Abstract: A pneumatic servo booster includes a housing, a flexible diaphragm partitioning the interior of the housing into front and rear chambers, a valve body slidably mounted in the housing and connected to the diaphragm, and a valve mechanism incorporated in the valve body and including a poppet valve cooperating with a valve seat formed on the valve body and with another valve seat formed on a plunger which is connected to an input rod and is slidably mounted in the valve body. A return movement restricting member restricts the return movement of the plunger with respect to the housing when the valve body returns to its return position.

Abstract: A pneumatic servo booster including a shell housing having front and rear shells, a valve body incorporating therein, a valve mechanism slidably supported by the rear shell, a partitioning member cooperating with the valve body for partitioning the interior of the shell housing into front and rear chambers, and a connecting rod axially extending in the front and rear directions through the front and rear chambers and through the partitioning member with the opposite ends thereof being connected to respective shells. An annular tubular extendable member is provided for surrounding a portion of the connecting rod. One end of the tubular member is connected to the peripheral surface of a bore which is formed in the partitioning member for passing therethrough the connecting rod, and the other end of the tubular member is connected to either the front or rear shell and surrounds the connecting rod.

Abstract: A pneumatic servo booster includes a shell housing consisting of front and rear shells, a valve body incorporating therein a valve mechanism and sealingly extending through and being slidably supported by the rear shell, and a reinforcing plate provided on the inner surface of the rear shell. The inner circumference of the reinforcing plate is utilized to locate a seal member which is provided between the rear shell and the valve body.

Abstract: A servo booster including a piston plate for receiving a differential pressure produced across two chambers which are defined in a shell casing, a cylindrical valve body having a valve mechanism therein for controlling the pressure across the two chambers, an aperture and a head portion formed respectively at the center portion of the piston plate and at an end portion of the valve body and being engageable with each other at a predetermined angular position, and the relative movement of the valve body and the piston plate in the direction of the axis of the servo booster being prevented by rotating the head portion through a predetermined angle in the aperture, wherein the improvement comprises a rotation preventing member rigidly mounted on the piston plate and having one portion thereof in fitting engagement with the valve body to prevent the relative rotation of the valve body and the piston plate.

Abstract: A fluid pressure operated servomotor such as a vacuum booster including a power piston having a differential pressure acting thereacross, an input rod for actuating a valve mechanism mounted in the power piston, a reaction lever disposed between the power piston and an output rod for transmitting a force to the output rod and transmitting a reaction force to the input rod. A return spring for urging the power piston in the return direction acts through the reaction lever on the power piston, whereby the reaction force is not transmitted to the input rod until the force transmitted to the output rod exceeds a predetermined value.

Abstract: A vacuum booster including a casing, a power piston having a resilient diaphragm and dividing the interior of the casing into two chambers, an input rod for actuating a valve mechanism to generate differential pressure between the two chambers, and an output rod receiving a force in accordance with the differential pressure from the power piston, wherein the inner end of the output rod is received slidably on a member of power piston side with male and female engagement therebetween, and a groove is formed in the male member for engaging with a clip which allows a predetermined amount of relative sliding movement between the male and female members.

Abstract: A vacuum booster device has a casing defining two chambers partitioned by a diaphragm, a valve body connected to the diaphragm, a plunger slidably and sealingly inserted in the valve body and connected to an input rod, two valve seats formed respectively on the valve body and the plunger, and a poppet valve for engaging and disengaging with the valve seats to connect or disconnect the two chambers and to connect one of the chambers to or disconnect it from the atmosphere. One end portion of the poppet valve is fitted and retained in the inner periphery of the valve body and has an annular projection on the outer periphery of the end portion for sealingly engaging with the valve body.

Abstract: A vacuum augmentation device for use with a vehicle braking system and of the type having a body, a diaphragm-piston mechanism providing a pair of fluid chambers in the body, valving for isolating or communicating the chambers, a push rod actuated plunger assembly for operating the valving, an output rod shiftably mounted in the body and carrying a fulcrum plate, and a number of reaction levers for effecting a lever type coupling between the diaphragm-piston mechanism, the shiftable plunger assembly and the fulcrum plate on the output rod is provided with improved structure for coupling the reaction levers with the diaphragm-piston mechanism, which structure employs a mounting plate member engaged with the mechanism and carrying on the opposite side thereof an elongate fulcrum pin for each reaction lever which is longitudinally engageable with the latter in line contacting relationship to provide a radially fixed fulcrum for each of the reaction levers.

Abstract: A vacuum degree augmentation device for use in brake apparatus is provided in which a diaphragm-piston divides the body of a valve mechanism into two air-tight chambers, the valve mechanism is shiftable in response to the operation of a plunger which in turn operates in response to the operation of an input rod, the operation of the valve normally maintains the chambers in communication with each other under low pressure, but, during braking, one chamber is placed in communication with the open air to produce a differential pressure between the chambers so as to operate the piston, with the force operating the piston being transferred through a reaction lever, a fulcrum plate and an output rod to a master cylinder.