Abstract: A hydraulic brake actuation assembly with a first and a second spool is disclosed. The hydraulic brake actuation assembly includes a first and a second subassembly which are configured to be mounted to each other in a pre-assembled manner. The first subassembly includes the first spool and a first actuation piston which are moveable along a first axis respectively. At least one first spring is located between the first spool and the first actuation piston along the first axis. The first subassembly includes the second spool and a second actuation piston which are moveable along a second axis respectively. At least one second spring is located between the second spool and the second actuation piston along the second axis. The first and the second axis are parallel to each other. The second subassembly includes a third and a fourth actuation piston. The third actuation piston is moveable along the first axis.

Abstract: Disclosed herein is a pedal simulator for an active brake system.

Abstract: According to one embodiment, a vacuum booster includes a booster shell and a booster piston which divides an interior of the booster shell into a front vacuum chamber and a rear operation chamber. The vacuum booster further includes a valve cylinder in which a control valve controls a communication state of the operation chamber depending on a movement of an input rod. A bearing cylinder is provided on a rear wall of the booster shell. A bearing bush is mounted in the bearing cylinder to support the valve cylinder, and a seal lip is provided at a rear end of the bearing bush integrally therewith to contact elastically closely with the valve cylinder. A grease reservoir is provided in an inner surface of the bearing bush, and an extension grease reservoir is provided in an inner surface of the seal lip.

Abstract: A braking system includes an emulator cylinder, an emulator actuator piston within the emulator cylinder, an emulator actuator chamber within the emulator cylinder defined in part by the emulator actuator piston, a pedal feel simulator including an input port in fluid communication with the emulator actuator chamber and an output port, a selector piston movable within the emulator cylinder between a first position and a second position, and a poppet valve operably connected to the emulator actuator piston, the poppet valve movable by the emulator actuator piston between a deactivated position and an actuated position and configured such that (i) when the selector piston is in the first position and the poppet valve is in the actuated position, the poppet valve is closed and the emulator actuator chamber is not in fluid communication with the reservoir through the poppet valve, and (ii) when the selector piston is in the second position and the poppet valve is in the actuated position, the poppet valve is open

Abstract: A vehicle brake system. The system includes a wheel brake, a brake pedal, a master cylinder, a first valve, a second valve, a pump, a pressure sensor, a pressure controlling device, and a controller. The master cylinder increases a pressure of a brake fluid in the brake system based on a user depressing the brake pedal. The pump pumps the brake fluid through the first valve to the wheel brake and to draw the brake fluid from the wheel brake through the second valve. The pressure sensor senses a pressure of the brake fluid in the brake system. The pressure controlling device reduces a pressure of the brake fluid at the master cylinder. The controller operates the first and second valves, the pump, and the pressure controlling device during a controlled braking event.

Abstract: A brake booster coupling device is described having a braking piston, an input piston, which is displaceable in the event of an operation of a brake input element from its starting position by a driver braking distance, a force transmission between the input piston, which is displaced by a driver braking distance below a predefined threshold value, and the braking piston is suppressed, and a booster piston, which is displaceable with the aid of the brake booster drive in such a way that the braking piston, which contacts the booster piston, is displaceable with the aid of the brake booster drive from a non-braking position into at least one braking position, the brake booster coupling device including a contact element, which is displaceable and/or deformable in the event of a displacement of the braking piston from the non-braking position into the at least one braking position in such a way that a first contact surface of the contact element contacts a second contact surface of the input piston, which is di

Abstract: Brake apparatus includes a transmission unit for operatively connecting a brake pedal to a master cylinder, and the transmission unit is a mechanism capable of varying a ratio between an output amount of a push rod connected to a master cylinder and an operation amount of the brake pedal. Further, the transmission unit is constructed in such a manner that, in an initial operation region of the brake pedal, a ratio of the operation amount of the brake pedal to the output amount of the push rod is set to be greater than in another operation region immediately following the initial operation region.

Abstract: A hydraulic brake booster for use in a brake system having a housing with a power piston located in a first bore and a control valve located in a second bore. An input member is connected to the power piston and linked to the control valve by a lever arrangement. The input member is characterized by a cylindrical body with a shaft attached thereto. A bracket with a radial opening is carried by the shaft and urged toward a head on the shaft by a spring. The lever arrangement is characterized by a first lever with a first end pivotally secured in the housing by a first pin and a second end located in the radial opening of the bracket and a second lever pivotally secured at a fulcrum on the first lever by a second pin extending through the first and second levers.

Abstract: A hydraulic brake booster has a housing with a stepped bore for retaining a cylindrical piston and a control bore for retaining a control valve. The cylindrical piston defines, with the stepped bore, an output chamber, a relief chamber and a power chamber; and includes a second stepped bore for a reaction piston. The reaction piston includes an axial bore, receiving a plunger defining an actuation chamber and a poppet valve. The input force initially moves the plunger and poppet valve to interrupt communication between the actuation and relief chambers; and thereafter moves the plunger to pressurize fluid in the actuation chamber, creating an input signal. The input signal activates the control valve; generating a regulated pressurized fluid, supplied directly to a second set of wheel brakes and acts on the cylindrical piston, to pressurize operational fluid supplied to a first set of wheel brakes.

Abstract: In a proportional booster valve V, a primary reaction piston 37 and a secondary reaction piston 38 are provided between a control piston 23 which faces at one end thereof toward a control pressure chamber 25 into which hydraulic pressure outputted from a primary master cylinder is inputted a boost pressure chambers 44 connected to secondary master cylinders, the primary reaction piston 37 being adapted to transmit at all times to the control piston 23 a reaction force corresponding to hydraulic pressure of the boost pressure chamber 44, the secondary reaction piston 38 being adapted to transmit to the control piston 23 a reaction force corresponding to the hydraulic pressure of the boost pressure chamber 44 as the hydraulic pressure of the boost pressure chamber 44 exceeds a set hydraulic pressure.

Abstract: A primary pipe system includes a master cylinder with corresponding pressure sensor that produces a primary electrical signal. A secondary pipe system includes a working cylinder with a pressure sensor that produces a secondary electrical signal. The secondary pipe system generates a secondary pressure on the working cylinder as a function of the primary electrical signal. A computer continuously processes the primary and secondary electrical signals to transmit an electrical signal at a fixed frequency with a period that is divided into two intervals to an electromagnetic valve. During the first interval the electromagnetic valve is kept in a first operational position and during the second interval it is kept in a second operational position. The computer varies the intervals according to an algorithm for rapid actuation of the working cylinder.

Abstract: A clutch-servo for vehicles which constitutes a working device arranged for fluid connection with a master cylinder to be operated by the vehicle's driver. The servo comprises a working cylinder unit (50) with a piston (5) arranged in a working cylinder (1), which piston is connected to the clutch's engaging mechanism, and a control valve unit (60) for the working cylinder unit (50), with a valve body (21) arranged in the valve housing (44). The master cylinder has a fluid connection with the working cylinder unit (50) and the control valve unit (60), so that the fluid in the master cylinder simultaneously exerts a force on the piston (5) and the valve body (21), in order to try to release the clutch and to move the valve body (21) in order to connect the working cylinder unit (50) to a servo pressure fluid source when the driver operates the master cylinder. According to the invention the valve unit is constituted by a slide valve.

Abstract: A brake system (10) comprising: a master cylinder (20) including a primary (24) and a secondary (26) chamber and a reservoir (26); an accumulator (40), a pump (42) having first inlet port connected to a reservoir (26) of the master cylinder (20) and the second outlet port (b) connected to the accumulator (40), a motor (50) for selectively driving the pump as a function of system pressure, a pressure boost mechanism (60) connected to the accumulator (40) and the primary and secondary chambers of the master cylinder for generating a boosted pressure at a fixed multiple of the pressure in either the primary or secondary master cylinder chambers.

Abstract: The invention relates to an integrated pressure amplification and modulation system for a hydraulic brake circuit, comprising at least one master cylinder (10), a hydraulic motor, a source of fluid under high pressure (48) and a reservoir of fluid under low pressure (14), a computer-controlled solenoid (32) modulating by way of a magnetic core (30) the position of a slide (22) which slides in a bore (20). According to the invention, the fluid under pressure coming from the master cylinder (10) is applied to one face (24) of the slide (22), the other face of which bears on the magnetic core (30l ) and receives the force exerted by a spring (34) for return to rest. A reaction chamber (40) formed in the slide (22) is connected permanently to the hydraulic motor (38), and the hydraulic motor (38) is connected either to the reservoir (14) or to the source of fluid under pressure (48), depending on the position of the slide (22).

Abstract: There is disclosed an automotive hydraulic brake booster in which a driver feels a brake pedal moving smoothly as he or she pushes down on the brake pedal. The booster includes a housing connected with a master cylinder, an input rod, a booster chamber formed in the housing, a power piston sliding inside the booster chamber, and a reaction piston connected to the input rod and inserted in a hole formed in the power piston. A linkage is connected to a valve for boosting the force supplied to the master cylinder and connected to the reaction piston. The reaction piston can move a given distance relative to the power piston in response to the input rod, this distance being determined by a stop. The stop and the connection between the input rod and the reaction piston are on the same side of the connection between the linkage and the reaction piston. A reaction chamber is formed in said hole by the reaction piston.

Abstract: A hydraulic power booster having a lever device disposed in operative association with a reaction piston, a power piston and a valve spool, for moving the valve spool in one of opposite axial directions thereof for applying a pressure of a pressure source into a power chamber to advance the power piston, in response to a relative movement between the reaction and power pistons. The booster is provided with a backup actuator including a cylinder, and a valve drive piston which slidably engages the cylinder. The cylinder and the valve drive piston cooperate with each other to define a first fluid chamber communicating with the power chamber, and a second fluid chamber communicating with a pressure chamber in which a pressure is generated according to an advancing force of the power piston.

Abstract: Disclosed is a brake fluid pressure control apparatus in which an anti-lock control mechanism is connected to a hydraulic booster. A large-diameter piston is combined with a small-diameter piston so that the pressurization effected by the master cylinder M/C can be augmented by virtue of the difference in diameter between these pistons before it is transmitted to the wheel cylinder W/C. By moving forwards, the pistons cause a fluid supply passage between the fluid pressure source and a wheel cylinder W/C to be opened. With this structure, the size and weight of a brake fluid pressure control apparatus can be reduced.

Abstract: In order to increase the efficiency of a booster (10), the rear chamber (18) of which contains an auxiliary drive member (28) having a pressure chamber (30) connected to a pressure source (34) via a control device (36), the latter comprises a normally closed valve (38), via which the source (34) can communicate with the pressure chamber (30), and a mechanism (40) actuating this valve, which controls the opening of the latter automatically when the pressure in the rear chamber (18) exceeds the pressure in the front chamber (16) of the booster by a given value. Such an assembly can be used particularly on a braking system of a motor vehicle.

Abstract: A fluid pressure booster device includes a booster body, a control piston in the booster body for forward and rearward movements to define a boosting chamber between the control piston and a rear surface of a master piston of a master cylinder, a valve piston in the control piston for forward and rearward movements and communicating at its front face with the boosting chamber, a reaction piston in the control piston for forward and rearward movements and connected to an operating member, the reaction piston defining a reaction chamber between itself and a rear face of the valve piston, a stroke accumulator having an accumulation chamber connected to the reaction chamber, an inlet valve disposed between the control piston and the valve piston and interposed in a flow passage extending between the boosting chamber and a fluid pressure source, the inlet valve being closed when the valve piston is retracted and opening when the valve piston advances, and an outlet valve disposed between the control piston and the

Abstract: A braking apparatus for a vehicle has a booster for receiving, as a pilot pressure, a pressure of a master cylinder and for regulating a pressure from an auxiliary pressure source to a level predetermined times the pilot pressure. The booster is provided with an initial pressure raising mechanism for causing the booster to output a predetermined initial pressure in response to an initial actuation of a brake pedal.

Abstract: A modular brake actuator useful in automotove vehicles includes a mounting base adapted to fit into a complementary opening in and form part of the fire wall between the engine compartment and the driver's cockpit. On one side of the mounting base there are assembled brake operating components and on the other side there are assembled hydraulic components. This module can be easily installed during assembly of the vehicle.

Abstract: A hydraulic braking system for an automotive vehicle having a power source for generating a hydraulic power pressure, a reservoir, a master cylinder, a regulator and a plurality of wheel brake cylinders for braking respective road wheels, which are divided into a first group of wheel brake cylinders communicated with the master cylinder and a second group of wheel brake cylinders communicated with the regulator. The regulator has a housing defining therein a regulator chamber for introducing the hydraulic power pressure thereinto from the power source and regulating the hydraulic power pressure into a regulated hydraulic pressure in response to the hydraulic braking pressure generated in the master cylinder, and which is positioned in substantially coaxial relationship with the master cylinder and responsive mechanically to depression of a brake pedal.

Abstract: A brake power-controlled brake device for automotive vehicles is provided with a hydraulic master cylinder (11) which is, via a pneumatically actuated pressure modulator (12), connected to at least one wheel cylinder brake circuit I. The pressure modulator (12) comprises a vacuum power generator (20) and a compensating cylinder (18) equipped with a hydraulic piston (16, 16' or 16"), connected to which compensating cylinder is the wheel cylinder brake circuit I. If a brake slip signal occurs, the piston wall (14) of the vacuum power generator (20), which piston wall is normally applied by a vacuum on both sides, is temporarily connected with a higher pressure in the direction in which the volume in the compensating chamber (32) is increased. In addition, an isolating valve (15) is provided which is normally open but is closed when a brake slip signal occurs, and which is inserted in the connecting line (19) from the master cylinder (11) to the compensating chamber (32).

Abstract: A brake system wherein an input from an operator operates a first master cylinder (12) produces first and second hydraulic fluid pressures. Flexible conduit (22 and 24) carries the first and second hydraulic fluid pressures to an actuator (26) for a hydraulic power booster (28). A plunger (58) in the actuator (26) reacts either to the first hydraulic fluid pressure or the second hydraulic fluid pressure by moving to operate the hydraulic power booster (28). Operation of the hydraulic power booster (28) provides an input force to develop first and second operation fluid pressures in a second master cylinder (30) to effect a brake application.

Abstract: A servo-assisted master cylinder assembly for a vehicle hydraulic braking system has a tandem master cylinder with primary and secondary pistons operative to pressurise primary and secondary pressure spaces for primary and secondary brake circuits. A servo chamber is defined behind the primary piston, and pressurisation of the servo chamber from a source of pressure fluid is controlled by a valve in response to an input force applied to the primary piston. The valve comprises a spool operated solely by pressure in the primary space and a bias force from servo pressure in a bias chamber and a spring. The secondary piston has a smaller effective area than the primary piston, so that the pistons are in abutment in their retracted positions. To reduce pedal travel, one of the brakes of the primary circuit can be supplied from the servo chamber instead of the primary pressure space.

Abstract: A braking pressure generator (1,21) for a vehicular hydraulic brake system, wherein a booster piston (15) which is slidable by hydraulic pressure is displaceable in the actuating direction. The booster piston (15) is arranged as a stepped piston with a smaller-diameter portion (16) close to the pedal. The booster piston (15) includes a blind-end bore remote from the pedal in which a master cylinder piston (43) is sealedly guided, wherein the smaller-diameter portion (16) of the booster piston (15) confines an annular chamber (18) diminishing upon brake application. A valve (30) is connected to the annular chamber (18) controllable by the pressure in the pressure chamber (14) of the hydraulic power booster. The valve closes a connection between the annular chamber (18) and an unpressurized supply reservoir (9). A direct connection can be established between the annular chamber (18) and the working chamber (22) by way of the valve (30) and by circumventing a sealing collar.

Abstract: In a brake valve of the type in which a given ratio is maintained between a master pressure developed by a brake pedal and an actual brake pressure, an arrangement is provided for continuous, rather than stepwise, adjustment of this ratio. The brake valve includes a control piston which is subjected to the master pressure and which, by the displacement thereof, opens and closes connecting channels between an accumulator containing a primary pressure fluid and a brake, as well as between the brake and a fluid collecting tank. The control piston and a measurement piston apply counter forces to the arms of a balance beam whose lever ratio determines the degree of feedback of the instantaneous brake pressure to the control piston. A stop is provided in the path of the axis of the control piston, which limits the stroke of the piston, to prevent the overloading of the balance beam during abnormally high braking pressures such as occur, for instance, during panic braking.

Abstract: A brake system having a master cylinder for generating brake pressures in at least one closed brake circuit (I, II) and having an associated brake booster including a booster cylinder, a displaceable booster piston having a piston rod oriented into the master cylinder and a tappet arranged to plunge into the booster cylinder by means of a brake pedal and be displaced counter to the booster piston and is equipped with a brake valve connected to a pressure supply device, which brake valve is controllable by means of the relative movement of the tappet with respect to the booster piston. The brake system may be modified to become an anti-drive-slip apparatus via brake pressure maintenance valves built into the brake circuits (I, II), as well as a 3/3-way valve, by means of which pressure medium can be sent directly from the pressure supply device for exerting boosting action on the booster piston into the booster cylinder.

Abstract: Hydraulic assistance device of the mixed hydrodynamic/hydrostatic type incorporating a body (10) in which a first piston (18) is slideably mounted and moveable between a first position allowing the communication of a first chamber (53), joined to a braking circuit, to a reservoir (12), and isolating this chamber (53) from a source of high pressure fluid (86), and a second position isolating the chamber (53) from the reservoir (12) and connecting it with the source (86); a second chamber (30) in the body (10) connected by a passage (90) to the brakes (66), and valve mechanism (92) normally closing the passage (90) and sensitive to the pressure in the chamber (30) so that, when the latter pressure reaches a value which is greater than that existing in the first chamber (53), the valve mechanism (92) opens allowing fluid to flow between the second chamber (30) and the brakes (66).

Abstract: A brake booster is operated both by braking actuated by a brake pedal and by a solenoid. A moving core of the solenoid and a relay valve piston of the brake booster are linked by a balance lever, and the moving core of the solenoid has a much larger mobility than the relay valve piston during braking because the fulcrum of the lever is positioned nearer to the relay valve piston to enable the solenoid to be miniaturized. When the solenoid is actuated, the moving core requires much more time to move than to return. In an automobile equipped with this brake booster, the braking force can be increased gently but interrupted quickly during braking actuated by the solenoid.

Abstract: In a master cylinder assembly the pressure spaces in advance of pedal-operated pistons of two separate master cylinders are interconnected by a transfer passage, and each master cylinder incorporates a boost chamber to which hydraulic fluid from a pressure source is admitted to act on the piston and augment the force applied to the piston by the pedal when the master cylinder is operated. Each master cylinder incorporates a control valve having a valve spool which is normally urged by a spring into a retracted position to close a transfer port providing communication between the pressure space and the transfer passage and to close an inlet port to cut-off communication between the pressure source and the boost chamber.

Abstract: An air/hydraulic servomotor unit for providing power assistance for a clutch hydraulic operating system and comprising a compressed air cylinder, a hydraulic slave cylinder, a load proportioning means that determines what ratio of the unit output is derived from the hydraulic and air cylinders, and a clutch operating member.The hydraulic slave cylinder is secured to one end of the air cylinder housing and has a piston which passes through the air cylinder piston so that both pistons can act against the proportioning means. All the unit output loads pass through the proportioning means prior to being transmitted to the operating member.

Abstract: A motor vehicle provided with servo-assisted controls for the brakes and steering, has an hydraulic system of the type comprising a volumetric pump the input of which is connected to a reservoir, and first and second distributor devices the first of which is associated with the steering control device and the second of which is associated with the master cylinder for control of the brakes. The said second distributor device is formed in such a way as to function also as a pressure modulating valve.

Abstract: In a servo-motor assembly for a vehicle braking system a valve controlling the servo pressure is operated by an operating assembly including a rotary valve actuator positioned between a pedal-operated input member and an abutment member. The valve actuator is axially movable through a limited distance and a camming mechanism translates axial movement of the actuator into angular movement which operates the valve.

Abstract: A device for the power-assisted control of a hydraulic transmitter is disclosed which includes a transmitter cylinder having a first and second bore provided therein, a main piston with a bore hole, disposed in the cylinder, valve means disposed in the bore of the cylinder, a fluid source communicated with the cylinder, a control piston movably disposed in the second bore and having a control section and a second section formed thereon wherein the control section of the control piston is larger than the second section of the control piston.

Abstract: A control mechanism through which pressurized fluid from a source is communicated into a brake system and a steering system in response to independent operator brake and steering signals. The control mechanism has a housing with a first bore and a second bore therein. A piston located in the first bore separates a first chamber and a second chamber. A spool valve located in the second bore separates a brake pressure chamber created therein from a series of lands that control the flow of the pressurized fluid through the housing. When an operator effects a brake application, the piston moves in the first bore and creates a brake pressure in the first chamber. The brake pressure which is communicated to the brake pressure chamber in the second bore linearly moves the spool valve and allows pressurized fluid to be communicated to the second chamber in the first bore.

Abstract: A servo-assisted hydrodynamic braking system of the type in which brake pedal pressure is used to control a modulating valve which restricts an output line of a pump thereby increasing the pressure in the output line which is connected to the master cylinder of the braking system in such a way as to apply this increased pressure as a servo-assisting pressure, in which the master cylinder and modulating valve are made as a composite assembly and the pressure within the master cylinder part is used to control the modulating valve so that no direct mechanical interconnection between the brake pedal and the modulating valve is needed.

Abstract: A tandem brake master cylinder has a proportioning valve between two pressure regions therein. The pressure in a second pressure region changes by a proportion of the change in a first pressure region at least over a part of the pressure range of the first pressure region.

Abstract: Servo-assisted hydraulic braking system of the type in which brake pedal pressure is reinforced by a pressure dependent thereon and fed to a master cylinder driving piston by a distributor device which is fed with fluid under pressure from a pressure source and control pressure from control chambers defined by plungers within the master cylinder itself, which plungers are displaced directly or indirectly by the displacement of the driving piston of the master cylinder. The distributor plungers are balanced so that for a given brake pedal pressure they feed through a certain reinforcing pressure and then close off the driving piston chamber from the pressure source, locking in the reinforcing pressure so far applied, so that variations in the pressure generated by the pressure generating device are not fed back to the brake pedal via the driving piston of the master cylinder.

Abstract: A powered assist braking system having a pressurized fluid source which also supplies fluid to the steering system of a vehicle is disclosed herein. The braking system includes left and right-hand brake actuators that cooperate with a power brake valve and the actuators are designed so that, when actuated, hydraulic fluid is trapped in a chamber and this fluid is supplied to actuate the brake while the pressurized fluid source assists in pressurizing the trapped fluid. The power brake valve has a pressure release assembly incorporated therein which controls the maximum pressure of the inlet fluid and also controls the flow of fluid to the steering system. The system also is designed to equalize the pressure of the fluid when both brakes are simultaneously actuated.

Abstract: A brake booster for use in a braking system having a control valve which is responsive to a hydraulic output force created by manually moving a piston in a bore of a master cylinder. The hydraulic output force actuates the control valve which proportionally directs a portion of the fluid output of a pump which supplies a power steering gear with hydraulic fluid, into the bore. This portion of the output of the pump acts on the piston and provides an auxiliary force for moving the piston through which the hydraulic output force is created. When the hydraulic output force of the brake booster reaches a predetermined value, the control valve engages a stop member to limit the diversion of the fluid output from the pump and thereby assure that a minimal quantity of the fluid output is continually available to operate the power steering gear.