Abstract: A method operates a braking device for motor vehicles, in particular for utility vehicles. Along a trailer supply line for supplying air to a parking brake of a trailer and/or a trailer control line for supplying air to an operating brake of a trailer, the air pressure is measured by at least one pressure transducer and is transmitted in the form of an electric signal to an electronic control unit of the motor vehicle. In the event of a faulty pressure change response, an open trailer supply line and/or an open trailer control line is detected.

Abstract: A vehicle deceleration controller includes: a brake pedal; an accelerator pedal which is operated when an acceleration/deceleration request of a vehicle is inputted; a target acceleration/deceleration setting part configured to set a target deceleration based on a deceleration operation of the accelerator pedal; and an acceleration/deceleration control part configured to, when the accelerator pedal is operated to decelerate the vehicle, provide deceleration control over the vehicle such that an actual deceleration follows the target deceleration set by the target acceleration/deceleration setting part.

Abstract: A braking system for a vehicle includes devices that are configured to apply braking force to a wheel in response to a braking command. A first sensor is disposed to monitor a parameter associated with the braking force, and a spatial sensor is disposed to determine a linear range between the vehicle and a predefined locus point. A controller is operatively connected to the braking system and in communication with the first sensor and the spatial sensor. The controller detects a braking event and determines a time to stop and an applied braking force during the braking event, which is integrated over the time to stop. The braking system is evaluated based upon the total stopping distance and the integrated applied braking force during the braking event. A fault associated with the braking system is determined based upon the evaluation of the braking system.

Abstract: The invention relates to a disk brake system for hoisting machines and winches, equipped with at least two brake circuits, wherein to each brake circuit at least one brake caliper with associated brake pads is allocated, and wherein two redundant, active control circuits (10, 12, 14, 16) are provided per brake circuit.

Abstract: A motor vehicle includes multiple wheels, each having at least one assigned hydraulically actuatable brake; first and second separate hydraulic braking circuits each including multiple valves for modulating a braking pressure in the two separate hydraulic braking circuits, the multiple valves forming a valve assembly; a first control device controlling the multiple valves; third and fourth separate hydraulic braking circuits and a second control device respectively of same construction as the first and second braking circuits and the first control device; a brake booster, operably connectable to the two separate hydraulic braking circuits and the two further separate hydraulic braking circuits; and a valve unit arranged downstream of the brake booster.

Abstract: An electric motor system that triggers brake and steering function upon engine failure featuring an electric motor; and a vacuum pump, an oil pump, and a sensor each operatively connected to the electric motor. The vacuum pump is connected to the vehicle's brake servo and the oil pump is connected to an oil reservoir and to the vehicle's steering sector. The sensor is adapted to detect when the engine is turned off. When the engine is turned off the sensor is activated and causes activation of the electric motor. Activation of the electric motor causes activation of the vacuum pump and the oil pump. The vacuum pump functions to provide a vacuum in the servo brake of the vehicle and the oil pump functions to create oil pressure with oil in the oil reservoir and direct oil pressure to the steering sector.

Abstract: A brake control apparatus includes: a master cylinder; a wheel cylinder; a hydraulic pressure source; a control valve arranged to increase or reduce the pressure of the wheel cylinder; an outside gate valve arranged to connect or disconnect between the master cylinder and the wheel cylinder; a brake operation sensing section configured to sense a driver's brake operation; and a control unit configured to control the hydraulic pressure source, the control valve, and the outside gate valve, to perform an automatic-brake pressure-increasing control to control the outside gate valve in a valve closing direction, to drive the hydraulic pressure source, and thereby to increase the pressure of the wheel cylinder in accordance with a vehicle condition, and to increase a driving quantity of the hydraulic pressure source when the brake operation is sensed during the automatic-brake pressure-increasing control.

Abstract: A vehicle brake system for a vehicle comprises at least one source of pressurized air for pressurizing the vehicle brake system, and a brake actuator configured to receive air from the source of pressurized air. A control is operatively associated with the source of pressurized air for selective application of the brake actuator. A supplemental parking brake control system is in communication with the control and the brake actuator. The control system is responsive to data indicative of gradient and speed vehicle conditions. The control system is configured to send a signal to the brake actuator to allow gradient and speed dependent supplemental parking. The control system is configured to prevent application of the brake actuator.

Abstract: A method for determining whether a panic braking maneuver has been initiated in a vehicle with a brake pedal includes the steps of receiving brake pedal travel data, receiving brake pedal force data, determining a rate of change of acceleration of the brake pedal from the brake pedal travel data, determining a rate of change of acceleration of force applied to the brake pedal from the brake pedal force data, comparing the rate of change of acceleration of the brake pedal with a first predetermined value and a third predetermined value, and comparing the rate of change of acceleration of force applied to the brake pedal with a second predetermined value and a fourth predetermined value.

Abstract: A pressure assisted park servo assembly for an automatic transmission includes a servo or spool valve which receives pressurized hydraulic fluid from various sources including two solenoid valves and transmission ports. The servo valve controls two flows of pressurized hydraulic fluid to a servo assembly to place the transmission in or release it from park. The improved park servo assembly exhibits enhanced operating speed.

Abstract: A vent valve made from a standard emergency brake valve portion. It includes an emergency portion body with an interface to be mated with the emergency portion interface of the pipe bracket. The body includes a casting with at least one cover and the casting including all the cast cavities and passages for an emergency portion. A vent valve selectively connects a first brake pipe port to a vent port on the body, A vent piston controls the vent valve and a discharge valve pneumatically controls the vent piston. An emergency piston is responsive to brake pipe pressure for controlling the discharge valve. The body does not include at least one of an inshot valve and an accelerated application valve.

Abstract: A vehicle brake system for a vehicle comprises at least one source of pressurized air for pressurizing the vehicle brake system, and a brake actuator configured to receive air from the source of pressurized air. A control is operatively associated with the source of pressurized air for selective application of the brake actuator. A supplemental parking brake control system is in communication with the control and the brake actuator. The control system is responsive to data indicative of gradient and speed vehicle conditions. The control system is configured to send a signal to the brake actuator to allow gradient and speed dependent supplemental parking. The control system is configured to prevent application of the brake actuator.

Abstract: A combination quick release and service relay brake valve assembly is used to consolidate multiple valve functions within a common valve assembly, which reduces cost and overall complexity in an associated vehicle brake system. The combination quick release and service relay brake valve assembly includes a valve body with a quick release portion that has a parking brake port and a service brake control port, which is in fluid communication with an anti-compounding passage. The valve body also includes a service relay portion that has a supply port fluidly connected to a service brake air reservoir and a delivery port fluidly connected to a brake actuator that generates service brake requests.

Abstract: A self-centering brake for a lift provides for the same braking moment in the case of normal operation and in the case of failure of a brake half. The brake consists of a housing which is U-shaped in cross-section, wherein a limb of the U corresponds with a brake half. The brake halves are of identical construction. An active brake lining and a passive brake lining are provided for each brake half. The active brake lining is loaded by a spring force of a compression spring. In the case of failure of a brake half the passive brake lining takes over the function of the active brake lining.

Abstract: A parking brake system pneumatically actuates an air cylinder to mechanically lock a wheel brake in an applied position in response to a parking demand request. The parking brake system includes a dual hand control that has an electronic control element and a pneumatic control element. The electronic control element communicates with an electronic braking system control unit and the pneumatic control element communicates with a parking brake air reservoir. When the dual hand control is moved to a park position, the electronic control element generates an electronic control signal that applies a parking brake force to the wheel brake. The pneumatic control element generates an air signal that is sent to the air cylinder. The air cylinder includes an extendable shaft that supports a lock member. The air signal moves the lock member into engagement with a brake operating member to lock the wheel brake in the applied condition.

Abstract: The invention relates to a brake system for a railway vehicle. Said brake system comprises a main air reservoir line which is fed by an air compressor unit. Every bogie truck is provided with at least one compressed-air line which is connected to the main air reservoir line either directly or via a stop valve, a non-return valve and a compressed-air reservoir. The compressed-air line feeds, for example, the service brake valves for impinging the brakes of the bogie truck or a control unit for the spring-loaded brake and/or other control units for other auxiliary components. The service brake valves and/or the spring-loaded brake and/or other auxiliary components are controlled via at least one local, electronic brake control unit.

Abstract: The device for automatically resetting the emergency brake on trains, allows the railway staff to maintain control over the train, above all in critical situations, so that the said train can be moved far enough to bring it out of a tunnel or a dangerous situation. The device essentially comprises a handle designed to control the brake, a rotary plate, designed to rotate under the control of the handle and a couple of levers, a main piston which slides inside a couple of chambers designed to realize the automatic resetting of the brake, a tank for storing the air to be used for resetting the device after its activation connected to the main conduit which is used to stop the train, and resetting and monitoring means.

Abstract: An automotive braking system controls the flow of pressurized brake fluid from a tandem master cylinder to several wheel brakes via a pair of braking circuits. Each circuit features a pressure relief line having, in series, a normally-closed valve, low-pressure accumulator, pump, check valve, damping chamber, and throttling orifice. A bypass line includes a normally-closed bypass valve that is operated to interconnect the pressure relief lines of the first and second braking circuits downstream of the pump outlets to thereby reduce system response time when, for example, one or more wheel brakes are actuated to enhance vehicle traction or stability. Braking system redundancy is enhanced with a check valve incorporated in either or both circuits downstream of the bypass connection, or a second normally-closed bypass valve in the bypass line. Fluid pressure monitoring in either or both circuits is further useful in identifying bypass valve leakage.

Abstract: Hydraulic braking apparatus for a motor vehicle, comprising: a service braking system (A), fed by a central hydraulic unit (3); an emergency braking system (B); a hand-control member (D, 16); a master cylinder (17); at least one safety valve (26, 28); a simulator (M), intended to resist the forward motion of the hand-control member (D, 16) with a reaction corresponding to the progress of a braking operation, such simulator comprising a cylinder (30) in which a simulator piston (31) slides while being subjected, in one direction, to a fluid pressure coming from the master cylinder (17) and, in the opposite direction, to a counterforce dependent on the travel of the hand-control member; admission solenoid valves (9a-9d) and exhaust solenoid valves (14a-14d), connected to the wheel brakes (2a-2d); sensors (8, 13a-13d, 24, 29) for the detection of various braking parameters; and a computer (C) capable of controlling the solenoid valves.

Abstract: To monitor the emergency braking capability of an electro-hydraulic braking system (EHBwherein, during normal operation, the brake pressure in the wheel brakes is generated by means of a pressure source comprised of a hydraulic pump, an umulator, and hydraulic valves, and wherein a switch-over to a hydraulic connection between a master cylinder and the wheel brakes is executed in the event of an emergency braking situation. With predetermined events, e.g.

Abstract: The present invention relates to an actuating travel simulator for a vehicle actuating unit, preferably a brake pedal, which simulator includes a hydraulic simulator piston in a hydraulic simulator chamber containing a hydraulic fluid, said simulator being characterized in that the simulator chamber includes at least one opening through which fluid is discharged from or supplied to the simulator chamber when the vehicle actuating unit is actuated, and that an adjusting means is provided to control the fluid volume discharged from the simulator chamber and/or supplied to the simulator chamber in such a way that a defined force-travel characteristic curve of the actuating unit is produced.

Abstract: A brake auxiliary device is proposed, including a resilient mechanism having an upper support member mounted on a bottom surface of a vehicle, and a lower support member properly spaced apart from the upper support member at a position above a wheel shaft of the vehicle; a transmission mechanism positioned between the upper and lower support members of the resilient mechanism, and rotatably abutting against the lower support member; and a drive mechanism coupled to the transmission mechanism, for outputting power to operationally drive the transmission mechanism. The transmission mechanism is adapted to operate to induce displacement of the lower support member with respect to the upper support member, and to generate up and down movement for the vehicle, so as to raise vertical upright pressure applied from wheels of the vehicle to the ground, and thereby increase friction between the wheels and the ground in favor of braking implementation.

Abstract: The invention relates to a brake system (100) for a railway vehicle (1). Said brake system comprises a main air reservoir line which is fed by an air compressor unit (22). Every bogie truck (3) is provided with at least one compressed-air line which is connected to the main air reservoir line either directly or via a stop valve, a non-return valve and a compressed-air reservoir. The compressed-air line feeds, for example, the service brake valves for impinging the brakes of the bogie truck (3) or a control unit for the spring-loaded brake and/or other control units for other auxiliary components. The service brake valves and/or the spring-loaded brake and/or other auxiliary components are controlled via at least one local, electronic brake control unit (31).

Abstract: A combination valve assembly provides dual functionality within a single valve housing. In one example, the valve operates as a combination inversion valve and quick release valve. In another example, the combination valve operates as an inversion valve and a relay valve. The valve is particularly useful for controlling the operation of a spring applied, air release brake actuator in a heavy vehicle braking arrangement. A valve designed according to this invention preferably also provides anti-compounding features.

Abstract: An enhanced emergency brake assist system includes an accelerator pedal operated by the driver coupled to a braking system and used to control the overall vehicle speed. When a forward detection apparatus detects an imminent contact, the braking system automatically applies braking force to the vehicle after the driver fully releases the accelerator pedal. The braking force may be reduced when the driver or passenger are unbuckled.

Abstract: The invention provides an emergency brake apparatus for a vehicle which can brake both of front and rear tire wheels of a vehicle by using an oil pressure, at an emergency time. For this purpose, a pressure oil of a hydraulic power source is changed to a pilot oil pressure which is reduced from a high pressure to a low pressure in correspondence to an operation amount of an emergency brake valve (77) operated at the emergency time, and this pressure is output to a relay valve (3). The pressure oil of the hydraulic power source is increased in an inverse proportional manner from a low pressure to a high pressure in correspondence to the pilot oil pressure, and this pressure is output to a front tire wheel brake (64), thereby urgently braking the front tire wheel.

Abstract: The invention relates to a device for controlling a braking arrangement on a heavy vehicle. The braking arrangement comprises a main brake, which includes braking devices (1a -f), for example disc brakes, that are each arranged to act on one of the vehicle wheels (2a-f). Furthermore, the braking arrangement comprises at least one auxiliary brake (3) and a brake control (10) with which the named main brake (1a-f) and auxiliary brake (3) are activated. When a driver activates the brake control (10), a control unit (9) in the arrangement is arranged to initiate activation of the main brakes (1a-f) and the auxiliary brake (3) and thus distributes the braking effect between these brakes in such a way that the braking effect requested by the driver is obtained in the shortest possible time and in such a way that the use of the brake devices (1a-f) of the main brake is minimised after an initial period. The invention relates to a braking system for a heavy vehicle, which comprises an arrangement described above.

Abstract: An enhanced emergency brake assist system includes an accelerator pedal operated by the driver coupled to a braking system and used to control the overall vehicle speed. When a forward detection apparatus detects an imminent contact, the braking system automatically applies braking force to the vehicle after the driver fully releases the accelerator pedal. The braking force may be reduced when the driver or passenger are unbuckled.

Abstract: A supplementary brake for a vehicle adapted for use in a heavy duty vehicle to supplement the capacity of a main brake system for obtaining sufficient braking efficiency. The brake comprises an oil pressure supplying unit, an oil pressure control unit for controlling oil pressure, a pulsatory pressure forming unit for forming a pulsatory pressure to the oil pressure supplied from the oil pressure control unit to the profile of an engine injection cam, a valve opening and closing unit for opening an closing an exhaust valve of an engine according to the pulsatory pressure formed by the pulsatory pressure forming unit, and a controller for controlling the oil pressure supply unit according to the operating state of the engine.

Abstract: An electrical circuit for selectively operating a vehicle parking brake (16) with the energizing and de-energizing of a coil (50) of a solenoid valve (30) in response to an operator input. The electrical circuit comprising a source of electrical energy (V Bat), an operator actuable switch (47) connected by line (59) to the coil (50) and a first microprocessor (49) which in turn is connected by an electronically controllable switch (45) through a low side driver (51) to connect line (57) from coil (50) with a ground (55) and a second microprocessor (53) connected to the first microprocessor (49) and electronically controllable switch (45) for detecting erroneous first microprocessor (49) operation.

Abstract: A rear axle braking system for a vehicle has a primary electronic braking circuit supplied with a source of primary braking pressure and a mechanical back-up braking circuit supplied with a source of back-up braking pressure. The braking actuator receives braking pressure and thereby brakes a wheel on a vehicle axle. During braking, a changeover valve is normally actuated to apply the primary braking pressure to the braking actuator. In the event of an electronic system failure, the changeover valve is not applied and instead the source of back-up braking pressure is supplied to the actuator. A regulating valve is located in the back-up braking circuit between the source and the changeover valve and is operable as a function of axle loading and back-up brake pressure to control the supply of back-up braking pressure to the changeover valve. The application of additional braking pressure to a wheel can be limited if the loading on the axle is likely to result in vehicle instability when braking.

Abstract: An autonomous emergency braking system includes an accelerator pedal operated by the driver coupled to a braking system and used to control the overall vehicle speed. When a forward detection apparatus detects an imminent contact, the braking system automatically applies braking force to the vehicle while the vehicle engine speed is reduced. The amount of brake force applied is a continuous function of relative speed, relative distance, collision probability and target classification. The braking force may be reduced when the driver or passenger are unbuckled or may be disabled if the driver applies full throttle.

Abstract: An electropneumatic brake system for motor vehicles includes a multiple-circuit service brake and a foot activated braking power transmitter that provides the desired brake pressure values pneumatically and electrically. The braking power transmitter is connected at least to one braking circuit which has pneumatic brakes on at least two vehicle axles, including at least one electric, sensor-influenced control device and including electromagnetic valves that are combined in modulators for adjusting or controlling the compressed air that is supplied to the brake cylinders. During normal drive operation, the modulators allocate the compressed air electrically to the brakes while, during emergency operation, the modulators allocate the compressed air pneumatically to the brakes. The brake system has at least two separate pneumatic braking circuits, which can make due with relatively few modules and short compressed-air paths.

Abstract: An electric control system for an automotive vehicle, including a peripheral control device for electrically controlling an actuator device, a central control device connected to the peripheral control device, and an input device, wherein the central control device and the peripheral control device cooperate with each other to control the actuator device on the basis of an output of the input device. The input device is connected to both of the central control device and the peripheral control device.

Abstract: A dual mode brake system includes a first fluid actuated brake and a second spring actuated fluid released brake configured to spring actuate the first brake in the absence of receiving sufficient fluid pressure at the second brake. A first fluid control circuit variably supplies fluid to the first brake from a source of pressurized fluid. A second fluid control circuit controllably supplies fluid to the second brake from the source of pressurized fluid. The third fluid control circuit controllably supplies fluid to the second brake based on the pressure of the fluid received by the third fluid control circuit from the first fluid control circuit and the pressure of the fluid received by the third fluid control circuit from the second fluid control circuit.

Abstract: A system reliably communicates brake commands from a master controller on a lead locomotive to the brake equipment on each rail vehicle of a freight train. The system includes a mechanism for detecting whether the brake commands are being successfully communicated over a communications channel that is normally used to convey such commands from the master controller to the brake equipment on each rail vehicle. The system also includes on each rail vehicle a mechanism for communicating the brake commands that is independent of the communications channel. The mechanism for communicating conveys the brake commands from the lead locomotive to the rail vehicles only when the mechanism for detecting determines that communication over the communications channel has failed. The system further includes on each rail vehicle a mechanism for receiving the brake commands from the lead locomotive via the mechanism for communicating.

Abstract: A pneumatically-operated braking system for a tractor-trailer combination incorporates a trailer control valve (4) for providing braking pressure for the trailer. The control valve (4) is adapted to be actuated by a pressure differential acting across it to limit the flow of air in the supply line (2) when a leak is present in the trailer control line (12), and the pressure differential is generated between the pressure in the supply line (2) and pressure supply from another independent source (1).

Abstract: A vehicle capable of performing automatic driving can be braked with a hydraulic braking pressure produced by a master cylinder having a vacuum booster and a hydraulic braking pressure produced by a hydraulic pressure pump provided to an ABS/B-TCS hydraulic pressure control unit. During normal braking, the vehicle performs braking with the hydraulic braking pressure produced by the master cylinder, by controlling a linear solenoid of the vacuum booster in accordance with a command from an automatic driving electronic control unit. If an insufficient braking force is obtained from the hydraulic braking pressure produced by the master cylinder or a failure occurs in the braking system of the master cylinder, the vehicle performs emergency braking with the hydraulic braking pressure produced by the hydraulic pressure pump of the ABS/B-TCS hydraulic pressure control unit HU.

Abstract: A brake system valve having an anti-compounding feature is provided, comprising: a brake housing; a vent port in the housing; first and second control ports in the housing; a piston mounted within the housing, the piston having a passage connecting the vent port in fluid communication with the first control port when the piston is in a first position, the piston moveable to a second position to seal the vent within the housing.

Abstract: An automatic emergency brake system for an automotive vehicle with an assistor having a backward push rod connected to a forward push rod coupled with a master cylinder's piston via a power piston and pushing the power piston so as to augment a force applied to a brake pedal by a driver, including a partition fixed to the backward push rod; a return spring disposed between the partition and a poppet; moving stoppers each having a moving rod, going in and out of a backward pushing rod housing, to support the back of the partition; an emergency spring disposed compressed between the moving stoppers and a housing end; a controller electrically connected to the moving stoppers to output a driving signal to the moving stoppers in accordance with a deceleration; and a deceleration/acceleration sensor electrically connected to the controller to input a reduced speed of the vehicle to the controller.

Abstract: Process for temperature-dependent actuation of a supplemental pressure medium source in slippage-controlled motor vehicle braking systems. The invention pertains to a process for operating a slippage-controlled motor vehicle braking system with regulation of driving dynamics. In such systems it has thus far been proposed to turn on supplemental pressure medium sources to support the supply pump when regulation starts, in order to shorten the regulation time. Practical studies have shown that such supplemental sources are, first of all, not needed for each regulation process and, second, cause disruptive noise. The invention thus proposes to turn on the supplemental pressure medium source only in the presence of special situations, such as if the pressure medium is very viscous due to low temperatures. Advantageous refinements are concerned with determination of the temperature.

Abstract: The invention provides a real time process control system for control of machinery. The system has a master control module and a slave control module which receives control signals from the master control module. Both control modules send control signals to a control effector and cause changes in at least one effect causing quality of the control effector. The slave control module establishes a target value for the effect causing quality of the control effector based on the signal it receives from the master microprocessor. A sensor connected to the control effector and to the slave control module provides signals in the slave control module which indicate an actual value for the effect causing quality of the control effector. A feedback loop controls the control signal from the slave microprocessor to the control effector to adjust the value of its effect causing quality in accordance with the target value.

Abstract: A braking system is disclosed that has a manually-actuatable master cylinder having two pressure chambers. A first pressure chamber hydraulically controls a flow control valve through which the pressure medium flows during servo-braking in order to adjust its regulating cross-section to produce a defined dynamic pressure that is applied to a first piston/cylinder arrangement, connected to the flow control valve, of a brake application element to produce a braking force. A second pressure chamber can be connected to a second piston of a brake application element so that a braking force can be applied to the brake application element if the servo-force fails. Also, instead of the second piston/cylinder arrangement, a separate separator piston/cylinder arrangement can be provided that is inserted between the second pressure chamber and the piston/cylinder arrangement. As a result, sufficient braking force is produced both in servo-force braking and if the servo-force fails.

Abstract: A braking system including a brakepipe control valve which controls pressure on a brakepipe in response to braking pressure signal from an electropneumatic converter. An electropneumatic cutoff valve connects the control valve to the brake pipe. A controller controls the converter and cutoff valve. A parking brake system and retarder control system are also included and are controlled by the controller.

Abstract: A simplified integrated full-function valve for heavy duty brake systems comprising a valve body having individual ports for fluid communication with spring brake chambers, service brake chambers, pressurized-air reservoir and exhaust and for receiving pressurized control and supply air from respective sources thereof; internal passageways within the valve body providing selected fluid communication with the various ports; a plurality of valve modules within the valve body comprising a spring brake valve module, a relay valve module and a biased one-way pressure protection valve module, and disposed to selectively determine the fluid communications within the internal passageways and ports responsive to the respective positions of the valve modules; the port and related internal passageways for the spring brake chambers being fluid-communicatively-isolated from the reservoir, the service brake chambers and the control air, whereby the number of the internal passageways within the valve body is minimized; the

Abstract: A travel simulator having a progressive pedal characteristic to be in operation in a power-actuated service brake. The hydraulic brake system has a valve assembly for the switching of the brake system into operation as either a service brake or as an emergency brake. The master cylinder has a pressure fluid reservoir, two pressure chambers, and an intermediate piston as well. The intermediate piston is supported on a travel simulator spring. When the service brake is in operation, pressure fluid can be diverted from the second pressure chamber into the reservoir, and the intermediate piston is moved against the resistance of the spring. When the emergency brake is in operation, both pressure chambers communicate with one another so that the intermediate piston is pressure balanced. When the pedal is actuated, pressure fluid is expelled from the first pressure chamber. The intermediate piston is not subject to any motion during an emergency brake operation. The brake system is for use in road vehicles.

Abstract: An electronic braking system for a vehicle having foundation brakes (137, 138) and a vehicle retarder (129), wherein an electrical braking demand signal (D) is generated from a single brake pedal and wherein the retarder (129) is operated variably or in small steps as the brake pedal movement is increased from a zero or rest position up to a partial point in its movement range which is calculated to give substantially maximum retarder powder based on the total mass of the vehicle. As a result, for a fully loaded condition this partial point occurs at low pedal deflection and, in an unloaded condition where a given retarder will produce a higher deceleration, this point occurs at a higher pedal deflection, wherein in both cases pushing the pedal beyond the calculated partial point causes foundation braking to be commenced to supplement the retarder torque.

Abstract: A full function valve incorporating a proportioning valve module that initially directs supply air pressure during initial system charging to the spring brake chambers to prepare the spring brakes for prompt release when there is sufficient system supply air pressure to operate the service brakes. The proportioning valve module then opens to increase supply air pressure to the reservoir, while charging of the spring brake chambers continues, until the service brakes become operable and the spring brakes disengage.

Abstract: A unitary full-function valve is used to control the operation of a service brake system and a spring brake system. The valve includes a valve body that has multiple ports, including separate ports for providing fluid communication to a spring brake chamber, a service brake chamber, a fluid reservoir and an exhaust port. The valve body also has ports for receiving pressurized supply fluid and control fluid. The supply fluid inhibits the activation of the spring brakes so that the spring brakes are activated when no supply fluid is present. The control fluid is used to activate the service brakes on demand. A biased one-way pressure protection valve is disposed in the valve body to isolate fluid in the service brake system from fluid in the spring brake system when the pressure in the service brake system falls below a variable pressure level.

Abstract: A braking system for a vehicle having primary and secondary braking circuits includes a secondary braking circuit having a secondary source of braking pressure connectable to a braking actuator and including a three-port, two-position, inlet solenoid valve having two inlet ports and one outlet port. One of the inlet ports is connected to an outlet of an inlet solenoid valve of the primary braking circuit and to the inlet of an exhaust solenoid valve of the primary braking circuit. The other inlet is connected to a secondary source of braking pressure. The outlet port is connected to the braking actuator. The inlet solenoid valve is movable by an output signal from an electronic control unit.