Abstract: In an anti-skid control system for a motor vehicle, brake fluid pressure reduction-control mode and brake fluid pressure buildup-control mode occurs cyclically; in the reduction-control mode, reduction of the brake fluid pressure is started on the basis of detection of an abrupt drop in wheel speed which occurs when the wheel is braked; and in buildup-control mode, a valve is repetitively opened and closed so that brake fluid pressure buildup and holding operations are performed alternatley and repetitively, whereby the brake fluid pressure is caused to build up gradually.

Abstract: In an anti-lock system for a vehicle having a first valve arranged in a brake fluid pressure transmission line from a master cylinder to each brake device to operate under an anti-lock control signal, a second valve arranged to open for reducing the brake fluid pressure, a pressure fluid return device arranged to bring a brake pressure fluid into an accumulator for returning the pressure fluid to the upstream side of the first valve and a gate valve arranged in between the first valve and the master cylinder, the gate valve is provided with a balance piston which is arranged to receive at one end thereof the pressure fluid brought into the accumulator and to receive the pressure fluid of the brake device at the other end; and a shut-off valve device arranged at an axially intermediate part of the balance piston to close a passage between the master cylinder and the first valve according to the balance piston.

Abstract: An antiskid control system for a vehicle, comprises a gate valve device inserted in a braking hydraulic pressure transmission line disposed between a master cylinder device and a braking device and is provided with a valve mechanism receives a pressure fluid from a pressure accumulator and is arranged to close the braking hydraulic pressure transmission line and to initiate communication with the braking device through a branch line; an electromagnetic valve device including a first solenoid valve which is arranged to normally close a transmission pressure fluid supply line provided for supplying the pressure fluid from the accumulator to the gate valve device and to open the transmission pressure fluid supply line when the pressure of the braking device must be lowered and a second solenoid valve which is arranged to normally open a hydraulic pressure release line to release hydraulic pressure from the pressure fluid input chamber of the gate valve device to a reservoir and to close the release line when the

Abstract: An automatic stop valve device adapted to be mounted in the fluid pressure brake system of a vehicle and having a valve mechanism capable of being shifted between an open and a closed state and operative by closing to maintain fluid pressure in the system to hold the brakes in an applied condition. An electromagnetic mechanism having a coil and an armature actuated by the coil is capable of shifting the valve mechanism to its closed state. The electromagnetic mechanism is arranged to be energized to hold the brakes in the applied condition when a moving vehicle is brought to a stop, to maintain the valve mechanism closed while the vehicle remains stopped to hold the brakes in the applied condition and to open the valve mechanism when the operation of the vehicle resumes to release the brakes.

Abstract: A wheel lock prevention apparatus for use in a motor vehicle includes a main passage connected between a master cylinder and a brake unit for transmitting a brake fluid pressure, a first normally-open solenoid-operated valve disposed in the main passage, a reservoir mechanism for storing a brake fluid, a second normally-closed solenoid-operated valve having one end connected to the main passage between the brake unit and the first normally-open solenoid-operated valve and an opposite end to the reservoir mechanism, and a pump mechanism disposed between the reservoir mechanism and the brake unit for returning the brake fluid from the reservoir mechanism to the brake unit. The pump mechanism is actuated when there is no signal indicating wheel locking and there is a signal representative of a movement of a reservoir piston in the reservoir mechanism.

Abstract: Herein disclosed is a vehicular anti-lock system of the type, in which a valve mechanism is disposed in a main passage which connects a master cylinder and a brake system such that its opening and closing operations are controlled by the movement of a control piston having its one end subjected to the pressure of the brake system. A fail-safe piston is made movable in a cylinder and has its one end engaging with the valve seat member of the valve mechanism and its other end connected with a liquid pressure source which is independent of the master cylinder. The control piston is made movable in the fail-safe piston and has its other end facing a control chamber. Between the liquid pressure source and the control chamber, there is connected a first valve which is adapted to be closed in response to a brake releasing signal. Between the control chamber and a reservoir, there is connected a second valve which is adapted to be opened in response to the brake releasing signal.

Abstract: In a device for preventing a wheel lock condition of a vehicle, a fluid passage switching valve is inserted in a rear wheel brake fluid pressure transmission system. The fluid pressure switching valve is closed during brake application in so far as it is within a braking force range in which a rear wheel braking force must be lower than a front wheel braking force. The speeds of revolution or deceleration of the front and rear wheels are compared by comparison means. When the comparison means detects that the deceleration of the front wheel becomes greater than the deceleration state of the rear wheel by a predetermined value, the fluid passage switching valve opens for a given length of time to allow the rear wheel brake fluid pressure to increase.

Abstract: A differential master cylinder adapted for use as fluid pressure generating source in a brake system comprises a cylinder body having a stepped cylinder formed therein; a stepped piston arranged to be slidable within the stepped cylinder; a first chamber defined by the end of a portion of smaller diameter of the stepped piston and a portion of smaller diameter of the stepped cylinder; a second chamber defined by the stepped piston and a portion of larger diameter of the stepped cylinder; a first fluid passage provided at the stepped piston and arranged to have the first and second chambers intercommunicate; a check valve arranged in the first fluid passage to close when fluid pressure within the second chamber reaches a first setting value; and a relief valve arranged to open to return the fluid from the second chamber to a reservoir when the fluid pressure within the second chamber reaches a second setting value which is higher than the first value.

Abstract: A deceleration sensing type fluid pressure control device for vehicle brake system having a control piston; a proportioning action mechanism capable of varying the reducing value of output pressure from input pressure in relation to a load imposed on the control piston; an adjusting piston one end of which is connected to a fluid pressure source through a passage arrangement; and a valve mechanism which is disposed in the passage arrangement and closes when the deceleration of the vehicle reaches a predetermined value. The fluid pressure control device is provided with a swaying lever which has a middle point thereof serving as a fulcrum. One end of the lever engages the control piston. Between the other end of the lever and the other end of the adjusting piston, there is provided a control spring which imposes the above stated load on the control piston.

Abstract: A double piping type hydraulic pressure control device in which hydraulic pressure control of a hydraulic pressure channel A is transmitted to another channel B in such a manner that the hydraulic pressure to be exerted on a balance piston for hydraulic pressure control is obtained solely from the hydraulic pressures of the two output chambers while two input hydraulic pressures are arranged to have nothing to do with the control action.

Abstract: An improvement of a hydraulic pressure control device for a double piping type hydraulic system for vehicle brakes not only performs braking pressure control over both of two independent hydraulic pressure channels but also is capable of transmitting the same degree of hydraulic pressure to the rear wheels of a vehicle as the front wheels thereof by releasing one hydraulic pressure channel from a control action when the other hydraulic pressure channel becomes defective, so that insufficiency in the braking force on the whole vehicle resulting from such a defect can be effectively compensated.

Abstract: A device for automatically adjusting a braking clearance for a disc brake in which at least one friction pad is directly placed in frictional engagement with a disc rotor by means of a piston. The device comprises an adjusting bolt, stop means for controlling movement of the adjusting bolt, an adjusting nut threaded on the adjusting bolt, first spring means retained between a main piston and the adjusting nut, a stepped piston slidably mounted within the main piston, frictional surfaces opposedly disposed on the stepped piston and the adjusting nut, and second spring means for biasing the stepped piston. When pressure within the liquid chamber of the cylinder reaches a predetermined level, the stepped piston is moved against the force of the second spring means so that both frictional surfaces are engaged to impede rotation of the adjusting nut.

Abstract: A tandem master cylinder device having a cylinder body slidably receiving therein a driving piston and a floating piston so as to define a first liquid chamber and a second liquid chamber, the device housing a liquid pressure control valve by which a differential in output liquid pressure between a front brake pressure and a rear brake pressure is produced. A stepped piston is mounted on the floating piston to open and close a poppet valve.

Abstract: A disc brake is provided with a fluid pressure operating mechanism for a service brake and concurrently with a mechanical operating mechanism for a parking brake. A parking lever of the parking brake is connected to an adjusting bolt through a spindle and a connecting link and further connected to a piston slidable in a cylinder through a sleeve nut. The adjusting bolt is prevented from rotation by a stopper plate fixed to the cylinder. The adjusting bolt and the sleeve nut are connected by thread and provided therebetween with a stopping means of rotation which allows a forward rotation of the sleeve nut toward a disc but limits a retracting rotation of the sleeve nut from the disc. The stopping means of rotation is provided with a locking means which effectively prevents a retraction of the sleeve nut. A clearance between friction pads and the disc is automatically adjusted by the fluid pressure operating mechanism when linings of the friction pads are worn more than a predetermined amount.

Abstract: A deceleration sensing type proportioning valve for oppositely distributing front and rear wheel braking forces in a vehicle. A valve seat is arranged to follow the movement of an adjustment piston in such a way as to increase the degree of compression of a control spring before a plunger comes into contact with the valve seat. The piston and the plunger move in the same direction to permit arrangement of a valve body portion of the plunger to be carried by the adjustment piston in an embracing manner for reduction in size of the whole proportioning valve assembly.

Abstract: A pad clip for disc brakes wherein one side portion of the pad clip is attached to the backing plate of a friction pad and another side portion of the pad clip has an end projecting to an allowable limit of wear of the lining of a friction pad. The pad clip produces an audible warning sound when the projecting end portion of the pad clip is resiliently pressed against the disc during braking after the lining of the friction pad has worn to the allowable limit. The projecting side portion of the pad clip resists movement in a direction away from the plane of the disc so as to prevent failure of the warning sound activation while still providing sufficient resilience to bias the disc.

Abstract: A pad clip device is provided comprising a U-shaped resilient spring, one portion of which is formed as a loop attached to the backing plate and having another portion extending beyond the plate to indicate the wear of the brake lining.