Abstract: A vacuum brake booster assembly comprising front and rear housing shells connected to form a single piece their output peripheral edges and mounted within the passenger compartment of a vehicle, a piston body axially movable in the housing shells, a diaphragm member hermetically secured at its inner peripheral edge to the piston body and clamped at its outer peripheral edge by the outer peripheral edges of the housing shells to subdivide the interior of the housing shells into a vacuum chamber and a variable pressure chamber, and a pressure control valve cooperable with the piston body for selectively communicating the variable pressure chamber to the vacuum chamber or the atmospheric air in response to movements of the piston body, wherein at least the rear housing shell is formed as a double or multi layer wall for the variable pressure chamber to dampen air suction noises caused by expansion and vibration of the air flowing through the valve into the variable pressure chamber from the passenger compartment

Abstract: A pneumatic booster device having an elliptical housing is formed of two stamped metal sections having mating flange and opening portions, the two sections being joined in a simple, effective, easily diassembleable manner without the use of standard nut and bolt fasteners.

Abstract: A tandem brake booster for automotive vehicles comprises a housing the interior of which is subdivided into front and rear chambers by means of a partition wall, a front movable wall assembled within the front chamber to subdivide the front chamber into front constant and variable pressure chambers and being integrally provided at its inner peripheral portion with a front cylindrical hub member extending from the front chamber into the rear chamber across the partition wall, a rear movable wall assembled within the rear chamber to subdivide the rear chamber into rear constant and variable pressure chambers and being integrally provided at its inner peripheral portion with a rear hub member. The rear hub member is engaged with the rear end of the front hub member and is formed with a cylindrical portion which extends into the front variable pressure chamber across the partition wall and is arranged in surrounding relationship with the front cylindrical hub member.

Abstract: A vacuum booster having a master cylinder and which includes a body having a bent portion, a reinforcing member connected to the body and having a flange member extending therefrom and a mechanism for installing the master cylinder onto the body as reinforced by the reinforcing member wherein a bending center of the bent portion of the body is located further inside the body than the location of the bending center of such flange of the reinforcing member.

Abstract: A brake master cylinder having a push rod including a body which includes resin material, a metal liner inserted within the body, a seal member disposed between the body and the metal liner, a piston slidably positioned within the metal liner and actuated by the push rod wherein the length of metal liner is slightly longer than the length of large diameter portion of the piston which is in contact with an inside wall of the metal liner plus a length defined by the range in stroke of the piston and a support member for securely holding the metal liner and limiting movement of the push rod.

Abstract: A vacuum booster which includes a push rod, a housing having a first and second compartment, a power piston located in the housing and operated by a pressure differential between the first and second compartments and which further includes a small and large diameter portion, a control valve operatively associated with the push rod and located within the power piston for controlling the pressure differential between the first and second compartments in response to movement of the push rod, an output member having a first end slidably disposed within the large diameter portion of the power piston wherein the control valve includes an air-valve element one end of which is slidably disposed in the small diameter portion of the power piston a resilient reaction disc located adjacent the first end of the output member and disposed within the large diameter portion of the power piston, a metallic sleeve provided between an outer peripheral portion of the first end of the output member and an outer peripheral portion

Abstract: A tandem-type brake booster including a closed shell assembly composed of front and rear chambers defined by a partition member therein and power pistons coaxially disposed in the front and rear chambers, respectively, the power pistons being operatively coupled with each other and passing through a substantially central portion of the partition member, each of the front and rear chambers being divided into a constant-pressure chamber subjected to a vacuum and a variable-pressure chamber communicable selectively with the constant-pressure chamber and atmosphere, the constant-pressure chambers in the front and rear chambers being held in communication with each other, the variable-pressure chambers in the front and rear chambers being held in communication with each other, the power pistons being axially movable in unison by pressure differences between the constant-pressure chambers and the variable-pressure chambers, respectively, one of the front and rear chambers having an outside diameter smaller than tha

Abstract: A negative pressure booster for an automobile brake system includes a housing having an inside cavity, a power piston being provided in the housing for dividing the inside cavity of the housing into a suction pressure chamber and an atmospheric pressure chamber. An output rod is associated with the power piston and extends outwardly through the housing. A manually actuated control valve is carried by the power piston for controlling the communication between the suction pressure and atmospheric pressure chambers and the communication between the atmospheric pressure chamber and atmosphere. A pipe is provided for connecting the suction pressure chamber with a source of negative pressure.

Abstract: A float stopper is attached to the free end of a thermoplastic switch case constituting part of a liquid level sensor by forming the free end of the switch case into a hollow, cylindrically shaped projection, fitting the float stopper over the projection through a hole formed in the stopper and, forcibly inserting a caulking tool, heated to a temperature which is lower than the melting point of the thermoplastic material constituting the switch case, into the cylindrically shaped projection to soften and spread the projection until its outer surface abuts against the rim of the hole formed in the float stopper. Upon curing the spread portion of the caulking projection holds the float stopper rigidly in place with excellent mechanical strength.

Abstract: A brake booster includes a body having a central wall portion on which a, doughnut-shaped reinforcement plate is securely mounted, and bolts mounted on the reinforcement plate for fastening a master cylinder to the central wall portion. The reinforcement plate has an annular ridge extending along an inner peripheral edge thereof and projecting against the reinforcement plate. The master cylinder includes a flange mounted on the body and having an inner peripheral portion held against the central wall portion of the body in axial alignment with the annular ridge, and an outer peripheral portion spaced from the central wall portion by a distance such that the outer peripheral portion of the flange will not be forced into contact with the central wall portion when the master cylinder is actuated for braking action. Therefore, no localized forces are applied by the outer peripheral portion of the flange to the central wall portion of the body.

Abstract: A reservoir is disclosed which has a tank made of synthetic resin and incorporated a liquid level sensing device whereby the sensing device has a magnetically actuable switch enclosed in a depending hollow tubular portion of the tank and a float having a magnet which is axially slidable on the tubular portion in order to actuate the switch when the magnet and the switch are in proximity with the tank having both upper and lower shells with the upper shell being formed integrally with the hollow tubular portion and one of the shells being formed integrally with a heat shielding skirt portion which surrounds the tubular portion. The heat shielding portion extends into the interior of the lower shell for shielding the tubular portion against the welding heat during the connection of the upper and lower shells.

Abstract: A fluid reservoir assembly including a reservoir cap for closing a cylindrical opening of the reservoir, the reservoir assembly including an outward flange formed on an outer periphery of an upper portion of the reservoir, nail members provided on the reservoir cap and having a tip portion bent radially inwardly, a biasing member biasing the nail members into engagement with the outward flange and a nail operating mechanism connected to the nail members for moving the nail members against the biasing member.

Abstract: A reaction structure of a brake booster comprises a deformable reaction disc with a peripheral edge rounded at a radius off corresonding to the radius of the rounded edge of a larger bore receiving the reaction disc. On a brake operation, the reaction disc is coaxially compressed between a second valve element interposed with a clearance thereto and connected to an input pushing rod and a power output rod, thereby resulting in a definite jumping value without indefinite delay of output power rise.

Abstract: In a sealed fluid reservoir for a hydraulic brake master cylinder, inlet and outlet check valves are compactly assembled with a reservoir cap to constantly seal brake fluid stored in the reservoir against the surrounding air. The inlet and outlet check valves are selectively opened in response to rise or drop of the level of fluid in the reservoir to ensure smooth fluid supply to the brake master cylinder.

Abstract: A reservoir cap assembly of a vehicle master cylinder includes a cap body detachably mounted on an open end of a reservoir a caution plate on which directions or the like are inscribed, and a rivet having head and leg portions for respectively securing the cap body and the caution plate.The head portion of the rivet is firstly caulked to a bottom surface of the caution plate, and thereafter the leg portion of the head caulked rivet is fixedly secured in the cap body thereby to tightly attaching the caution plate to the cap body.

Abstract: A liquid level reduction alarm device for a braking liquid reservoir vessel in communication with a brake master cylinder wherein the reservoir is closed at its upper open end by an elastic cover member and an elongated hollow case member is suspended from the cover member into the interior space of the reservoir a magnetically operated reed switch is mounted within the interior of the case member and connected with an alarm circuit including an alarm lamp.