Abstract: A negative-pressure booster is provided with a housing, two movable walls, a power piston, an input member, an air valve seat, a negative-pressure valve seat, a control valve having an air sealing valve portion and a negative-pressure sealing portion, an output rod, an reaction disc, a slider valve, and an actuator. The output of the negative-pressure booster can be adjusted by adjusting the driving force of the actuator.

Abstract: A vacuum servo apparatus capable of reducing variations in the input and output characteristics includes a housing, movable walls, a power piston, an input member, an input rod, a valve mechanism, an output rod and a reaction disk. The length of the input member in the front and rear direction is increased or decreased in accordance with a change in the air temperature.

Abstract: An automatically operable negative pressure type booster can be applied for a front stage pressurizing function in a braking fluid pressure control apparatus with braking and steering control. The booster includes a housing, a movable wall dividing the housing interior into a front chamber and a rear chamber, a valve housing outputting a braking force to an output rod, an input member, and a control valve. The output rod can be divided into a first member and a second member. The booster further includes an auxiliary movable wall which can be engaged with the first member, a partition wall forming an auxiliary variable pressure chamber behind the auxiliary movable wall, and an electromagnetic valve unit selectively communicating the auxiliary variable pressure chamber with the front chamber or atmosphere.

Abstract: A pressure generator includes a housing in which is formed at least one pressure chamber, and a power piston disposed inside the housing for advancing and retreating movement with respect to the housing. A moving wall divides the pressure chamber into a front chamber connected to a vacuum source and a rear chamber selectively connected to the vacuum source and the atmosphere, and a valve housing is attached to the moving wall. A valve mechanism disposed inside the valve housing has a vacuum valve for connecting the rear chamber with the front chamber. The valve mechanism also has an atmospheric air valve for connecting the rear chamber with the atmosphere. An output member outputs a thrust force accompanying movement of the moveable wall, and a cylinder body is provided which has a cylinder bore and which is mounted on the front part of the housing. A piston is located in the cylinder bore for advancing and retreating movement.

Abstract: A vacuum type brake booster for a vehicle is capable of compensating for inadequacy of the force with which a driver steps on a brake pedal during emergency braking whereby a reaction force corresponding to the output of the booster is applied to the brake pedal. A good brake pedal operation feeling is thereby obtained in both the outward and return strokes of the brake pedal and during when the booster has been switched to normal braking and when it has been switched to emergency braking.

Abstract: A negative pressure type booster 1 includes a housing 2, a movable wall 3 which divides the interior portion of the housing 2 into a constant pressure chamber 4 and a variable pressure chamber 5, a power piston 6 which outputs a brake output toward an output rod 10, an input member 8 which can be moved by a brake actuation, and a control valve 13. The output rod 10 can be divided into a first output rod 101 and a second output rod 102.

Abstract: A vacuum servo unit includes a partition member having an outer periphery that engages the movable wall member in an air tight manner. A receiving chamber is defined between the partition member and the movable wall member, and the receiving chamber is adapted to be communicated with the atmosphere. A passage that introduces atmospheric air into the receiving chamber is engaged in an air tight manner with the partition member and extends through the constant pressure chamber. A change member in the form of a solenoid valve selectively communicates the receiving chamber with the constant pressure chamber or with the atmosphere. Accordingly, the servo efficiency of the vacuum servo unit is increased. In addition, the unit can be operated automatically by supplying electric power to thereby increase brake force so that the brake feeling is advanced.

Abstract: A brake booster apparatus for a vehicle has a constant pressure chamber, a variable pressure chamber, a control valve, a power piston, a plunger member and a solenoid coil. The plunger member is actuated under the energized condition of the solenoid coil. The power piston is actuated in response to the depression of a brake pedal and/or plunger movement. The output force of the brake booster is amplified by the pressure difference between the variable and constant pressure chambers. A clearance is provided between the input member and the plunger member to permit relative movement of the input member and the plunger member. The relative movement generates a continuous variable output force of the brake booster.

Abstract: A vacuum brake booster with an automatic braking actuation system of the type which includes an electric actuator assembled with a power piston to effect forward movement of a valve plunger assembly when activated under control of an electronic controller, wherein a depression amount of a brake pedal is detected to calculate a depression speed of the brake pedal based on the detected depression amount, and wherein the electric actuator is activated when the calculated depression speed of a brake pedal exceeds a predetermined threshold value and is deactivated when a release amount of the brake pedal is more than a predetermined value.

Abstract: A vacuum servo unit has a housing, a movable wall member, a constant pressure chamber, a variable pressure chamber, a movable power piston, an input member, an output member, a control member, an operation member for applying an axial propulsion on the output member when electric power is supplied thereto, a first input rod connected to a brake operation member, a second input rod, an electric switch member provided on either the first input rod or the second input rod, a switch operate member changing the state of the electric switch member according to a movement of the first input rod against the second input rod. Accordingly, when a driver returns a brake operation member in the condition that the operation member is applying the axial propulsion on the output member, a first input rod is pulled back. Therefore, the first input rod moves respectively to the second input rod, which changes a state of an electric switch member.

Abstract: A vacuum servo unit includes a movable power piston having a base portion and a cylindrical portion whose output side end portion is connected to the input side end portion of the base portion. The base portion has an annular first projection projecting into the inside of the cylindrical portion and a second projection projecting into the inside of the cylindrical portion. the second projection divides the space surrounded by the annular first projection into a first space and a second space. A vacuum path communicates the constant pressure chamber with the first space, and an air path communicates the variable pressure chamber with the second path. Thus, the area of the cross-section of the second space in a plane perpendicular to the axis of the movable power piston can be enlarged so that atmospheric air can smoothly flow into the variable pressure chamber.

Abstract: The present invention is directed to a vacuum servo unit which is characterized in that the negative pressure controlling valve seat is arranged in a position spaced from the atmosphere controlling valve seat in an axial direction, and the atmosphere and the negative pressure controlling seal portions of the control valve are spaced in the axial direction to cooperate with the atmosphere and the negative pressure controlling valve seats. The control valve is in air tightly engagement with an internal surface of the movable power piston at an external surface thereof, and the control valve has a path provided between the atmosphere controlling seal portion and the negative pressure controlling seal portion. Accordingly, when the brake operating member is operated, large quantities of the atmosphere can be introduced to the variable pressure chamber through the clearance between the atmosphere controlling valve seat and the atmosphere controlling seal portion.

Abstract: In a vacuum brake booster including a housing the interior of which is subdivided into negative and variable pressure chambers by means of a movable wall assembled therein, a piston body assembled with the movable wall to be axially movable in the housing, a valve plunger axially slidably coupled within the piston body, a first annular valve element formed on an outer end of the valve plunger, a second valve element formed on an internal cylindrical portion of the piston body, and a control valve assembly having a first annular sealing portion cooperable with the first valve element and a second annular sealing portion united with the first annular sealing portion to cooperate with the second valve element, the first valve element is arranged in a position spaced in an axial direction from the first valve element, and the first and second annular sealing portions of the control valve assembly are spaced in the axial direction to cooperate with the first and second valve elements.

Abstract: A vacuum servo apparatus in which, in a performance diagram having an input coordinate axis perpendicular to an output coordinate axis, the normal operation is represented by a first operating line and, after a plunger member is moved by a solenoid so that movement of the plunger member with respect to a transmission member is controlled, the operation is represented by a second operating line following additional jump biasing force to be supplemented and generated is appropriately set and an output of the apparatus is designed to be faster during the return stroke for straightforwardly reflecting the intention of the driver.

Abstract: A vacuum servo unit which is designed so that when a valve member associated with the plunger that is connected to an input member is out of engagement with the plunger, the power piston moves due to the pressure differential between a variable-pressure chamber and a constant pressure chamber for boosting the force to the input member, is provided with an arrangement for inhibiting or preventing inclination of the input member. The arrangement includes a plurality of projections extending outwardly from the input member, and a plurality of slots formed in the plunger for receiving the projections.

Abstract: The use of a blotting material in an air dryer used in vehicle suspension system is disclosed. The blotting material absorbs moisture from the intake air and prevents desiccant material contains in the air dryer from being damaged by the moisture. The blotting material also prevents rusting the intake and exhausting valve.

Abstract: An inlet assembly for a brake master cylinder includes an inlet member made of synthetic resin installed in the cylinder body of the master cylinder which has at least two inlet portions and one outlet portion positioned between the inlet portions at the same side. The master cylinder is connected through the inlet portion to a hose communicating with a reservoir installed in a vehicle body. The inlet member includes a first member integrally formed of a first tubular portion on a cylinder body side of the inlet member which is fitted into an inlet portion of cylinder body, a second tubular portion for operative engagement with the hose, and a second member having a mounting portion for mounting on the cylinder body by apparatus for positioning the inlet member on the cylinder body and an opening portion which is fitted by a boss portion surrounding the outlet portion of cylinder body.

Abstract: A hand brake lever assembly includes a plunger mounted on a support for axial slidable movement and for rotation about its axis and being connected at its one end to a parking brake, a locking mechanism associated with the plunger to retain the plunger in a pulled out position against a returning effort of the parking brake acting thereon and being arranged to be released by rotation of the plunger, a sleeve member secured to the other end of the plunger and having an annular end wall formed with a first annular cam surface and an axial key groove, a handle having a shaft extending therefrom and inserted into the sleeve member, the handle shaft being formed with an axial guide groove and being integrally provided with a cam member which is formed with a second annular cam surface complementary with the first cam surface and is axially slidably coupled within the sleeve member, a first spring for pressing the annular cam surfaces in contact with each other, a release rod axially slidably coupled with the guide

Abstract: A relief valve used for hydraulic devices such as the master cylinder for motor vehicles, comprising a housing for passing hydraulic fluid therethrough to adjust the hydraulic pressure, a ball valve disposed in the housing, a coil spring for pushing the ball valve in the housing and plural finger-like portions formed in the inside of the housing to resiliently nip the ball valve so as to prevent the vibration of ball valve in the direction of diameter of the housing at the time of releasing hydraulic fluid through the inside of the housing, thereby making it possible to avoid the generation of strange noise by the vibration of ball valve. It is desirable to form the surface of valve body or the valve body side surface of the finger-like portions so that it has a surface roughness within a specific range in order to make the noise prevention effect more perfect.

Abstract: A piston defines in a cylinder housing a pressure chamber connected to a brake pipe and a fluid supply chamber connected to an oil reservoir. The piston has a recess facing the pressure chamber at one end thereof. A valve member is provided in the recess for making or breaking fluid communication between the pressure chamber and the oil reservoir through the supply chamber. A compression spring is disposed in the recess for urging the valve member into its closed position. A spring retainer is fitted about the end of the piston for holding the spring in the recess. A supporting member is provided in the housing on the opposite side of the pressure chamber from the piston. The valve member is supported by a connecting rod extending axially movably through the spring retainer and the supporting member. A compression spring is connected between the spring retainer and the supporting member for urging the connecting rod in the direction which causes the valve member to open.