Abstract: A system (e.g., a vehicle control system) includes a brake control unit that is configured to be operably deployed onboard a vehicle. The brake control unit has one or more sensor inputs and one or more control outputs. One of the sensor units is configured to receive a speed signal from a speed sensor of the vehicle; the speed signal is indicative of a vehicle speed detected by the speed sensor. One of the control outputs is configured for connection to a brake system of the vehicle. The brake control unit is configured to generate a vehicle control signal to initiate a vehicle brake operation responsive to the speed indicated by the speed signal going above a designated first speed threshold and the speed signal meeting one or more first designated criteria in addition to the first speed threshold.

Abstract: A brake fluid pressure supply unit includes a fluid pressure generation device in which a piston that slides in a cylinder is driven by an electric motor to generate fluid pressure in a fluid pressure chamber formed in the cylinder; and a housing in which a fluid path connected to the fluid pressure chamber is formed. The electric motor and the cylinder are both attached to the housing. The electric motor is positioned more on upper side of the brake fluid pressure supply unit than the cylinder in a vertical direction. Thus, even if fluid leaks from the cylinder, the fluid having leaked can be prevented from entering inside of the electric motor. Thus, the operation of the electric motor is not impaired, whereby the reliability of the brake fluid pressure supply unit can be improved.

Abstract: A communication method between a brake booster of a vehicle and an ESP control unit of the vehicle. In the method, a signal is coupled into a brake fluid, transported between the brake booster and the brake control unit over a brake line filled with the brake fluid, and extracted again from the brake fluid.

Abstract: A vehicle braking system includes an assistance device having a vacuum pump driven by an engine for communicating vacuum to a chamber of the assistance device. A control valve is interposed along a fluid line between the pump and the chamber. The control valve is in its first operative condition, where the inlet side of the vacuum pump communicates with the chamber, when pressure within the chamber is above a predetermined value; and is in its second operative condition, where the inlet side of the vacuum pump communicates with the atmosphere, when pressure within the chamber is below a predetermined value. In this second condition the pump intakes air from and feeds air into the atmosphere, thereby reducing the energy consumption by the engine required for driving the pump during stages where, within the chamber, there is a vacuum sufficient for the regular operation of the braking system.

Abstract: An electronic antiskid brake assembly with a portable power source that can retrofit onto a working manual brake system to provide antiskid capabilities without effecting the manual brake system's normal operation. The antiskid system can be applied anywhere on a brake linkage. When a force is applied to a brake pad, an electronic controller utilizes detects a skidding event, and then automatically powers on an actuator. The actuator moves a brake linkage to create a pulse mode on the brake linkage. The pulse mode modulates the force that is applied to the brake pad. A one way cylinder can be included with a manual hydraulic brake system to provide a mechanical means for generating pulse mode on the brake linkage. The power source can move with the brake linkage so that the actuator pulses the brake linkage a small amount, while the brake linkage applies full braking.

Abstract: Systems and methods for auto-location of tire pressure monitoring sensor units on a vehicle measure the angle of a wheel at two different times using a rim mounted or a tire mounted sensor and determines a difference in measured angles. The systems and methods provide for transmitting the angles and/or the difference in the measured angles along with a sensor identification to an electronic control module. Alternatively, the systems and methods provide for transmitting time differences to the electronic control module. The electronic control module correlates information transmitted from the wheel unit with antilock brake system data. A location of the wheel mounting the sensor is determined and the sensor identification is assigned.

Abstract: The present invention provides a brake heat reducing system for reducing the temperature of brake components in vehicles, the brake heat reducing system cooperating with the braking system of the vehicle and having a control device having an accelerometer that is energized in response to vehicular braking and a timer relay. A modulating device has a solenoid valve connected to the timer relay and is activated by the control device in response to vehicular braking for modulating braking pressure during occurrence of vehicular braking.

Abstract: An hydraulic brake system that rapidly and precisely slows or reduces speed by constraining or stopping the movement of a link mechanism connected between a piston and a rotational driving shaft of a power system with physical force generated due to the incompressible fluid characteristic by constraining or stopping the flow of oil filled in an hydraulic oil chamber. The hydraulic brake system includes a lubricating section for supplying the oil reserved in a protective casing to friction sliding parts of respective components through pumping movement by utilizing the reciprocal movement of a piston rod, and an oil supplement section for supplementing the hydraulic oil chamber with the oil. The hydraulic brake system has improved durability and anti-abrasion, and provides emergency braking in the event of oil leakage.

Abstract: An hydraulic brake system that rapidly and precisely slows or reduces speed by constraining or stopping the movement of a link mechanism connected between a piston and a rotational driving shaft of a power system with physical force generated due to the incompressible fluid characteristic by constraining or stopping the flow of oil filled in an hydraulic oil chamber. The hydraulic brake system includes a lubricating section for supplying the oil reserved in a protective casing to friction sliding parts of respective components through pumping movement by utilizing the reciprocal movement of a piston rod, and an oil supplement section for supplementing the hydraulic oil chamber with the oil. Accordingly, the possible abrasion of the respective friction sliding parts is constrained, and the durability is improved. Further, in the event of oil leakage, the oil is supplemented for emergency-braking, so that a possible accident can be prevented.

Abstract: An hydraulic brake system that rapidly and precisely slows or reduces speed by constraining or stopping the movement of a link mechanism connected between a piston and a rotational driving shaft of a power system with physical force generated due to the incompressible fluid characteristic by constraining or stopping the flow of oil filled in an hydraulic oil chamber. The hydraulic brake system includes a lubricating section for supplying the oil reserved in a protective casing to friction sliding parts of respective components through pumping movement by utilizing the reciprocal movement of a piston rod, and an oil supplement section for supplementing the hydraulic oil chamber with the oil. Accordingly, the possible abrasion of the respective friction sliding parts is constrained, and the durability is improved. Further, in the event of an oil leakage, the oil is supplemented for emergency-braking, so that a possible accident can be prevented.

Abstract: A brake force control valve for use with an electrically controlled braking system having a housing with first and second fluid channels, a coil coupled to the housing, a ferrous core magnetically interacting with the coil, a spool coupled to the ferrous core, where the spool in conjunction with the housing forms a compression volume, a plurality of seals to fluidly seal the compression volume and where the coil is energized and deenergized to move the spool back and forth, the spool varying the volume of the compression volume to create positive pressure, thereby creating a pumping action.

Abstract: A method of preventing a vacuum from developing in a low-pressure area of a vehicle anti-lock brake system comprises providing periodically opening normally closed electromagnet valves when brakes are not applied, the valves connecting wheel brakes to a tandem master cylinder by low pressure lines passing through the low-pressure area. As a result, pressures in a tandem master cylinder of the system and the low-pressure area level off and thus a vacuum trapped in the low-pressure area is eliminated.

Abstract: A locking device for a parking brake on a bus having air brakes prevents accidental release of the parking brake when a sensing switch indicates that the bus should not move (e.g., when the driver is absent from the driver's seat, or a passenger-access door is open). The locking device of the invention is affixed to a portion of the bus adjacent a parking brake air valve that has an air valve shaft moving along its axis between a fully extended position, in which the valve is in a brake-applied status, and a frilly retracted position in which the valve is in a brake-released status. The locking device has a locking arm moving between a locked position in which it prohibits the parking brake valve shaft from moving into the fully retracted position and an unlocked position in which it does not affect the motion of the valve shaft. Conventionally, the valve shaft has a knob on the end distal from the valve body, and the locking arm in the locked position, prevents the knob from being pushed in all the way.

Abstract: A rotary actuated braking system includes a motor driven shaft that operates two pairs of piston pumps and an allocation valve which, in combination with a single solenoid valve, effects ABS operation of the braking system. A combination of pressure operated control valves and pressure operated release valves for each control wheel brake respond to operation of the rotary actuator and solenoid valve to effect ABS pressure release and reapply from the corresponding wheel brake. A power boosted master cylinder provides base brake operation independent of the rotary actuator effected ABS operation.

Abstract: The invention is generally described as a housing having an inlet port for receiving brake fluid and two opposing outlet ports for delivering the fluid to brake cylinders. A fluid screw designed to seal either outlet port is provided on an actuator having a screw mounting and an actuator leg. Between the screw mounting and the actuator leg is a pivot holding the actuator. The movement of the actuator on this pivot is controlled by the movement of the actuator leg which is in turn controlled by the movement of a sliding armature which moves in a channel defined by the housing. The armature movement is, in turn, controlled by two opposing solenoids on either side of the channel. Springs bias the armature back to a central position. The armatures are controlled by a manual switch available to the operator.

Abstract: An anti-lock braking control device includes a housing which defines cylindrical first chamber, two second chambers and a third chamber. The housing has two which are inlet ports connected to two master cylinders and two outlets ports which are connected to rear and front brakes. The third chamber is communicated with the inlet ports and is connected to two second chambers by two oil passages. The second chambers are aligned with one another and are connected to the first chamber. A rotor shaft with a driving disk is mounted rotatably in the first chamber. An oil regulator assembly is mounted in the third chamber for controlling the flow rate of hydraulic oil from the master cylinders to the second chambers. Each of a pair of reciprocating pump assemblies has a rod member which is driven by the driving disk to move reciprocally in a respective one of the second chambers.

Abstract: A vehicle braking system including, a pump operated by a pump actuator driven by a DC power source, an electrically operated pressure control device having operating states which are selectively established to electrically control the fluid pressure in wheel brake cylinder and which includes a pressure-increase state for fluid communication of the wheel brake cylinder with at least one of a master cylinder and pump and a pressure-decrease state for fluid communication of the wheel brake cylinder with a reservoir, and a pump actuator control device having a power supply portion for intermittently supplying electric power from the DC power source to the pump actuator such that the duty ratio of the pump actuator is controlled in response to a duty ratio signal, and a signal generating portion for generating the duty ratio signal.

Abstract: The parking brake of a vehicle is automatically operated whenever the driver or operator leaves the operator's seat and/or opens the door to the vehicle. A seat switch and a separate door switch are electrically wired to an electrical solenoid which operates a valve that controls the supply of air from an air tank through a manual air valve to the brakes. The seat and door switches are connected in parallel to the ignition switch wired to the battery which is grounded to a common ground with the solenoid, whereby either the seat switch or the door switch be closed to release the brakes.

Abstract: A braking apparatus includes: a multi-pass rotary valve and an expansion-cylinder mounted in between a brake master cylinder and a plurality of wheel cylinders provided on the front wheels and the rear wheels, whereby upon treading of a brake pedal of a vehicle braking system and upon rotation of a rotor in the multi-pass rotary valve to alternatively flow a hydraulic oil towards the wheels cylinders and towards the expansion-cylinder to intermittently the vehicle wheels without locking the wheels for anti-locking safety purpose.

Abstract: A hydraulic brake control system for a vehicle includes a return line for reducing a pressure built up in a wheel cylinder. The return line includes therein a switching valve for opening and blocking the return line. The return line further includes therein cylinders each having therein a piston for defining a piston chamber therein. Each piston has a first state where a brake fluid flowing from the wheel cylinder via the switching valve is allowed to flow into the piston chamber, and a second state where the brake fluid is allowed to be discharged from the piston chamber so as to be returned to a master cylinder. An operation control mechanism is provided for controlling the pistons into the first states and the second states, respectively, at different timings from each other in turn.

Abstract: An active compensation system for an anti-locking brake system eliminates undesirable brake fluid pressure buildup and, therefore, brake drag by controlling the normally closed valves within the anti-locking brake system through the anti-locking brake system electronic control module to allow the undesired pressure to be released as the brake fluid passes through the normally closed outlet valves into pressure relieving conduits.

Abstract: The present invention relates to a hydraulic brake system with anti-lock control, including a main pressure line leading from a master cylinder to at least one wheel brake and into which a normally open inlet valve is inserted. A pressure fluid return delivery line is connected to an outlet valve and accommodates a pressure fluid accumulator. Connected downstream of the pressure fluid accumulator, an auxiliary pressure pump takes pressure fluid from the pressure fluid accumulator and delivers the fluid via an auxiliary pressure line to the wheel brake. The auxiliary pressure line is connected to the pressure side of the auxiliary pressure pump and establishes a permanent direct hydraulic connection to the wheel brake so that the auxiliary pressure pump is adapted to be isolated from the master cylinder by the inlet valve. A low-noise brake system is accomplished thereby which permits a reactionless positioning of the brake pedal without complicated controls.

Abstract: When skidding of a wheel is detected at braking of the wheel, a passage changeover valve is changed over to allow a brake fluid within a brake cylinder to escape to a low-pressure accumulator, thereby reducing the pressure within the brake cylinder. In addition, by driving a pump, the brake fluid, which has accumulated in the low-pressure accumulator, is fed under pressure to circulate this brake fluid to a brake fluid passage between the master cylinder and the passage changeover valve. When wheel velocity recovers a predetermined amount, the passage changeover valve is changed over, thereby supplying the brake fluid from the pump to the brake cylinder so as to increase the pressure of the brake cylinder again. When the wheel velocity of the braked wheel has recovered to a predetermined wheel velocity, brake hydraulic pressure is generated a predetermined number of times in pulsed fashion, after which the brake hydraulic pressure is increased again.

Abstract: A hydraulic pump comprises at least one alternating-cycle piston (20) having a suction phase and a delivery phase, and sliding in a fixed cylinder (22). The pump possesses in addition a nonreturn suction valve (32) placed between a source of fluid under low pressure (28) and a working chamber (30) defined in the cylinder, and a nonreturn delivery valve (34) placed between the working chamber (30) and an output chamber (16) for the fluid under high pressure, connected to an application circuit 10, 12). The output chamber (16) possesses a wall (40) which is movable as a function of the pressure which prevails in the output chamber (16), the movable wall (40) being capable of controlling the locking of the delivery valve (34) in an open position substantially during the greater part of the suction phase when the pressure in the output chamber (16) is greater than a given pressure, in such a way that the suction valve (32) stays closed in a corresponding manner.

Abstract: An auxiliary mechanism for an auto brake system, the mechanism includes a power cylinder, the interior of the power cylinder has a power piston and drive unit for pushing-up the power piston. A rectangular case body is joined to the rear end of the power cylinder and its interior has a rotational cam unit. An inductive unit including several on/off switches that are located on the power cylinder and a power box for driving said cam unit are provided. When oil pressure is transmitted into the power cylinder, the inductive unit will conduct the circuit and drive the cam unit to rotate for pushing-up the drive unit permitting the power piston to provide a boosting and pressure retaining function for each brake branch pump in order to achieve effective braking.

Abstract: A fluid control device for a braking system has a fluid flow path between an inlet port (9) and an outlet port (10) controlled by a first valve (17,18), and a fluid flow path between the outlet port (10) and an exhaust port (11,12) controlled by a second valve (20,22) and a stepper motor (30) actuated by an electronic controller (2) for driving a valve control piston (22) to which a pilot inlet pressure is applied (23) according to driver braking demand (5A). The stepper motor (30) and pilot inlet pressure act in parallel on piston (22) to control operation of the valves and thereby regulate braking. The stepper motor may operate in response to one or more vehicle operational parameters (A,B,C,D) fed to the controller (7).

Abstract: A vehicle anti-lock braking system is provided. In a preferred embodiment the system has an actuator frame with a bore fluidly connected to the wheel brake and to a master cylinder via a solenoid valve. A piston, mounted within the bore, is operationally associated with a non-rotative nut which is threadably engaged by a power screw. To maximize reaction speed, a high efficiency thread is utilized between the power screw and the non-rotative nut. Therefore, pressure within the actuator can back drive the piston. To prevent backdriving of the piston there is a spring locking mechanism.

Abstract: A vehicle wheel anti-lock braking system (ABS) is provided including a master cylinder and a wheel brake. An ABS controller cognizant of the rotational condition of the wheel provide a signal when the wheel condition is within preset parameters. An isolation valve responsive to close upon an activation signal given by said controller prevents fluid communication between the master cylinder and the wheel brake. An actuator frame is also provided having a bore fluidly communicating with the wheel brake. A piston is mounted within the bore for providing a variable control volume in communication with said wheel brake for and modulating the pressure therein. A reversible motor reciprocally powers piston. The motor has a rotor with a connected disc. A friction surface is provided for engagement with the disc to lock the position of the piston. A plunger is also provided to urge said friction surface into engagement with said disc.

Abstract: A fluid pressure circuit is provided in which two independent systems are provided with a pressure generator for supplying pressure through each of the circuits so as to operate the brake system of a vehicle in an antiskid mode. The fluid pressure circuits have a phase difference of a half a period with respect to each other so as to provide for a continuous pressure to each of the brake systems of the independent fluid pressure systems. By providing such an arrangement, pulsation effects of each independent system are reduced without adversely influencing the pressure generator apparatus and while decreasing the noise associated with the operation of the fluid pressure system under such operating conditions.

Abstract: An electric motor-driven brake pressure modulator motor is designed and controlled to exhibit different speed/torque performance characteristics depending on the direction of motor rotation. In the forward direction when the brake pressure is being applied, the torque characteristic of the motor is maximized to develop adequate brake pressure. In the reverse direction when the brake pressure is being relieved, the speed characteristic of the motor is maximized to quickly relieve the brake pressure. The result is an antilock braking system in which the braking performance is maximized without the design compromise penalties of presently known systems.

Abstract: A vehicle used for training drivers in driving techniques such as skid control has front and rear axles each with steerable wheels. The two signals used to drive motors which control the steering angles of the front and rear wheels respectively are independently generated, may be changed while the vehicle is in motion to simulate a particular event such as a skid and respond to the drivers attempts to control the vehicle.

Abstract: An automatic wheel lock-up control apparatus alternately and cyclically applies brake-pedal controlled pressure to the primary and secondary brake lines driving the slave cylinders of a vehicle's wheel brakes when the brake-pedal pressure exceeds a predetermined value. The apparatus includes an elongated cylindrical body having identical halves, one containing a primary valve for removing or applying primary master cylinder pressure to the primary brakes, and the other containing an identical secondary valve for removing or applying secondary master cylinder pressure to the secondary brakes. An eccentric rotated by an electric motor reciprocally drives a pushrod longitudinally within the body of the apparatus to operate the primary and secondary valves in an alternate, push-pull fashion.

Abstract: In a hydraulic anti-lock braking system a modulator incorporates a solenoid-operated valve responsive to anti-lock signals, a re-application valve and an expansion chamber to which fluid relieved from the brake in an anti-lock mode. The solenoid-operated valve determines the pressure in a control chamber, a poppet valve controls communication between the master cylinder and the brake, and a restricted connection is provided between the master cylinder and the output from a re-application pump.

Abstract: An anti-locking brake control system for a motor vehicle comprises wheel speed sensors for determining the speeds of the individual vehicle wheels, an evaluation circuit which receives the wheels speed signals and generates brake pressure control signals, and a brake pressure control device responsive to the brake pressure control signals for controlling the brake pressure applied to the wheels. The evaluation (processing) circuit includes a brake pressure control unit which operates in such a manner that, after brake pressure decays, the brake pressure is first increased in a timed build-up with reference to the brake pressure build-up in a preceding control cycle, and thereafter the brake pressure is further increased by a sequence of pulses until an instability is again detected.

Abstract: A pneumatic pressure control arrangement for controlling the brakes of railway vehicles. A manual brake command controller converts a selected brake position into a corresponding electrical signal. An application magnet valve is connectable to a source of air pressure and to a storage device. A release magnet valve is connectable to atmosphere and to the storage device. An electropneumatic transducer senses the pressure in the storage device and provides a feedback signal. A microprocessor receives and compares the electrical signal with the feedback signal to develop an error signal which initially energizes the application magnet valve and the release magnet valve upon request of braking effort, and which subsequently pulses the application magnet valve when the pressure in the storage device is within a preselected control range, and which finally deenergizes the application magnet valve when the pressure in the storage device is within a preselected deadband range to cause a lap condition.

Abstract: A hydraulic brake system with slip control wherein at least one wheel brake (11) of an automotive vehicle is connected to a master cylinder (1). A normally opened inlet valve (8) which is adapted to be switched into a closed position is inserted in the connection between the master cylinder (1) and the wheel brake (11). The supply reservoir (6) of the master cylinder (1) contains an opening (13) which can be tightly closed by a filling device. To speed up the filling procedure of like brake systems, an additional connection is established between the supply reservoir (6) and the wheel brake (11) which is controllable by a valve (15). A like arrangement accelerates the venting and filling procedure, since the inlet valve (8) and its throttling action are by-passed.

Abstract: A hydraulic anti-lock braking system incorporates a pump for generating the energy necessary to re-apply a brake automatically after pressure applied to the brake from a master cylinder has first been released to prevent the wheel controlled by that brake from locking. The pump is adapted to pump fluid back both to the brake and to the master cylinder. Pumping the fluid back to the brake achieves a satisfactory pedal feel, and pumping fluid back to the master cylinder ensures the use of a fail-safe re-application of brake pressure.

Abstract: In a brake-slip-controlled automotive vehicle brake system, a pedal-operated master cylinder is provided which applies hydraulic fluid to the wheel brake circuits via at least one braking pressure modulator and via one electromagnetically operated closing valve at a time. The pressure modulator comprises a volume receiver and a pneumatic piston-and-cylinder arrangement acting on the volume receiver and connected with a vacuum source and a pressure source via a change-over valve actuated by a brake slip control circuit. Inserted into each hydraulic line between the master cylinder and the pressure modulator is an electromagnetically operated pilot valve having a normal operating position and a suction position. A traction slip control circuit switches the pilot valves over upon the occurrence of traction slip and ensures that the pressure modulator is reversed to the direction of increasing volume admission.

Abstract: A vehicle braking system such as an anti-lock brake system and/or a traction control utilizes a separate solenoid-actuated, two position, three-way valve in each controlled channel of the brake system for controlling the application of pressure to the respective wheel brake circuit. The valve includes a first port connected to the controlled wheel brake(s), a second port connected to an outlet of a hydraulic pump, and a third port connected to the inlet of the hydraulic pump. The valve is only moveable between a first position wherein the outlet of the pump is connected to the wheel brake to increase pressure to the wheel brake, and a second position wherein the wheel brake is connected to the inlet of the pump to decrease pressure to the wheel brake. An electronic control is provided for operating the valve to control the application of pressure to the selected wheel brakes.

Abstract: A valve is coupled with a brake line of a vehicle for causing or maintaining vehicle brake application. A switch coupled with a vehicle door regulates operation of the valve. When the vehicle door is open, the switch signals the valve to cause or maintain brake application. A timer coupled with the valve maintains the valve in an applied condition for a predetermined period of time after the door has been closed to allow disembarking passengers adequate time to move away from the vehicle. A sensor may be coupled with the vehicle for determining vehicle speed and preventing operation of the valve when the vehicle is traveling above a predetermined speed.

Abstract: A brake system with anti-lock control and/or traction slip control is disclosed including a hydraulic braking pressure generator, a central plunger system, separating valves between the braking pressure generator and the plunger system as well as wheel valves. Further, there is provided an electronic controller which serves to modulate during a control action the braking pressure in the wheel brakes by actuation of the central plunger system and the wheel valves according to the so-termed Multiplex method. The system includes a braking pressure modulator substantially composed of the plunger system, an electric drive motor which is coupled to the plunger system by a single or double unit of planets and a worm drive.

Abstract: A control valve for an anti-lock brake system includes a one-piece valve body having an inlet opening in one end and an outlet opening in an opposite end. The valve body is provided with four other openings extending into the body and defining separate associated chambers for respectively receiving an isolation valve assembly, a pressure differential switch assembly, a dump valve assembly and an accumulator assembly. The inlet, outlet, and the four internal chambers are connected by appropriate internal passageways. The control valve is used to selectively hold, dump, or reapply brake fluid pressure to selected wheel brakes to prevent lock-up of the associated wheels.

Abstract: Disclosed is a brake system wherein the wheel brake is hydraulically connected with a relief chamber of periodically variable volume. A valve 11 controlled by control electronics is switched to connect the chamber to either the wheel brake or a reservoir synchronously to the direction of movement of a piston in the relief chamber to either increase or decrease pressure at the brake for the purpose of antilock and slip control of the brake.

Abstract: A brake control apparatus for a vehicle includes a brake apparatus of the drum brake type; an electromagnetic valve arranged in a conduit between a wheel cylinder and a master cylinder; and a detector for detecting one directional movement of the brake friction members of the brake apparatus due to a backward rotational force of a wheel and another directional movement of the brake friction members due to a forward rotational force of the wheel when the brake friction members are pressed to the frictional surface of the rotator. The brake friction members being able to move within a predetermine range in accordance with the torque of the wheel. The detector includes a slide anchor slidably fitted to a through hold in a stationary anchor, the brake friction members being engaged with the slide anchor, and an electrical switch for detecting the movement of the slide anchor. The valve being closed and opened by the detecting output of the electrical switch.

Abstract: The present invention concerns a vehicle anti-lock brake control system which does not require the use of an auxiliary hydraulic pump and, in the preferred embodiment, is adapted to control only the rear brakes of a four-wheel vehicle. The control system includes a normally open solenoid actuated isolation valve connected between the master cylinder and the rear wheel brakes, and a normally closed solenoid actuated dump valve connected between the rear wheel brakes and a fluid accumulator. A computer control is connected to monitor the rear wheel speed and deceleration and, during breaking of the vehicle, functions to control the application of hydraulic pressure to the rear brakes via the isolation and dump valves in order to prevent lock-up of the brakes. In the event excessive rear wheel deceleration is detected during a vehicle stop, the computer control closes the isolation valve to hold pressure to the rear brakes at a relatively constant level.

Abstract: An anti-lock braking system includes a master cylinder for supplying pressurized fluid to the vehicle brakes and a pump which operates during anti-lock control to supply fluid during brake pressure build cycles. A braking circuit includes decay valves and build valves to control communication of fluid pressure to the vehicle brakes in response to commands generated by an electronic control unit. A braking source control valve responds to signals generated by the electronic control unit to switch communication of fluid pressure to the braking circuit between the master cylinder and the pump.

Abstract: In order to reapply the fluid operating pressure to the braking members of the wheels after an anti-locking operation has been carried out, a pumping device is provided which are driven by the subatmospheric pressure (vacuum) existing in the inlet manifold of the engine. The application of the braking pressure is controlled by a valve which receives an opening command signal consisting of a train of pulses from a control device. At least one vacuum sensor is provided which generates a monitoring signal indicative of the level of vacuum present in the inlet manifold. The control device causes opening of the valve with a command signal whose average is inversely proportional to the level of the monitoring signal generated by the vacuum sensor.

Abstract: An antiskid control system wherein the conventional method of performing an opening/closing change-over operation by a pulse train signal on a electromagnetic valve for increasing hydraulic braking pressure at a variable rate of increase is not employed but the pressure increasing rate is arranged to be variable by the use of an electromagnetic valve having some throttled position.

Abstract: A control valve assembly for use in an anti-lock braking system wherein a 3-way isolation valve normally connects a wheel cylinder to a master cylinder and isolates that wheel cylinder(s) from the master cylinder and simultaneously connects the wheel cylinder to the common connection of a pressure modulating unit when the anti-lock system has been energized. The assembly enables use of a three channel anti-lock system in a dual circuit cross split brake system and increases the protection of the normal brake circuit from leakage in the modulating unit.

Abstract: An hydraulic anti-skid braking device to produce pulsating or "on and off" operation (intermittent control) of a pair of brakes connected to the front and rear brakes of a motor vehicle. The device includes a pair of pistons each piston including a completely radially extending through-passage, and off-set and bleed portions.