Abstract: An electromagnetic valve device having two electromagnetic valves comprises a solenoid unit having a unit construction in the form of a hollow cylinder and having a pair of solenoids, and a valve unit having a pair of valve mechanisms and having a unit construction in the form of a substantially solid cylinder. The solenoid unit has a pair of coil bobbins, and a pair of caps accommodating said coil bobbins. The valve unit is fitted through a central through hole of the solenoid unit and thus mounted therein. The coil bobbins are fixed to a yoke interposed therebetween and thus joined together.

Abstract: A hydraulic braking pressure control system which includes a sleeve slidably received in a housing with opposite ends facing an output chamber connected to a brake device, and a pilot chamber connected to a control hydraulic pressure source. A control piston is slidably received in the sleeve, with one end of the control piston facing the output chamber and the other end facing a control chamber connected to the control hydraulic pressure source through a lock valve which is adapted to be closed in response to the movement of the sleeve, in a direction to increase the volume of the output chamber. A cut-off valve located between an input chamber leading to a master cylinder and the output chamber includes a valve member having a maximum amount of movement in a seating direction which is regulated to a position of the valve member spaced apart from a valve seat when a valve seat member follows movement of the sleeve in a direction to reduce the volume of the pilot chamber to the maximum amount.

Abstract: A four-wheel-drive vehicle in which the brakes are individually controlled to prevent locking. According to the invention, during anti-locking brake, the torque transmitted between the front and rear wheels is reduced, either by disconnecting the inter-axle transmission or switching to a loosely coupled viscous coupling.

Abstract: A hydraulic brake pressure control device for a vehicle including a casing having first and second cylinder portions in coaxial arrangement and a pillar-like cylinder projecting portion which projects into the first cylinder portion. A piston is disposed in the casing having first and second piston portions which are connected together and slidably fitted in the first and second cylinder portions, repsectively. A third cylinder portion in the piston is slidably fitted around the projecting portion. A spring is provided in the casing urging the piston in one direction. A control chamber is defined in the first cylinder portion and exerts, upon introduction of a liquid pressure thereinto, a pressing force onto the piston in the opposite direction.

Abstract: A method and mechanism for selectively transmitting and interrupting power between an input shaft and an output shaft arranged in coaxial relation in which a rotary member is coupled to one of the shafts to provide first and second states therebetween and wherein in the first state the rotary member is free to rotate and rotation is transmitted between the input and output shafts, whereas in the second state the input shaft can rotate relative to the output shaft and transmission of rotation is interrupted. The rotary member and the one shaft are angularly rotated relative to one another between first and second relative positions in the first and second states, and rotation of the rotary member is halted by a disc brake in the second state.

Abstract: A four-wheel-drive vehicle in which the brakes are individually controlled to prevent locking. According to the invention, during anti-locking brake, the torque transmitted between the front and rear wheels is reduced, either by disconnecting the inter-axle transmission or switching to a loosely coupled viscous coupling.

Abstract: A four-wheel-drive vehicle in which the brakes are individually controlled to prevent locking. According to the invention, during anti-locking brake, the torque transmitted between the front and rear wheels is reduced, either by disconnecting the inter-axle transmission or switching to a loosely coupled viscous coupling.

Abstract: An antilock brake method and device for a four wheel drive vehicle having front and rear axles, left and right wheels on each axle with brakes associated with each wheel, a power unit drivingly connected to one of the axles, the other axle being coupled for drive together with the driven axle, a hydraulic braking system for controlling the hydraulic pressure applied to the brakes, and an antilock control system coupled to the braking system for controlling the hydraulic braking pressure to reduce the brake pressure when a wheel is about to be locked. The antilock control system includes a front wheel control section for controlling the brakes of the front wheels, a rear wheel control section for controlling the brakes of the rear wheels, and circuit elements included in the front and rear wheel control sections for keeping the hyraulic braking pressure reduced up to the completion of a braking operation, when any of the wheels is about to be locked.

Abstract: A pressure responsive switch of the amorphous diaphragm type in which an orifice plate having an orifice for passing a pressure medium and an amorphous diaphragm which receives the pressure of said pressure medium are mounted in a case so that they are slidable along an inside surface of said case, whereby the amorphous diaphragm is not subjected to any binding effect of the case.

Abstract: A control unit used for antilock brake systems, which comprises a support base having a hydraulic channel, an oil tank, and an electro-magnetic valve provided with openings communicating with the hydraulic channel and the oil tank, the valve being supported on the support base and in turn supporting the oil tank. The control unit is characterized in that a support hole and a connecting wall covering the support hole are formed in the bottom wall of the oil tank, the support hole is oil-tightly fitted around the upper end section of electro-magnetic valve and the connecting wall is connected by a screw to a shaft projected from the upper end face of the electro-magnetic valve, and that in the connecting wall is provided a through hole for communicating the inside of the oil tank to the electro-magnetic valve.

Abstract: Disclosed is an antilock braking device including a first braking hydraulic adjusting member actuated so as to restrain braking oil pressure of wheel cylinders individually corresponding to left and right front wheels in response to antilock braking oil pressure for front wheels; a second braking hydraulic adjusting member actuated so as to restrain braking oil pressure of wheel cylinders individually corresponding to left and right rear wheels in response to antilock braking oil pressure for rear wheels; an antilock control system having a reservoir and a pump for pressurizing control oil from said reservoir to generate said antilock control oil pressure; and a tandem type master cylinder having a pair of output ports independent of each other connected to said both braking hydraulic adjusting members to generate braking oil pressure of each of said wheel cylinders, characterized in that a proportional reducing valve is interposed between both braking hydraulic adjusting members in order to supply braking oi

Abstract: A solenoid valve assembly includes an inner valve section and an outer valve section incorporated integrally in a symmetrical relationship with respect to each other in the interior of a single casing. A common hydraulic fluid passage extends through both valve sections.

Abstract: A hydraulic fluid circuit for use in an anti-lock braking system of a vehicle includes a relieved hydraulic fluid chamber of a hydraulic pressure modulator and a reservoir of a master brake cylinder which are operatively connected with each other by way of a hydraulic fluid line. Hydraulic operating fluid existing in the relieved hydraulic fluid chamber is relieved into the reservoir. The reservoir of the master brake cylinder is disposed at a position higher than the level of the suction joint or inlet of the relieved hydraulic fluid chamber of the hydraulic pressure modulator.

Abstract: An anti-lock braking system for a four-wheel vehicle having a pair of left and right front wheels and a pair of left and right rear wheels in which one pair of wheels carries a greater load than the other, the system comprising a first braking pressure regulator operative to simultaneously reduce the braking pressures in a pair of wheel cylinders of the left and right front wheels in response to an anti-lock control pressure for the front wheels and a second braking pressure regulator operative to simultaneously reduce the braking pressures in a pair of wheel cylinders of the left and right rear wheels in response to an anti-lock control pressure for the rear wheels. A late-period operation type anti-lock control pressure supply device is associated with the pair of left and right wheels carrying the greater load to supply the anti-lock control pressure to the corresponding regulator upon detection of locking of a wheel later than the other in the pair of left and right wheels carrying the greater load.

Abstract: An antilock braking system and associated method for a four wheel automotive vehicle having front left and right wheels and rear left and right wheels with a determined weight distribution of the vehicle on the front and rear wheels, each wheel having a respective brake cylinder adapted for applying braking pressure to the wheel in response to pressure fluid supplied from a master cylinder. The supply of pressure fluid from the master cylinder to the brake cylinders during a braking operation is controlled in accordance with the weight distribution of the vehicle on the wheels to enable the front and rear wheels normally to undergo incipient wheel slip at substantially the same time. A fluid pressure regulating unit relieves the fluid pressure transmitted to the respective brake cylinders of the four wheels of the vehicle all at the same time when one of the two front wheels rotates at a higher circumferential speed than the other front wheel and indicates incipient wheel slip.

Abstract: A method and apparatus for simultaneously adjusting the fluid pressures in a dual hydraulic circuit arrangement in which in a first hydraulic circuit pressurized fluid is supplied from a first pressure source to a first fluid pressure activated device and in a second hydraulic circuit pressurized fluid is supplied from a second pressure source to a second pressure activated device, comprising a cylinder having opposite closed ends and spaced bulkheads therein defining a central chamber between the bulkheads and a pair of chambers on respective opposite sides of the bulkheads. A pair of spaced first pistons are slidably mounted in the central chamber to define a control pressure chamber therebetween and first and second primary fluid pressure chambers between respective pistons and the bulkheads. The first primary fluid pressure chamber is connected to the first pressure source while the second primary fluid chamber is connected to the second pressure source.

Abstract: A braking oil pressure control device for a hydraulically operated anti-skid brake system comprising a pair of serially aligned first and second cylinder chambers defined in a cylinder body on the opposite sides of a partition wall. The first cylinder chamber is divided by a brake piston on the opposite sides thereof into a first brake chamber communicating with a brake master cylinder and a second brake chamber communicating with a wheel brake such that when the pressure in the first brake chamber is pressurized under the action of the master cylinder, the brake piston is moved to pressurize the second brake chamber for actuation of the wheel brake. A control piston is slidably received in the second cylinder chamber and cooperates with the partition wall to define a control chamber communicating with an anti-skid brake control hydraulic circuit.

Abstract: A master cylinder apparatus of a type of wherein a master cylinder which is in communication through a connecting port with an oil reservoir on its upper side. A piston is provided having at its front and rear surfaces respective elastic cups, whereby the piston may be pushed to advance against the action of a spring on its front side by a push rod. The piston comprises a front main piston and a rear subsidiary piston connected thereto, and is further defined by an axially extending return port communicating between front and rear oil chambers and with a check valve interposed in the return port arranged to be closed by the action of a releasable spring supported by a stopper at the rear surface, during advance motion of the piston.

Abstract: An anti-skid brake control device including a wheel cylinder having defined therein a first hydraulic chamber connected with a brake fluid line extending from the master cylinder and a second hydraulic chamber connected with a pressure controlling fluid circuit. As the brake fluid line is isolated from the pressure controlling circuit by the output member of the wheel cylinder, the brake system can operate effectively, though in a conventional manner, should oil leakage occur in the controlling circuit. On a four-wheeled vehicle, each pair of front or rear wheel cylinders can be served by a common arrangement of such pressure controlling circuit for anti-skid control.

Abstract: A skid prevention method for reducing braking torque during a wheel lock while braking, using a main control system of an anti-skid brake device regardless of the brake input by the driver. When wheel lock is overcome, reduction of braking torque ceases. When wheel lock lasts more than a preset period without reduction in breaking torque, even when wheel lock results from failure of the main control system, the braking torque is reduced for a preset period through an auxiliary system. If the main control system reduces the braking torque for a period longer than a preset time, braking torque reduction by the main control system may be nullified, and when wheel lock lasts longer than a preset period, the braking torque may be reduced by the auxiliary control system for the preset period. An anti-skid device for carrying out this method has a brake for applying the braking torque to the wheels, a main control system for controlling the brake to reduce braking torque in case of wheel lock.