Abstract: In order to provide a brake booster negative pressure controller which reduces deterioration in the fuel consumption due to operation for closing a throttle to assure a brake booster negative pressure while assuring the braking capability required according to driving conditions and can safely assure a braking capability even when a failure occurs in a negative pressure sensing system, said brake booster negative pressure controller comprises a brake booster for assuring a master vac negative pressure by using a negative pressure of an engine, a throttle valve whose opening angle can be operated independently from the stroke of an accel pedal, and a brake operation sensing means, wherein the negative pressure controller has a speed sensing means and a means for closing the throttle valve by a predetermined amount when the vehicle speed sensed by the vehicle speed sensing means is equal to or higher than a predetermined value and application of the brake is sensed by the brake operating sensing means.

Abstract: In a fluid pressure booster, an input rod 7 and a valve member 6 are stroked forward during the operation so as to cause a control valve to be switched over. The atmosphere is introduced into a working pressure chamber 30 via the control valve 41 and a power piston 19 then operates to make a negative pressure booster 1 produces an output from a output rod 13. As the atmosphere in the working pressure chamber 30 acts backward on a control piston 25 at this time, the valve member 6 will not be stroke further. However, the output rod 13 is continuously stroked forward and kept producing the output. Due to the stop of stroke of the valve member 6, the stroke of the input rod 7 is suppressed and set at an extremely short stroke. When the negative pressure falls, the negative pressure booster 12 produces an output from the output rod 13 since the input rod 7, the valve member 6 and the output rod 13 integrally give a stroke forward.

Abstract: In an arrangement for producing a vacuum in a motor vehicle system including an internal combustion engine with an air intake system, a vacuum-operated power brake system for braking the vehicle and a fuel vapor adsorption system for collecting fuel vapors, a vacuum pump is provided which has a suction side in communication selectively with the vacuum operated power brake system and the fuel vapor adsorption system and a discharge side in communication with the air intake system of the internal combustion engine.

Abstract: A brake system for motor vehicles with an adjustable pneumatic brake force booster includes a control valve which can be actuated by an electromagnet independently of the driver's actions. A brake pressure controller generates signals which serve to actuate the electromagnet. In order to be able to implement a quick-action, low-noise pressure regulating system at low cost, the brake pressure controller (8) is formed by connecting in parallel an electromagnetic control circuit (60) that processes the nominal brake pressure signal (Pnominal) into a first current value (IA) and a regulating circuit (70) that processes a control difference (&Dgr;P) formed from the nominal brake pressure signal (Pnominal) and the actual pressure signal (Pactual) into a second current value IB, with the output variable (Inominal) of the brake pressure controller (8) being formed by adding together the two current values (IA, IB).

Abstract: When a stroke speed exceeds a reference value of a stroke speed threshold value, a solenoid is energized to tract an armature, thereby opening an atmospheric valve independently of the position of a plunger. Consequently, power pistons, together with an output rod, are moved forward by a thrust corresponding to a pressure difference between a constant-pressure chamber and a variable-pressure chamber to perform a full-power braking operation. A reaction-adjusting mechanism contributes to an improvement in safety by functioning in such a way that when the part of the reaction force from the output shaft that is transmitted to an input rod reaches a predetermined value, a boosting ratio is increased, so that the reference value of the stroke speed threshold value can be set high to prevent unnecessary braking.

Abstract: In a brake force control apparatus selectively performing a brake assist (BA) control for generating a brake force greater than that of a normal control time, an unnecessary restart of the BA control immediately after the BA control is terminated is prevented. The BA control is terminated when it is determined that an emergency braking is unnecessary since a master cylinder pressure (PM/C) has been reduced to a value less than a predetermined value. A restart of the BA control which is caused by a sharp change in the master cylinder pressure (PM/C) and a rate of change (.DELTA.PM/C) thereof due to a rapid decrease in a fluid pressure when the BA control is terminated is prohibited until a predetermined time has been passed after the BA control was terminated.

Abstract: A tripper/hopper car rides on a conveyor via four wheel tires running on T-section rails, with respective hold down wheels riding adjacent the underside of the rails and respective caster side wheels riding adjacent the vertical edges of the T-rails. Each wheel tire is driven by a motor drive unit employing a shaft-mount gearbox with a motor brake that utilizes the reduction of the drive gearbox to increase the effective braking torque developed. A pair of caliper-type brakes is further provided for redundancy.

Abstract: In the case of a brake system for motor vehicles, having a brake pedal, a brake booster, a master brake cylinder and an electronically regulatable brake unit, which is arranged between the master brake cylinder and the wheel brakes and by which, via an electronic control unit, the brake pressure in the wheel brakes can be set independently of the preliminary pressure existing at the output of the master brake cylinder, when the brake booster fails, using the electronic control unit and the electronically regulatable brake unit, the brake pressure in the wheel brakes is generated such that a predetermined minimum desired deceleration course is obtained as a function of the pedal force applied by the driver by way of the brake pedal.

Abstract: The present invention is directed to a brake control system, which includes a first pressure circuit and a second pressure circuit for communicating a master cylinder with two sets of wheel cylinders, respectively. In each pressure circuit, a modulator is arranged to modulate the braking pressure in each wheel cylinder, a pressure pump is disposed to supply pressurized brake fluid to each wheel cylinder through each modulator, a normally open first valve is arranged to open or close a first passage for communicating the master cylinder with the modulator, and a normally closed second valve is arranged to open or close a second passage for communicating a reservoir directly with the inlet of each pump, or communicating the reservoir with it through the master cylinder. The pressurized brake fluid is supplied to each pressure circuit including the second valve at the inlet of the pump to perform an auxiliary pressurization.

Abstract: A brake force control apparatus performs both a brake assist control and an antilock brake control without interference therebetween. A master cylinder generates a brake fluid pressure corresponding to a magnitude of a brake operation. A pump has an inlet port and an outlet port, the inlet port being communicable with the master cylinder. An inlet control valve controls communication between the master cylinder and the inlet port of the pump. A wheel cylinder is communicable with each of the master cylinder and the outlet port of the pump. A supplementary reservoir is communicable with each of the wheel cylinder and the inlet port of the pump. The brake assist control is performed, when the emergency brake operation is performed by the driver, by opening the inlet control valve and actuating the pump.

Abstract: The invention relates to an electronically controllable braking system for motor vehicles with a brake pressure generator unit (2) which can be actuated by a brake pedal (1), which supplies hydraulic fluid via a hydraulic fluid path (3) to at least one wheel brake (4) of the motor vehicle, a first electromagnetic valve arrangement (5a, 5b) which is arranged in the hydraulic fluid path between the brake pressure generator unit (2) and the wheel brake (4) for controlling the pressure build-up, pressure relief and pressure holding phases in the wheel brake, a motor-powered controllable hydraulic pressure source (7) which, in addition to or in lieu of the brake pressure generator unit (2), supplies hydraulic fluid to the wheel brake (4), and a motor-powered controllable auxiliary energy source (15, 30) which boosts an actuation of the brake pressure generator unit (2) by the brake pedal (1) or which effects an actuation of the brake pressure generator unit (2) in lieu of the brake pedal (1), with the controllable

Abstract: When a vacuum booster fails, an pressure amplifying mechanism increases a wheel brake pressure. After that, even when it is detected that the vehicle is brought into a stopped state, the state in which an increased brake fluid pressure is applied to wheel cylinders is held. If a condition for terminating control to maintain a stationary state of the vehicle is satisfied, that is, if a predetermined time period has elapsed since when the vehicle stops, the operation of the pressure amplifying mechanism is stopped to reduce the wheel cylinder pressure.

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 brake system includes a controllable a pneumatic brake booster, whose control valve can be actuated independently of the driver's will by a solenoid. A control structure consisting of a brake pressure controller and a control valve positioning controller generate signals which represent the electrical current to be applied to the solenoid.

Abstract: A boosted braking system for a motor vehicle having a master cylinder (200) and a pneumatic booster (100). The master cylinder (200) causes an increase in pressure of brake fluid supplied to at least one wheel brake (300). The pneumatic booster (100) is controlled by the application of an input force (F2) to a control rod (26) to actuate the master cylinder (200). A main hydraulic piston (30) of the master cylinder (200) has a hollow cylinder (32) in which a reaction piston (34) slides in a leaktight and axial direction. The reaction piston (34) receives at least the input force (F2). An elastic member (46) located between the reaction piston (34) and hollow cylinder (32) exerts an elastic force for urging the reaction piston (34) toward the master cylinder (200). The reaction piston (34) delimits within the cylinder a reaction chamber (36) which is isolated from the interior volume (V) of the master cylinder (200).

Abstract: A vacuum servo unit includes a partition member having an outer periphery that engages the movable wall member in an air tight manner. A receiving chamber is defined between the partition member and the movable wall member, and the receiving chamber is adapted to be communicated with the atmosphere. A passage that introduces atmospheric air into the receiving chamber is engaged in an air tight manner with the partition member and extends through the constant pressure chamber. A change member in the form of a solenoid valve selectively communicates the receiving chamber with the constant pressure chamber or with the atmosphere. Accordingly, the servo efficiency of the vacuum servo unit is increased. In addition, the unit can be operated automatically by supplying electric power to thereby increase brake force so that the brake feeling is advanced.

Abstract: An electronically controlled brake booster for a vehicle brake system including a housing having a vacuum chamber and a servo chamber separated from the vacuum chamber by a movable wall. The brake booster further includes a control valve operable by an electromagnet. The control valve is coupled to the wall for common relative movement with respect to the housing. The electromagnet is connectable to a control unit generating a drive signal to operate the electromagnet. A braking pressure generation unit is connected to the movable wall for generating a braking pressure for a brake of the vehicle in dependance on the position of the movable wall. The drive signal is generated in the control unit in dependance on a control parameter, the parameter being adjusted in dependance on a dead time of the braking pressure between supplying the electromagnet with the signal and a rising of the braking pressure in response thereto.

Abstract: A pneumatic brake booster for providing braking assistance. The brake booster has a housing (10) with an axis of symmetry (X--X') separated sealingly by at least one movable partition (12) to define at least a first chamber (14) connected permanently to a source of low pressure and at least a second chamber (16). The second chamber (16) being selectively connected to the first chamber (14) or a source of high pressure through a three way valve structure actuated by a control rod (30,130). The three way valve structure have a valve member (36,136) which cooperates through an a first annular face (40,140) with a first annular valve seat (34,134) formed on a plunger (28,128) which slides in a bore (26,126) of a piston (20,90). The annular face (40,140) of the valve member (36,136) being urged forward in the direction of the annular valve seat (34,134) by a valve spring (42,142).

Abstract: The invented apparatus is designed for use with a tow vehicle and trailer combination. The apparatus includes a controller, and can also include a vacuum sensor and a vacuum pump. The vacuum sensor is communicatively coupled to sense the vacuum supply available to operate a trailer brake system that is interfaced to the tow vehicle's brake system to coordinate braking of the trailer and vehicle. The vacuum sensor generates a vacuum pressure level signal supplied to the controller. The controller periodically determines whether the vacuum pressure level is less than a first predetermined vacuum pressure level. If so, the controller activates the vacuum pump by generating a vacuum pump switch signal. On the other hand, if the vacuum pressure level is greater than the first predetermined level, the controller does not activate the vacuum pump switch signal.

Abstract: A valve assembly for controlling a pneumatic brake booster (10) comprises a control housing (30) in which a first and a second valve seat (32, 34) are arranged. A valve body (40) is adapted to contact both valve seats. The brake booster (10) is provided with two chambers (24 26) in the usual manner, one chamber (24) of which can be evacuated while the other chamber (26) can be supplied with pressurized air. An additional valve seat (66) is provided. The additional valve seat (66) can be opened by a sleeve (72) which radially surrounds the control housing (30) of the brake booster, in order to form an additional ventilation duct (80) to one of the two chambers. The sleeve (72) can be actuated mechanically and/or electromagnetically by an electromagnetic actuation device (90).

Abstract: A valve seat (50) is provided on and along the end face of the end tubular portion (16a) of the valve body (16) of a power brake device. A valve member (49) is slidably put on the input shaft (8). The valve member (49) is moved forward and backward by an actuator (51). When the valve member (49) is seated on the valve seat (50), the valve member (49) closes a pressure path (35). In this state, the operation of amplifying a braking force by the power brake device is not performed. The brake system may be incorporated into a vehicle with a regenerative brake device. The operation of amplifying a braking force by the power brake device can be interrupted. Therefore, the brake system produces a braking force optimal for a current loading state of a vehicle. The braking force amplifying operation of the power brake device can be stopped until the regenerative brake device produces a large regenerative braking force. Therefore, the regenerative braking force can be effectively used.

Abstract: A vehicle braking system with an electronically controllable brake servo unit which comprises a first pneumatic working chamber (13) and a second pneumatic working chamber (14) which are separated from each other by a movable wall (11), wherein a travel sensor (20) is provided for the detection of displacements of the movable wall (11) relative to a stationary wall (5b) of at least one of the two working chambers (13, 14) is improved to simplify assembly and adjustment of the travel sensor in such a manner that a wall (11) is provided with an opening (19) through which a measuring element (10) being connected with another wall (5b) is projecting, and that the travel sensor (20) converts a relative movement between the measuring element (10) and the travel sensor (20) in the direction of the movement of the movable wall (11) into a signal used for controlling the brake servo unit.

Abstract: An automatic brake booster having the functioning of an automatic brake, or more specifically, an improvement of bellows contained in a shell thereof is disclosed. The bellows comprises a stepped tubular member having portions of different diameters, namely, a reduced diameter, a medium diameter and an increased diameter. By using a reinforcing ring having a rigidity in the step, an expansion to increase the diameter of the bellows when the atmosphere is introduced into the internal space of the bellows can be prevented. Different diameters of the portions of the bellows allows the likelihood to be minimized that an output loss of the brake booster may be caused by contact of bellows portions to each other as the bellows is axially shrunk. As compared with an accordion-like bellows, the stepped tubular bellows can utilize a simplified die assembly and manufacturing steps and thus can be manufactured inexpensively.

Abstract: A vacuum servo apparatus in which, in a performance diagram having an input coordinate axis perpendicular to an output coordinate axis, the normal operation is represented by a first operating line and, after a plunger member is moved by a solenoid so that movement of the plunger member with respect to a transmission member is controlled, the operation is represented by a second operating line following additional jump biasing force to be supplemented and generated is appropriately set and an output of the apparatus is designed to be faster during the return stroke for straightforwardly reflecting the intention of the driver.

Abstract: The vehicle brake system including an electronically controlled brake booster (10), comprising a first actuator (350) which is connected to a second actuator (360) for transmitting to the same an actuating movement (P) of a brake pedal, wherein the second actuator (360) transmits the movement to a master brake cylinder, a signal generator (365) disposed between first and second actuators (350, 360) for generating a signal to be supplied to the controller of the brake booster (10), wherein the signal generator (365) is triggered by a relative movement between the first actuator and the housing of the brake booster.

Abstract: A vacuum servo unit which is designed so that when a valve member associated with the plunger that is connected to an input member is out of engagement with the plunger, the power piston moves due to the pressure differential between a variable-pressure chamber and a constant pressure chamber for boosting the force to the input member, is provided with an arrangement for inhibiting or preventing inclination of the input member. The arrangement includes a plurality of projections extending outwardly from the input member, and a plurality of slots formed in the plunger for receiving the projections.

Abstract: In a brake booster of the present invention, a valve plunger (20) rapidly moves forward to come into contact with a shaft portion (33a) of a first piston (33) and then presses the first piston (33)to quickly move forward according to the pedal pressure developed by quickly pedaling a brake pedal during emergency braking. Therefore, before an output shaft (32) outputs, i.e., before pressure is developed in a first fluid chamber (36) filled with fluid, the front end of a second cup packing (39) passes an open end of a first fluid path (31) formed at the first piston (33) side. As a result, the communication between the first fluid chamber (36) and the second fluid chamber (37) is permitted through the first fluid path (31) and a second fluid path (34) so that the fluid within the first fluid chamber (36) flows to the second fluid chamber (37), thereby stopping a reaction mechanism of the pressure in the first fluid chamber (36) and allowing the full load output of the brake booster (1) all at once.

Abstract: A hydraulic braking pressure control apparatus for an automotive vehicle, having a master cylinder integrally provided with an ABS actuator or an ABS actuator and a TRC actuator, the ABS actuator being in the form of an anti-lock actuator which is activated under control of a computer for controlling hydraulic braking pressure applied to each road wheel of the vehicle in braking operation, and the TRC actuator being in the form of a traction control actuator which is activated under control of the computer for controlling slippage of driven road wheels during travel of the vehicle, wherein a solenoid valve assembly composed of a plurality of solenoid valves of the ABS actuator or the ABS and TRC actuators is mounted on one side of a cylinder body of the master cylinder, while other component parts of the ABS actuator or the ABS and TRC actuators are mounted within a housing structure integrally formed with the cylinder body of the master cylinder a the other side thereof.

Abstract: The invention relates to an electronically controlled vehicle braking system with a brake booster comprising an electromagnetically operable control valve arrangement, an electronic control device supplying the control valve arrangement with control signals for initiating or cancelling an automatic braking sequence, and a load sensor connected with the electronic control device for sensing the pedal actuation force acting upon a brake pedal coupled with the brake booster, characterized in that the electronic control device is adapted to effect a brake pressure relief depending upon a reduction of the pedal actuation force acting on the brake pedal after the initiation of an automatic braking sequence.

Abstract: To infinitely variably adjust the distance between a reaction disc and an interacting second part of a bipartite valve piston in a completely assembled vacuum brake power booster, which is already mounted to the automotive vehicle, a tubular sleeve is provided, arranged coaxially to a piston rod that actuates the valve piston, and is in engagement with a first part of the valve piston, connected with the second part by a threaded union, to apply a torque to the first piston part. For this purpose, the sleeve has at its end projecting from the control housing with an extension permitting rotation of the sleeve.

Abstract: A method for determining the triggering sensitivity of an automatic braking process in motor vehicles. By a control element the driver can control within a specific range the threshold value which is effective for triggering. The permissible range is selected so that the effective threshold value can neither be reduced to such an extent that automatic braking is triggered at actuation speeds of the brake pedal which are normal for travel mode, nor increased to such an extend that it is impossible to trigger automatic braking process.

Abstract: An anti-lock brake system having an electronic control responsive to wheel speed sensors associated with each wheel of the vehicle. The electronic control generates a pedal inhibit signal activating a hydraulic cylinder to inhibit further depression of the brake foot pedal in response to detecting at least one of the wheels approaching a locked state. The electronic control will also generate brake pressure control signals activating an anti-lock brake actuator connected between the brake foot pedal and the input to the vacuum power booster of the brake system. The anti-lock brake actuator, in response to the brake pressure control signals, will maintain a maximum friction between the wheels of the vehicle and the road surface.

Abstract: The invention covers a brake-booster of the partial vacuum type comprising a direct braking control mechanism (hill-holder or traction control). In order to implement these functions, the piston (20, 22) of the booster is "double" through a partition (52) which is attached securely to the piston and defines with the piston a third chamber (50). This chamber is connected by a flexible pipe (66) and a double valve (72) either to partial vacuum (78) or to atmospheric pressure (76).

Abstract: A vacuum brake booster (12) for use in a brake system (10) having a traction control function to selectively effect a brake application of driving wheels of a vehicle to synchronize the rotational spin thereof. The vacuum brake booster (12) has movable wall (62) which separates a housing (56) into a front chamber (58) and a rear chamber (60). The front chamber (58) is connected to the rear chamber (60) by a first passage (61), a bore (59) and a second passage (63) in the movable wall (62). A first control valve (66) located in the bore (59) controls communication of a first fluid through the first passage (61) to the bore (59) and a second fluid to create a first pressure differential in the brake booster (12) and produce a first operational output to effect a brake application in an operational mode of operation. The first operational output force is supplied to a master cylinder (14) from which pressurized fluid is supplied to the wheel brakes to effect a brake application for the vehicle.

Abstract: A brake-pressure control device for a road vehicle with a hydraulic brake system has a pneumatic brake booster provided with a change-over device which changes over the brake booster to a mode with an increased boost factor when the speed with which the driver actuates the brake pedal exceeds a threshold value. A reaction piston of the axial force-transmission train, leading from the brake pedal via the reaction piston, a flexible reaction element and the driving piston of the brake booster to the master cylinder, is constructed in two parts. One of the two part-pistons engages axially on the reaction element and the other of the part-pistons acts as a valve element of the inlet valve and via which the driving chamber of the brake booster can be exposed to the ambient pressure. The two part-pistons have complementary threads which engage one another.

Abstract: A servomotor having a control valve independently by a manual input applied to an operator pedal assembly to effect a brake application or a traction control force derived from a signal developed by a controller to selectively apply brake force to synchronize rotational spin of the wheels of a vehicle. An input rod connected to the control valve has a housing attached thereto with a traction control chamber therein. A sleeve which surrounds the input rod has a first flange that engages a shoulder on the input rod and a second flange that is connected to a diaphragm retained in the traction control chamber. A return spring acts on the first flange to urge the second flange and diaphragm against a stop in the housing. In response to an input signal the controller allows vacuum to be communicated to the traction control chamber to create a traction control pressure differential.

Abstract: A traction servomotor for supplying a control valve with an operational input independently of an operator pedal assembly in response to a signal supplied to a controller indicating a different rotational spin of the wheels of a vehicle. The traction servomotor has a housing with an input rod with a first section retained in axial openings in the housing and a second section is pivotally connected to the operator pedal assembly. The interior of the housing is divided by a diaphragm which is attached to the first portion of the input rod. The controller is connected to the housing such that in a first mode of operation wherein the activation of the control valve is dependent on an input from the operator pedal assembly a first fluid pressure is presented to both sides of the diaphragm and in a second mode of operation, a second fluid pressure is presented to one side of the diaphragm to create an actuation pressure differential.

Abstract: The invention relates to a brake-booster (10) of a vehicle, comprising a casing (12) and a diaphragm (14) which divides in a sealed manner the interior of the casing into a front chamber (16) and a back chamber (18), a hollow piston (20) movable in the casing receiving an input member (24) adapted to be connected to a brake pedal, an output assembly comprising a lid (30) and an output rod (32) adapted to be connected to a piston (34) of a master cylinder (36), a reaction disk (28) in a deformable material arranged between the hollow piston (20) and the lid (30) so as to receive an image of the output force of the booster (10) when it is put into operation in order to cause a deformation of the reaction disk (28) tending to push back the input member (24) as a function of the image.

Abstract: The invention relates to a double brake booster for a motor vehicle, provided with a valve enabling the boost ratio to be varied as a function of the load of the vehicle. In addition to two pistons (64, 66) articulated to an arm (72), this valve comprises a pusher (80) driven by a third piston (68), to a first face of which is applied a first force representative of the load of the vehicle and to a second face of which is applied a second force of elastic nature, in opposition to the first, this third piston adopting, under the effect of the first and second forces, an equilibrium position which determines that of a variable bearing point for the lever which constitutes the arm (72). Moreover, the arm, the pusher and the three pistons are mounted in the same body, the arm and the pusher being housed in a single cavity (74) which is defined in this body and subjected to a low pressure, and toward which the second faces of the three pistons are turned.

Abstract: The invention relates to a pneumatic brake-booster comprising a casing (10), inside which is situated a movable wall (12, 14) returned to a rear position of rest by a resilient mechanism and defining a front chamber (16) permanently connected to a vacuum source (61) and a rear chamber (18) selectively connected to the front chamber (16) or to the atmosphere by a valve mechanism (20a, 32a, 40) actuated by a control rod (34) adapted to bear, by way of a plunger (32), against one face of a reaction disk (58) fastened to a push rod (56). According to the invention, the resilient mechanism returning the movable wall (12, 14) to its rear position of rest exerts a modulable force on the movable wall (12, 14).

Abstract: The boosted brake system comprises two tandem master cylinders (15, 16), each controlled by way of the piston of a vacuum booster (10, 11) comprising at least two chambers, one (10) of these brake boosters being controlled by way of a pedal and comprising a valve mechanism making it possible to generate a difference between the pressures prevailing in the two corresponding chambers, and a reservoir (17) for feeding brake fluid to the associated hydraulic circuits the two chambers of one (10) of these boosters communicate respectively with the two corresponding chambers of the other booster (11), and the two hydraulic circuits (30, 32) associated with one (15) of the master cylinders communicate respectively with the two hydraulic circuits (30, 32) of the other master cylinder (16).

Abstract: The invention relates to a motor vehicle braking system, comprising a brake pedal (P) to generate brake pressure in an hydraulic fluid, a brake pressure booster (12) operated by differential pressure and adapted to be actuated by a first valve (V.sub.1) which is pressurized mechanically by the brake pedal (P), and a first sensor (S.sub.1) to detect the pressure generated by the brake pedal. A second sensor (S.sub.R, S.sub.L) is provided to detect vehicle deceleration or rotational retardation of braked wheel, and a data processing unit serves to compare the data determined by the sensors (S.sub.1, S.sub.R, S.sub.L) and to generate a control signal in response to the result of the comparison for a second valve (V.sub.2) which is controllable electrically and by which a pressure difference is adjustable in the brake pressure booster (12).

Abstract: The present specification discloses a servo unit for use in a vehicle braking system, the servo unit comprising a housing within which a flexible diaphragm separates a vacuum pressure chamber from an atmospheric pressure chamber. An actuator rod assembly extends through the housing and includes a valve assembly having a valve control piston which has a laterally extending key, the key being engageable with a fixed stop in the housing to limit the movement of the valve control piston and cause a balance in the valve assembly between the vacuum and atmospheric pressure. A solenoid valve is also provided, the solenoid valve being controllable to either connect a flexible passage member extending around the actuator rod assembly across the vacuum pressure chamber between the housing and the diaphragm in the region of the valve assembly, to the vacuum pressure chamber, or to connect both the flexible passage member and a bypass leading from the solenoid valve to the atmospheric pressure chamber, to the atmosphere.

Abstract: A vacuum booster for use with a vehicle anti-locking brake system to constitute a traction control system for preventing the slip operation of the vehicle driving wheel during starting or accelerating the vehicle, comprising a main opposing pressure chamber, an auxiliary opposing pressure chamber, a continuous pressure chamber, an operation rod and a pair of valves for independently controlling each of the main and auxiliary opposing pressure chambers so that control of the slip operation of the vehicle driving wheel can be performed without depressing the vehicle brake pedal.

Abstract: A device for the generation of auxiliary pressure for slip-controlled brake systems with a pedal-force-operated brake booster connected to a tandem master cylinder (19). A pressure is transmittable in the brake booster housing (7) of the brake booster to the wheel brakes connected downstream. This pressure is controlled by an electromagnetically operated control valve (5) in that the pressure as a hydraulic pressure is influenced by the pneumatic actuation of a servo piston (2). The servo piston (2) is fastened on an auxiliary pressure control piston (1) within the brake booster housing (7) and the influence is a function of thermodynamic state variables of different energy sources (11). Thus, a device is provided for the generation of auxiliary pressure which, while using simple constructional configuration, provides an operationally reliable and economical use of available thermodynamic state variables such as the atmospheric pressure and of the gas throttling of an internal combustion engine.

Abstract: As an improvement on conventional brake systems of the type having a multiple-chamber vacuum brake force booster, a modification is disclosed to the effect that, in the brake releasing position, there is a pressure medium communication between a booster chamber and a simulator chamber. A modulator chamber requires only one external connection, thereby substantially simplifying the construction of the brake force booster and readily permitting an extension of the system's use to include traction slip control.

Abstract: To substantially eliminate the noise arising upon actuation of a vacuum brake force booster caused by incoming air, the housing section confining the ventable working chamber and/or the intervals in the control valve housing are lined with an insulating composition for attenuating noise.

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: A resettable booster is disclosed including a booster chamber in communication with a resetting chamber through a closable connection. For pressure relief of the master brake cylinder, valves are switched so that the booster piston is pressure-balanced and the master brake cylinder force shifts the booster piston back into the brake release position. The pressure fluid is supplied from the booster chamber into the resetting chamber. Advantageously, the volume intake of the booster is small, hence allowing the use of an extremely simple pressure source construction. The pressure source is a cylinder with an accumulator chamber that is confined by a piston, wherein the piston is moved by the difference in pressure between the atmosphere and the vacuum in the intake side internal-combustion engine of the vehicle.

Abstract: A vacuum servo apparatus in which, in a performance diagram having an input coordinate axis perpendicular to an output coordinate axis, the normal operation is represented by a first operating line and, after a plunger member is moved by a solenoid so that movement of the plunger member with respect to a transmission member is controlled, the operation is represented by a second operating line following additional jump biasing force to be supplemented and generated is appropriately set and an output of the apparatus is designed to be faster during the return stroke for straightforwardly reflecting the intention of the driver.