Abstract: A pneumatic booster (40) disposed between a brake pedal (5) and a master cylinder (7) includes a cylindrical member (60) provided on an outer circumferential side of an output rod (58). A seal member (62) seals between an outer circumferential side of the cylindrical member and a cylindrical portion of a front shell, and an O-ring seals between the cylindrical member and the output rod. The cylindrical member causes a differential pressure between a negative pressure chamber (A) and an atmosphere chamber (C) to be applied to a valve body (46). One axial side of the cylindrical member is configured to cause an atmosphere pressure to be applied to the valve body by abutting against a cylindrical protruding portion of the valve body, thereby pushing the valve body with the aid of the differential pressure in the direction as a biasing direction of a return spring.

Abstract: An all-in-one braking system for a vehicle is described. The braking system includes an operating rod, a first piston system, a second piston system, and a fail safe plate. The operating rod is couplable to a brake actuator operated by the driver of the vehicle. The first piston system and the second piston system each include a piston, a fail recovery key, and a motor. The motor is coupled to the piston to affect lateral movement of the piston which, in turn, causes a braking pressure to be applied to a wheel of the vehicle. The fail safe plate is fixedly coupled to the operating rod such that lateral movement of the operating rod causes lateral movement of the fail safe plate. A controller is configured to operate the motors to control the lateral movement of the pistons based at least in part on detected movement of the operating rod.

Abstract: A brake booster includes a casing divided into a constant pressure chamber and a variable pressure chamber by a diaphragm, a power piston attached to the diaphragm, a disc-shaped stem coupled to the center of the power piston and having a through-hole, a plunger interposed between the stem and an input shaft to press/release the stem during reciprocation of the input shaft, and an air intake valve having a vacuum passage interconnecting the constant and variable pressure chambers. The air intake valve is inserted into the diaphragm and the power piston for close contact with the through-hole of the casing, and regulates air flowing from an atmosphere into the variable pressure chamber and from the variable pressure chamber into the constant pressure chamber during the reciprocation of the input shaft.

Abstract: A brake booster includes a housing configured for mounting to the master cylinder of a braking system. The housing defines a bore for receiving a power piston and an end cap, with a return spring disposed between the head of the piston and end cap. The housing and end cap define a recess and a rib sized to be received within the rib but configured for an interference fit between the end cap and housing outside the recess. The interference fit is calibrated to require a force to push the end cap into the bore that exceeds the force generated by the return spring when it is compressed between the end cap and the piston head. The recess and rib at least temporarily retains the spring within the bore until the brake booster is mounted to the master cylinder.

Abstract: In a fluid pressure booster, when an input shaft and a valve plunger advance, an atmosphere valve opens to introduce air into a variable pressure chamber. At this time, the input shaft has not moved by a predetermined stroke, and thus a projection of the valve plunger is positioned within an inner peripheral surface of a control valve body, thus forming an orifice, which causes air to be sucked at a restricted flow rate. As a result, generation of noise is suppressed. When the input shaft moves the predetermined stroke, the projection of the valve plunger is positioned away from the inner peripheral surface of the control valve body and the orifice is no longer formed. Accordingly, the flow rate of the air is not restricted by the orifice, and thus a relatively large amount of air is sucked into and introduced into the pressure variation chamber.

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: A brake servo whose valve piston has a concentric sealing seat which projects axially beyond a second sealing seat, with the concentric sealing seat having at least one recess for throttling the air volume flow. The controllability and also the noise characteristics of the brake servo can be improved in this way.

Abstract: A brake booster system for a motor vehicle of a type having an internal combustion engine without a conventional throttle-type valve in an intake manifold for engine output control. In accordance with the present invention, a throttleless-type IC engine of the above described type is modified to include a valve which can periodically close or obstruct the path of intake air to the IC engine to generate intake manifold vacuum to provide a needed pressure differential for brake booster operation. The system includes a pressure transducer which controls operation of the valve to provide the desired control of engine brake booster vacuum.

Abstract: The invention relates to a brake control system for motor vehicles and, in particular, to a hydraulic control system. The invention also applies to hybrid braking systems such as those provided in hybrid vehicles (vehicles propelled electrically and propelled using internal combustion engines) comprising a hydraulically operating braking system which comprises a simulator (3) not mechanically coupled to the brake booster piston (42) and an electric braking system using the electric propulsion motor or motors as electric generators.

Abstract: A compliance spring is disposed between the brake pedal and the primary piston of a master cylinder, preferably between the push rod and the primary piston of the master cylinder. Selection of the initial spring compression load of the compliance spring, its permitted spring compression travel and its spring constant, allow for both a simplified and fine adjustment of the brake pedal feel per a brake feel index.

Abstract: A servobrake for motor vehicles including a control valve which can be actuated by an electromagnet independently of an actuating rod which displaces a valve piston, which electromagnet actuates a third seal seat which makes possible ventilation of a working chamber. The third seal seat is formed on a sleeve which cooperates with the electromagnet, an annular element being provided which is arranged displaceably with respect to the third seal seat and which bears against the sleeve via an interposed elastic or compressible element. The annular element has means for guiding an air flow produced during normal braking in the direction of the working chamber.

Abstract: There is provided a pneumatic booster, comprising: a front shell; a rear shell; a housing formed as that respective openings of the front shell and the rear shell are integrally connected to each other, and a power piston arranged in the housing so as to divide an interior of the housing into a constant-pressure chamber on the front shell side and a working-pressure chamber on the rear shell side, wherein thrust force of the power piston generated by pressure difference between the constant-pressure chamber and the working-pressure chamber is applied to inputted force transmitted from a brake pedal to an input rod so as to obtain combined force, the combined force being outputted with a given boost ratio from an output rod, and wherein a thickness of the front shell is made to be thinner than a thickness of the rear shell.

Abstract: The invention relates to a travel limiting element in a brake booster device for a motor vehicle brake system, comprising a pair of longitudinal legs which are connected together via at least one transverse leg, wherein the travel limiting element can be brought into contact with a stop of the brake booster device. In favour of a simple design and cost-effective production, the travel limiting element comprises two dimensionally stable reinforcement braces which extend along the longitudinal legs, and the transverse leg is made of a damping material which surrounds the two longitudinal legs at least in sections.

Abstract: A negative pressure booster according to the present invention is configured in such a manner that a vacuum valve seat member (30) does not move, a reaction disk (25) protrudes and comes into contact only with a reduced diameter portion (24a) of a spacer member (24) under an operation in which an input is equal to or smaller than a preset input. Accordingly, the servo ratio becomes the normal servo ratio. Under the operation in which the input exceeds the preset input, the vacuum valve seat member (30) moves rearward (input side) with respect to a valve body (4) by the pressure in a variable pressure chamber (9), and a reaction disk (25) is significantly protruded to come into contact also with an increased diameter portion (24b) in addition to a reduced diameter portion (24a).

Abstract: A brake booster includes a casing divided into a constant pressure chamber and a variable pressure chamber by a diaphragm, a power piston attached to the diaphragm, a disc-shaped stem coupled to the center of the power piston and having a through-hole, a plunger interposed between the stem and an input shaft to press/release the stem during reciprocation of the input shaft, and an air intake valve having a vacuum passage interconnecting the constant and variable pressure chambers. The air intake valve is inserted into the diaphragm and the power piston for close contact with the through-hole of the casing, and regulates air flowing from an atmosphere into the variable pressure chamber and from the variable pressure chamber into the constant pressure chamber during the reciprocation of the input shaft.

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: The invention relates to a sensor feeler device for a brake booster. In this device, the sensor feeler device (4) comprises: 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), 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 vacuum booster includes a housing defining a control volume in which a movable diaphragm separates the control volume into an apply chamber and a vacuum chamber. A power piston extends through and engages the diaphragm and has an axial bore containing a valve assembly that controls a diaphragm pressure differential across the diaphragm. The power piston drives an output rod in the forward direction. The output rod has a rearward portion exposed to pressure within the vacuum chamber and a forward face exposed to atmospheric pressure. When the pressure within vacuum chamber is less than atmospheric, a piston pressure differential across the power piston provides a return force in the rearward direction to the power piston.

Abstract: A brake hydraulic pressure generator is proposed which is simple in structure and can suppress fluctuations in the brake pedal operating amount due to fluctuations in the amount of brake fluid consumed in the brake circuit. The brake hydraulic pressure generator includes an input shaft operated by a brake pedal, a stroke simulator for imparting a stroke and a reaction force corresponding to the brake pedal operating amount to the input shaft, a master cylinder for generating brake hydraulic pressure, and a pressure detector member for applying a reaction force corresponding to the hydraulic pressure in the master cylinder to a valve member of the control valve. The reaction force is transmitted through the pressure detector member to the control member. The input to the brake pedal is transmitted to the control valve through the stroke simulator so as to oppose the reaction force. The control valve operates to balance the reaction force and the input.

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 valve body 2 is connected to a power piston, which divides a housing into a constant pressure chamber (negative pressure) and a variable pressure chamber. In the valve body 2, there is provided a brake assisting mechanism 10 between a reaction disk 3 and a plunger 9. A poppet seal 12 is opened by movement of the plunger 9, to thereby introduce atmospheric air into the variable pressure chamber and generate a thrust force in the power piston. During rapid braking, a plunger rod 23 advances relative to a sleeve 21, and balls 30 shift outward and the plunger rod 23 directly abuts against a reaction rod 22, resulting in contraction of the brake assisting mechanism 10. Therefore, the amount of movement of the plunger 9 can be increased without being affected by a reaction force from the reaction disk 3, thus enabling rapid development of servo power.

Abstract: The present invention relates to a brake force transmission device for a brake force booster with an elastic reaction element, and input member with an associated effective surface, an output member with an associated effective surface, and a first transmission ratio that is defined by a ratio of the effective surfaces being in operative engagement with the reaction element. An object of the present invention is to provide means of a simple design, if possible arranged in the form of an assembly, giving the operator of an automotive vehicle increased support when high braking forces are required. The essence of the invention is the provision of means which starting from a determined pressure prevailing in the reaction element will reduce the reaction force introduced into the input member by a defined amount. The driver is thus given additional support, requiring a proportionately reduced increase in input force for a further increase in output force.

Abstract: A tubular member 18 is slidably fitted into a valve body, and is formed with a vacuum valve seat 21. The tubular member 18, a valve plunger 16 and the valve body 3 are maintained in their inoperative positions shown by abutment against a key member 13. A holder 14 is formed with a tapered surface 14a to assist in allowing an elastic deformation of a reaction disc 15. Immediately after the commencement of operation of a valve mechanism 7 as an input shaft 8 is driven forward, the input shaft 8 and the tubular member 18 are maintained in their inoperative positions until a rear end face of a variable pressure passage 28 abuts against the key member 13. The operating stroke of an input shaft 6 can be chosen to be less than the operating stroke of an output shaft 11 while preventing the jumping value from increasing to an excessively high value.

Abstract: When a booster is inoperative, a first atmosphere valve and a second atmosphere valve are both closed to block a communication of an orifice passage with a variable pressure chamber. At the commencement of operation of the booster, the first atmosphere valve opens while the second atmosphere valve remains closed to allow the atmosphere to be introduced into the variable pressure chamber through the orifice passage, followed by an opening of the second atmosphere valve to allow the atmosphere to be introduced into the variable pressure chamber through the second atmosphere valve and the first atmosphere valve. This arrangement allows the occurrence of oscillations of or abnormal sounds from a valve mechanism to be prevented during the initial phase of the brake operation.

Abstract: The present invention relates to a pneumatic brake force booster with means for fastening the said to a vehicle wall which extend through the interior of the brake force booster, wherein a fixed stop for a first housing part is provided on a first end and a stop that is adjustable by means of a rotation for a second housing part is provided on a second end, and with means for the pneumatic sealing of housing openings for the fastening means. The gist of the present invention resides in that the fastening means has a smooth sealing portion adjacent to the adjustment area of the adjustable stop, and in that the sealing means, by multilateral abutment on a conical abutment surface of the adjustable stop, on the smooth sealing portion and the associated housing portion, closes a slot between the fastening means and the adjustable stop and a slot between the stop and the housing part. This achieves a simple and low-cost sealing of housing openings for the fastening means.

Abstract: An intelligent input push rod assembly for applying an input force from a brake pedal to a power booster of a brake system. The input push rod assembly includes a sensor that is capable of generating an electrical output having a magnitude that varies with the amount of force applied to the input push rod by the brake pedal. Preferably, the sensor generates an output voltage signal that is generally proportional to the input force applied to the input push rod. A shunt is provided so that springs associated with the sensor operate in a generally linear force-deflection range of the springs. The output signal generated by the sensor is applied to a brake light control system that is supported by the input push rod assembly. The brake light control system uses the signal generated by the sensor to determine whether the vehicle brake lights should be illuminated and also to cause direct illumination of the brake lights during a braking operation.

Abstract: A vacuum servo unit is provided with an actuator for controlling the distance between the engaging portion of a first input member with a reaction disc and an air pressure valve seat in response to a driving force. The vacuum servo unit further includes a rubber member disposed between the first input member and a movable core. The rubber member is deformable in response to the relative movement of the first input member and the movable member forming a part of the actuator. When the actuator is inactive, an axial space is formed between the reaction member and the first input member and between the first input member and a second input member.

Abstract: The present invention discloses a brake system for automotive vehicles including a vacuum brake power booster which is operable preferably by a solenoid irrespective of the actuation by the driver. In order to sense the actuating speed during actuation introduced at a brake pedal by the driver, the present invention provides a travel sensor of proportional operation which is operable by the axial movement of the movable wall of the vacuum brake power booster, and the output signal of the travel sensor is directly proportional to the actuating travel of the movable wall and is subjected to a time differentiation processing operation in an electronic control unit.

Abstract: A boosted braking device for a motor vehicle having a master cylinder (M) and a pneumatic booster (S). The booster (S) has a rigid casting (10) divided by a mobile partition (12) into at least a front chamber (14) and a rear chamber (16). A three-way valve (18) carried by the mobile partition (12) is actuated by a control rod (20) to control the pressure in the rear chamber (16) for operating the master cylinder (M). The casing (10) includes a front shell (24) and a rear shell (26) each of which comprises a radial shoulder (28,30) and being secured together by hooping (40) interconnecting with the shoulders (28,30) of the front shell (24) and rear shell (26). The hooping (40) comprises first (40A) and second (40B) part hoops. The first (40A) and second (40B) part hoops are joined together by at least one locking element (50) which is rendered non-functional when the master cylinder (M) is subjected to substantial stress as a result of a frontal or oblique impact of the vehicle.

Abstract: A counter-force mechanism (37), which produces a counter force when a brake booster is operated, is made up of an input-side member (38) slidably disposed within a valve body (3), a second constant-pressure chamber (39) formed on the rear side of the input-side member and into which a pressure is introduced from a constant pressure chamber (A), and a second constant-pressure chamber (39) formed on the front side of the input-side member and into which a pressure is introduced from a variable pressure chamber (B). The counter force from the counter-force mechanism (37) is reduced by an orifice passage (43) as a counter-force reducing means in rapid operation of the brake.