Abstract: A pressure device control apparatus including a pressure source having a pump, and an accumulator connected to the pump and a pressure device, and a pressure detector for detecting the pressure in the accumulator; a normally-closed type solenoid valve interposed between the pressure device and the accumulator or a fluid tank; and a control unit having a drive control device for outputting a driving signal indicative of a command to operate the pump in response to a detection pressure detected in the pressure detector becoming equal to or less than a first predetermined pressure and a drive stopping signal indicative of a command for stopping the operation of the pump in response to the detection pressure becoming equal to or more than a second predetermined pressure which is higher than the first predetermined pressure.

Abstract: A pressure transmitter for a brake control system is provided with a piston having a passage extending between an input pressure chamber and an output pressure chamber and a seal fixedly installed on one end of the piston for sealing closing an end of the passage. The seal is resiliently deformable for transmission of pressure between the input pressure chamber and the output pressure chamber. A pressure control valve for a brake control system includes a valve spool for controlling communication between a pressure source and a wheel cylinder for producing a control pressure which is boosted on the basis of a master cylinder pressure and a vehicle running condition, a set of plungers for urging the valve spool in the direction of increasing the control pressure in response to increase of the master cylinder pressure and a solenoid for urging in the valve spool in the direction of causing decrease of the control pressure in response to increase of current supplied to the solenoid.

Abstract: The invention is directed to an control system for a motor vehicle and includes: a plurality of control elements coacting for carrying out control tasks with reference to engine power, drive power and braking operation, respectively, and a plurality of coordinating elements for coordinating the coaction of the first elements to effect a control of operating performance of the motor vehicle in correspondence to a request of the driver. The elements are arranged in the form of a plurality of hierarchial levels. At least one of the coordinating elements of one of the hierarchial levels is adapted for acting on the elements of an adjacent hierarchial level when translating the request of the driver into a corresponding operating performance of the motor vehicle thereby acting on a pregiven subordinate system of the driver-vehicle system while providing the performance required from the higher hierarchial level for this subordinate system.

Abstract: A brake control system comprises a simulator (4) for disconnecting a master cylinder (1) from a wheel cylinder (3) to vary the volume of the master cylinder in response to output pressure from the master cylinder when a brake is applied, and a wheel cylinder pressure control device (10) for controlling pressure supplied to the wheel cylinder. The wheel cylinder pressure control device includes a first pressure chamber (23) connected to the wheel cylinder, and a pressure control piston (18) for varying the volume of the first pressure chamber.

Abstract: A brake control system for a vehicle in which a brake pressure is generated in accordance with a signal from an electronic control unit for applying the brake pressure to vehicle wheels, characterized in that a mechanical brake system is automatically actuated when an unexpected electrical fault has occurred in an electrical brake system.

Abstract: An anti-lock control method for preventing a vehicle from yawing during braking, while driving on a split road surface. The amounts of the pressure increase in a right wheel and a left wheel control system, controlled independently of each other, are compared with each other. When there is a difference between the two pressure increase amounts, it is determined that the control system having the greater pressure increase amount is the high road-side control system whereas the other control system, having the smaller pressure increase amount, is the low road-side control system. The brake hydraulic pressure in the high road-side control system is controlled so that it does not excessively increase.

Abstract: The invention relates to a method and a device for controlling the operating brake pressure to pressure medium brakes in a vehicle combination comprising a tractor vehicle and at least one trailer vehicle. The vehicles in this case are connected by a conventional coupling device that includes standard brakeline connections. Forces developing in the coupling device are measured during the course of braking and are reduced to a predetermined value by adjusting the brake pressure for at least the brakes of the trailer vehicle in dependence on the longitudinal inclination of the tractor vehicle and of the actual deceleration thereof. The adjusted value of the brake pressure is retained for the purpose of being the starting value at the next braking of the vehicles.

Abstract: The circuit configuration for a brake system having an anti-locking control generates pulse-type brake pressure control signals. For pressure rebuild-up after a pressure decrease, brake pressure is applied first at a steep and subsequently at a flatter gradient, this being achieved by a variable pulse (P1) and by short fixed pulses (P2) succeeding one another at a large interval. Circuits are provided rendering dependent the pulse and pulse break times (T.sub.1, T.sub.2, T.sub.k) determining the pressure build-upon the duration of the pressure build-up (T.sub.1) during the steep-rise build-up in the preceding cycle,on the duration (T.sub.1 +nT.sub.2) of the entire pressure build-up in the preceding cycle, andon the duration (T.sub.o) of the preceding pressure decrease, with the pulse times being so dimensionedthat, at a constant coefficient of friction and at a constant static pressure, the locking limit of the wheel is rereached after a predetermined period of time or after a predetermined pulse number.

Abstract: In a braking pressure control apparatus for a vehicle, a first valve connected between a hydraulic pressure source and a wheel cylinder serves to permit and inhibit a supply of brake fluid to the wheel cylinder from the hydraulic pressure source. A second valve connected between the wheel cylinder and a reservoir serves to permit and inhibit an escape of the brake fluid from the wheel cylinder toward the reservoir. A control device serves to output control signals to the first and second valves respectively to control the braking pressure in the wheel cylinder in response to a detected running condition of the vehicle.

Abstract: A brake holding apparatus for vehicles with conventional hydraulic systems for the purpose of locking the least loaded brakes only, after the vehicle has been braked to a stop which permits unloading, during stops, the most loaded brakes, thereby prolonging their life and making driving easier for the operator. A hold mode indicator light is provided to alert the driver that the system is in the holding mode.

Abstract: An anti-skid brake system for the automotive vehicle is disclosed which is arranged to increase or decrease the braking oil pressure periodically on the basis of a comparison between the wheel speed and the assumed vehicle body speed. When the state in which the wheel is incipient to lock before the wheel speed is returned to the assumed vehicle body speed, the braking oil pressure is inhibited from being increased, thereby preventing the assumed vehicle body speed from deviating too far from the actual vehicle body speed. This anti-skid brake system can prevent the wheel from being locked due to having the assumed vehicle body speed set to too low a value relative to the actual wheel speed.

Abstract: A brake system having a master brake cylinder that can be acted upon by fluid pressure of a brake pedal and which communicates with wheel brake cylinders via brake lines, a reversing valve that is closable for traction control and pressure holding and pressure reduction valves for anti-lock control are incorporated into at least one brake line to the wheel brake cylinder. Traction control is effected via a return pump that is connected on the inlet side to at least one brake line. The hydraulic circuit is intended to have a reservoir, which communicates on the inlet side with a self-aspirating return pump via an intermediate line with the brake line via a pressure limiting valve, where the pressure limiting valve has at least one blocking position and an open position on both ends.

Abstract: Brake force proportioning system for a vehicle includes a two-way valve in the line between a diagonally connected front and rear wheel. A controller opens the valve continuously in a first region of brake pressure so that the brake force proportioning follows a fixed proportioning characteristic. Outside this region the valve is opened in pulses so that the proportioning follows an ideal characteristic curve. If the controller fails, a pressure limiting valve takes the place of the two-way valve and effects a pressure distribution according to a characteristic parallel to the fixed slope characteristic.

Abstract: A hydraulic power unit for a vehicle comprises a motor, a pump to be driven by the motor to pump up an oil stored in an oil tank, a gas filling type accumulator connected to the pump, a pressure sensor disposed at a portion near an outlet port of the accumulator for detecting a pressure of the oil in the accumulator, a control unit operatively connected to the pressure sensor and a relay opertively connected to the control unit for controlling an operation of the motor.

Abstract: A method of controlling the operation of a vehicle brake system, the brake system including a master cylinder controlled by the operator of the vehicle to vary applied brake pressure to various brake mechanisms during normal service brake operation and an antiskid brake subsystem, activated when one or more vehicle wheels are skidding, for controlling brake pressure in the various brake mechanisms to permit various wheels to operate in a nonskidding manner. The method comprising the steps of: 1) determining and storing a control relationship which relates changes in vehicle deceleration and changes in applied brake pressure, with none of the wheels of the vehicle skidding, 2) subsequently measuring at least two values (P.sub.1 P.sub.2) of applied brake pressure to determine changes in applied brake pressure .DELTA.P during a measurement interval and calculating the change in control deceleration .DELTA.D.sub.ci corresponding to the change .DELTA.

Abstract: A system which reduces an electric load on an on-board electrical system of a vehicle. The brake system has an anti-lock and traction control system. The latter has a high-pressure pump, with which pressure fluid can be withdrawn from a supply container and fed into a brake line. A charging valve that can be switched out of its shutoff position into its open position by a control unit is disposed in an intake line of the high-pressure pump. The control unit switches the charging valve into its open position at least whenever feeding of pressure fluid into the brake line is demanded. The brake system is especially well-suited to passenger cars, which have a very severely fluctuating rear axle load status.

Abstract: A fluid leakage preventing device incorporated in a hydraulically-operated system which includes an accumulator for storing a working fluid under pressure, an actuator operated by the fluid supplied from the accumulator, and a control valve having an open position and a closed position for fluid communication and disconnection between the accumulator and the actuator, respectively. The fluid leakage preventing device includes a fluid leakage detector for generating an output signal indicative of the leakage flow of the fluid from said accumulator through the control valve placed in the closed position. The device further includes a valve reciprocating arrangement responsive to the output signal of said fluid leakage detector, for effecting at least one reciprocating movement of a valving member of the control valve.

Abstract: A hydraulic dual-circuit brake system with front/rear brake circuit distribution, an anti-skid system (ABS) and traction control (ASR) for motor vehicles including a four-channel hydraulic unit with control valves and with one return pump and a separate pump element for each brake circuit. An apparatus to supply brake pressure to the rear axle brake circuit in traction control has a reversing valve, which in traction control disconnects the rear-axle brake circuit from the master brake cylinder, and a pump feed apparatus, which upon activation feeds brake fluid into the pump element of the rear axle brake circuit.

Abstract: A brake system with anti-lock and/or traction slip control, wherein quantities (.DELTA.t.sub.EV, .DELTA.t.sub.AV) determining the pressure in the wheel brakes (10, 11) are measured and assessed. A wheel pressure pattern (p(t)) is formed from these quantities by integration which, by approximation, represents the pressure variation in the wheel brakes (10, 11). The output signal of the integrator (20) is fed back to the control logic (16) and assessed for slip control and/or braking pressure control. For the integration, taken into account are the braking-pressure-increase and braking-pressure-decrease characteristic curves (P.sub.A, P.sub.E) and the initial conditions (21) which represent the initial pressure upon commencement of the control.

Abstract: A pressure supply system for a vehicle according to the invention incorporates a pump and an accumulator in which an output pressure of the pump is maintained within a prescribed range by controlling the on-off operation of the pump according to the inner pressure of the accumulator. By changing the prescribed range of pressure according to the actual pressure requirement, for instance according to the change in the travelling speed of the vehicle, the burden on the system is reduced. The prescribed range can be changed either by simply changing the upper and/or lower pressure limits at which the pump is deactivated and activated, respectively, or by operating the pump for a prescribed time period which is dependent on the pressure requirement after a certain reference pressure value is reached. Thus, the structure of the fluid pressure system is simplified, and the generation of unnecessary high pressure can be avoided.

Abstract: A brake system having a master brake cylinder for producing a brake pressure controllable by a brake pedal and transmitting it to at least one brake circuit, which connects the master brake cylinder with corresponding wheel brake cylinders of the front and rear wheels. At least one shutoff valve for anti-skid control is incorporated into each main line of the brake circuits. A first and second brake circuit communicate downstream of the shutoff valves with a feed system, which has devices for feeding brake fluid at different pressures to the first and second brake circuit.

Abstract: When ASR is running, the driver can brake at any time and does not encounter a stiff brake pedal. The ABS is equipped with an aspirating return pump which serves as a pressure producer in the ASR case with the aid of two auxiliary valves, i.e. a changeover valve and a loading valve. The brake pressure on the wheel on a selected axle that first shows a tendency to slip is modulated by way of the auxiliary valves, while the brake pressure on all other wheels is modulated by the ABS valves. In this manner brake pressure can always reach at least one wheel brake. If the ABS responds, the ASR is shut off.

Abstract: A hydraulic braking system for an automotive vehicle having a power pressure source for generating a hydraulic power pressure, a master cylinder generating a hydraulic braking pressure in response to depression of a brake pedal, a dynamic hydraulic pressure generator for regulating the hydraulic power pressure in response to depression of the brake pedal and generating a regulated braking pressure, and a plurality of wheel brake cylinders for braking respective road wheels with one of the hydraulic braking pressure supplied from the master cylinder and the regulated braking pressure supplied from the dynamic hydraulic pressure generator.

Abstract: An air brake system for a truck includes a treadle valve, a pilot control isolation valve, an exhaust valve, a relay valve, an air pressure transducer, a wheel speed sensor, an electronic control unit (ECU) and an air brake chamber associated with a brake actuator. In heavy braking operations, the pilot system pressure rise rate is monitored and restricted by modulation of the pilot control isolation valve. During heavy braking operations, if braking of the vehicle wheel results in a wheel velocity change which exceeds a predetermined deceleration threshold, the pressure rise rate is further restricted in attempt to "creep" up on the brake system pressure at which the lock condition is expected to occur. At another predetermined deceleration threshold, the brake system pressure is vented. The brake system pressure decreases resulting in a reduction in the applied brake force thereby permitting the vehicle wheel to roll back up to speed. The roll up rate is a function of the friction force.

Abstract: A brake system wherein an auxiliary power based on a manual force is electronically controlled to control the braking force so as to obtain braking effects corresponding to a manual control input. The braking force is controlled so that a vehicle deceleration corresponding to the control input can be obtained when the control input is equal to or greater than a comparatively small predetermined control input value Lo. When the control input is smaller than Lo, the braking force is controlled so that the vehicle acceleration will not exceed a value corresponding to the control input.

Abstract: A brake system for the rear wheels of a vehicle applies brake pressure to each rear wheel so as to establish the rear wheel speed at a predetermined relationship to the speed of the front wheel on the same side of the vehicle. The brake pressure applied to each of the front and rear wheels is limited by antilock controlled braking in response to a sensed incipient lockup condition of the wheel. When a front wheel first enters into an antilock controlled braking, in response to an incipient wheel lockup condition, the brake pressure to the rear wheel on the same side of the vehicle is rapidly increased to induce an incipient wheel lockup condition thereby inducing antilock controlled braking of the rear wheel.

Abstract: A method utilizes components of an existing anti-lock brake system (ABS) in order thereby to achieve an automatically self-optimizing inter-axle brake-pressure distribution acting far below the wheel lock limit. For this purpose, the brake pressure and, hence, the brake-force distribution are regulated axle-specifically far below the wheel lock limit too. An immediate dynamic intervention is, on one hand, effected in the case of sufficiently large wheel-speed differences between the axles. On the other hand, an adaptive predetermination of correct brake-force distributions is made the basis for each current regulating intervention. Even before the occurrence of large speed differences, the brake-force distribution expedient in each case for these is here predictively determined, stored, and, if required, correspondingly adapted to current requirements, i.e. corrected, in the course of subsequent dynamic braking demands.

Abstract: A process is described for controlling the brake pressure wherein a brake pressure is supplied which corresponds to the desired signal. This pressure is measured. The factors b.sup.+/- and the response times T.sub.o.sup.+/- are identified from the pressure pulses P in the individual control cycles and the actuating times .+-.T of the valves and they are used to convert the desired signal P.sup.x into a control signal .+-.T of such a length that the desired pressure is supplied.

Abstract: A hydraulic dual-circuit brake system for a road vehicle with front-axle/rear-axle brake circuit division has a tandem main cylinder as a brake device. The primary output pressure space of the cylinders is associated with the front-axle brake circuit, and the secondary output pressure space of the cylinders is associated with the rear-axle brake circuit. A pressure modulator adjusts the front-axle/rear-axle braking force distribution in the direction of an approach to the, in each case, ideal braking force distribution, as a braking-pressure actuator for the rear-axle brake circuit. The pressure modulator has a drive pressure space, by the charging of which with the output pressure of an auxiliary pressure source under solenoid valve control, a braking pressure which can be coupled into the rear-wheel brakes can be built up in an output pressure space of the pressure modulator.

Abstract: In a vehicle combination consisting of a haulage truck (1) and a semitrailer (2) the brake system of the haulage truck (1) comprises a control valve (8) which allows the brake pressure imparted to the brakes (4) of the semitrailer (2) to be adapted to the brake pressure imparted to the brakes (3) of the haulage truck (1). The adaptation is carried out with the use of an electrical control unit (16), in which the actual deceleration of the vehicle during a braking sequence is compared to an expected deceleration. In the event of a discrepancy between these, a control member (15) on the control valve (8) is actuated automatically so that the semitrailer (2) is supplied with a higher or lower brake pressure relative to the haulage vehicle (1) depending on whether the actual deceleration was lower or higher than the expected deceleration. As a result of the adaptation, the brakes of the haulage truck (1) and of the semitrailer (2) can be used better under various operating conditons.

Abstract: An automobile brake safety system wherein braking is automatically maintained once a brake pedal of an automobile is depressed. The brake safety system comprises a solenoid compresor valve (SCV) assembly provided between the master cylinder and wheel cylinder of an automobile, and an electronic control circuit for controlling the SCV. The brake system is operative for increasing the pressure in a wheel cylinder in the event that pressure in the wheel cylinder decreases after braking has been maintained for a prolonged period of time, or in the event that the master cylinder malfunctions. The brake system is further operative for reducing the pressure in the wheel cylinder of a vehicle when the vehicle is accelerated by an operator thereof. The SCV is mounted in the oil path between the master cylinder and the wheel cylinder and it comprises a brake solenoid coil, a compressor solenoid coil, and a release solenoid coil.

Abstract: An overload warning system for a trailer brake cylinder of a trailer brake system having a nominal deceleration rate. It has been found that previous temperature sensing overdue warning systems have a disadvantage that undue delay occurs and that no warning signal is initiated until after damage to the trailer brakes occurs. The present invention proposes that the tractor brake system and the trailer brake system compare their received operating control signals from which they form a ratio factor and then produce a warning signal when the ratio factor changes beyond a predetermined critical change velocity. The present invention employs the rapid drop in braking force caused by a brake overload and uses the rapid drop and increase brake demand for readjusting the brake deceleration. The present invention is used for uniquely recognizing the "Fading" effect of the trailer brake system.

Abstract: A vehicle brake system having at least two brake pressure lines, via which a master brake cylinder communicates with wheel brake cylinders, at least one valve is incorporated in each brake pressure line to close the brake pressure lines in the event of anti-skid control. Each brake pressure line is also assigned a return pump, which bypasses the valve. At least one valve, in the currentless state or with the absence of pressure buildup in a brake pressure line, blocks this brake pressure line and communicates with a control unit for pulsed opening upon pressure buildup in the brake pressure line. Because of the additional disposition of a pressure valve and check valve in a bypass around the pulsed valve, expensive pressure reducers are dispensed with, with little additional expense in the anti-skid control system. Even if the anti-skid control system fails, stability during braking is assured.

Abstract: A vehicle brake system comprising a hydraulically controllable 2/2-way valve, which has a first control inlet and a second control inlet. The first control inlet receives its control pressure from a first brake pressure source, while the second control inlet contrarily receives its control pressure from a second brake pressure source, such as a so-called return pump apparatus. The vehicle brake system can be used in passenger cars, vans, small buses, and small trucks as well as motor cycles.

Abstract: The period of an initial apply motor current in each apply phase of an antilock brake pressure cycle in a motor driven pressure modulator antilock braking system is adaptively controlled following a sensed recovery from an incipient wheel lockup condition to establish substantially a steady state condition relationship between current and pressure before motor current is ramped to ramp brake pressure. The period of the initial apply motor current is made a function of the amount of pressure decrease during a prior release phase portion of the antilock brake cycle to account for the greater increase in brake pressure to the initial reapply value.

Abstract: A schedule of brake pressure ramp rates is provided in a vehicle antilock brake controller as a function of predetermined wheel parameters. The ramp rates associated with the specific values of the wheel parameters are filtered by limiting the changes in ramp rate to a next higher ramp rate from the schedule of rates when the ramp rate called for by the wheel parameters is greater than the present ramp rate and to a next lower ramp rate from the schedule of rates when the ramp rate called for by the wheel parameters is less than the present ramp rate.

Abstract: The motor current in a vehicle antilock brake system motor driven pressure modulator is increased in stepwise fashion to ramp the brake pressure in the apply phase of an antilock braking cycle. At the beginning of each current step as the motor current is increased in stepwise fashion, the motor torque is increased momentarily at least by an amount to assure that the static friction of the pressure modulator is overcome and that motor rotation is initiated. The motor torque is increased to a value to initiate motor rotation at the beginning of each current step by momentarily increasing the motor current to a value greater than the current step value by a predetermined amount that assures that the increase of motor torque exceeds the static friction of the pressure modulator.

Abstract: A high performance anti-lock brake system is suitable for both original equipment and after-market applications. The system comprises a conventional hydraulic link between a master cylinder and a wheel cylinder. A cut-off valve is provided to separate the hydraulic link into an upstream portion and a downstream portion. A one-way valve is provided in parallel relation to the cut-off valve to ensure the possibility of hydraulic communication from the wheel cylinder to the master cylinder at all times. Downstream of the valves, piezoelectric discs are provided within the hydraulic link. When a skid condition is sensed, for example, by monitoring a ratio between the rate of change of wheel deceleration and the rate of change of hydraulic force at the wheel cylinder, brake force control is initiated. A controller closes the cut-off valve and controls the voltage applied to the piezoelectric discs to contract the discs, thereby reducing the pressure in the wheel cylinder.

Abstract: A brake and anti-skid control utilizing optical input sensors for determining wheel speed or position and suitable for aircraft use is disclosed. A valve control has a continuous source of pressurized hydraulic fluid, a hydraulically actuated wheel rotation brake device which responds to applied hydraulic pressure to apply a braking force to the wheel to arrest wheel rotation, a low pressure hydraulic fluid return, and a flow control servo valve interconnecting the source, the return, and the braking device for directing fluid from the source to the braking device when in a first state and for directing fluid from the braking device to the return when in a second state. Applied hydraulic pressure is monitored and if that monitored pressure exceeds a command pressure, further fluid from the braking device is diverted to the return.

Abstract: A hydraulic brake system for a vehicle including, brake pressure modulators that prevent the locking of vehicle wheels caused by excessively high braking pressures. Such brake pressure modulators include brake line blocking valves and cylinders with pistons, where upon piston displacement, pressure fluid escapes from the wheel brakes to lower the brake pressure. The displacements of the pistons are controlled via valve assemblies that are connected to a servo pressure source. Failure of the servo pressure source, if there is even a small leak of a valve assembly, can lead to at least partial loss of a brake force during a braking event. To recognize and indicate any leak that might be present, a control unit which acts upon the valve assemblies is arranged such that it directs the valve assemblies into various switching positions and in this process, via a pressure sensor, observes whether logically observed pressures are varying impermissibly.

Abstract: The invention relates to an anti-skid apparatus operatively positioned between a master brake cylinder and wheel brakes of a vehicle brake system. The anti-skid apparatus protects the wheel brakes from locking. The apparatus includes a controllable master brake line valve, which is open in its basic position and during normal braking; only in anti-skid braking operation does it disconnect the outlet of the return pump from the master brake cylinder.

Abstract: A process for load dependent braking regulations (ALB) utilizing components, signal paths and transmitters of an existing anti-lock braking system (ABS) to perform an automatically load-dependent braking function which takes effect well below the locking limit. The brake pressure and consequently the brake distribution are controlled by processing only wheel-speed differences as actual values of an electronic brake-pressure controller instead of absolute wheel slips. To compensate for changing load situations and roadway properties, the precontrollable brake-force distribution and the brake-pressure level control triggerable at the pedal are corrected in a self-learning and adaptive manner. The device for carrying out the ALB process consists essentially of a computer and software program using input from the ABS systems. The process according to the invention makes axle-load sensors superfluous.

Abstract: A vehicle dual wheel braking system of the type in which a respective electronically controlled pressure adjustment channel is provided for each of the wheels at the opposite ends of an axle of the vehicle for setting the braking pressures individually for each wheel in dependence upon a common electrical signal representative of the braking demand level set by a driver of the vehicle, each channel comprising a pressure control loop containing a pressure controller, a pressure control valve which adjusts the supply of fluid from a reservoir to the brake actuators for applying and releasing the brakes by solenoid control of the inlet and exhaust functions of the pressure control valve, and a feedback transducer which supplies a signal representative of the pressure in the pressure control valve.

Abstract: In an anti-lock brake system (ABS) for a motorcycle the driving stabilty is improved by measuring the position of lateral inclination of the motorcycle and adjusting at least one threshold value for the anti-skid control in response to the measurement. In another embodiment the transverse acceleration of the motor cycle is measured and an ABS threshold value adjusted accordingly.

Abstract: An accumulator assembly for a vehicle anti-lock brake system receives and temporarily stores fluid during pressure reduction phases of the anti-lock operation, and maintains fluid stored therein substantially at or near zero pressure during anti-lock operation. The accumulator enables the fluid pressure to the controlled brakes to be reduced to substantially near zero pressure. The accumulator is further operative, after braking of the vehicle, to apply a predetermined pressure above zero pressure to the brake fluid stored therein to enable the fluid to be returned to the brake system. The accumulator is advantageously used in a pumpless anti-lock system which is operative to control the rear disc brakes of a light pick-up truck.

Abstract: An anti-lock control device of a hydraulic brake system which enables a rapid building up of braking hydraulic pressure during normal braking but, once an anti-lock control is commenced, reduces the rise of the recovery of the braking hydraulic pressure so as to optimize the same for anti-lock control. The hydraulic braking system having a pneumatic pressure source, a brake valve, converting device for receiving the pneumatic pressure supplied from the pneumatic pressure source through the brake valve and converting the received pneumatic pressure into braking hydraulic pressure, wheel cylinders for receiving the braking hydraulic pressure, and pneumatic pressure control valves for controlling the pneumatic pressure in a pneumatic pressure chamber of the converting means so as to control the braking hydraulic pressure.

Abstract: Controlled movement of a motor driven pressure modulator is provided by commanding maximum current to the motor by application of system voltage resulting in the motor current initially rising rapidly to the motor stall current. The motor accelerates at a rate that is a function of the difference between the motor torque and the load torque represented by the load on the modulator. As the motor speed increases, the motor current decreases. When the motor current decreases below the stall current by a predetermined amount representing a predetermined speed of the motor, the motor current is turned off for a wait period that is based upon the time that it took for the motor speed to attain the predetermined speed. Thereafter, maximum motor current is again commanded and the cycle repeated to provide for motor speed control.

Abstract: An anti-locking automotive vehicle braking unit wherein to achieve a reduction of the costs of manufacture and of mounting with an increase of reliability in operation, a pneumatic device (39, 40) is provided for venting of the first power chamber (5) and/or evacuation of the second power chamber (6) of the vacuum brake power booster (1) in the event of a slip control action. This renders the boosting power of the vacuum brake power booster effective or ineffective in a direction opposed to the direction of actuation of the master brake cylinder (2).

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: A brake control system is described that prevents a wheel lockup condition by identifying the brake pressure that produces the maximum possible braking effort during each brake pressure application period and applying a predetermined fraction of the identified pressure after an incipient wheel lockup condition is sensed. The predetermined fraction provides for adaptive adjustment of the brake pressure if the identified brake pressure is in error until a pressure is applied that produces substantially the maximum possible braking effort.