Abstract: In an anti-lock vehicle braking system the brake pressure acting at the controlled wheel is controlled in such a manner that the threshold value with respect to the rotational retardation of the wheel at the beginning of a lowering or raising of pressure is increased briefly, during a control cycle, by a constant amount (S.sub.H -S.sub.G) with respect to a threshold base value (S.sub.G) in order to avoid any undesired control operations caused especially by axle vibrations, pot holes, and the like. The threshold value is then decreased in response to the period of time of the pressure reduction in the preceding control cycle. The decreasing of the threshold value is carried on to values S.sub.T below the threshold base value and maintained for a given time interval (t.sub.x -t.sub.y).

Abstract: An anti-locking brake system is described in which pressure drops produced in the event of rapidly succeeding wheel retardations and wheel accelerations are restrained. This is achieved by a summing circuit having a sum to which a numerical value is added; the sum is reduced according to a given function. The sum value present in each case is a measure of how the pressure reduction is to be restrained, for example, by raising thresholds.

Abstract: A method of controlling the brake pressure in an antilock (ABS) vehicle brake system provides for adapting the wheel at which the brake is applied to the optimum course of the coefficient of friction/slip curve by determining the rotational retardation of the braked wheel, upon initiation of a braking action, after given time intervals each and comparing it with the rotational retardation of the preceding time interval. Moreover, the brake pressure is varied in response to the result of the comparison. The renewed acceleration of the retarded wheel also is monitored accordingly so as to effect further lowering of the brake pressure if the renewed acceleration or the gain in acceleration is too small.

Abstract: An anti-lock system for controlling the slip level on one or more wheels of a vehicle by comparing the actual wheel speed with a vehicle reference speed obtained by processing wheel speed signals through a filtering system, the filtering system comprising a selection device which produces an input signal from one or a combination of the wheel speeds, an error forming device which subtracts the required vehicle speed estimate from the input signal to produce a speed error, a non-linear device which is effective to limit the slew rate of the filtering system in both positive and negative directions in accordance with vehicle characteristics, a secondary filter which reduces transients present in the error signal, and an integration device which accumulates the error signal and whose output is fed back to the error forming device as the required vehicle speed estimate.

Abstract: An antiskid device according to this invention controls the hydraulic pressure to vehicle brakes based on the rotational speed of the wheel having the smallest coefficient of friction until a standard vehicle velocity becomes less than a predetermined velocity. Further, the antiskid device controls the hydraulic pressure to the brakes based on the speed of each wheel if the standard vehicle velocity becomes less than the predetermined velocity. Accordingly, directional stabilization of the vehicle is maintained when the vehicle runs at high speed, and at low speed, the braking range for stopping the vehicle is mainimized by utilizing the braking force more efficiently.

Abstract: An antiskid control device including a vehicle speed estimating device for estimating a vehicle speed from a plurality of wheel speeds of the driven and undriven wheels of a motor vehicle. The vehicle speed estimating device includes a first comparator for comparing the speeds of the wheels, a storage for temporarily storing the estimated vehicle speed or an ultimately selected wheel speed, a second comparator for comparing the speed stored in the storage with the speeds of the driven wheels and a storage updating device for causing, at the time when antiskid control has been started, the storage of the estimated vehicle speed obtained at the time or the ultimately selected wheel speed obtained at the time.

Abstract: In an anti-lock brake control system for a vehicle (1) equipped with tandem axles (3), incipient or actual lockup is sensed on the forward or more lightly loaded axle (10) of the tandem axle pair, which sensing gives early warning of incipient lockup of the rear or more heavily loaded axle (12) of the pair.

Abstract: A antilock brake system utilizes a microprocessor controller to monitor the rate of speed decay of a braked wheel of a vehicle and to cause release of braking force under incipient wheel lock-up conditions. The microprocessor receives a single digital wheel speed input signal and processes the latter in accordance with a program whereby a reference signal is generated and is periodically compared with the wheel speed signal to determine if a lock-up condition is in progress. The microprocessor compares the speed signal with the reference signal at frequent sampling intervals and when the wheel speed decreases at a rate exceeding a desired value, the reference signal is varied by the microprocessor to decrease at a predetermined first rate of decrement until the wheel speed signal and the reference signal correspond to each other, indicating that the wheel speed is dropping at a rate in excess of a desired rate of speed decay.

Abstract: A vehicular anti-lock control method including the steps of comparing a wheel speed with a reference value which is based on a vehicle speed estimated from the wheel speed, judging the locking tendency of a wheel from the result of such comparison and reducing a brake pressure to be applied to the wheel which is on the way to locking, a first vehicle speed is estimated based on the speed of a wheel including a driving wheel and a second vehicle speed is estimated based on the speed of a follower wheel, the driving wheel being judged to be in a racing state when the first vehicle speed is larger than the second vehicle speed above a predetermined value. When the driving wheel is racing, the first vehicle speed is held constant and as far as such racing is present the constant vehicle speed is used to determine the reference value for comparison with the wheel speed.

Abstract: Rotational speed of a vehicle wheel is detected. An actuator serves to brake the vehicle wheel. A braking condition of the actuator is derived. Speed of a vehicle is derived from the detected vehicle wheel speed and the derived braking condition of the actuator. The actuator is controlled in accordance with the detected vehicle wheel speed and the derived vehicle speed.

Abstract: An anti-skid control apparatus for a vehicle braking system includes first and second fluid pressure control valve devices for controlling the brake fluid pressure of the wheel cylinders of the front and rear wheels each arranged between respective fluid pressure generating chamber of a tandem master cylinder and the associated wheel cylinder of the associated front or rear wheel; first and second wheel speed sensors associated with the front or rear wheels, respectively; and a third wheel speed sensor associated in common with the rear or front wheels.

Abstract: An anti-skid control apparatus for diagonally connected vehicle wheels including control valve devices arranged between fluid pressure generating chambers of a tandem master cylinder and the wheel cylinders of the front wheels, respectively, and a control unit receiving outputs of speed sensors for judging the skid conditions of the wheels and for instructing the control valve devices. The control unit determines the frictionally lower side of the road on which the wheels are running, and combines logically the judging result of the skid condition of the rear wheel running on that side of the road, with that of the front wheel running on that side. The apparatus then generates instructions for controlling the first or second valve device for the corresponding front wheel, and for controlling the second or first valve device for the other front wheel, on the basis of judging the skid condition of the other front wheel running on the other side of the road independently of the rear wheels.

Abstract: An anti-skid control system for motor vehicles is provided wherein a computed wheel speed Vv is set up on the basis of the highest one of the wheel speeds of the motor vehicle; a first reference speed VT1 and a second reference speed VT2 are set up which are lower than and follow the computed vehicle speed Vv either with a first and second predetermined speed difference respectively or with a first and a second predetermined ratio respectively, the first reference speed VT1 being higher than the second reference speed VT2 (VT1>VT2); in the case where the wheel speed continues decreasing with a deceleration lower than a predetermined threshold level of deceleration, reduction of brake pressure is started at a point of time when a predetermined time period T1 elapsed from a point of time when the wheel speed reached the level of the second reference speed VT2; and the reduction of the brake pressure is stopped at a point of time when the wheel speed was increased up to the level of the first reference speed

Abstract: An anti-skid control vehicle braking apparatus with pairs of front and rear wheels; wheel speed sensors associated with the wheels; first and second fluid pressure control valve devices for respectively controlling the brake fluid pressure of the wheel cylinders of the front wheels; a control unit receiving outputs of the wheel speed sensors for measuring or judging the skid conditions of the front and rear wheels and for generating instructions for controlling the fluid pressure control valve devices; and a valve apparatus for generating a fluid pressure in accordance with the lower one of the brake fluid pressures of the front wheels controlled with the control valve devices, being arranged between the front wheel cylinders and rear wheel cylinders the control unit discriminates the frictionally lower one of the sides of the road on which the wheels are running, on the basis of the measuring or judging results of the skid conditions of rear wheels, combines logically the measuring or judging results of the

Abstract: There is disclosed herein a braking system for use in safely reducing the speed and stopping movement of vehicles, such as cars or trucks, or airplanes, by minimizing brake failure due to heat build-up and by providing auxiliary braking capacity. The system includes primary and secondary brake sections associated with weight-supporting and braking wheels, temperature sensors for sensing the temperature in each brake section, friction force sensors for sensing frictional forces in each section and pressure sensors for sensing hydraulic or pneumatic pressure. Controls receive the sensed temperature, friction forces and pressures and selectively activate, individually or in combination, the primary and secondary brake sections. The controls include an apparatus for comparing the measured pressure, friction forces and brake temperatures with predetermined values and automatically operating the braking system in response to those comparisons.

Abstract: An escalator having improved brake control, to limit the rate of deceleration immediately following a stop command, and to quickly cause the actual speed of the escalator to closely follow a linearly declining speed ramp of a speed pattern signal. The signal controlling the brake is pulse duration modulated such that the brake responds to the average pulse duration, and braking torque is applied gradually and essentially linearly. The reference speed pattern has a substantially constant portion and a declining ramp portion. To limit the initial deceleration, the constant portion of the speed pattern is controlled to be a function of the actual speed signal, and the declining ramp portion of the reference signal is controlled to start when the actual speed is equal to the constant portion of the reference speed signal.

Abstract: The braking control system includes a generator for generating a first electrical control signal, a controllable fluid source suitable for delivering the fluid at a predetermined pressure at an outlet from the source, a slide valve for connecting the outlet of the source to a brake actuator, a circuit for measuring the value of the pressure at the outlet from the source, a circuit being suitable for delivering a second signal having a value representative of the measured pressure, and a controller for controlling the source of fluid as a function of the first and second signals in such a manner that the fluid pressure at the outlet from the source has a value which is a function of the first signal as corrected by the second signal.

Abstract: In an antiskid control system, first and second wheel speed values are derived from pulse signals supplied from wheel speed sensors to indicate respectively the rotational speeds of first and second wheels of the vehicle. A trimming value is derived from the difference between the first and second wheel speed values and used as a multiplier by which the first wheel speed value is multiplied to compensate for the deviation of the speed of the first wheel with respect to the speed of the second wheel. The compensated first wheel speed value compared with a variable threshold that is a function of the speed of the vehicle to determine the down pressure timing.

Abstract: An antilock braking apparatus is disclosed which is constructed so as to operate by way of the steps of detecting wheel speed signals from each of wheels and thereafter releasing antilock control in dependence on a value of difference in the level of wheel speed signals arbitrarily selected. The apparatus makes it possible to detect the existence of a tire having a smaller diameter such as provisional tire or the like if any and moreover to inhibit an occurrance of malfunction of the apparatus due to the existence of such a smaller diameter tire while maintaining required braking force.

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

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

Abstract: In an antilock system for vehicle brake control, the wheel having the worst road contact is disregarded and the remaining wheel brake pressures are regulated in accordance with the "select-low" principle. In a brake system which is divided into two circuits each controlling diagonally opposite wheels, the circuit containing the minimum contact wheel is regulated according to "select-low". In this way, the assignment of the wheel to the group regulated at select-high will be optimized.

Abstract: A braking system for a mobile medical diagnostic device having forward support wheels operatively associated with proportional electromechanical brakes and a single central steerable wheel assembly at the rear of the device. Means are provided for generating throttle command signals and actual velocity signals and for comparing the two and for applying current to the proportional brakes to a degree which is proportional to the difference in those two signals. When this difference exceeds a predetermined level, a motor brake is further actuated to augment the proportional braking system. Also included is a means for automatically reducing the throttle command signal in proportion to the degree that the steerable wheel assembly is turned from the straight-ahead position.

Abstract: A braking system utilizing a hydrodynamic brake has a control circuit that adjust the torque exerted by the hydrodynamic brake to adjust the deceleration of the axle on which the hydrodynamic brake is mounted toward a desired value of deceleration, which desired value may be zero.

Abstract: Brake control systems and methods particularly suited for small trailers and the like wherein the angular velocity of each wheel in a selected pair of wheels is sensed and compared against each other to develop a control signal representing the differential in angular velocity between the respective paired wheels. In a skid control embodiment, while the brakes are being applied by the operator, the system automatically releases the brakes at both wheels in proportion to a velocity differential between the wheels indicating an impending skid. In the case of a trailer equipped with a sway control embodiment, the system automatically applies the brakes at both wheels in proportion to the wheel velocity differential representing excessive trailer sway. The respective skid control and sway control embodiments are useful alone or in a combined system.

Abstract: A system is disclosed for monitoring operation of a speed sensor which produces a pulse signal with a repetition frequency related to the speed being sensed.An analogue speed signal is derived from a pulse signal having a repetition frequency related to the sensed speed and is fed to an integrator which, under the control of the pulse signal, performs successive separate integrating operations on the analogue speed signal in the periods between successive pulses, and a comparator compares the integrated sum thus produced with a reference value corresponding to a limit for normal generation of pulses, to produce a warning signal if the integrated sum exceeds the reference value. The system may include a timer to respond to successive warning signals and produce a malfunction signal if they occur with less than a predetermined time interval between them.

Abstract: A vehicle skid control braking system of the type that includes circuit components for generating a signal varying in accordance with braking conditions, such as vehicle speed, wheel speed and road surface conditions. The vehicle skid control braking system includes a ramp generator responsive to the signal generating circuitry, wherein the ramp generator has a charge storage device for storing a charge proportional to the varying signal, control circuitry having an output signal varying between first and second valves, and a discharge circuit for discharging the storage device at a controlled rate to a level determined by the varying of the output signal of the control circuitry from the first value to the second value. The ramp generator produces an output current that varies inversely with vehicle speed.

Abstract: A signal corresponding to the difference between wheel and vehicle speeds is generated when this difference exceeds a first predetermined value and this difference signal is stopped when the difference decreases below a second predetermined value. The difference signal is integrated linearly upwardly until the difference signal decreases to the second predetermined value at which point it is integrated linearly downwardly. An auxiliary signal is generated when the integrated signal is above a third predetermined value. An anti-locking signal is generated in response to the generated difference signal to release the vehicles brakes and this anti-locking signal is continued to be generated until both the difference signal and the auxiliary signal cease and at that point the brakes are again applied.

Abstract: An electronic antiskid control device which comprises a frequency multiplier of the phase locked-loop type, which receives repetitive pulses of predetermined frequency representing the speed of one wheel. The phase locked-loop multiplier normally outputs a second pulse signal, the frequency of which is normally equal to the frequency of the wheel speed signal multiplied by a given number. A digital counter which is periodically reset at a frequency equal to that of the wheel speed signal measures the number of pulses of the second pulse signal during each period. The measured number is transfered into a memory element and calculating apparatus responsive to the value stored in the memory element control an antiskid cycle. In operation under normal conditions, the number stored in the memory element is constant and has no action on the calculating apparatus.

Abstract: In a skid control system a pressure modulator reduces the pressure applied by a master cylinder to a wheel cylinder when the wheel velocity as measured by a wheel detector decreases faster than a deceleration predetermined by a deceleration control. A control unit which regulates the pressure modulator corrects the predetermined deceleration when the wheel has exceeded the slip ratio at which the coefficient of friction is maximum so as to achieve an optimum deceleration that corresponds to the road surface condition. The control unit induces the pressure modulator to reduce the pressure of the brake fluid and restore the wheel velocity when the coefficient of friction of the wheel reaches the maximum. Emergency braking is thus performed with an average slip ratio at which the coefficient of friction is maximum.

Abstract: A brake control system for vehicles in which the difference in speed of rotation of a corresponding pair of wheels is detected in a prebraking mode of operation. If the difference in rotational speed exceeds a predetermined amount, the brakes on the pair of wheels are disabled. In one embodiment of the invention, the prebraking rotational speed ratio of the pair of wheels is determined by a comparator and electronic voltage control circuit, and the electrical output thereof fed to a valve control circuit for controlling the brake valves to maintain the braking rotational speed ratio of the wheels substantially equal to the prebraking rotational speed ratio.

Abstract: An improved anti-skid system for a vehicle which effectively utilizes an approximated slip ratio between vehicle or body velocity and wheel velocity to generate a brake release signal for a brake release valve but without actually utilizing a vehicle or body velocity detector. Storage apparatus is used to store a reference signal representing vehicle velocity but actually corresponding to a present or just past maximum value of wheel velocity. Control apparatus is then utilized for removing energy from the storage apparatus at a controlled predetermined rate chosen to approximate the expected vehicle deceleration (but without using an actual vehicle or body deceleration detector) such that the reference signal (capacitor voltage) will continue to accurately represent approximate vehicle velocities even during periods of deceleration.

Abstract: A method for predicting vehicle speed in a braking control system for wheeled vehicles, where a signal representing wheel speed before braking is used to trigger charging of a capacitor in an electronic unit. The capacitor voltage is reduced during braking in response to a predetermined retardation value in order to correspond to an instantaneous value for the vehicle speed. The vehicle speed signal is compared with a wheel speed signal, which comparison triggers, when the wheel speed signal exceeds the vehicle speed signal, up-dating of the capacitor voltage level to a value corresponding to the actual wheel speed signal. When up-dating the vehicle speed signal, the preselected retardation value is gradually lowered by a value corresponding to the magnitude of the actual up-dating.

Abstract: The present invention is a brake actuating and brake system for maintaining a predetermined proportional relationship between the rotational speeds of vehicle wheels by both applying and/or releasing hydraulic fluid brake pressure, and distributing released pressure back into the brake system.

Abstract: A vehicle controlling device wherein an output signal proportional to vehicle velocity obtained from a vehicle velocity detector and an output signal proportional to wheel velocity obtained from a wheel velocity detector are to be compared by a comparator and the slip state of the wheel is to be detected from the result of the comparison, thereby to control a brake mechanism, characterized in that an adder circuit is provided which adds an output signal proportional to a predetermined wheel velocity at a low vehicle running speed to the output signal obtained from the wheel velocity detector and that the output signal of the adder circuit and the output signal from the vehicle velocity detector are compared by the comparator to ensure accurate brake control at all vehicle speeds.

Abstract: The inventive system comprises a magnetic pulse generator mounted on each axle of a railroad car. The outputs from the resulting pulse generators are fed to a detector which compares the speeds of the axles. When wheel slip indicated by a pulse count difference between axles is encountered, the detector operates solenoid-operated dump valves to increase brake pressure on both axles of the slipping axle truck. When axle speed recovers to a non-slipping condition, the dump valves are reset and brake pressure is reduced. The detector circuitry is also able to detect wheel slide thus permitting corrective action. In addition to the above, the system includes provision to prevent synchronous sliding of all axles by sensing the rate of change of count.

Abstract: In X-ray examining apparatus in which a compression counterweight is uncoupled in the vertical position, a problem exists in that, when the examining apparatus is turned over, the compression counterweight is coupled to the X-ray image section with a jolt. So as to avoid this jolt, pneumatic damping devices are known which, however, are very voluminous. According to the invention, a simple and efficient device for the damped coupling comprises a control circuit which brakes the counterweight when it exceeds a given speed.

Abstract: An anti-skid control system for an automotive vehicle comprising apparatus for inhibiting the operation of anti-skid apparatus in a vehicle speed range lower than a predetermined value at which the full braking force can be imparted to the wheels without giving rise to any danger, so that the anti-skid control system can operate with improved reliability.

Abstract: The present invention refers to an electronic control device applicable to anti-skid equipment in automobile vehicles which compares the speed of the wheel with a voltage corresponding to the level of optimum vehicle-wheel slip. On the basis of the result of this comparison, the device operates an actuating system that increases or decreases the pressure on the brakes with the aim of maintaining the slip of the wheel around the skid for which maximum adherence is presented.

Abstract: An anti-skid control system for preventing skidding of a vehicle caused by the braking of the vehicle while it is in motion in the system when a vehicle speed signal generated from vehicle speed detecting apparatus becomes lower than a predetermined value, discriminating apparatus generates a discrimination signal and the braking pressure applied to the wheel is modulated through limiting apparatus including a logical gate and controlled by the discrimination signal. On the other hand, when the vehicle body speed becomes lower than a predetermined value, the generation of the discrimination signal is prevented by a deceleration sensor, thus suitably controlling the braking pressure in accordance with the surface conditions of the road.

Abstract: An anti-skid control system for vehicles wherein, in view of the fact that while it is desirable for a vehicle anti-skid control system to detect the speed of the vehicle body and the speed of the wheel to positively prevent the skidding of the vehicle, it is very difficult to detect the speed of the vehicle body, a plurality of control patterns for decreasing the wheel speed to prevent the locking of the wheels under an excessively large braking pressure are predetermined, whereby the selection among the control patterns is effected according to the conditions of the road surface detected by a vehicle body deceleration sensor and a reference wheel speed according to the selected control pattern is compared with the actual wheel speed to forcibly reduce the braking pressure when there is a tendency for the wheels to lock, thereby preventing the locking of the vehicle and hence the skidding of the vehicle without detecting the speed of the vehicle body.

Abstract: Aircraft velocity information signals are utilized to provide a brake release signal to one or more, but not more than half of the wheels in each locked wheel set e.g. the two rear wheels in a four wheel set on a gear, so that if all braked wheels lock up and hydroplane, the brake relase signal holds half the brakes released and when the released wheels come out of hydroplaning and spinup, then they, in turn, provide conventional locked wheel protection to the remaining wheels in the same locked wheel set.

Abstract: An electronic antiskid control unit for an adaptive braking system of the speed reference type wherein a signal for controlling decay of pressure is generated in response to comparison of the wheel speed signal with another signal. In a first phase, the wheel speed signal is compared with a reference signal derived from the wheel speed signal for generating the decay signal as long as the wheel speed reference signal is greater than wheel speed signal. At the end of this first phase, the wheel speed and speed reference signals have the same value and the speed reference signal is overridden by another increasing signal for comparison with the wheel speed signal thereby increasing duration of the decay. The other signal has three portions and is derived from a base signal having an exponential characteristic. At the end of the third portion, corresponding to intersection of the other signal with the wheel speed signal, the decay signal is extinguished.

Abstract: A hydrodynamic brake system wherein the extent to which the working chamber between the rotor and stator is filled with braking liquid is regulated by a valve which is adjustable by a measuring device having an overflow line communicating with two spaced-apart portions of the working chamber and containing two flow restrictors. The end portions of the overflow line are positioned in such a way that a continuous stream of liquid flows through the overflow line when the rotor is driven. At least one of the flow restrictors is adjustable so as to insure that the pressure of liquid in the overflow line between the flow restrictors is indicative of the real braking action of the system. Such pressure is used for adjustment of the valve to thus insure that the extent to which the working chamber is filled varies in response to changes in rotational speed of the rotor so as to guarantee a reproducible progress of the braking action.

Abstract: A skid control system for fluid-actuated brake of a wheeled vehicle which comprises a release and reapplication signals generator for producing a release signal or a reapplication signal, a wheel velocity sensor, an actuating circuit for producing an actuating signal in accordance with the release signal, a reference wheel velocity signal generator for producing a reference wheel velocity signal in response to the actuation signal and the actual wheel velocity signal from the wheel velocity detector, a comparator for producing a gate signal when the actual wheel velocity signal voltage exceeds the reference wheel velocity signal voltage, an AND gate for passing therethrough the reapplication signal when triggered by the gate signal, and a brake pressure modulator for modulating the brake pressure in accordance with the release signal and the reapplication signal passed through the AND gate.

Abstract: A traction control system is disclosed for use with a vehicle braking system including a plurality of driven wheels connected by differential means, wheel brake means associated with each driven wheel, and spring brake-operating means for operating each of the wheel brakes, respectively, each of said spring brake means including a brake diaphragm operable between brake-engaged and brake-released positions, a locking spring operable to place the brake diaphragm in the brake-engaged position, and a spring diaphragm operable between a normal spring-disabling position and a spring-enabling position in which the locking spring is inoperative and operative, respectively; characterized by the provision of means for generating for each driven wheel a velocity sensing signal, comparison circuit means for comparing said sensing signals to produce a control voltage when the rotational velocity of one driven wheel exceeds another by a predetermined amount, and means operable by said control signal for placing in the spri

Abstract: Apparatus for controlling a two-circuit brake system for motor vehicles with the aid of a controllable pressure reducing valve which reduces the pressure in the rear wheel brake circuit compared to that in the front wheel brake circuit and which includes a by-pass line between the pressure inlet from the master cylinder and the pressure connection to the rear wheel brakes which is controllable by a solenoid valve; the brake slippage at the front and at the rear wheels is thereby measured, the thus-obtained values are compared with each other, and the solenoid valve is then controlled by a pulse sequence as long as the brake slippage at the front wheels is larger by a predetermined value than that at the rear wheels.

Abstract: In an input control unit for a vehicle anti-skid braking system, a wheel-speed sensor delivers speed signals to the first input of a differential amplifier. Simultaneously, a capacitor is charged through a resistor and a diode. The capacitor is discharged at a constant rate into a device connected to the second input of the differential amplifier. Another diode prevents the voltage across the capacitor from becoming higher than the voltage of the speed signals. The braking pressure is released for the duration of output signals produced by the differential amplifier. The duration of these signals is kept within safe limits due to the fact that the additional diode limits the voltage across the capacitor.

Abstract: An anti-skid brake control system wherein the brake force is automatically reduced in response to the relationship between the sensed values of the vehicle velocity and the wheel velocity, may erroneously operate at an undesired time when the vehicle is making a turn. The above-mentioned erroneous operation is caused by the misdetermination of the vehicle velocity which based on the difference of the velocities between the outside rear wheel and the inside rear wheel while making the turn. To avoid the erroneous operation, a steering wheel sensor is provided for sensing the angle of a steering wheel. Output signals of the steering wheel sensor are applied to a compensation circuit for compensating output signals of a wheel sensor which detects the velocity of the wheel of a wheeled vehicle, the detected value being used for the determination of the velocity of the vehicle, for the purpose of minimizing the difference of the wheel velocities.

Abstract: A method and the apparatus to carry out the method produce an electric antiskid control signal for each braked wheel of a motor vehicle having an antiskid system. A reference value, approximating the vehicle speed, is produced from the output of the speed sensor of each braked wheel. The antiskid control signal for each braked wheel to correct the brake pressure therein is determined by the difference between the reference value and the momentary speed of the associated one of the braked wheels.