Abstract: A brake-pressure control device is disclosed with a service-brake valve for allocating pressure from a supply source, and via an automatically load-dependent brake-power controller to the wheel-brake cylinders of a rear axle and from a supply source to the wheel-brake cylinders of a front axle of a motor vehicle. Wear sensors are provided for detecting the respective residual lining thickness of the wheel-brake linings, the output signals from the wear sensors being fed to control electronics which, in the event of differing wear of the linings on the two axles, generate a signal for activating a solenoid valve, which corrects the brake pressure on the wheel brakes of one axle. Instead of correcting the brake pressure on the wheel brakes of the respective axle which have greater wear in comparison with the wheel brakes of the other axle, according to the invention a correction of the brake pressure takes place always only on the wheel brakes of one axle only this axle being assigned a solenoid valve.

Abstract: A hydraulic brake system operates so that under anti-lock control, the braking forces for the rear wheels are enhanced in order to reduce braking loads for the front wheels. Further, upon the occurrence of a malfunction of the anti-locking control, the hydraulic pressure which is supplied to the front and the rear wheels is equalized in order to prevent the rear wheels from locking. In preferred embodiments, a small hydraulic pressure is supplied from a master cylinder to the front wheels while a large pressure is supplied from a brake booster to the rear wheels. Due to the large fluid pressure, the braking forces of the rear wheels are enhanced so that the rear wheels might tend to lock easily. However, anti-lock control can be performed effectively in order to avoid the rear wheels from locking. Upon the malfunction of the anti-lock control, a switching valve is operated so that the brake pressure which is supplied to the front and the rear wheels is equalized.

Abstract: A dual circuit brake valve system comprises first and second brake circuits, first and second combined inlet and outlet valves through which first and second braking pressures respectively are delivered to said first and second brake circuits, and first and second pistons which actuate the first and second combined inlet and outlet valves respectively. The second piston is actuated by the first braking pressure which serves as a control pressure therefor. To achieve simultaneous actuation of the first and second combined inlet and outlet valves, a compression spring is installed between the first and second pistons and mechanically connects these to each other. Thereby, a pressure difference of .DELTA.p between the pressure in the first brake circuit and the pressure in the second brake circuit, which approaches zero, is achieved. In order to be able to increase the pressure difference .DELTA.p in the two brake circuits, a third piston is provided between the first and second pistons.

Abstract: A seating for an inertia ball (101) of a deceleration-sensitive brake power control is disclosed, featuring a substantially stepped feature (114) located above a bottom area (105) and which feature engages the inertia ball so as to not allow any horizontal free movement of the inertia ball (101). Advantageously, a positive restraint is provided engaging the inertia ball (101) in a backward direction with respect to the driving direction (v). The chamber (120) beneath the inertia ball (101) collects pressure fluid, so that the inertia ball (101) remains dry.

Abstract: A fluid pressure braking system for a tractor-trailer combination vehicle includes a proportioning relay valve which controls communication to the rear wheel brakes of the tractor. When the tractor pulls a trailer, the proportioning control within the relay valve is disabled, but when the vehicle is operated in the "bobtail" mode without pulling a trailer a proportioned brake application is effected in which the braking pressure communicated to the rear brake actuator is a predetermined percentage of that in the front wheel braking circuit. The proportioning mechanism is also disabled when the front axle braking circuit malfunctions, so that upon loss of pressure of the front axle system, the driver effects a non-proportioned rear brake application.

Abstract: A proportioning valve of the present invention has a columnar portion protruding at the head of a retainer for slidably retaining a plunger. The outside diameter of columnar portion is set in such a manner that when a retaining ring, which inhibits the movement of the retainer in one direction, is completely set into an annular groove in a valve housing, the retaining ring is positioned around the columnar portion, and when the retaining ring gets out of the annular groove, the retaining ring is positioned at the end of columnar portion. A stopper for the plunger is disposed on the retainer so that a valve element cannot abut against a valve seat when the retainer is located at a position shifting in the output pressure direction.

Abstract: An anti-lock hydraulic control device is composed of a front-wheel brake and rear-wheel brake for effecting brake control through a hydraulic system which is connected with a master cylinder and circulates hydraulic fluid; a front-wheel side control valve and rear-wheel side control valve between the master cylinder and front-wheel brake, and master cylinder and rear-wheel brake respectively; a reserve between the front-wheel side control valve and rear-wheel side control valve; a proportioning valve between the master cylinder and rear-wheel side control valve; and a pump connected to the reserve and provided with a discharge opening connected between the proportioning valve and the rear-wheel control valve. When anti-lock control starts, the pump operates and discharges hydraulic fluid to the rear-wheel side control valve, thus increasing rear-wheel brake fluid pressure, and so avoiding the problem of insufficient braking power in the rear-brakes during anti-lock control, and increasing braking efficiency.

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 hydraulic brake system having an anti-skid system in which its rear axle brake circuit has a pressure control device switchable by a control pressure; if the anti-skid system should fail, this device reduces the brake pressure in the rear wheel brake cylinders. The hydraulic brake system includes the pressure control device which acts as a proportional pressure regulating valve and is switchable by a pressure prevailing on a master brake cylinder side of a return pump; if the anti-skid system should fail, this device reduces the pressure of the pressure fluid in the wheel brake cylinders by a fixed proportion compared with the pressure toward the master brake cylinder. The pressure control device has a very simple, compact design and is especially suitable for use in the rear axle brake circuit of a motor vehicle.

Abstract: In a brake apparatus for a two-axle vehicle to obtain uniform wear of the brake linings a conventional ABS control device is so configured that on braking a braking pressure is supplied to the brakes of the rear wheels which is greater than a braking pressure supplied to the brakes of the front wheels for as long as the rotational deceleration of the rear wheels remains below a predetermined value.

Abstract: A vehicle braking system has a master cylinder, a first brake associated with a front wheel of the vehicle and a second brake (11) associated with a rear wheel of the vehicle, the master cylinder being connected to the first and second brakes in a common circuit. The second brake includes brake actuator (10) with a valve (30, 35) which will vary the rate at which fluid pressure is applied to the brake actuator (10) at a predetermined brake pressure, a spring loaded lever (50) acts on the valve (30, 35) to set the predetermined pressure at which the rate of application of pressure is varied and a linkage mechanism (70) varies to loading of the lever (50) to vary the predetermined pressure in proportion to the load applied to the rear wheel with which the brake (11) is associated.

Abstract: To dispense with a proportioning valve for the rear wheel brake fluid pressure line system of a brake anti-locking controller for a vehicle to reduce the cost of the controller. A brake fluid pressure controller comprises a controller for opening and closing the hold valves of a rear wheel brake fluid pressure line system at the time of brake fluid pressure increase after the start of braking of the vehicle but before the start of the brake anti-locking control thereof in order to keep the rate of the break fluid pressure increase in the rear wheel brake fluid pressure system lower than that of the brake fluid pressure increase in the front wheel brake fluid pressure line system.

Abstract: The invention relates to a brake compensator for a hydraulic braking circuit comprising a master cylinder (10) with two working chambers respectively connected to a subcircuit (I, II), the compensator being arranged in a subcircuit (I) comprising a first piston (22) carrying a valve mechanism (24) arranged in a communication between a working chamber of the master cylinder (10) and at least one rear wheel (16) in such a way that, in the rest position, this communication is open, and a second piston (42) subjected to the pressure prevailing in the other subcircuit (II) so as to lock the first piston (22) in the rest position in the event of the absence of a substantial pressure in the other subcircuit (II).

Abstract: In a hydraulic braking pressure control system for a rear wheel brake wherein a control piston normally works to provide a hydraulic braking pressure control by cooperation with a cut-off valve interposed between an input chamber leading to a master cylinder and an output chamber leading to a wheel cylinder of the brake, the cut-off valve has a valve seat piston whose pressure-receiving area facing the output chamber is larger than the pressure-receiving area facing the output chamber. This ensures that opening and closing of the cut-off valve can be repeated in accordance with the output pressure from the master cylinder, so that the output pressure from the master cylinder can be reduced and applied to the brake wheel cylinder.

Abstract: In a fluid pressure control apparatus for a vehicle which includes a main body in which an input opening is formed in communication with a master cylinder side and an output opening is formed in communication with a wheel cylinder side, a stepped bore made in the main body, in communication with the input opening and output opening; a stepped piston slidably fitted into the stepped bore, a poppet type movable body for limiting fluid flowing from the wheel cylinder side towards the master cylinder side in response to a predetermined length movement of the stepped piston; a path for connecting the input opening side of the stepped piston with the output opening side of the stepped piston; and a valve for closing the path in response to a movement longer than the predetermined length.

Abstract: An anti-locking brake system for automotive vehicles, comprising a tandem master cylinder (1), a device (3, 4) for modulating the pressure supplied to the wheel brakes, an anti-locking control device (2) including a pressure reducing valve (10) located in the rear-axle brake circuit (7). The pressure reducing valve can be activated only in the event of failure of the anti-locking device. To attain a particularly simple and compact design of the re-switchable brakes force distributor (10, 110), an electromagnetic drive (21, 25, 121, 125) is provided and includes an actuating element (20, 120) through which pressure is directly applicable to the valve closing member (16, 116) of the pressure reducing valve (14, 15, 16, 114, 115, 116). To ensure the pressure reducing function even in the event of a failure of the anti-locking device during a brake actuation, an additional arrangement (134, 135, 136) for the volume expansion is provided.

Abstract: The present invention relates to a braking pressure control device for automotive vehicles including a regulating valve, composed of a regulating piston (5) and a valve closure member (6), which governs the connection between a pressure-fluid inlet (3) and a pressure-fluid outlet (4). The valve closure member (6) is coupled to a pressure-responsive displaceable control piston (20). The control device also includes a deceleration responsive deflectable inertia member (33). The displacement of the control piston (20) is controlled as a function of the position of the inertia member. In order to simply accomplish an abrupt and temperature-independent locking of the control piston when a deceleration value is exceeded, the inertia member (33) moves into a mechanical latching engagement with the control piston (20).

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: An electrically controlled braking system, in which the operation of the brake actuation is split into three bands depending upon the brake demand level, such that at low demand in a first band the braking pressures are set to generate equal wear at the vehicle axles, and at higher demands in a third band braking pressures are set to apportion braking between axles dependent upon the axle loads being carried, while in a second band, located intermediate the first and second bands, the braking is gradually changed from being equal to being fully apportioned, the extent of this change-over depending upon the actual level of demand within this second band.

Abstract: The hydraulic brake pressure control valve is provided including a valve casing mounted on a master cylinder of a hydraulic brake system. A valve piston is provided with a stepped configuration with an enlarged diameter portion and a reduced diameter portion. The valve piston is mounted slidably and longitudinally along the longitudinal bore of the valve casing. The valve piston is normally urged into a non-operating position and is shiftable longitudinally in an opposite direction from the non-operating position under the effect of a difference in the cross-sectional areas of the enlarged and reduced diameter portions, upon which hydraulic brake fluid pressure acts. The stepped valve piston is defined with a brake fluid passage extending longitudinally therein providing communication between brake fluid passages adjacent the reduced diameter portion and the enlarged diameter portion of the stepped valve piston.

Abstract: A brake fluid pressure controller is interposed between a master cylinder and the rear wheel cylinders. The controller comprises a housing having an inlet, an outlet and a chamber which provides communication between the inlet and the outlet. An annular sealing member is disposed around a piston in the chamber with a clearance left therebetween. The sealing member has an inner perimeter defining a valve seat and an outer perimeter defining a flexible lip portion which is in contact with the internal wall of the chamber. When a valve head of the piston sits on the valve seat of the sealing member, the inner perimeter of the valve seat cuts off the communication between the inlet and the outlet. Meanwhile, the outer perimeter permits a communication from the outlet to the inlet but shuts off a communication from the inlet to the outlet. A spring urges the piston to a direction in which the valve head separates from the valve seat.

Abstract: The hydraulic proportioning valve comprises a body (10) having a stepped bore (12) which receives a cylindrical piston (22) biased toward a rest position by a spring (40), and an inlet (16) and an outlet (14) communicating with the bore (12). The piston (22) includes a part (30) with an adjacent valve member (42). The valve member (42) includes a central opening into which the part (30) may be received slideably and sealingly. The sealing engagement between the part (30) and valve member (42) is maintained even though a pressure differential across the valve member (42) may cause the valve member (42) to be displaced in the bore (12).

Abstract: A pressure control device for brake systems of automotive vehicles. The device includes a stepped control piston (5) which is guided axially displaceably within a housing (1, 2) and which, cooperating with a valve element (14), controls the pressure medium passage between an inlet chamber (8) and an outlet chamber (9). The smaller diameter portion (6) of the control piston (5) is associated with the inlet chamber (8) containing the valve element (14). In order to optimally adapt the control characteristic to the specific requirements of the vehicles it is provided that the valve element (14) is applied by a displaceable stop (17).

Abstract: A hydraulic pressure control valve for use in a brake system of a vehicle includes a valve member having a first projection which extends into an annular groove, in which a sealing member is disposed, when the valve member is at a predetermined position. Either the valve member or a cap that is disposed at an inlet port of the valve has a second projection through which the valve member can abut against the cap when the valve member moves toward the cap. The dimensions of the first and second projections are determined so that the distal end of the first projection is positioned so as to prevent the sealing member from coming out of the annular groove even when the valve member abuts against the cap. Thus, the sealing member is surely prevented from coming out of the annular groove when the hydraulic pressure control valve is assembled to the vehicle body, or when it is reassembled after being overhauled.

Abstract: A friction brake mechanism having a pair of front brake assemblies and a pair of rear brake assemblies receives pressurized fluid at the same time and at the same pressure from a hydraulic control apparatus. Each of the brake assemblies has a brake piston movable in a chamber between a holding position and a releasing position and a plurality of brake plates and a plurality of brake disks interleaved with the brake plates. A first spring system is associated with the pair of front brake assemblies and a second spring system is associated with the rear brake assemblies. The first spring system provides a different force than the second spring system to cause the rear brake assemblies to be engaged a predetermined period of time ahead of the pair of front brake assemblies without any design change in the hydraulic control apparatus.

Abstract: A braking system for an aircraft towing vehicle which supports the nose wheel of an aircraft in a raised position and firmly clamps it to the vehicle. The braking force generated by the front wheels of the towing vehicle is greater by about 2:1 to 8:1 than the braking force at the rear wheels. The braking system has two hydraulic circuits employing identical braking cylinders at all four wheels of the vehicle. The number of cylinders per wheel are varied and different effective lever arms are used to generate like braking forces at each side of the vehicle, and the relatively greater braking force at the front wheels, even if one of the hydraulic circuits fails. The system limits the braking force at the front and rear wheels to maximum values to prevent excessive forces from damaging the nose gear of relatively smaller aircraft.

Abstract: A valve for use in the brake system of an automobile vehicle and more specifically to a proportioning valve located between the master cylinder and the wheel cylinders in a hydraulic braking system. The valve is constructed with a one-piece housing screw threaded directly into a port on the master cylinder and provided with an outlet port at the opposite end of the housing. The exterior of the housing includes a groove receiving an O-ring which overlies a radially extending vent passageway communicating with the interior chamber within the housing. A spring biased piston is positioned in the chamber together with a removable insert and poppet associated with a passage through the piston with these components retained in place by retaining ring structures, springs and the like and sealed by O-ring seals. The construction of the housing and piston enables increased expansion volume which provides for an increased pressure drop downstream of the valve when the pressure is released upstream of the valve.

Abstract: The present invention provides an apparatus and method of utilization thereof of a vehicle brake master cylinder proportioning valve. The valve includes a valve body having a main bore fluidly connected with the master cylinder, primary and secondary circuits. A first housing fluidly seals the main bore into first and second chambers. A second housing fluidly separates the main bore second chamber from the secondary circuit. A valve piston spring biased away from the first chamber is mounted within a bore of the housing. The valve also has fluid communication between the second circuit and second chamber when the fluid pressure within the second circuit exceeds the fluid pressure within the second chamber. At an increase in master cylinder pressure past a first predetermined pressure the valve piston moves towards the first chamber, reaching a pressure balanced position metering pressurized fluid flow from the master cylinder to the second circuit.

Abstract: A proportioning control valve for an antilock control device having a cylinder and first and second pistons mounted therein. The first piston has braking output pressure and first input pressure receiving portions. The second piston slidably mounted on a small-diameter portion of the first piston has a second input pressure receiving portion. A spring is interposed between the two pistons to bias them away from each other. A stopper is provided between the two pistons to limit the movement of the second piston toward the first piston. The cylinder is formed with a control input pressure port communicating with the input pressure receiving portion and an output pressure port communicating with the output pressure receiving portion, and a brake pressure input port.

Abstract: Disclosed is a pressure control device including a housing incorporating a pressure control valve which governs a connection between a pressure-fluid inlet and a pressure-fluid outlet. Included is a deceleration-responsively movable inertia member, and control piston arranged in the housing and being slidable in dependence upon the pressure of the pressure fluid and the position of the inertia member and acting upon the pressure control valve. In order to provide for a pressure control device which is more cost-efficient and which switches precisely irrespective of the viscosity and the flow velocity of the pressure fluid, the inertia member is arranged in a chamber of the pressure control device which is substantially free from pressure fluid and the inertia member controls a valve which isolates a compartment confined by the housing and the control pisotn from the chamber.

Abstract: A master cylinder includes a hydraulic pressure control valve having a valve member mounted in a valve body and normally held apart from a valve seat by a valve spring. The valve member is seated on the valve seat when a pressure in a pressure chamber of a housing of the master cylinder reaches a predetermined level. A control device includes a body received in the bore and having one end portion of a convex shape. The body of the control device is urged by a spring in such a manner that the one end portion projects through a port of the housing into the pressure chamber.

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

Abstract: A vehicle braking control system is provided for sensing (76) the magnitude of the vehicle operator's demand for braking effort and for distributing the braking effort between the individually controllable vehicle (22) brake sites to achieve balanced braking (12) if relatively low braking effort demand (0% to A%) is sensed and to achieve proportional braking (14) if relatively high braking effort demand (B% to 100%) is sensed.

Abstract: A braking system having a pressure modulator which, during normal braking operation, delivers a fluid pressure which is a predetermined multiple of a fluid pressure generated by the master cylinder to a wheel cylinder. The pressure modulator has a solenoid actuator which is energized during braking force proportioning and anti-skid operations to reduce the delivery pressure. In a preferred embodiment, the pressure modulator further includes another solenoid actuator for increasing the delivery pressure during braking force proportioning operation and for delivering fluid pressure during traction control operation.

Abstract: The invention is a hydraulic failure compensating switch which incorporates a differential pressure valve which responds to a hydraulic failure in one of a pair of vehicle braking circuits and altering the pressure reducing function of the braking system proportioning valve(s) in response thereto to increase braking torque at the vehicle's rear wheels.

Abstract: A motor vehicle comprises two driven axles (5, 8), which are interconnected by an interaxle coupling (10) for transmitting a torque only when the halves of the coupling (10) rotate at different speeds and by a speed-changing transmission (9) connected in series with the coupling (10). A brake system (12 to 15) is provided for braking the wheels of both axles (5, 8). In order to ensure that the wheels of the driven rear axle (8) will not block before the wheels of the driven front axle (5), a pressure-setting controller (17) is adapted to control a brake pressure regulator (16) associated with the driven rear axle (8) and is responsive to a reversal of the direction in which torque is transmitted to and from the driven rear axle (8).

Abstract: A hydraulic dual-circuit brake system for automobiles, comprising wheel brakes positioned at the front and rear wheels, a master brake cylinder, brake lines for transmitting brake pressure from the master brake cylinder to the wheel brakes to actuate the latter, a brake pressure regulator device incorporating a hydraulically operated switching off device interposed between the rear wheel brakes and the master brake cylinder, and a brake slip regulation device including a hydraulic unit, sensors for providing a signal output representative of wheel movement behavior, and an electronic anti-skid control and regulating device responsive to the signal output for controlling the hydraulic unit to affect the brake pressure transmitted by the hydraulic unit to the switching off endangered wheel brake.

Abstract: An electromagnetically actuatable pressure modulator for anti-locking brake systems utilizes a variable lever-type transmission interposed between a pressure relief piston of the modulator and the compression spring biased armature of an electromagnet whereby the non-linear force/air-gap relationship of the electromagnet is converted to a linear variation of the force applied to the pressure relief piston for moving same. When a predetermined maximum brake pressure is applied to the modulator, the latter automatically isolates the wheel cylinder from the master cylinder.

Abstract: A hydraulic braking pressure control apparatus provided with a modulator for controlling the supply of control hydraulic pressure to a wheel brake of the vehicle, wherein a partition is provided between a first cylinder portion and a second cylinder portion which are formed in a casing, a first piston adapted to divide the first cylinder portion into an input hydraulic chamber on the partition side and a control chamber on the opposite side is secured to one end of a piston rod extending through the partition slidably and oil-tightly, and a second piston adapted to define an output hydraulic chamber on the partition side within the second cylinder portion is mounted on the other end of the piston rod for axial relative movement. The partition is provided with a valve mechanism capable of disconnecting communication between the input and output hydraulic chambers.

Abstract: In a brake pressure control valve of a double piping system, there is employed a compression spring for biasing the free-piston unit to assume its neutral position, so that even when a pressure difference smaller than a predetermined magnitude is created between the respective inlets of the two proportioning valves, the free-piston unit is prevented from moving from the neutral position, and even if such movement occurs, it is quickly returned to the neutral position by the biasing force of the spring. Thus, rapid self-centering of the free-piston unit is achieved thereby assuring a stable braking of the vehicle.

Abstract: A hydraulic control valve may have a first chamber having an input port, to which an input hydraulic pressure is applied and an output port, and a second chamber having a third port to which a hydraulic control pressure is applied. When a hydraulic pressure below a predetermined level is applied to the first port, the same hydraulic pressure is produced at the second port. When a hydraulic pressure above the predetermined level is applied to the first port, the hydraulic pressure is reduced at a fixed ratio, and thereby a hydraulic pressure lower than the hydraulic pressure applied to the first port is produced at the second port. Thus the hydraulic control valve functions as a proportional valve. When a hydraulic control pressure is applied to the third port, the first and second port are disconnected. Thus the hydraulic control valve functions as a cutoff valve.

Abstract: A fluid pressure control apparatus for a vehicle includes: an inlet port connected to a master cylinder; an outlet port connected to a wheel cylinder of a brake apparatus for a front wheel; a valve apparatus arranged in a path connecting the inlet and outlet ports; a movable plunger for closing and opening the valve apparatus, receiving fluid pressures at both sides; a first spring for urging the plunger in the direction to open the valve apparatus; an electromagnetic coil to be energized by a signal transmitted on the basis of the driver's operation for driving the vehicle backwards; the valve apparatus including a valve body which can be separated from and slated on a valve seat formed on the plunger; a second spring for urging the valve body to the first position where the valve body cannot contact with the valve seat of the plunger in spite of movement of the plunger; and the valve body being moved by energization of the electromagnetic coil to the second position where the valve body can contact with the

Abstract: A brake system for automotive vehicles is equipped with devices for the electric control of the brake force distribution and/or for the control of slip. The front wheels are connected to a pedal-actuated braking-pressure generator (1). In contrast thereto, the rear wheels (HR, HL) are acted upon with braking pressure by virtue of a braking pressure generator unit (5) which is composed of a vacuum servo unit (6) and a master cylinder (7) and which is actuated by a multidirectional control valve (4), such as a three-way/three-position rotary spool valve. The switch position of the valve (4) is responsive to the electric output signals of an electronic combining circuit (17, 17') which is, by way of wheel sensors, furnished with information about the rotational behavior of the wheels and the output of which circuit is electrically connected to the drive (19) of the three-way/three-position rotary spool valve (4).

Abstract: A load conscious brake pressure reducing valve assembly comprises a piston (2A) mounted on a piston rod (2) and movable to control a valve (6) for controlling the connection between an inlet (4) and outlet (3). The valve body (1) is mounted on a sprung part (7) of a vehicle and the piston rod (2) is coupled to an unsprung part (9) by a position sensing lever (10) and springs (32,20) nominal separation of the sprung and unsprung parts the sensing device (8) exerts no force on the piston rod. For greater spacings of the sprung and unsprung parts the spring (20) exert a force on the piston rod which opposes the force of an internal spring (5), and for lesser spacings the spring (32) exert a force on the piston rod which enhances the force of the internal spring. As a result the net spring force acting on the piston always decreases as the separation of the sprung and unsprung parts increases.

Abstract: A brake control apparatus for a vehicle includes brake apparatus for the respective wheels which are operated by pressurized fluid from a master cylinder; an electro-magnetic valve arranged in a conduit connecting the master cylinder with at least one of the brake apparatus, the electro-magnetic valve being normally in the communicating state and being changed over into the intercepting state by an external instruction; at least one of the brake apparatus being of the disc brake type, the one comprising; (a) a disc rotor; (b) first and second friction pad assemblies for engagement with opposite sides of the disc rotor, the assemblies being guided for movement towards the disc rotor; (c) a caliper body straddling the peripheral edge of the disc rotor and the first and second friction assemblies; (d) an actuating member arranged in the caliper body for urging the first and second friction pad assemblies into engagement with the disc rotor, and (e) elastically deformable retainers for supporting the first and se

Abstract: A proportioning valve assembly (10) in a housing (12) is pressure responsive to control the flow of fluid to a wheel brake cylinder. The proportioning valve (20) is connected to a channel (31) opening into a reservoir or fluid-containing chamber (13), a second valve (34) being disposed in the channel (31) and engaging at one end an inertia sensitive ball (40) located on a variable slope surface (17), and engaging a third valve (35) at the other end. The proportioning valve (20) includes a second piston (80) having a reduced diameter end (82) engaging a third piston (105) of enlarged diameter disposed in a portion of the channel (31), the channel (31) communicating by an opening (90) with the fluid-containing chamber (13). During initial brake application by the operator, the third valve (35) remains closed so that the third piston (105) does not move and prevents further movement of the second piston (80), thereby preventing higher braking pressure from being communicated to the wheel brake cylinder.

Abstract: A master cylinder-reducing valve assembly has a master cylinder and a reducing valve for transmitting output hydraulic pressure from the master cylinder to a rear wheel brake at a reduced level. The reducing valve includes a valve housing provided on the master cylinder and having an inlet communicating with the output port of the master cylinder and an outlet communicating with a rear wheel brake. A pressure receiving piston is slidably received in the valve housing to divide the interior of the housing into an input hydraulic chamber communicating with the inlet and an output hydraulic chamber communicating with the outlet. The pressure receiving piston has a communication bore connecting between the input and output hydraulic chambers. A valve member is disposed in the input hydraulic chamber to open and close the communication bore. A valve spring is received in the valve housing and biases the valve member toward the pressure receiving piston.

Abstract: An air bleeder is disclosed for a fluid system such as a braking liquid pressure control valve which operates to reduce a braking liquid pressure supplied to a rear wheel cylinder at a given proportion to a braking liquid pressure supplied to a front wheel cylinder as a braking liquid pressure is supplied from a master cylinder. An air bleeder is disposed for use with such a fluid system, in particular, with a fluid system in which a plunger is slidably received in a bore formed in a housing in which a plate is fitted to serve as a stop member and an end of the plunger is maintained in abutment against the plate when it is inoperative. A space which is defined between the periphery of the plunger in the region of its end and the internal surface of the bore and which communicates with a fluid passage extending through the plunger and the plate is sealed against an exterior by a seal member.

Abstract: A braking pressure control unit comprises a valve assembly with a valve seat (25) formed fast with the housing and a closure member (26) which latter, with the brake circuits (I, II) intact, when performing its relative movement to the valve seat (25), is kept in abutment on an extension (II) of a stepped piston (6) by a closure spring (28) supported on a malfunction piston (7). The valve (25, 26) is prevented from closing by the extension (11) at the stepped piston (6) and by a stop (29) for the closure member (26) at the malfunction piston (7). Because of the closure member (26) being in constant abutment on the extension (11) of the stepped piston (6) during its relative movement, there results a smaller stroke of the malfunction piston (7) and thus less fluid input of the braking pressure control unit and less wear of the sealing elements (22, 23) at the malfunction piston (7).

Abstract: An electronic brake control system, according to the present invention, has a controller. The controller employs a memory which stores a table or map representing split point values relative to vertical displacement between the sprung mass and the unsprung mass of the vehicle. The split point data stored in the memory are determined in accordance with the unique spring characteristics of the specific vehicle to which the brake control system is applied. The controller derives a reference pressure corresponding to the split point and compares the reference pressure with an actual hydraulic braking pressure. When the actual braking pressure is lower than the reference pressure, the controller holds a proportioning valve device inactive so as to distribute hydraulic braking pressure built up in a master cylinder among individual wheel cylinders so that the braking pressure in the wheel cylinders increases at a rate matching the rate of increase of the fluid pressure in the master cylinder.