Abstract: A hydraulic reservoir for tandem master cylinder includes a body formed by upper, lower and side walls, two brake fluid reserving chambers formed by two partitioning walls in the body, and oblong passages formed by the side walls and ancillary walls integrally formed with the partitioning walls to make the two brake fluid reserving chambers communicate with each other, the oblong passages being open to the two brake fluid reserving chambers, respectively, having bottoms higher by a predetermined length than the lower wall, and having at least such length that a flow amount of brake fluid between the two brake fluid reserving chambers is limited to a predetermined value on the inclination of the brake fluid level relative to the body.

Abstract: A fluid reservoir with a fluid-level sensor includes a manual testing device consisting of two separate but cooperative rods. The fluid-level sensor consists of a float within the reservoir and a reed switch which is closed to cause a low fluid-level alarm when the float is lower than a predetermined level. The testing device serves to depress the float to below that level to ensure that the switch and the alarm are working. A first rod is supported by a filter mounted at the top of the reservoir. A second rod is supported by a flexible cover which fits over the top of the reservoir. The rods are coaxial and free to move downward far enough to push the float to below the above level. Having the two rods separable allows the cover to be removed easily without damaging the manual testing device.

Abstract: A method of forming concavities in a cast iron valve seat to which lubricating oil may be applied to reduce the abrasion between the valve seat and a handle operated rotary valve that is slidably engagable with the valve seat. Pockets of graphite are formed at the valve seat surface by heat treating the valve seat, following which the valve seat undergoes a lapping process that removes the graphite and leaves numerous concavities in the valve seat surface. These concavities hold the lubrication and thus extend the abrasion-free life of the rotary valve and valve seat interface to enhance the metal-to-metal seal thereat.

Abstract: An elastomeric sleeve is inserted in the hole in the cock body which has multiple passages for the fluid. A plug, which may be positioned to connect selected passages, is placed within the sleeve in the hole. Either the contacting surfaces between the hole and sleeve or the rubbing surfaces between the sleeve and plug are tapered. A spring, seated on the base of the body or a plug flange, exerts upward pressure on the sleeve to assure tight contact between adjacent surfaces to eliminate fluid leaks.

Abstract: A brake fluid pressure control apparatus in a skid control system includes electromagnetic valves arranged between a master cylinder and a wheel cylinder, receiving control signals of a control unit measuring the skid condition of the wheel to control a brake fluid pressure to the wheel cylinder; a hydraulic reservoir reserving the brake fluid discharged through the electromagnetic valves from the wheel cylinder; a pressure fluid supply conduit connecting the master cylinder with the electromagnetic valves and containing a first check valve which allows the flow of fluid in the direction of the electromagnetic valves; a fluid pump for returning brake fluid from the hydraulic reservoir into a portion of the fluid pressure supply conduit between the first check valve and the electromagnetic valves; a pressure fluid return conduit connecting the master cylinder with the wheel cylinder and containing a second check valve which allows the flow of fluid in the direction of the master cylinder; and a controllable ch

Abstract: A skid control system for a vehicle having at least one wheel and a brake for the wheel includes a wheel speed detector for providing an output signal representative of the speed of the wheel; differentiater for differentiating the output signal of the wheel speed detector and providing an output signal representative of acceleration or deceleration of the wheel; a deceleration signal generator connected to the differentiater, the deceleration signal generator generating a deceleration signal when the output signal of the differentiater exceeds a predetermined threshold deceleration; an acceleration signal generator connected to the differentiater, the acceleration signal generator generating an acceleration signal when the output signal of the differentiater exceeds a predetermined threshold acceleration; a brake relieving circuit for decreasing the brake pressure to the brake for the wheel in response to the deceleration signal of the deceleration signal generator; a first brake control circuit for maintain

Abstract: A skid control system for a vehicle having a wheel and a brake for the wheel includes a wheel speed sensor for providing an output signal representative of the speed of the wheel; a skid control circuit arrangement responsive to the output signal of the wheel speed sensor for relieving and reapplying the brake for the wheel; a failure detecting circuit for detecting failure of the skid control circuit arrangement, a battery and a safety device responsive to the detecting signal of the failure detecting circuit for disconnecting the skid control circuit arrangement from the battery and gradually increasing braking action for the wheel for a predetermined time.

Abstract: A brake fluid pressure control apparatus in a skid control system for a vehicle having at least one wheel and a brake for the wheel includes a control unit for measuring the skid condition of the wheel; a fluid pressure control valve device arranged between a master cylinder and a wheel cylinder of a brake for the wheel, the fluid pressure control valve device receiving control signals of the control unit to control the brake fluid pressure to the wheel cylinder; a hydraulic reservoir which, when the brake fluid pressure to the wheel cylinder is decreased with control of the fluid pressure control valve device, reserves the brake fluid discharged through the fluid pressure control valve device from the wheel cylinder; a pressure fluid supply conduit connecting the master cylinder with the fluid pressure control valve device; a fluid pump with motor receiving a pump drive signal of the control unit for returning the brake fluid from the hydraulic reservoir into the pressure fluid supply conduit; a switching ar

Abstract: A skid control system for a vehicle having two or more wheels and the respective brakes for the wheels, includes two or more skid control circuits, each of which includes a wheel speed sensor for providing an output signal representative of the speed of the wheel or the mean speed of the wheels, an approximate vehicle speed generator for providing an output signal representative of the approximate speed of the vehicle on the basis of the output signal of the wheel speed sensor, a slip signal generator receiving the output signal of the wheel speed sensor, an acceleration/deceleration signal generator receiving the output signal of the wheel speed sensor, a valve control circuit receiving the outputs of the slip signal generator and acceleration/deceleration signal generator, and electromagnetic inlet and outlet valves receiving the output of the valve control circuit.

Abstract: A wheel speed measuring circuit includes a counter controlled by a wheel speed signal having a frequency proportional to the rotational speed of the wheel sensed by a wheel speed sensor associated with a wheel; a comparator for comparing the digital output of the counter with a predetermined digital value; a wheel speed generating circuit for generating a digital output corresponding to the rotational speed of the wheel on the basis of the output of the comparator; and a pulse generator for generating pulses of a frequency proportional to the digital output of the wheel speed generating circuit, the pulse generator receiving the digital output of the wheel speed generating circuit, wherein the counter receives the output pulses of the pulse generator to count the output pulses thereof for the period of the wheel speed signal or for a time interval relating to the period of the wheel speed signal, and the digital output of the counter is compared with the predetermined digital value in the comparator.

Abstract: A brake fluid pressure control apparatus in a skid control system for a vehicle includes a brake fluid pressure control valve device arranged between a master cylinder and wheel cylinders. The device receives control signals from a control unit that measures the skid condition of wheels. The device controls the brake fluid pressure to the wheel cylinders in response to the control signals. A hydraulic reservoir stores the fluid discharged through the device from the wheel cylinders when the pressure to the wheel cylinders is decreased under the control of the device. A fluid pump returns fluid from the reservoir into a pressure fluid supply conduit connecting the master cylinder and the device. A check valve arranged in the supply conduit opens when the fluid flows from the master cylinder towards the device, the outlet of the pump being connected to the conduit between the check valve and the device. A pressure fluid return conduit connects the master cylinder and the wheel cylinders.

Abstract: A change-over valve device having a pair of oppositely disposed control pressure chambers subject to respective control pressures from two independent pressure input systems and operable for diverting the lower control pressure to a delivery chamber so as to increase the degree of the pressure normally delivered from the delivery chamber by an amount corresponding to the degree of such lower control pressure.

Abstract: A compound check valve device comprising a housing having a pair of oppositely disposed inlet ports and an outlet port therebetween, a hollow, two-part valve carrier reciprocably operable in the housing between the inlet ports for selectively communicating the inlet ports, singly or concurrently, to the outlet port, and a spring disposed between the two parts of the valve carrier for biasing respective valves mounted on the valve carrier toward respective valve seats surrounding the two inlet ports so that, in the absence of pressure at the inlet ports, the valve carrier assumes a neutral position in which the inlet ports are cut off from the outlet port, and when pressure is supplied to the inlet ports, the valve carrier assumes a position according to the relative pressures at the inlet ports to communicate either both inlet ports or one inlet port to the outlet port.

Abstract: A dehumidifier for use in a compressed air system between an air compressor and a storage reservoir for removing moisture from the compressed air supplied to the storage reservoir. The dehumidifier is provided with a moisture-collecting chamber connected to a conventional drain valve which operates automatically periodically for draining the moisture from the moisture-collecting chamber. A high speed fan is installed adjacent the moisture-collecting chamber for subjecting the compressed air passing therethrough to centrifugal force, thereby removing moisture and other foreign particles contained in the compressed air, such moisture being forced by gravity to the bottom of the collecting chamber.

Abstract: A fluid level detector comprising a cylindrical member which includes a mounting portion fitting in the opening of a fluid reservoir and a float guide portion extending downwardly from the mounting portion. A float, provided with a magnet, is slidably fitted over the float guide portion. A lead switch is disposed in the float guide portion. A terminal is connected to the lead switch via a lead 18. A lid member is mounted to close the opening of the reservoir. A terminal holder is integrally formed on the cylindrical member. The lid member includes an upper cover covering the upper portions of the mounting portion and the cylindrical member, and a lower cover. In assembly, after interposing the terminal holder between the upper and lower covers, the cylindrical member and the lid member are mounted to the reservoir as a unit.

Abstract: A diaphragm type valve device comprising a housing having a pair of valve chambers separated by a diaphragm piston and connected to respective fluid pressure input ports, oppositely disposed valve seats fixed in the housing in facing relation to each side of the diaphragm piston and connected to respective output ports, a pair of valve members reciprocably disposed in a central bore in the diaphragm piston and being axially biased in opposite directions by a spring compressibly installed in the central bore between the valve members, one or the other of the valve members being seatable on one or the other of the valve seats when the diaphragm piston is axially displaced by dominating pressure acting on one or the other side thereof, and stop rings concentrically fixed in the central bore adjacent the respective ends thereof for limiting axial displacement of said valve members by the spring to a spaced-apart distance somewhat greater than the fixed axial distance between the valve seats.

Abstract: A liquid level detecting and warning device of the kind including a tubular member having a mounting portion fitted on an opening of a reservoir and a float guiding portion downwardly extending from the mounting portion, a float having a magnet and slidably fitted around the float guiding portion, a reed switch disposed within the float guiding portion, terminals connected to the reed switch through lead wires, and a cover member covering the opening of the reservoir and the mounting portion of the tubular member. The tubular member is formed to have at least two projection radially outwardly projecting from the upper end portion thereof.

Abstract: A vehicle load responsive control valve device in which the output pressure regulating valve assembly is controlled by multiple diaphragm pistons, which are arranged separately in tandem relationship and are operative responsive to the fluid pressure of different air springs of the vehicle. Being of equal pressure areas, these diaphragm pistons are effective to exert a control force on the valve assembly according to the higher of the respective air spring pressures to ensure against low brake forces when the pressure of one of the air springs is inadvertently lost under loaded car conditions. Under empty car conditions, a bias spring is effective to obtain a predetermined output pressure.

Abstract: A brake fluid pressure control valve is inserted into a brake line connecting the master brake cylinder to the rear wheels of an automobile, and varies the braking pressure applied to the rear wheel brakes at a predetermined value of deceleration to prevent the rear wheels from locking up. Such a valve includes a main body having cylindrical bores of different diameters including a pressure-regulating piston and a hollow control piston slidably fitted within the cylindrical bores. A ball valve responsive to deceleration is disposed within the hollow of the control piston to selectively open and close a passage connecting the hollow to a pressure chamber. The ball closes the passage when the deceleration of an automobile has reached a predetermined value.

Abstract: A brake control valve for an automobile includes a main body having first and second bores intersecting with each other; a ball valve member arranged in the first bore, and rolled by its weight when the automobile is facing upwardly on an inclined road-way; a valve seat arranged in the first bore, and engageable with the ball valve member to check brake fluid flow between a master cylinder and a wheel cylinder; and a cam shaft slidably fitted into the second bore and inter-connected to a clutch pedal, having a cam portion in a brake fluid passage. Areas of the cam shaft at both sides of the cam portion receiving fluid pressure are substantially equal to each other. The cam shaft is rotated round its axis with actuation of the clutch pedal to displace the ball valve member through the cam portion for opening and closing the valve seat when the automobile is facing upwardly on the inclined roadway.