections are provided at axially close locations and in a region where an input and an output shaft abut against each other. This arrangement is preferred in consideration of the mechanical strength.

Abstract: A plurality of pump sections are received in a stack in a body. Each of the pump sections include a cam ring disposed in surrounding relationship with a rotor having vanes thereon, and a pair of sideplates which closes the opposite sides of the cam ring. All of the pump sections are driven by a common drive shaft, thereby providing a compact pump unit having a reduced axial length. The outermost sideplates are subject to a discharge pressure from the respective pump sections to urge the various components of the individual pump sections to be held against the body. In this manner, the components are maintained at given accurate locations, eliminating the likelihood of a liquid leakage and simplifying the arrangement.

Abstract: A pair of pump bodies are disposed on the opposite sides of a rotor having vanes and a cam ring disposed in surrounding relationship with the rotor. These pump bodies serve the function of a sideplate and a pressure plate. The rotary shaft of the rotor is rotatably journaled in one of the pump bodies. A flow control valve is disposed in alignment with the axis of the other pump body, and a relief valve is disposed in surrounding relationship with the flow control valve. In this manner, the construction of various parts is simplified and the number of parts is reduced while simultaneously facilitating the machining operation. The overall length and the outer diameter as well as the weight of the pump can be reduced, advantageously reducing the manufacturing cost of the pump.

Abstract: An electromagnetic pump is disclosed in which a pair of check valves and a pressure-regulating mechanism are inserted in series in a fluid passage extending from a suction inlet to a discharge outlet and a pressure chamber operatively connected with a plunger is provided between the check valves. When a solenoid coil surrounding the plunger is supplied with an intermittent electric current, the plunger moves to and fro, thereby the pressure in the pressure chamber being varied to have the check valves given rise to pumping action. The pressure-regulating mechanism function to control the pressure of fluid discharged from the outlet, thereby absorbing the pulsation generated by the reciprocal pumping action of the plunger.

Abstract: An hydraulic braking pressure control unit for a vehicle includes a first valve member installed at an intermediate point in a flow passage providing communication between the rear brake system of a tandem master cylinder and rear wheel cylinders, the valve member is adapted to open and close the passage, and a proportioning valve is normally urged in one direction to keep the valve member away from its seat to establish communication between the tandem master cylinder and the rear wheel cylinders. The proportioning valve is adapted, when the braking pressure is supplied from the tandem master cylinder, to reduce the braking pressure at a predetermined rate and supply the reduced braking pressure to the rear wheel cylinders. A passage is provided for communication between passages formed upstream and downstream of the proportioning valve, and a second valve member is arranged to open and close the communicating passage.

Abstract: A hydraulic brake control assembly is provided in which a proportioning valve is actuated to reduce fluid pressure to be supplied to rear cylinders from a master cylinder in accordance with the vehicle deceleration. An inertia ball is adapted to control the movement of the proportioning valve via a flexible disc valve to increase or reduce the fluid pressure supply to the rear cylinders. The disc valve is deformable to open the proportioning valve if the pressure of the master cylinder exceeds a predetermined level.

Abstract: A fluid-pressure regulating valve for adjusting a supply pressure from either of two air reservoirs according to the payload of a vehicle and supplying the adjusted pressure to a control pressure chamber in a pressure-proportioning relay valve, the regulating valve comprising: a valve assembly for controlling the supply pressure, said assembly including a pressure piston reciprocably disposed in the valve body and formed with an air passage through the wall on one side, a supply valve accommodated in a supply pressure chamber inside the pressure piston and seated on a valve seat provided at the lower end of the supply pressure chamber, and an exhaust valve having an exhaust valve seat engageable with the supply valve and also having an upward protrusion extended through an exhaust bore formed in the axial center of the supply valve; an output pressure chamber defined between the underside of the pressure piston and the inner wall of the valve body; a balance spring disposed above the pressure piston in commun

Abstract: The valve includes a main valve member having an axial exhaust passage and held in the normally closed state, and a control piston assembly for opening the valve member depending on the payload of the vehicle on which the air brake is installed. The control piston assembly comprises a control piston having a valve seat on its underside cooperable with the main valve member, a stepped piston composed of two portions with different diameters and located substantially coaxially with, and in spaced relation to, the control piston in a passage leading from an indicated-pressure inlet to the upper surface of the control piston, a valve assembly adapted to be opened and closed by the axial movement of the stepped piston to control the indicated pressure applicable to the upper surface of the control piston and to the stepped piston, and a loading spring engaging the upper end of the stepped piston, with its compressive load adjustable according to the payload of the vehicle.

Abstract: A combined load-sensing proportion and relay valve for an air brake system, comprising a valve disk having an exhaust hole in the axial center, and a control piston assembly for adjustably moving the valve disk to open the valve, characterized in that the control piston assembly consists of two pressure-sensitive pistons, the first of the pistons being formed with a downward projection having a valve seat at its lower end for face-to-face engagement with the valve seat, an indicated-pressure chamber communicated with an indicated-pressure inlet port is formed between the upper side of the first pressure-sensitive piston and the underside of the second piston, a control-pressure chamber communicated with a control-pressure inlet port is provided above the second pressure-sensitive piston, and engaging means is located between the first and second pistons.