Abstract: A method and apparatus for controlling activation of a brake pump during controlled braking conditions include a controller for determining pump activation conditions based on four empirically obtained tables stored in the controller: a pressure series table, volume consumption table, pressure gradient table, and a pump output table. The four tables are used to determine when the brake pump is activated as well as at what capacity the pump should be operated in order to achieve optimal braking performance with least amount of driver discomfort.

Abstract: A brake pressure control system is proposed which operates on the fluid-return principle. This system includes a low pressure accumulator which must be emptied upon termination of a braking operation with brake pressure control. In this way, the emptying period is kept as short as possible. To this end, the pump is driven for a defined period. In this emptying period, the motor is controlled by pulse-width modulation, and the electromotive counterforce is measured in the phases of the control signal in which no voltage is applied to the motor. This counterforce is a standard of the rotational speed of the motor or the rotational speed of the connected pump. When the rotational speed or the rotational speed variation exceeds a given value, this can be considered as an indication that the low pressure accumulator is empty. As soon as such a signal appears, the emptying period is terminated by deactivation of the motor.

Abstract: A brake assist control for generating a brake force greater than that of a normal time is performed. It is determined (102) that a brake pedal is operated at a high speed when a rate of change .DELTA.PM/C of a master cylinder pressure PM/C exceeds a first threshold value .alpha.. When the cause of the braking operation is an external disturbance, the rate of change .DELTA.PM/C the rate of change .DELTA.PM/C changes immediately thereafter. When a period during which the rate of change .DELTA.PM/C becomes less than a second threshold value .beta. is shorter than a predetermined period T0, it is determined that the cause of the braking operation is the external disturbance such as a rough road or a step and an execution of the brake assist control is prohibited (104, 108, 110, 112).

Abstract: A method and an apparatus for controlling the brake system of a vehicle consisting of at least two component vehicles are proposed, where at least one of these component vehicles is equipped with an electrically controlled brake system. As a function of the actuation of the brake pedal, nominal values for the control of the wheel brakes are formed. An actuating variable for controlling the wheel brakes of the second component vehicle is formed in this first component vehicle. During a braking operation of the complete vehicle, the actuating variable for one component vehicle is modified by a value which, in the event that the brakes of the first component vehicle are not engaged, is determined by adjustment of the actuating variable for the second component vehicle or by adjustment of the nominal values for the wheel brake of the first component vehicle.

Abstract: In an electrically operated vehicle in which a regenerative braking operation is performed to apply a regenerative braking torque to a wheel, if the regenerative braking torque reaches its maximum value and is insufficient to brake the wheel, a static hydraulic pressure outputted from a master cylinder is supplied to the wheel brake cylinder mounted on the wheel until the brake pedal reaches a retained position. Thereafter, a dynamic hydraulic pressure is supplied to the wheel brake cylinder. While the brake pedal is in movement from the rest position to the retained position, the wheel brake cylinder is supplied with only the static hydraulic pressure and while the brake pedal is being retained at the retained position the wheel brake cylinder is supplied with the static hydraulic pressure and the dynamic hydraulic pressure.

Abstract: Piping associated with interlocked brakes for front and rear wheel brakes is to be simplified to improve maintainability and provide a brake system suitable particularly for a two-wheeled motor vehicle satisfying racing specifications. A braking system includes hydraulic brakes with three hydraulic systems which are a lever hydraulic system for a front wheel brake, an interlocked hydraulic system for a rear wheel brake and a pedal hydraulic system. A pressure sensor detects a hydraulic pressure in the lever hydraulic system and outputs the detected signal to a control unit in the interlocked hydraulic system through an electric wire. The control unit controls the operation of a motor, thereby causing a hydraulic pressure to be developed in a submaster cylinder, which hydraulic pressure is fed to the rear wheel brake through a control valve.

Abstract: A method and device for regulating the pressure in at least one wheel brake, such that a controller is provided for pressure regulation which forms at least one activation signal magnitude for a pressure-influencing valve arrangement on the basis of, among other things, a stored correlation between the activation signal magnitude and the pressure conditions at the valve arrangement. The method and device allow for the correlation to be adapted to changes to the braking system during operation.

Abstract: A hydraulic automotive vehicle brake system with brake slip control and automatic brake management for traction control and/or driving dynamics control includes a braking pressure generator which is hydraulically connectable to at least one wheel brake and a pressure fluid accumulator by way of pressure modulation valves, at least one pump which is connected with its suction side to a pressure fluid accumulator and with its pressure side to a pressure fluid conduit that extends from the braking pressure generator to the wheel brake, the pressure fluid conduit comprising the pressure modulation valves and a pressure sensor that is connected to the pressure fluid conduit in between the braking pressure generator and the pressure modulation valves. The pressure sensor is accommodated in a housing which houses the pressure modulation valves.

Abstract: A brake system with electronic braking pressure control, including a braking pressure generator, electrically operable hydraulic valves, and an electronic analyzing, is provided with an acoustic sensor which is used to determine the change-over behavior of the hydraulic valves for the approximate determination of the braking pressure prevailing in the braking pressure generator and/or in the wheel brakes. The measured pressure values, in the capacity of control quantities, are taken into account for braking pressure control or analyzed for monitoring purposes.

Abstract: Two methods of calibrating Fax machines are disclosed. The first method utilizes a pre-printed calibration chart and a computer connected to the Fax machine to be calibrated. The calibration chart is fed into the Fax machine which sends the resultant data to the computer. This data is analyzed by the computer to determine when the Fax machine started to scan the calibration chart. If the scan process did not occur at an optimum point, the computer sends a correction value back to the Fax machine to cause the Fax machine to begin scanning subsequent documents at an optimum point. In the second method, a calibration chart is printed by the Fax machine and then fed back into the machine. A copy of the scanned calibration chart is made to determine at what point the Fax machine began scanning the chart. If the Fax machine did not begin scanning at an optimum point, a user reads the copy and manually enters a corrective offset in to the Fax machine such that subsequent documents are scanned properly.

Abstract: A brake system for automotive vehicles has a pneumatic brake power booster with two chambers one of the chambers being adapted to be acted upon by a low pressure and the other one by a higher pressure, and at least one of the chambers being adapted to be connected to a pneumatic pump. A device is provided to activate and deactivate the pump in response to the pressure that prevails in the chamber of the brake power booster associated with the pump.

Abstract: A device for detecting operation of a brake pedal comprises: a first hydraulic chamber 9 in which fluid is pressurized by a first piston 7 connected with a brake pedal 1 when the brake pedal 1 is pushed downward; a second hydraulic chamber 13 communicated with the first hydraulic chamber 9 via an orifice 11 of small diameter; a first hydraulic pressure sensor 19 for detecting hydraulic pressure in the first hydraulic chamber; and a second hydraulic pressure sensor 20 for detecting hydraulic pressure in the second hydraulic chamber. The control unit 24 controls a motor (braking device) 22 in accordance with a difference .increment.P in pressure obtained by the values of detection conducted by the first hydraulic pressure sensor 19 and the second hydraulic pressure sensor 20.

Abstract: An improved electro-hydraulic brake system having features for improving the pedal feel of the system, while further having design features which contribute to the economy of manufacture of certain components of the system. The system provides for an electrically powered normal source of pressurized hydraulic brake fluid, and a manually powered backup source of pressurized hydraulic brake fluid to the vehicle brakes in the event of failure of the normal source. During normal braking, fluid from the backup source is redirected from the vehicle brakes to a pedal simulator. The pedal simulator preferably includes arrangements of spring loaded pistons, expansion volumes, and damping orifices, together with valves selectively controlling the flow of fluid to and from the pedal simulator which provides for an improved pedal feel during vehicle braking.

Abstract: In a microprocessor-controlled electro-pneumatic brake control system for a railway train, pressure in the brake cylinder is maintained despite the loss of pressure in the "20 pipe" brake line, or failure of a key relay valve that controls pressure to that brake line. Feedback signals derived from the "20 pipe" brake line when found to be inappropriate after a predetermined amount of time are substituted for by brake command signals generated by the brake controller.

Abstract: A method and apparatus for permitting use of an ABS electrical power circuit associated with a tractor-trailer vehicle to provide auxiliary power whenever the trailer is parked and which provides for full power to an ABS brake control circuit through the ABS electrical power circuit in response to air pressure in the emergency brake supply line of the tractor-trailer vehicle being above a predetermined minimum which is sufficient to release the trailer's emergency brake and permit movement of the trailer.

Abstract: A brake apparatus for an electric vehicle which maintains the regenerative energy generated in a traction motor of each of wheels to be at a maximum. A hydraulic pressure brake and a regenerative brake are provided in the same brake apparatus. The hydraulic pressure brake generates a brake torque by providing a hydraulic pressure to a wheel cylinder of each wheel of the vehicle. The regenerative brake generates a brake torque by regeneration in a traction motor for each wheel. The brake torque to be provided is calculated for each wheel. A maximum regenerative energy is calculated for each wheel. A hydraulic pressure calculating unit calculates a hydraulic pressure to be provided to the wheel cylinder of each wheel based on the brake torque and the maximum regenerative energy so that the regenerative energy generated by the traction motor of each wheel becomes a maximum.

Abstract: In a selected operating situation, the automatic control circuit, which is closed during normal operation, is opened, the final control element of the wheel brake being actuated within the scope of an open-loop control process. The drive signal value for the wheel brake changes in accordance with a predetermined time function, and the application pressure or release pressure is found on the basis of the characteristic behavior of a value representing the braking action.

Abstract: A wheel brake pressure supplying device for supplying fluid pressure for a wheel brake cylinder of a wheel on an automotive vehicle includes a reservoir, a pump, a motor, an accumulator connected to the wheel brake cylinder, a fluid pressure sensor, an electric source, an operation time determining device and a motor control device. The reservoir stores a fluid and the pump is connected to the reservoir for pumping fluid in the reservoir. The motor operates the pump and the accumulator is connected to the pump for storing the fluid pumped by the pump so that fluid pressure in the accumulator increases through operation of the pump. The fluid pressure sensor senses when the fluid pressure in the accumulator is less than a predetermined pressure. The electric source is connected to the motor for supplying voltage to the motor and the operation time determining device determines a target operation time of the motor based on the voltage of the electric source.

Abstract: An auxiliary energy brake system of automotive vehicles has a central pressure source and a hydraulic system which includes pressure medium lines, electrically controllable hydraulic valves, and pressure medium orifices. A pressure sensor is located at the outlet of the pressure source. The braking pressure in the wheel brakes (P.sub.Rb) is established from the measured values (P.sub.meas), determined by the pressure sensor, and from the hydraulic conductance (D) of the orifices of the hydraulic system in accordance with formulaP.sub.Rb f (D,P.sub.meas).

Abstract: In a brake system with a controllable hydraulic pump in a hydraulic circuit, and with at least one solenoid valve, the operating state of the valve is changed in response to a control signal. As a result of the change in the operating state of the solenoid valve, the flow resistance in the hydraulic circuit is changed. Monitoring structure is provided which, in the presence of certain operating conditions, monitor the run-down behavior of the hydraulic pump in different operating states of the solenoid valve and actuate a display device to display a malfunction of the brake system when a malfunction is detected. Additionally, or alternatively, the automatic brake control can be turned off in reaction to the detection of a malfunction. It is possible for the control unit and the hydraulic unit to be replaced separately and for the installation to be tested for proper functioning.

Abstract: A method and a device for electronically controlling or adjusting a brake system of a vehicle is proposed, in which brake system the characteristic braking curve of the trailer is adapted to a prescribed characteristic braking curve of the towing vehicle, in order to minimize the longitudinal forces between a towing vehicle and a trailer during a braking process, in such a way that the braking of the entire road train takes place in accordance with the prescribed characteristic braking curve of the towing vehicle.

Abstract: A power-assisted brake system which can be activated by a pedal including a travel simulator and a desired value transmitter which is coupled thereto and a second sensor which can be used alternatively as a desired value transmitter. The second desired value transmitter is a pressure transmitter. The signals of both desired value transmitters are monitored in an electronic control unit for essentially corresponding signal values. If there is an unacceptable difference in signal value, power-assisted braking operation is suppressed. Braking is then possible by an emergency brake cylinder. The power-assisted brake system can be used for motor vehicles for passenger transport and goods transport, in motor vehicles which are equipped with an anti-lock brake system (ABS) or with a traction control system (TCS).

Abstract: A brake system for automotive vehicles with electric drive is operable by an actuating pedal and uses hydraulic friction brakes to augment the braking effect generated by the electric drive motors. The coaction of the drive motors with the hydraulic friction brakes is controlled by an electronic controller. In order to largely conform the pedal characteristics of the mentioned brake system to that of a standard passenger car, an actuating pedal (5) is in force-transmitting and travel-transmitting connection with a spring (8) exhibiting a predetermined characteristic curve, and the master brake cylinder (11), uncoupled from the actuating pedal (5), is operable by an electromagnet (9) which is responsive to the controller (70). If the master brake cylinder accommodates two pressure cheers, a single valve is arranged in or on the master cylinder housing, and acts as both a bypass valve and a differential-pressure valve.

Abstract: The instant invention is a positive shutoff valve for use on emergency vehicles so as to maintain air within a reservoir tank allowing immediate movement of an emergency vehicle upon start up. The shutoff valve is operated by a switch located in the operator's compartment of the emergency vehicle providing movement of a solenoid located in the shutoff valve which is biased in a normally closed position. A manual bypass lever is provided should the electric solenoid fail to operate correctly. The shutoff valve positively maintains air within the reservoir tank and is monitored by a low pressure switch and alarm sensor which will indicate low air pressure in the reservoir tank even when the vehicle is in an off position.

Abstract: A system is disclosed to selectively initiate braking at a rear section of a railway train upon initiation of a selected front braking condition at the front section of the railway vehicle. The system utilizes an air sensor preferably constructed in the form of an insect excluder device to detect release of brake pipe air from an exhaust port upon initiation of braking at the front section of the vehicle. An appropriate signal is produced by the air sensor, thus permitting detector circuitry to detect that front braking has been initiated. A transmitter, typically located in the cab of the locomotive, is electrically connected to the detector circuitry. When the detector circuitry indicates that the selected front braking condition has been initiated, the transmitter transmits a brake initiation signal to a receiver located at the rear of the vehicle. The receiver then actuates pneumatic braking equipment at the rear to initiate rear braking.

Abstract: A system and method of calibrating pressure transducers in an electro-pneumatic brake system for a railroad train in which a locomotive microprocessor generates a respective best fit curve for the train brake pipe, supply reservoir and brake cylinder pressures that approximates the actual train pressure therefore. These best fit curves are generated from the pressure transducer readings of these pressures at each car by employing an equation based on a fourth order polynomial. Each car is then provided with a theoretical reference pressure signal from the best fit curve for each of the mentioned brake pipe, supply reservoir and brake cylinder pressures, according to the position of the car in the train. The theoretical reference signal is then compared at each car with the car pressure transducer reading for the respective brake pipe, supply reservoir and brake cylinder pressures to obtain a transducer error correction factor that remains constant through a full range of pressures.

Abstract: A system is disclosed to selectively initiate braking at a rear section of a railway train upon initiation of a selected front braking condition at the front section of the railway vehicle. The system utilizes an air sensor preferably constructed in the form of an insect excluder device to detect release of brake pipe air from an exhaust port upon initiation of braking at the front section of the vehicle. An appropriate signal is produced by the air sensor, thus permitting detector circuitry to detect that front braking has been initiated. A transmitter, typically located in the cab of the locomotive, is electrically connected to the detector circuitry. When the detector circuitry indicates that the selected front braking condition has been initiated, the transmitter transmits a brake initiation signal to a receiver located at the rear of the vehicle. The receiver then actuates pneumatic braking equipment at the rear to initiate rear braking.

Abstract: A work brake system applies a reduced air pressure service brake application as a work brake to hold a heavy duty vehicle in place without actuation of conventional spring brakes during frequent start-and-stop operations of the vehicle, such as in refuse collection. The work brake system includes fail safe features to prevent vehicle roll in the event of loss of air pressure, by providing separate primary and secondary sources of pressurized air, and by automatically diverting to application of spring brakes in the event of primary pressure or signal loss.

Abstract: A brake system for automotive vehicles with electric drive is operable by an actuating pedal and uses hydraulic friction brakes to augment the braking effect generated by the electric drive motors. The coaction of the drive motors with the hydraulic friction brakes is controlled by an electronic controller. In order to largely conform the pedal characteristics of the mentioned brake system to that of a standard passenger car, an actuating pedal (5) is in force-transmitting and travel-transmitting connection with a spring (8) exhibiting a predetermined characteristic curve, and the master brake cylinder (11), uncoupled from the actuating pedal (5), is operable by an electromagnet (9) which is responsive to the controller (70). If the master brake cylinder accommodates two pressure chambers, a single valve is arranged in or on the master cylinder housing, and acts as both a bypass valve and a differential-pressure valve.

Abstract: A large articulated vehicle, such as a tractor semi-trailer truck often has a number of braking locations each having a number of brake sites. To properly balance the work performed at the various brake sites in decelerating the vehicle, it is necessary to determine the relative brake factors of each site. The brake factors characterize the braking performance for a particular delivered braking pressure. A system and method for determining the relative brake factors for such a vehicle is provided. The vehicle is decelerated at a known rate while delivered braking pressure is measured and recorded for each braking location. A system of simultaneous equations is then solved to determine the relative brake factors. Once the brake factors have been determined during a sequence of controlled braking events, subsequent braking may be modified to achieve a work-balanced braking mode.

Abstract: A hydraulic motor vehicle brake system having anti-skid system and further developed to improve vehicle tracking, especially during cornering by means of automatic braking. With automatic braking an auxiliary pressure source delivers a pressure medium to an anti-skid system, by means of which braking pressures can be individually adjusted in the wheel brakes. For this purpose a cylinder with separating piston sections is located between the auxiliary pressure source and the anti-skid system, wherein the separating piston is installed into 2/2-way valves including lip sealing rings. The embodiment in accordance with the invention include cylinders, with valve openings in cooperation with the lip sealing rings, which results in economical 2/2-way valves.

Abstract: An operating brake valve for an electrically and pneumatically actuated braking system in a motor vehicle has a movable thrust piece (2) arranged within a housing (1) and a balance piston (4) actuated via a graduated spring (3), whereby a combined inlet/exhaust valve (7, 9, 10) is arranged downstream of the balanced piston. A position sensor (20) is provided which can be actuated via a push rod (17) connected to the thrust piece (2). A stop valve (29) is located in the connecting line (26) to the reservoir (12) or in the control line (15) coming from the balance chamber, whereby an electrically controlled solenoid valve (40) is provided for actuating the stop valve and, in the nonexcited state, for relieving the valve body of the stop valve (29) opposite to its closing direction.

Abstract: A brake fluid distribution control system for use in closed antilocking brake systems includes a switch in communication with low pressure accumulators for cyclically activating pumps that evacuate the low pressure accumulators of brake fluid under desired conditions. The method associated with this invention can be implemented by providing an indicator for indicating the amount of fluid within the accumulator and a switch for cyclically activating the pump when the fluid within the accumulator reaches a preselected capacity level. Alternatively, the antilocking brake system electronic controller is provided with appropriate software for cyclically activating the pump that evacuates the accumulators under preselected conditions.

Abstract: The electrohydraulic or electropneumatic braking-control device for axles of trailers having mechanical brakes includes a hydraulic or pneumatic circuit mounted on the trailer, made up principally of a pressure accumulator, the internal pressure of which is automatically adjusted above a minimum value, as well as of a control gate, the opening of which is proportional to a control current function of the pressure exerted on the brake pedal of the tractor vehicle and of an adjustment carried out as a function of the load of the trailer. In case of attachment parting or of unhitching of the trailer, the disconnection of the connection plug actuates a safety valve that automatically controls the energetic braking of the trailer. The safety valve includes a manual control. It is possible to unbrake, then to rebrake the trailer in order to maneuver it. The trailer braking device may be mounted from the outset or subsequently, requiring only few transformations of the tractor vehicle.

Abstract: An anti-theft device is coupled in series with a supply line and a service line of a trailer. When activated, the anti-theft device prevents theft of the trailer by decoupling the supply and service lines of the trailer from the reservoir and brake cylinders of the trailer, and by coupling the supply and service lines to the atmosphere, thereby preventing a prospective thief from releasing the trailer's brakes by restoring air to the supply and service lines. When the anti-theft device is deactivated, the supply and service lines are re-coupled to the reservoir and brake cylinders to allow the driver to release the trailer brakes.

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 source for a pressure device includes a pump for pumping fluid from fluid tank, an accumulator connected to the pump and a pressure device, a device for detecting the pressure in the accumulator, and a controller for controlling the operation of the pump in an ON-OFF manner on the basis of a result of detection by the pressure detecting device. In this pressure source, the controller includes first and second drive signal generating circuits each capable of independently generating a drive signal for determining the on-off operation of the pump, and a judging circuit which has a calculating function therein and to which at least the pressure detecting device is connected. The judging circuit is connected to the first drive signal generating circuit, and the pressure detecting device is connected to the second drive signal generating circuit.

Abstract: In a vehicle brake system having braking control responsive to a pressure signal from a pressure transducer in a hydraulic brake line, a method of operation comprising the steps of: (a) determining whether a brake pedal is depressed; (b) when the brake pedal is determined to be depressed: (i) controlling the brake system responsive to the pressure signal and a stored offset value for the pressure transducer, and (ii) resetting a timer; (c) when the brake pedal is determined to be not depressed: (i) cycling the timer, (ii) determining whether the timer has timed out, and (iii) if the timer has timed out, (iii.i) receiving the pressure signal from the pressure transducer, (iii.ii) comparing the pressure signal to a predetermined limit value indicative of an acceptable maximum sensor output when the pedal is not depressed, and (iii.iii) updating the stored offset value responsive to the pressure signal.

Abstract: A brake controlling apparatus in an electric vehicle comprising a hydraulic brake including a fluid pressure generating and applying device having a characteristic in which the fluid consumption rises in the fluid-pressure range of 0 to P.sub.0, and brakes the driving wheels by the fluid pressure of the fluid pressure applying device. A regenerative brake brakes the driving wheels by the regeneration of the power of a driving motor. A fluid flow cut-off device cuts off the flow of hydraulic fluid from the fluid pressure generating device to the fluid pressure applying device when the fluid pressure of the fluid pressure generating device exceeds P.sub.0. A fluid flow inducing device induces the flow of hydraulic fluid from the fluid pressure generating device to the fluid pressure applying device while maintaining the pressure difference between the fluid pressure generating and applying devices when the pressure difference exceeds .DELTA.P.sub.r.

Abstract: A first target value is set as an initial value of split point pressure, a master cylinder pressure is set as a second target value of split point pressure in a memory when ABS valves (17, 20, and 23) are operated, thereafter when a sign of locking of the rear wheels is detected, the target value is reduced even further and set in the memory, the target value is maintained for a predetermined time by timer control at every setting of a new target value, and when a braking deceleration generated while the target value is maintained in the memory, a controller (37) controls so that the target value is increased after the completion of braking. When the master cylinder pressure is higher than the target value stored in the memory, proportioning valves (26 and 27) are closed to decrease a ratio of the rear wheel braking force to the front wheel braking force, thereby always achieving appropriate control over the rear wheel braking force allocation.

Abstract: A system and method of controlling pressure in a wheel brake cylinder of a brake. The hydraulic cylinder is connected to an electrically driven pump and a flow control valve is connected between the pump and the wheel cylinder. The system and method operate to control the speed of a motor driven pump to generate a desired pressure in a cylinder of the brake; generate a differential pressure, in the flow control valve, proportional to pump flow and communication same to a spring biased valving element; cause the valving element to move, in response to pressure forces acting on the valving element, generated by the pressure differential, and the force of the bias spring, so as to selectively open and close an associated exhaust port, connected to a drain or sump, such that in the steady state an equilibrium condition is achieved where the pressure forces balance the spring force and the pressure in the hydraulic cylinder is constant.

Abstract: A braking apparatus for a motor vehicle equipped with a master cylinder and a wheel cylinder. The apparatus further includes a pump coupled to a reservoir tank to suck a braking liquid from the reservoir tank and pressurize and discharge the sucked braking liquid when a slip of the wheel occurs at the time of driving the wheel, a pressure adjusting valve provided in a pipe coupling a discharge side of the pump to the reservoir tank and arranged to be openable to restrict the discharge pressure of the pump to a predetermined value, and a change-over valve for establishing a communication between the discharge side of the pump and the wheel cylinder when a slip of the wheel occurs at the time of driving the wheel and for establishing a communication between the master cylinder and the wheel cylinder when the slip does not occur.

Abstract: A process for determining the wheel slip of individual wheels of a vehicle by time sequentially measuring the speeds of a particular wheel without braking force applied and with braking force applied.

Abstract: A brake control system mounted in an electrical vehicle for controlling a hydraulic brake and a regenerative brake. The hydraulic brake generates a hydraulic pressure depending on an amount of depression of a brake pedal so as to mechanically brake at least drive wheels. The regenerative brake brakes the drive wheels due to a regeneration of a running motor. A reducing valve is provided in a hydraulic pressure transmission path to the drive wheels to be braked by the hydraulic brake. The reducing valve is opened when the hydraulic pressure genrated in a cylinder is at least a valve open value to allow a hydraulic pressure transmission to drive wheel pipings. An ECU calculates a regenerative torque command value depending on a pressure difference between the front and rear of the reducing valve, detected by a sensor, and controls the regenerative brake on the basis of the regenerative torque command value.

Abstract: A fluid pressure braking system for a tractor trailer vehicle includes a supply line connecting the tractor and trailer braking systems. A low pressure responsive switch responds to the pressure level in the supply line for actuating a warning device when the pressure level in the supply line drops below a predetermined pressure level to thereby warn the driver before a brake actuation is effected that a low pressure level exists in the trailer braking system. A normally open stoplight switch is connected in series with the low-pressure responsive switch so that the signal generated by the low-pressure responsive switch is prevented from actuating the warning device when the tractor is operated in the "bobtail" mode without a trailer.

Abstract: The proposed brake system eliminates breather bores and central valves in the working pistons of the master brake cylinder and establishes short-term pressure fluid connections between the supply reservoir and the working chambers when the brake is not applied by controlling replenishment valves and outlet valves. Therefore, connection of the supply reservoir to the working chambers of the working cylinder is constituted solely via electromagnetically controllable connections.

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 (20) comprising: a master cylinder (26) and a pump (12) for selectively pressurizing an associated brake cylinder or cylinders; a motor (14) for powering the pump; a control circuit (16,90) for modulating motor speed in response to a signal indicative of desired braking effort and actual braking effort; and a control valve (30) responsive to master cylinder pressure for controlling pump flow and for permitting the decay of pressure in the brake cylinders.

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: The present invention provides a method of and an apparatus for regulating an electrically regulated brake circuit of a multi-circuit brake mechanism with pressure medium activated brakes. To decrease the expense of such multi-circuit brake mechanism, the invention transforms the pressure, modulated by the brake actuating mechanism, to an electrical signal and regulates or co-regulates the electrically regulated brake circuit (II) by this electrical signal.