Abstract: A brake system for selectively actuating at least one of a pair of front wheel brakes and a pair of rear wheel brakes includes a reservoir and a master cylinder. A power transmission unit is configured for selectively providing pressurized hydraulic fluid. A pair of rear brake motors selectively electrically actuate rear parking brakes. An electronic control unit controls at least one of the power transmission unit and the pair of rear brake motors. A normally-closed DAP valve is located hydraulically between the power transmission unit and at least one of a two-position three-way valve and at least the selected one of the pairs of wheel brakes. An isolation valve and a dump valve are associated with each wheel brake.

Abstract: The present disclosure concerns an assembly (100) for an electromechanical brake booster (200) of a vehicle braking system (1000). The assembly (100) comprises a housing (160) which has a longitudinal axis (L) and can be loaded with an electromechanically generated actuating force, and an output element (150) which extends away from the housing (160) and is configured for transmitting the actuating force to a brake cylinder (300) of the vehicle braking system (1000). The assembly (100) furthermore comprises an elastic element (190) which is supported on the housing (160) and configured to move the housing (160) away from the brake cylinder (300) into a starting position, and a guide (180) which is arranged on the housing (160) for the output element (150) and is configured to guide an angular deflection of the output element (150) with respect to the longitudinal axis (L) of the housing (160).

Abstract: An electric booster for a vehicle including: a disc holder accommodating a reaction disc, a screw nut rotated in conjunction with an operation of a motor, a screw bolt linearly moved in conjunction with a rotation of the screw nut, a boosting block disposed between the reaction disc and the screw bolt, and contacting a radially outer portion of the reaction disc when the screw bolt moves, a pedal rod contacting a radially central portion of the reaction disc through the screw bolt and the boosting block, a disc holder pressing hole connected to the screw bolt, and disposed to face the disc holder, and a first breakage prevention gap part formed between the disc holder and the disc holder pressing hole.

Abstract: A filter for use at an airflow opening of bellows of a shock absorber. The filter device includes a filter body through which a gas, in particular air, can flow in in the direction of an air inflow direction and out in the direction of an air outflow direction. The airflow opening is a joint air inlet and air outlet opening. A fastening means is disclosed that is fitted with a filter, in particular a fastening ring fitted therewith, for fastening bellows to a shock absorber.

Abstract: A system includes a helper piston that includes an axial sleeve that is integral with a guide bracket and that has a threaded exterior surface; a translationally fixed but rotational translation nut that has internal threads that complement those of the helper piston and that supports a gear connected to a drive motor; a plunger piston pushed by the helper piston and connected to a control rod; a trigger spring between the helper piston and the stop carried by the control rod for triggering brake assistance; a stop including a stop sleeve and a flange that is applied to the trigger spring, where the body of the control rod has a crimping area for securing the stop by crimping in an adjusted compression position.

Abstract: A vacuum brake booster includes: at least one movable wall, which separates a working chamber and a vacuum chamber in the vacuum brake booster from one another, and a control valve unit, which is coupled to the at least one movable wall, the control valve unit comprising a guide sleeve and an actuation piston guided displaceably in the control valve unit, which actuation piston is actuatable by way of a force input member which can be coupled in particular to a brake pedal, the actuation piston having at least one first valve seat, which in the open state is used to connect the working chamber to the ambient atmosphere.

Abstract: A vehicle includes a plurality of wheels; a motor configured to apply a driving force to the plurality of wheels; a rain detector configured to detect a precipitation; a temperature detector configured to detect outside temperature; and a controller configured to control a torque of the motor based on the precipitation detected by the rain detector and the outside temperature detected by the temperature detector.

Abstract: A vacuum brake booster for a motor vehicle brake system, comprising a displaceable force input member that is coupled to or can be coupled to a brake pedal, a chamber arrangement arranged in a booster housing having at least one working chamber and at least one vacuum chamber, which are separated from one another via at least one movable wall, a control valve assembly that can be actuated by the force input member, and a force output member for transmitting an operating force to a downstream brake system. The at least one working chamber can be fluidically connected optionally to a negative pressure source or the atmosphere by way of the control valve assembly. The control valve assembly comprises a control valve housing, in which an actuating piston that is coupled with the force input member s displaceably arranged, and a first valve seat, and a second valve seat.

Abstract: A pneumatic brake booster for a motor vehicle having a booster housing, the interior space of which is divided by at least one axially movable wall loadable with a pneumatic differential pressure into at least one working chamber and at least one vacuum chamber. The movable wall includes a diaphragm plate and a rolling diaphragm which is arranged sealingly between the booster housing and the control housing, having a control valve which controls the differential pressure, is arranged in the control housing, and which controls a connection of the working chamber to the vacuum chamber or atmosphere, having at least one extraction duct which is integrated into the control housing for connection of the vacuum chamber to the working chamber, wherein the extraction duct can be blocked by the control valve. A device is also provided between the vacuum chamber and working chamber to improve the noise behavior.

Abstract: A method of manufacturing a plate plunger with which a reaction disc comes into contact and which determines a servo ratio of a vacuum booster, the plate plunger manufacturing method comprising primarily processing a plate plunger base material in such a way that an outer peripheral diameter of a reaction disc contact surface of the plate plunger becomes equal to or greater than an outer peripheral diameter, and forming the reaction disc contact surface of the plate plunger in such a way that it has an outer peripheral diameter corresponding to a desired servo ratio by secondarily processing a servo ratio determination surface.

Abstract: The present invention provides a dual-rate brake vacuum booster including a control valve body, a rubber reaction plate and a reaction rod, the rubber reaction plate being clamped between an end face of the control valve body and a base plate of the reaction rod, wherein accommodating spaces for accommodating an expansion deformation of the rubber reaction plate are respectively provided between a periphery of an end portion on one side of the rubber reaction plate and a periphery of the end face of the control valve body, and between a periphery of an end portion on the other side of the rubber reaction plate and the base plate of the reaction rod. The dual-rate brake vacuum booster prolongs the service life of the rubber reaction plate and can realize the dual-rate braking without using an additional element, thereby resulting in easy processing, simple structure and reduced cost.

Abstract: An activation unit is disclosed having at least one actuator having a variable length disposed around at least one first axis. The activation unit operatively interacts with an activation element mounted so that it can be bi-directionally deflected along a second axis. The front side of the actuator is indirectly or directly engaged with a first piston, which can be deflected along the first axis in a mechanically positively driven manner. The first piston has a front side facing away from the actuator which axially borders at least regions of a transfer medium on one side. The transfer medium is radially surrounded relative to a first axis by a housing radially to the first axis, and axially borders at least regionally a front side of at least one second piston. The at least second piston can be deflected in a mechanically positively driven manner, and engages the activation element directly or indirectly.

Abstract: A tie rod-type brake booster including a casing provided with a front cell and a rear cell, the front cell and the rear cell sealingly joining to each other, a tie rod caulked to the rear cell through the casing, a reinforcement plate to closely contact an inner surface of the front cell to enhance rigidity of the casing, the reinforcement plate being provided with a through hole penetrated by the tie rod, and a support member formed at a penetration portion of the front cell penetrated by the tie rod to fix the reinforcement plate, wherein the support member comprises a bent portion bent from the penetration portion of the front cell, and a pressing portion perpendicularly extending from the bent portion with respect to an axial direction of the tie rod.

Abstract: A brake booster with regenerative brake force generation comprising a force input element coupled to a brake pedal. A chamber arrangement having a vacuum chamber and a working chamber that are separated from one another by a movable wall. A control valve actuated in accordance with a displacement of the force input element. The working chamber is connectable selectively to the vacuum chamber and the atmosphere to generate and reduce a differential pressure at the movable wall. The control valve has a control valve housing that is connected for joint movement to the movable wall. In a first actuation phase of the brake booster from its rest position, the force input element is displaceable relative to the control valve housing by an idle travel, in which the control valve remains non-actuated to suppress a build-up of a differential pressure at the movable wall.

Abstract: The present invention provides a dual-rate brake vacuum booster including a control valve body, a rubber reaction plate and a reaction rod, the rubber reaction plate being clamped between an end face of the control valve body and a base plate of the reaction rod, wherein accommodating spaces for accommodating an expansion deformation of the rubber reaction plate are respectively provided between a periphery of an end portion on one side of the rubber reaction plate and a periphery of the end face of the control valve body, and between a periphery of an end portion on the other side of the rubber reaction plate and the base plate of the reaction rod. The dual-rate brake vacuum booster prolongs the service life of the rubber reaction plate and can realize the dual-rate braking without using an additional element, thereby resulting in easy processing, simple structure and reduced cost.

Abstract: Actuator piston (100) formed by an injection-molded piece (120) consisting of a cylindrical body (121) and a collar (122) to receive the hydraulic actuator (110) and the travel detector (160). The piece (120) comprises a shell (150) covering its front face and receiving the return spring (250) and the thrust rod (130). The actuator piston (110) includes lugs (115) engaged behind the lugs (125) of the body (121), by a pivoting movement about the axis. The rotational position is blocked by a locking and guiding sleeve (180).

Abstract: Brake installation consisting of a master cylinder associated with a brake booster furnished with a motor driving an actuator piston and acting on the primary piston of the master cylinder by means of a reaction disk against which the piston rests. For a safety operation, the hydraulic actuator connected to the control rod actuated by the brake pedal rests on the rear face of the reaction disk. The actuator piston is combined with an auxiliary piston in order to interact with the reaction disk and it is guided by its sleeve-shaped portion in a bore of the body of the brake booster. An adapting shim is supported by the auxiliary piston in order to receive as a support the end of a rear rod, secured to the primary piston of the master cylinder. The thickness of the assembly formed by the adapting shim and the auxiliary piston is defined on mounting of the master cylinder and of the brake booster as a function of the free travel measured previously.

Abstract: A pneumatic brake servo which can be acted on by a pneumatic differential pressure is described. The brake servo includes an actuable input member comprising a valve piston, an output member for acting on a master brake cylinder, and a control valve which is arranged in a control housing and which can be actuated by the valve piston for controlling the differential pressure. An elastic reaction element is arranged in a control housing recess and against which the output member bears. The input member acts with an input effective area A1 on the reaction element, and the output member acts with an output effective area A2 on the reaction element. The ratio of output effective area A2 to input effective area A1 determines the force boost ratio of the brake servo. Means are provided for adjusting the output effective area A2 in the assembled brake servo.

Abstract: In a vacuum brake booster, a valve mechanism having a negative pressure valve which communicates and cuts off between a negative pressure chamber and a variable pressure chamber according to a retractable movement of the plunger with respect to a valve body, and an atmosphere valve which communicates and cuts off between the variable pressure chamber and the atmosphere is assembled in a shaft hole of a valve body. In addition, the plunger and the key member are assembled in the shaft hole. In addition, in the vacuum brake booster, when the valve body is in the forward moving position and the plunger is moved rearward from the forward moving position, a protrusion tilting and holding the key member with respect to the valve body is provided.

Abstract: An actuator apparatus includes a booster creating an infinite boost ratio while a plunger valve does not contact with a reaction disc, and an oil reservoir and a pedal simulator unit forming a hydraulic circuit to follow hydraulic hysteresis characteristics. Therefore, it is possible to achieve insensibility of pedal changes transmitted from a master cylinder, minimize changes in pedal feel according to changes of pedal effort correspondingly generated, while blocking vibration transmitted to the pedal when achieving regenerative braking, and provide pedal feel following or simulating the hydraulic hysteresis characteristics.

Abstract: In the negative pressure booster, when in operation, a reaction disc (35) deflects due to the reaction from an output shaft (34) and pushes a pin (28) backward, and the pin (28) pushes a vacuum valve seat member (21) backward via an arm (25). Thereafter, the vacuum valve seat member (21) pushes up a valve body (15) backward via a vacuum valve portion (17), and an atmosphere valve portion (16) moves backward relative to a valve body (4). The stroke of an input shaft (11) is shortened by an amount an atmosphere valve (20) and a vacuum valve (23) have moved backward. As the valve body (15) is pushed up backward, further, a balance position for the atmosphere valve (20) and the vacuum valve (23) shifts backward depending upon the output (input). Therefore, the stroke of the input member is shortened at the time of producing a large output.

Abstract: A sensor feeler device for a brake booster. The sensor feeler device (4) includes an axially moveable cylinder (40), the movement of which can be controlled by the control rod which is itself controlled by the brake pedal, a sensor feeler piston (5) able to move axially in said moving cylinder (40), and a spring (44) that tends to push the sensor feeler piston (5) forward and keep its front face substantially in the same plane as the front face of the moving cylinder.

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 boosted brake having a booster with a decompression arrangement wherein an output push rod has a head with a plurality of openings that extend into a stem and create a plurality of arcuate grooves. The openings receive a plurality of projections that extend from a piston retained in a sleeve held in a movable partition. A spring acts on the projections and urges the piston into engagement with a reaction disc through which an actuation force is supplied a master cylinder. A predetermined reaction force from the master cylinder acts on piston and overcomes the spring to allow the reaction disc to expand and thereby modify the reaction force. The arcuate grooves in the stem allow for a maximum diameter for spring with a minimum diameter for stem that corresponds to a diameter of piston in order to creates a desired braking in response to an emergency brake application.

Abstract: The invention relates to a brake booster intended to transmit handbrake commands. This booster essentially comprises a plunger (3) able to move axially under the command of the control rod (1). An enclosure (2) contains a working chamber (21) and a vacuum chamber (20) which are separated by a wall (22) able to move axially under the effect of the plunger (3) and/or of a difference in pressure between the vacuum chamber and the working chamber. A three-way valve (4) controlled by the plunger (3) allows the working chamber (21) to be connected either to the vacuum chamber or to atmospheric air. Finally, a bearing piece (17) controlled by the moving wall (22) allows the control rod (1) to be driven along.

Abstract: A pneumatic brake booster includes a booster housing, subdivided into at least two chambers by at least one axially movable wall to which a pneumatic differential pressure can be applied, a control valve controlling the differential pressure and being arranged in a control housing, an operable input member, connected to a valve piston, an output member which applies a boosting force to a master cylinder, as well as an accommodating element, which accommodates a rubber-elastic reaction element and the output member abutting thereon in a radial direction, with the accommodating element being axially and radially supported on the control housing and being held in an axial direction by means of a holding element.

Abstract: A pneumatic brake booster for motor vehicles includes a booster housing, subdivided into at least one working chamber and at least one vacuum chamber by at least one axially movable wall to which a pneumatic differential pressure can be applied, a control valve controlling the differential pressure and arranged in a control housing to connect the working chamber to the vacuum chamber or atmosphere, the valve having two concentrically arranged sealing seats and an elastically deformable valve member, an operable input member connected to a valve piston whose movement is limited by a transverse member that can be introduced in a radial direction into the control housing, an elastic reaction element, an output member applying a boosting force to a master cylinder, and ventilating and bleeding ducts in the control housing.

Abstract: A variable force rate vacuum booster including a reaction disk having an input surface and an output surface, the reaction disk being formed from a deformable material, an input rod position relative to the reaction disk to apply an input force to the input surface of the reaction disk, an output rod having a reaction surface generally engaged with the output surface of the reaction disk, the output rod defining a bore therein, and a plunger positioned in the bore and biased out of the bore by a biasing force, the plunger being adapted to resist deformation of the reaction disk into the bore until the input force reaches a threshold value.

Abstract: A valve piston 8 of a vacuum type booster device is provided with a bypass passage 51 which is defined between a sound-absorbing member 27 and an input rod 23 to communicate directly with the atmosphere and a sliding-type plate valve 52 composed of three plate valve parts 53, 54 55 which are arranged around the input rod 23 to be relatively slidable in radial directions. When the input rod 23 is advanced beyond a predetermined distance relative to the valve piston 8, the sliding-type plate valve 52 is separated between two of the plate valve parts 53, 54, 55 to make the bypass passage 51 communicate with the inside of the valve piston 8.

Abstract: A pneumatic brake booster with a booster housing, which comprises a first and a second housing shell and is subdivided into a working chamber and a vacuum chamber by an axially movable wall to which a pneumatic differential pressure can be applied, with the movable wall being formed of a diaphragm plate and a diaphragm abutting thereon that includes a radially inward sealing bead and a radially outward sealing bead for sealing the two chambers and the radially outward sealing bead is compressible between the housing shells. To improve the compression of the radially outward sealing bead, the radially outward sealing bead has a circumferential, uniform rib structure.

Abstract: A variable force rate vacuum booster including a reaction disk having an input surface and an output surface, the reaction disk being formed from a deformable material, an input rod position relative to the reaction disk to apply an input force to the input surface of the reaction disk, an output rod having a reaction surface generally engaged with the output surface of the reaction disk, the output rod defining a bore therein, and a plunger positioned in the bore and biased out of the bore by a biasing force, the plunger being adapted to resist deformation of the reaction disk into the bore until the input force reaches a threshold value.

Abstract: In a negative pressure type booster device, secondary passages 53 communicating directly with the atmosphere is formed between the internal surface of a sliding cylindrical portion 8b of a valve piston 8 and the external surface of a silencer 27, and communication means 60 is provided for being controlled to vary its path area in dependence on the advance amount of an input rod 23 when the same is moved beyond a predetermined distance relative to the valve piston 8. Thus, when a brake pedal 25 is stepped on strongly, the atmospheric air can be led from the secondary passages 53 through the communication means 60 to a variable pressure chamber 6, so that the property of the responsiveness in braking operation can be improved to a responsiveness enhancing property which varies in dependence on the manner of stepping the brake pedal 25.

Abstract: The invention relates to a tandem pneumatic brake booster (1) for a vehicle. The objective is to prevent a blocking of a booster thrust rod (4) in the maximum travel position. The blocking appears following a sealed adhesion of a first plate skirt (12) on a seal (22) of the tandem booster. This seal blocks a vacuum in a first front chamber (5). To prevent this blocking, provision is made to crenelate a first lip (23) pressed against the pneumatic piston (3) of a seal. Merlons prevent a sealed adhesion of the plate skirt (12) over the whole seal (22). This absence of adhesion creates a leakage of air to the first front chamber (5) and allows a return to a rest position.

Abstract: A method of controlling a machine having a hydraulically actuated linkage includes lowering a load suspended by the leakage at least in part by leaking hydraulic fluid from a portion of a hydraulic actuation system, and generating a drift compensation control signal responsive to leaking hydraulic fluid. A machine includes an electronic controller in control communication with a valve, the electronic controller being configured to compensate for leakage induced drift of at least one hydraulic actuator of a machine hydraulic system by selectively commanding adjusting of the valve if drift criteria for the hydraulic system are satisfied.

Abstract: A valve piston 8 of a vacuum type booster device is provided with a bypass passage 51 which is defined between a sound-absorbing member 27 and an input rod 23 to communicate directly with the atmosphere and a sliding-type plate valve 52 composed of three plate valve parts 53, 54 55 which are arranged around the input rod 23 to be relatively slidable in radial directions. When the input rod 23 is advanced beyond a predetermined distance relative to the valve piston 8, the sliding-type plate valve 52 is separated between two of the plate valve parts 53, 54, 55 to make the bypass passage 51 communicate with the inside of the valve piston 8.

Abstract: A pneumatic brake booster (10) for a motor vehicle comprising a casing (12) within a moving partition (14) is secured to a moving piston (12) having an inlet valve (52) and a re-equalizing valve (50) with offset seats borne by first (136) and second (142) tubular sleeves, The first sleeve (136) is slideably mounted in the moving piston (22) with a travel (d) which is determined by first bayonet-fitting (154) that is interposed between the first sleeve (136) and the moving piston (22) and that are locked against rotation by the second sleeve (142).

Abstract: Reaction force from a reaction member is divided and transmitted to a front shaft portion of a plunger via abutment member and to a flange portion of the plunger via a spring unit. The spring unit includes a tubular first holding member assembled to the front shaft portion of the plunger and being engageable, at its front end portion, with the reaction member, a second holding ember assembled to a rear end portion of the first holding member and having a rear end portion which extends rearward from the first holding member for engagement with the flange portion, and Belleville springs held between the first and second holding members. When the reaction force transmitted from the reaction member to the first holding member exceeds the load of the springs, the first holding member moves while compressing the springs and engages with a stepped portion of a valve body.

Abstract: A pneumatic servomotor (12) for power-assisted braking for a motor vehicle, which servomotor is of the type having a substantially cylindrical rigid casing (16) inside which a moving transverse partition (18) is movably mounted that has a peripheral skirt (28) which is made of sheet metal and which is covered, at least in the vicinity of its periphery (40), with a sealing diaphragm (30) made of an elastomer material and whose periphery (32) is fixed to the casing (16) in leaktight manner, said servomotor being characterized in that, in the vicinity of the periphery (40) of the skirt (28), the skirt is provided with a stamped annular recess (42) defining an internal groove (44) which serves to receive snugly a peripheral bead (46) which projects from the surface of the diaphragm (30) in order to fix the diaphragm (30) to the skirt (28) in leaktight manner.

Abstract: This invention mainly relates to a reaction-disk device, to its manufacturing process and to a pneumatic servomotor for an assisted braking, including such reaction device. A reaction device according to the present invention comprises a receiving cavity, fitted with a reaction disk made of incompressible or substantially incompressible materials, comprising: a) an applying surface for the plunger (or a similar member, connected to a member, actuated by the driver, such as the brake pedal, and advantageously connected to at least one element of the three-way valve of a pneumatic assistance servomotor); b) an applying surface for the push rod (or a similar member for a force transmission to the master cylinder, more particularly a tandem master cylinder); and c) a surface with a resilient response to the working pressures exerted on the reaction disk, so as to be elastically deformable on braking or, at the very least, during an emergency braking operation.

Abstract: A pneumatic servomotor for an assisted braking including an emergency-braking assistance device to increase the assistance ratio when an input force is applied to the control rod that is higher than a predetermined value through an extrusion of the reaction disk. The device (D) has a plastically-deformable first member (68) and second member (74) to accurately set a jump height of the servomotor and the activation force.

Abstract: A boosted brake (10) having a booster (12) for activating a primary piston (54) of a master cylinder (14) by way of a feeler (42), a reaction disk (28) and a push rod (52). The push rod (52) that is housed a decompression piston (62) and returned elastically by a spring (70) to a position of rest has at least two radial branches (64) in order to provide two boost ratios which differ according to the intensity of the input force.

Abstract: A negative pressure type booster device possesses a valve mechanism constructed to compensate for insufficient depressing force applied to a brake pedal upon emergency braking. Upon depression of the brake pedal, first negative pressure valves contact first negative pressure valve seats to block a variable pressure chamber from communication with a constant pressure chamber, and an atmosphere valve seat is separated from an atmosphere valve to communicate the variable pressure chamber with atmosphere. A partition member thus moves forwards depending on the pressure difference between the chambers to output a propelling force from an output rod. When the brake pedal is stepped on quickly, a valve member is urged backwards by a spring member causing second negative pressure valve seats to contact second negative pressure valves and move the valve member backwards. The atmosphere valve separates from the atmosphere valve seat, and the variable pressure chamber quickly communicates with atmosphere.

Abstract: A brake booster, in particular for motor vehicles, having a control valve for controlling the boosting force generated by the brake booster. The control valve comprises a control valve housing, an input element, an output element and a thrust piece, which is disposed between the input element and the output element and acts upon the output element. The thrust piece in dependence upon a relative movement between the thrust piece and the control valve housing caused by the input element is supported releasably against the control valve housing by means of a coupling element biased by a spring. The spring and the coupling element are designed as an integral coupling component, which is fastened to the control valve housing.

Abstract: A brake system having a master cylinder (14) actuated by a moving piston (24) that is fixed to a moving partition (18) in a booster (12). Piston (24) has a front face (26) that acts on a primary piston (30) of the master cylinder (14) by way of a reaction disk (28) located between a rear end of the primary piston (30). The front face (26) has a feeler (44) that is fixed to a control rod (36) of the booster (12) and comes into contact with the reaction disk (28) to transmit a reaction force from the master cylinder (14) to the control rod (36). The front end (48) of the feeler (44) includes at least one stud (50) which projects parallel to the axial direction and engages the reaction disk (28) to provide for proportionality between the force that is transmitted between the control rod (36) and the force exerted on the primary piston (30).

Abstract: Pneumatic brake booster, in particular for a motor vehicle, comprising a reaction disk (30) interposed between a plunger (28) carried by a control rod actuated by the brake pedal and a thrust rod (32) acting on the primary piston of a tandem master cylinder, the reaction disk (30) being housed inside an annular metal part (36) which cooperates with a stop (50) of the thrust rod (32) by the intermediary of thermal expansion element (48) designed to compensate for the thermal expansion of the reaction disk (30) and its effect on a point of change of assistance ratio.

Abstract: A pneumatic servomotor for power-assisted braking for a motor vehicle having a control rod (38) for opening and closing at least one axial inlet valve (52) that is interposed between a front chamber (16) connected to a pressure source having a pressure (Pa) greater than a first pressure (P1) and a back chamber (18) and at least one axial balancing valve (50) for actuating a moving partition (14) located between the front chamber (16) and the back chamber (18). The servomotor being characterized by one-piece floating tubular element (76) having axially offset transverse faces (78,80) that have sealing elements (82,84) for sealing the axial inlet valve (52) and the balancing valve (50) with the control rod (38) being activated by a dish-shaped washer (49) carrying two springs (40,122) of different stiffnesses.

Abstract: A pneumatic brake booster with reduced dead travel comprising a skirt (10) which can move in a sealed manner in a casing, delimiting a low-pressure chamber and a variable-pressure chamber, with respect to a pneumatic piston (16) over a certain travel. The displacement of the pneumatic piston being controlled by the skirt in a first direction when the skirt comes into contact with a first face of an annular plate (100) which is arranged in the low-pressure chamber and is fastened rigidly to the pneumatic piston, and the displacement of the piston in a second direction is controlled by an elastic means mounted in the low-pressure chamber and bearing by one of its ends on a second face of the annular plate (100).

Abstract: A vacuum servo brake has an input member by which a valve arrangement may be acted upon at an input force to connect a working chamber selectively to the outside or to a vacuum chamber (separated from the working chamber by a piston which may be brought into operative connection with a main cylinder via an output member to generate a braking pressure). Provided on the piston is an elastomeric reaction member through which a reaction force may be applied to the input member. The output member has a stop which, with a predetermined input force, abuts against the working piston to alter an amplification ratio of the brake. Arranged adjacent to the reaction member is at least one volume take-up means into which part of the reaction member may be displaced in the event of the vacuum servo brake being actuated. Furthermore, the stop is preferably of resilient construction.

Abstract: An elastic member is interposed between a reaction disk and a plunger. By moving the plunger to open a poppet seal such that atmospheric air is introduced into the variable pressure chambers, a pressure differential is created between the variable pressure chambers and constant pressure chambers (negative pressure). As a result, servo power is applied to an output rod, and a resulting reaction force is partly transmitted back to an input rod through the reaction disk. During a rapid braking operation, a piston is caused to retract by a pin, thus pushing the elastic member into an outer peripheral groove formed on the piston so that the elastic member is axially compressed. As a result, the movement amount of the plunger can be increased without receiving a reaction force, enabling the rapid development of servo power.

Abstract: The subject of the present invention is a pneumatic brake booster comprising an envelope in which a skirt (2) slides in a sealed manner, a pneumatic piston (8) rigidly attached to the skirt, a three-way valve (20) actuated by a control rod (22) operated at a first end by a pedal, a plunger (32) mounted at a second longitudinal end which is the opposite end and slideably mounted in the body of the piston, the control rod and the plunger forming a brake control (33), characterized in that the said booster comprises means (68) of damping the relative and in particular oscillatory movement between the brake control (33) and the pneumatic piston (8).