Abstract: A valve mechanism of this negative pressure type booster device has: a negative pressure valve seat provided on a valve body; an atmospheric valve seat provided on a plunger; and a valve part provided with a negative pressure valve section constituting a negative pressure valve together with the negative pressure valve seat and an atmospheric valve section constituting an atmospheric valve together with the atmospheric valve seat. The valve mechanism is provided with a tilting part which is provided on at least one of the valve body and the valve part and tilts the atmospheric valve section relative to a first plane formed when the negative pressure valve section and the negative pressure valve seat are brought into contact with each other to put the negative pressure valve in a closed state.

Abstract: A brake booster includes an atmosphere chamber, a working chamber, a valve assembly, and an air passageway. The atmosphere chamber includes an air inlet, and the working chamber is in fluid communication with the atmosphere chamber. The valve assembly is positioned between the atmosphere chamber and the working chamber, and the valve assembly includes a plunger configured to cooperate with a valve seat to selectively enable or prevent fluid flow from the atmosphere chamber to the working chamber. The air passageway is defined within the atmosphere chamber between the air inlet and the valve assembly. The air passageway is void of any springs.

Abstract: A brake booster includes an atmosphere chamber, a working chamber, a valve assembly, and an air passageway. The atmosphere chamber includes an air inlet, and the working chamber is in fluid communication with the atmosphere chamber. The valve assembly is positioned between the atmosphere chamber and the working chamber, and the valve assembly includes a plunger configured to cooperate with a valve seat to selectively enable or prevent fluid flow from the atmosphere chamber to the working chamber. The air passageway is defined within the atmosphere chamber between the air inlet and the valve assembly. The air passageway is void of any springs.

Abstract: An air valve assembly is provided for a power piston in a vacuum brake booster including an input element with a hollow axial extension. The hollow axial extension includes a retaining portion. An output element is provided that includes an input extension slidably positioned within the hollow axial extension. The input extension includes an outer groove formed thereon and a ring member is disposed in the outer groove, the ring positioned adjacent the retaining portion to prevent separation of the input element and outer element.

Abstract: An air valve assembly is provided for a power piston in a vacuum brake booster including an input element with a hollow axial extension. The hollow axial extension includes a retaining portion. An output element is provided that includes an input extension slidably positioned within the hollow axial extension. The input extension includes an outer groove formed thereon and a ring member is disposed in the outer groove, the ring positioned adjacent the retaining portion to prevent separation of the input element and outer element.

Abstract: A vacuum brake booster provides a braking speed of application enhancement by increasing the air valve opening when a vehicle operator applies braking force quickly and forcefully. This is accomplished with a two part air valve which is normally expanded axially to a normal length by an internal spring but which may be shortened to open the air valve by a greater amount when the brake pedal input force is sufficient to move the air valve axially against another spring into contact with a shoulder of the power piston. The internal spring has a much higher preload than the other spring so that the booster operates with a fully axially expanded air valve in normal, low force brake activation. Once the air valve axially engages the power piston, however, the increase in air valve opening is immediate and substantial with any further increase in braking force.

Abstract: This boosted brake device comprises a pneumatic brake booster (1) associated with a master cylinder (2), the booster operating according to a hydraulic reaction principle and comprising a movable pneumatic piston (5) carrying a control valve (7) actuated by a rod (8), as well as a partition (4) which can move under the effect of a pressure difference and which develops a boost force.The movable wall (4) is mounted slidingly with respect to the pneumatic piston (5) in order to act early on the master cylinder.The device of the invention allows greater braking for small values of the travel of the control rod.

Abstract: A housing is provided with a guide which projects into a cylindrical section of a power piston. A reaction piston is slidably supported by the guide, and an input shaft is in turn slidably supported by the reaction piston. A spring which urges the reaction piston is disposed in a clearance defined between the outer periphery of the guide and the inner periphery of the cylindrical section of the power piston. A first engaging portion is formed on the reaction piston to project radially outward, and a first stop is formed on the cylindrical section to restrict a rearward movement of the reaction piston. A second engaging portion is formed on the input shaft so as to project radially outward while a second stop is formed on the reaction piston to restrict a rearward movement thereof. With this arrangement, an increase in the axial and the diametrical dimension of a liquid pressure booster can be prevented.

Abstract: A brake booster includes a housing in which a constant-pressure chamber and a variable-pressure chamber are defined by a power piston. An input rod is operatively connected to one end of the power piston and receives an input force. A valve is provided in the power piston and operatively connected to the input piston so as to open upon receipt of the input force in such a manner that the differential pressure between the chambers moves the power piston. An output rod is operatively connected to the other end of the power piston. A wall member is provided across which a first auxiliary chamber at a side of the variable-pressure chamber and a second auxiliary chamber formed at a slide of the constant pressure are formed. An orifice passage connects the variable pressure chamber and the first auxiliary chamber.

Abstract: A cylindrical casing accommodates an operator pistion and a power piston separated by a fixed barrier which serves to define with the former a reservoir and with the latter a power chamber. A piston rod affixed to the operator piston extends through the barrier into manual brake actuating relation with the power piston. Hydraulic fluid under pressure is introduced to the reservoir from which it flows through barrier passages, past a check valve, into the power chamber and out through venting ports formed in the piston rod. To apply vehicle brakes linked to the power piston, the operator piston is manually propelled toward the barrier, and the power piston is thus forced away from the barrier by the piston rod, resulting in rapid transfer of hydraulic fluid from the reservoir to the power chamber. The venting ports then close, such that the power chamber is pressurized to exert a brake power assisting hydrostatic force on the power piston.

Abstract: The distributor comprises a star-shaped rotor (2) arranged between two concentric components which are spaced axially and are fixed in rotation to a second valve portion (60); a C-shaped centering return spring (40) is arranged around the rotor (2) and cooperates, by its facing ends, with a projection (100) of one of the arms (10.sub.1) of the rotor and with adjacent projections of the second valve portion.

Abstract: A pressure-unbalanced hydraulic amplifier valve assembly has an axially slidable amplifier piston and a control plunger axially slidably arranged in the amplifier piston with a loose fit to permit a slight radial movement thereof in the amplifier piston. For providing a tight seal in the zone of control ports arranged in the amplifier piston, the control plunger is urged in that zone radially against the amplifier piston by a transverse piston continuously exposed to the system pressure. A pressure piston engages one end of the control plunger and is exposed to an external force (such as a braking force applied by a pedal) for axially displacing the control plunger. In order to eliminate undesired axial force components from the force applied by the transverse piston, a force-transmitting ball contacts the transverse piston and an inner wall of the control plunger forming a throughgoing axial bore and constituting an axially linear track for the ball.

Abstract: A servo booster assembly comprises a housing having a fixed part and a movable part defining a chamber therebetween, a control valve for communicating the chamber alternately with vacuum and ambient air, and an input member movement of which operates the control valve. In response to operation of the control valve the movable housing part moves relative to the fixed part between an inoperative position and an operative, brake-applying position, the movable part being connected to an output member. The housing parts are interconnected by a tie bar the ends of which extend outside the housing and are adapted respectively for connection to a master cylinder and a vehicle bulkhead.

Abstract: A power assisted pedal assembly comprises a brake pedal pivotally connected at one end to a lever which is pivotal about a fixed point, the brake pedal having a connection intermediate its ends with an actuating member of a master cylinder to apply an operating force to the actuating member, and a power assistor operable in response to movement of the brake pedal to apply an assisting force to the brake pedal. The power assistor has a force-transmitting member which is separate from the actuating member and which is in force-transmitting engagement with the lever on or close to the line of action of the force applied to the actuating member by the brake pedal. The brake pedal and the lever pivot about the fixed point when the power assistor is operative and the pedal pivots about a point intermediate the fixed point and the connection between the lever and the actuating member upon failure of the power assistor.