Abstract: A pneumatic brake pedal module for a “brake-by-wire” brake system of a vehicle is disclosed. The brake pedal module has a pivotably mounted brake pedal and having a damping unit, which is mechanically coupled to the brake pedal to generate a resistance when the brake pedal is actuated, such that the damping unit is subjected to tension when the brake pedal is actuated.

Abstract: A pedal simulation device, comprising: a housing; an abutment region that is coupled with the housing in a substantially rigid manner; a piston that is received in the housing and can be moved in a direction of actuation by passing through successive first and second actuation phases; and a return device that is configured to exert a resetting force on the piston that acts counter to the displacement of the piston in the direction of actuation.

Abstract: Device for a brake travel emulator with at least one integrated sensor, comprising a housing (5), a force sensor (18) both being connected to a middle part of a connection means (4). The force sensor (18) being arranged at a static unit (2), the housing (5) further comprising at least one conical compression spring (6), an axially sliding component (7), a connecting rod (9) comprising a varying diameter geometry, an oscillating means (48) capable of creating an electric field, and a displacement sensor (46), the force sensor (18) further comprising, a micro-controller (50), means for receiving applied force (41) and at least four coils (30, 31, 32, 33).

Abstract: Systems, methods, apparatuses, and computer program products for node de-duplication. One method includes discovering, by a network monitoring apparatus, nodes in a network, and collecting a list of internet protocol (IP) addresses, media access control (MAC) addresses, domain name system (DNS) names, and sysnames for each of the nodes discovered in the network. The method may also include comparing the collected list of information for each of the discovered nodes with corresponding information for current nodes and other discovered nodes. The method may then includes determining duplicate nodes that are duplicates of the other discovered nodes and/or the current nodes based on the comparison of the IP addresses, MAC addresses, DNS names, and sysnames.

Abstract: A foot brake valve apparatus is provided for a heavy vehicle braking system. The foot brake valve apparatus comprises a valve body having a first side face and a second side face opposite the first side face. The apparatus further comprises a primary supply pressure port associated with a primary braking circuit and adjoining the first side face, and a primary delivery pressure port associated with the primary braking circuit and adjoining the first side face. The apparatus also comprises a secondary supply pressure port associated with a secondary braking circuit and adjoining the first side face, and a secondary delivery pressure port associated with the secondary braking circuit and adjoining the first side face.

Abstract: An air brake locking device for a vehicle includes a main body having a pair of internal channels capable of connecting to a vehicle air line, a valve interposed between the internal channels for controlling the flow of air, and a control unit for regulating the operation of the valve.

Abstract: To determine an inhomogeneous roadway in ?-split situation during active ABS control and active yaw torque control (YTC) of a front wheel (HM-wheel) on the high-coefficient-of-friction side, it is arranged that at least the following conditions must be satisfied before the ?-split situation is flagged: a) a front wheel (LM wheel) undergoes ABS control in a pressure reduction phase; a1) the LM front wheel is in the first ABS control cycle; b) the LM front wheel exhibits a deceleration exceeding a defined threshold; c) the locking pressure level of the LM front wheel is lower than a defined threshold; d) the front wheel on the high-coefficient-of-friction side (HM wheel) exhibits a filtered deceleration that is lower than a defined threshold; e) the vehicle deceleration calculated by ABS is lower than a defined threshold.

Abstract: A brake hydraulic pressure generator is proposed in which the brake stroke fluctuate less when the amount of brake fluid consumed in the wheel brakes fluctuates. Even when the brake pedal force is increased after the brake assisting force has reached its maximum, the reaction force to the pedal force as well as the master cylinder pressure increases corresponding to the increased pedal force. The brake hydraulic pressure generator has a control valve including a spool and a cylinder and adapted to control the hydraulic pressure in a dynamic pressure chamber to a value corresponding to the stroke of an input shaft. It further includes a pressure sensor, a solenoid valve and a fluid chamber.

Abstract: An actuating device for a brake unit of a vehicle EBS includes a tappet positioned in a housing of the brake unit for actuating a piston to operate a brake valve. A displacement sensor slide measures axial movement of the tappet. So that moving parts of the actuating device are guided with minimal friction and that torque acting on the tappet is compensated for, the tappet includes a base plate disposed non-rotatably in a receiver of a guide ring having spaced-apart oblong holes, a spacer ring disposed in the guide ring having angled edges which extend into the oblong holes, and a window on the guide ring protruding radially outwardly into a slit on the housing to receive the displacement sensor slide.

Abstract: An actuating device for a brake unit of a vehicle EBS includes a tappet positioned in a housing of the brake unit for actuating a piston to operate a brake valve. A displacement sensor slide measures axial movement of the tappet. So that moving parts of the actuating device are guided with minimal friction and that torque acting on the tappet is compensated for, the tappet includes a cylindrical attachment having a bottom with holes and a shell, a groove on the outer surface of the shell having openings, a spacer ring in the cylindrical attachment between the tappet and the piston having projections which extend into the holes, a guide ring in the groove having raised portions on its inner surface which extend into the openings and a window on its outer surface protruding through an opening into a slit on the housing to receive the displacement sensor slide.

Abstract: A hydraulic pressure brake device for a vehicle includes a first piston outputting brake pressure generated in a first pressure chamber and a second piston having a larger diameter than that of the first piston and provided rearward of the first piston and forming a second pressure chamber having a larger diameter than that of the first pressure chamber. The hydraulic pressure brake device further includes a valve device closing the second pressure chamber hydraulically when actuation of the first piston and the second piston is assisted by the assisting device and establishing hydraulic communication between the second pressure chamber and the reservoir when the assisting is not carried out. The first pressure chamber is connected with wheel cylinders provided on front wheels through a first hydraulic pressure system and the second pressure chamber is connected with wheel cylinders provided on rear wheels through a second hydraulic pressure system.

Abstract: A brake pedal emulator that produces a pedal characteristic not unlike conventional vacuum or hydraulic brake systems. The system includes an emulator housing, a damper positioned within the emulator housing, a shaft that is slidably received by the emulator housing, and a sequential spring system within the emulator housing in operable contact with the shaft. When a brake pedal force is manually applied, the sequential spring system compresses thereby providing a spring force, which in conjunction with the dynamic dampening force produced by the damper generates the desirable reaction force.

Abstract: An extension handle for a manual valve connected at its first end to the stem of the valve by a pin which extends through the extension handle, the standard handle and the valve stem. A handle bracket may be mounted to the manual valve.

Abstract: A brake system including a master cylinder for generating pressurized fluid, a wheel brake in fluid communication with the master cylinder, and a first valve for regulating the flow of fluid between the master cylinder and the wheel brake. The brake system further includes a pedal travel simulator including a housing having a bore formed therein. A piston is slidably disposed in the bore. The piston and the housing generally defining a fluid chamber which is in fluid communication with the master cylinder. The pedal travel simulator further includes a spring which biases the piston in a direction so as to contract the fluid chamber. The brake system further includes a source of pressurized fluid and a boost valve which is in fluid communication with the source of pressurized fluid and the wheel brake.

Abstract: A pressure control valve equipped with a solenoid valve, in which a main valve body is provided with an air-supply chamber connected to a pressurized air source, a control pressure chamber into which pilot pressure is input, an output chamber connected to an air-pressure apparatus, and an air-supply valve which establishes contact between and isolates such air-supply chamber and such output chamber. Such pressure control valve further includes a pressure-adjusting piston which is urged one way by a pressure-adjusting spring and is urged the other way by such pilot pressure of such control pressure chamber, and a hollow exhaust valve rod is provided integrally with such pressure-adjusting piston to open or close such air-supply valve in accordance with such pilot pressure; and in which such solenoid valve supplying such pilot pressure to such control pressure chamber is attached to such main valve body.

Abstract: A manually operable pneumatic emergency brake valve and electric switch including a valve body having an inlet port and an outlet port, an internal valve assembly normally seated by the biasing force of a helical spring, a pair of pivotal levers for operating a movable valve stem to unseat said internal valve assembly, and said movable stem including a cam surface for actuating the electric switch to signify an emergency brake application.

Abstract: A tamper-resistant independent brake valve device for use in a brake equipment on railway locomotives including a main body casing carrying a movable handle, a rotatable cam, a pivotal cam dog and an exhaust and supply valve assembly, a spring housing attached to the main body casing by a plurality of one-way screws, a break-away adjusting screw for setting the maximum brake cylinder pressure on the railway locomotive, the pivotal cam dog including an enlarged head portion to preclude the insertion of a prying tool, and the pivotal cam dog having cam engaging roller which is rotated on a round head roller pin.

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

Abstract: A brake apply control system for a vehicle. The control system has a selectively operable mechanical brake apply portion and a selectively operable hydraulic brake apply portion. The mechanical brake apply portion includes an operator linkage for connecting the operator with a mechanical brake apply mechanism and a hydraulic piston and valve combination for providing a hydraulic feedback force to the operator. The hydraulic brake apply portion includes a source of hydraulic pressure, a brake apply valve for supplying a selective brake signal of variable intensity in response to operator input, a conduit system which connects the source of hydraulic pressure to the hydraulic piston and valve combination and which communicates the brake signal to the hydraulic piston and valve combination.

Abstract: A braking system for a vehicle. The braking system provides continuous tactile feed back through the brake pedal to the operator of the vehicle that conforms to the degree to which the vehicle brakes are being applied so that the tactile feed-back to the operator conforms to the visual and kinesthetic input received by the operator. The braking system has a brake pedal that is mounted to be depressed in response to a force applied thereto by the vehicle operator. The braking system incorporates both a mechanical brake actuating mechanism and a hydraulic brake actuating mechanism. The braking system provides for selective actuation of the mechanical brake actuating mechanism sequentially in advance of the hydraulic brake actuating mechanism when the brake pedal is depressed. A linkage assembly is incorporated in the mechanical brake actuating mechanism. The linkage assembly provides tactile feed-back to the brake pedal throughout the range of operation of said braking system.

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: A brake pedal actuation sensor includes an optical coupler. In a preferred embodiment: the optical sensor is carried by a housing; a shutter is provided to interrupt the optical coupling according to the distance between the housing and a bearing; the shutter is carried by the bearing; and the distance between the housing and the bearing is dependent upon the force applied to the brake. Additionally, a circuit responsive to an output of the optical coupler is provided for generating an electrical output signal indicating brake pedal actuation.

Abstract: A brake control has a regulator valve to establish the pressure in the brake system during brake apply. A flow regulator valve permits a fast flow rate for filling of the system when brake apply is initiated and a slow flow rate when the brake system pressure approaches the value established by the regulator valve.

Abstract: An electronically controlled brake device for controlling a brake pressure according to a manual input. While the dynamic pressure line is functioning normally, the dynamic pressure acts on one end of a push rod associated with a brake pedal to give such a force as to counteract the control input to the brake pedal. If the dynamic pressure line fails, the push rod comes into contact with a dynamic pressure piston to transmit the control input force to a master cylinder. An electronic pressure control valve is provided to adjust the connection of the dynamic pressure source with a reservoir and with a dynamic pressure chamber in response to the commands of an electronic control unit so that its output pressure will be in a predetermined relationship with the pedal stroke. Thus in normal conditions, a desired deceleration is obtained with a shorter pedal stroke and in the failure of dynamic pressure, a minimum deceleration is obtained with a lighter pedal force.

Abstract: A hydraulic braking system for an automotive vehicle having a power source for generating a hydraulic power pressure, a reservoir, a master cylinder having a master piston, a hydraulic booster for actuating the master cylinder in response to depression of a brake pedal and a plurality of wheel brake cylinders connected to the master cylinder for braking respective road wheels. The hydraulic booster is provided with a power piston which is larger in diameter than the master piston. The power piston transmits a force to the master piston through a closed chamber which is defined between the power piston and the master piston, when the hydraulic power pressure is supplied to the hydraulic booster in response to depression of the brake pedal. The closed chamber is filled with a brake fluid which is supplied from the reservoir. Thus, a small stroke of the power piston will suffice for operating the master piston at a predetermined stroke, so that the stroke of the brake pedal is reduced.

Abstract: A port control member is depressed by either a mechanical force applied on it by the pilot, for moving it to meter pressure and flow from a supply pressure to the wheel brakes, or a hydraulic pressure force applied following take-off, to actuate the brakes for stopping the wheels from spinning. The valve housing defines an annular pressure chamber surrounding a portion of the port control member. The port control member includes a feedback passageway between the pressure chamber and a feedback chamber formed between the inner end of the port control member and the valve housing. The port control member is also surrounded by a sleeve which has an inner surface extending radially outwardly from the inner end of the port control member. The feedback passageway, which can include a damping orifice, produces a feedback force to the pilot which is increased when the sleeve is jammed with respect to the port control member.

Abstract: A vehicular brake lever arrangement is shown as having a brake lever pivotally supported at one end and a swingable other end provided with a pad for the application of a braking force thereto; a brake rod linkage leading to the vehicular braking system is pivotally connected to the brake lever as to have a slight translational movement relative to the brake lever; and a force sensitive resistor is placed as to experience a force thereagainst as such translational movement occurs between the brake lever and brake rod linkage.

Abstract: A vehicle hydraulic braking system for applying the wheel brakes of an automotive vehicle comprising: a reservoir for holding a hydraulic brake fluid; a pump fluidly connected with the reservoir for pressurizing the fluid; at least one first valve fluidly connected with the pressurized fluid from the pump and the first valve being connected with a modulation sump, the first valve delivering a modulated brake pressure to at least one wheel brake at a ratio of the master cylinder pressure to the wheel pressure so long as the fluid pressure from the pump is above a predetermined value; and a second valve fluidly connected with the wheel brake, the master cylinder, the modulated brake pressure, and with the pump and, whereby the second valve isolates the master cylinder from the wheel brake when the pump pressure is above a predetermined value delivering modulated pressure to the wheel brake and when the pump pressure is below a predetermined value the second valve connects the master cylinder with the wheel brak

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 braking device for use in a motor vehicle has a vacuum motor having a casing, a power piston displaceably mounted in the casing through a diaphragm which partitions the interior of the casing into a constant pressure chamber and a variable pressure chamber and which is adapted to be displaced by the pressure difference between the two chambers. A input rod of the braking device is connected to the brake pedal. A valve mechanism is disposed in the power piston and controls the pressure in the variable pressure chamber in response to force applied to the input rod. A control valve is connected to the vacuum motor and adapted to be electrically controlled by a controller to selectively supply driving pressure to the vacuum motor.

Abstract: An electrically-controlled motor vehicle brake system, which responds to fluid pressure supplied from a common source. The system includes an electronic control system to process information and issue brake commands. A brake cylinder, to apply and release brake pressure on each respective wheel brake, receives pressure from at least one solenoid valve, connected to receive pressure from the source. The pressure is communicated to the brake cylinder of each respective wheel brake upon receipt of a control signal from the control system. A brake power selector includes both a pedal-operated brake valve, connected on an input side to receive pressure from the source, and connected on an output side to a ventilation portion of the solenoid valve for modulating the brake pressure, and an electrical frequency selector is connected to provide an input signal to the electronic control system upon actuation by an operator of such vehicle during a brake application.

Abstract: A hydraulic booster including a power piston, a booster chamber for applying a boost pressure to the power piston, an input rod, an intermediate inlet chamber for introducing a power source pressure thereinto, a valve mechanism provided in a valve chamber of the power piston and a differential pressure regulating valve subjected to a valve opening pressure equal to a sum of a spring pressure and a pressure of the boost chamber and a valve closing pressure equal to a pressure of the intermediate inlet chamber so as to control opening and closing of a communicating path for introducing the power source pressure into the intermediate inlet chamber such that pressure of the intermediate chamber is kept higher than the pressure of the boost chamber by a predetermined value at all times.

Abstract: A control valve for a fluid pressure braking system includes a housing which receives a pair of identical plungers and corresponding springs acting on the plunger which activate automatically at different trip pressures. The differential trip pressures are attained by providing different valve seating areas on the housing and spring cavities of different depths.

Abstract: An automotive vehicle braking device comprises a hydraulic master cylinder (11) having at least one piston (21) for pressurization of the wheel cylinders connected thereto with hydraulic pressure and also having a vacuum brake force booster (12) inserted between the brake pedal (52) and the piston (21). The master cylinder (11) is integrated in the construction of the vacuum brake force booster (12).

Abstract: The present invention is a braking value transmitter with a pedal to modulate the braking pressure. The pedal is braced against a spring. The force exerted by the pedal or the position of the pedal is sensed by an electronic sensor. The output signal of the sensor is fed to an electronic system, which transforms the approximately linear characteristic of the sensor into a progressive characteristic.

Abstract: An integrated anti-lock braking system includes a master cylinder, a modulator valve assembly, an electric motor pump, a brake proportioning valve, and a differential pressure valve all integrated into a common assembly. Primary and secondary fluid passages defined within the housing are provided to communicate the various devices included within the assembly. The assembly includes a bracket engaging portion upon which a mounting bracket is provided to attach the assembly to the vehicle and which is capable of mounting the assembly to accommodate mounting at selected angles.

Abstract: A setpont adjuster for a brake pedal in a motor vehicle to control an electric brake system. The setpoint adjuster includes a displacement sensor and a force sensor in parallel-connection, in which the force sensor supplies the reference value. Electronic main circuits are connected subsequently to the sensors and test the signals of the sensors for reasonableness according to different criteria and control a warning light in case of a fault.

Abstract: In a hydraulic brake system for a vehicle of the kind comprising a fluid pressure source having a reservoir and a hydraulic booster having a power piston arranged to receive the pressure fluid of a control fluid chamber which is proportional to a stepping down force on a brake pedal, a normally open type valve is disposed in a fluid passage provided for returning the pressure fluid of the control fluid chamber to the reservoir and is arranged to close in response to a braking pressure retaining signal produced when the vehicle is stopped by brake application.

Abstract: For attaining an abrupt change in ratio, in a slip-controlled brake system for automotive vehicles, the chamber (11) of a fast-fill cylinder (4) is connected to a plunger chamber (41) of the braking pressure generator (1) which is acted upon by the booster piston (40), while the pressure line (7) leading from the plunger chamber (41) to the fast-fill cylinder (4) contains a pressure-controlled directional control valve (8) governing a pressure-fluid conduit to the pressure-supply reservoir (31). The annular chamber (50) of the fast-fill cylinder (4) is connected by way of a return line (55) to the pressure-supply reservoir (31) and with the prechamber (18) of the master cylinder (15) by way of a pressure line (56), while a pressure-controlled two-way/two-position directional control valve (9) with a non-return valve connected in parallel thereto is arranged in the return line (55).

Abstract: A method and a multi-circuit brake booster for feeding back disruptions of any arbitrary kind, even of an associated anti-skid brake system, to a then-changed brake pedal characteristic, the influence on the brake valve triggering being effected via a travel simulator device. The transmitting member in the travel simulator device is a travel simulator spring enabling a predetermined idle pedal travel, and this spring responds whenever, in response to an arbitrarily generated disruption signal, a lockable storage element assumes its other position and mechanically engages a transmitting member in the chain from brake pedal actuation to brake valve slide actuation in an arresting manner. Upon reaching a predetermined amount of biasing, as a result of the further compression of the travel simulator spring, the opening of the brake valve then takes place abruptly, with a corresponding increase in brake pressure and a corresponding increase in vehicle deceleration.

Abstract: A relay valve device which is actuated by the presence of a control signal pressure to a higher pressure supply into a consumer circuit than when the control signal pressure is not present. The relay valve device includes a first control surface and a second control surface, and includes a shut-off device disposed in the feed line of the control pressure to the second control surface. The shut-off device is opened when the control signal pressure is present and is closed when the control signal pressure is not present, and also causes the second control surface to be connected with atmosphere.

Abstract: A brake system wherein the piston (2) of a master cylinder (1) is actuated by the pressure controlled by a brake valve (6), a monitoring device is provided for detection of fail conditions. The monitoring device comprises a switch (18) which is closed by a trip cam (17) upon an actuating distance (s.sub.1) having been traveled by the actuating element (4), and further switches (20, 21), the switch (20) being closed after an actuating travel distance (s.sub.21) and the switch (21) being closed after an actuating travel distance (s.sub.22), each by a trip cam (19) at the master cylinder piston (2). If the master cylinder piston (2) has not yet traveled the actuating distance (s.sub.21) or has already traveled furher than the distance (s.sub.22) when the switch (18) closes, an evaluating circuit (22) which evaluates the positions of the switches (18, 20, 21) will switch on a signal lamp (23) to indicate a fail condition in the brake system.

Abstract: An hydraulic booster has a housing provided with an input member, a boost piston, an output member, and connections to a source of pressure and a fluid reservoir. A force applied to the input member is transmitted to the output member and augmented by the boost piston in response to pressurization of a boost chamber controlled by a valve mechanism in response to operation of the input member. An auxiliary chamber is defined between the boost piston and the output member. In a first stage of operation to take up lost-motion in the system, the auxiliary chamber is supplied with fluid from the source to advance the output member relative to the boost piston through a distance determined by a limiting mechanism. In a second stage of operation the output member and the boost piston move together in response to pressurization of the boost chamber. The area of the boost piston on which the auxiliary pressure acts is greater than or equal to the effective area of the boost piston.

Abstract: In an hydraulic booster for a vehicle braking system a boost piston provides an output force in response to pressurization of a boost chamber under the control of a boost valve mechanism, which controls communication between the boost chamber and a pressure source and the boost chamber and a fluid reservoir. The operation of the boost valve mechanism is controlled by pressure in a control chamber which is pressurized by operation of a pedal-operated input piston. A recuperation valve controls communication between the boost and control chambers, and is operated in response to movement of the input piston. Pressure in the boost chamber acts on the input piston to urge it in a direction to keep the recuperation valve closed. This enables the input piston to work in a bore in the boost piston, with the control chamber in the boost piston and forward of the boost chamber.

Abstract: A hydraulic system for a vehicle having an open-center hydraulic brake booster powered by an engine-driven single rotary pump with an unloader valve into which is incorporated a bypass valve to enable a fluid flow to bypass the unloader valve into the brake booster. The invention contemplates the use of the bypass valve for such purpose as pressurizing the fluid circuit upstream of the bypass valve for storaging fluid in a fluid storage member under pressure in case of rest position of the booster for actuating the booster when the pump failed.

Abstract: A manual/automatic brake valve of the OR configuration wherein either the servo command or the manual pedal force, whichever is the greatest, overpowers the other and is the exclusive controller of the brake pressure and springs are provided to generate a feel force during manual actuation. The feel force is independent of valve spool displacement as a result of the automatic servo input and as a result the feel force is relative to manual brake position and ignores brake force as a result of the servo command.

Abstract: Known brake actuating devices include a pressure source and a valve arrangement operated by a brake pedal with the pressure fluid being fed by the valve arrangement to a control chamber which has as one of its boundaries a pressure piston acting on a master cylinder piston. The pressure piston of the known device is operated mechanically by the brake pedal upon failure of the pressure fluid supply. However, the brake pedal travel is increased in so doing. According to the present invention the control chamber has a second piston forming a boundary thereof opposite the pressure piston which keeps a pressure fluid channel open between the control chamber and the valve arrangement in the normal operating condition and closes the pressure fluid channel during failure of the pressure fluid supply so that the pressure piston is operated by the second piston without any appreciable increase in brake pedal travel.

Abstract: A braking system for a tractor-trailer combination vehicle having air brakes includes a two plunger control valve in which one of the plungers controls the brakes on the tractor and the other plunger controls the brakes on the trailer. However, the valve is designed such that actuation of the plunger controlling the brakes on the tractor to a condition effecting an application of the spring brakes on the tractor automatically actuates the other plunger to effect an automatic actuation of the spring brakes on the trailer. Operation of the plunger controlling the trailer brakes is independent of the plunger controlling the tractor brakes, so that application of the trailer spring brakes may be effected without applying the tractor spring brakes. The tractor spring brakes may be released with the trailer brakes applied to permit bobtail tractor operation or permit the trailer to be parked with the tractor spring brakes released.

Abstract: PCT No. PCT/US79/00595 Sec. 371 Date Aug. 13, 1979 Sec. 102(e) Date Aug. 13, 1979 PCT Filed Aug. 13, 1979 PCT Pub. No. WO81/00386 PCT Pub. Date Feb. 19, 1981Conventional fluid control circuits for service brakes and the like do not always provide an operator with "pedal feel" to indicate the degree of brake engagement. Such "pedal feel" is particularly desirable in braking systems wherein the brakes thereof are spring-engaged and released by hydraulic fluid pressure. This invention provides a control valve (18) having an inlet (20), an outlet (21), a valve member (19) movable betweeen closed and open position, and a first spring (30) for urging the valve member (19) toward its closed position.