Abstract: A hydraulic brake assembly with pneumatic power assist has a master cylinder inserted in a housing in turn at least partially surrounded by an annular power-booster device comprising a pair of annular chambers divided by a membrane. The membrane is connected via a plate and a sleeve or tie rods to a tension rod axially traversing a substantial portion of the master cylinder. The tension rod engages an actuator piston placed in compression by a push rod upon the actuation of a brake pedal linked thereto. The force for actuating a fluid-compression piston in the master cylinder is thus transmitted thereto partly via tension-stressed elements and partly via compression-stressed elements. Force feedback to the brake pedal is implemented either hydraulically via fluid-flow channels in the tension rod or mechanically via a lever inside or outside the housing. A fluid reservoir is removably mounted on the housing in juxtaposition to the booster chambers and transversely to the housing axis.

Abstract: A hydraulic amplifier having a housing provided with pressure and return conduits, an amplifier piston, and a control slide. The piston is slidably arranged in an axial bore of the housing and itself has a blind axial bore within which the control slide is arranged. The piston and slide together constitute a unit which is free of pressure equalization and which is provided with two sets of passages for selectively placing the face of the piston in communication with the pressure and return conduits, respectively, depending on the axial position of the slide in the blind bore of the piston. The passages are asymmetrical with respect to the peripheral surface of the slide and are so constructed and arranged that whichever set of passages is closed, the slide is pressed radially against the closed passage under the influence of certain pressure differences which prevail in the hydraulic amplifier.

Abstract: A hydraulic power boost apparatus for use with the braking system of an automotive vehicle includes a power piston cooperating with a slide valve to define a plurality of spool valves to regulate the flow of a pressurized fluid therethrough to selectively apply the fluid to boost the force applied to the power piston. A resilient member is positioned within the power piston blind bore to modulate the force transmitted from the slide valve to the power piston. The power piston also includes an annular ridge for engaging a mating annular ridge of the slide valve to limit the travel of the slide valve to prevent the resilient member from being deformed beyond its elastic limit.

Abstract: A hydraulic braking force multiplying device has a:A body coupled to a master cylinder;A projecting portion provided in the body and projecting toward the master cylinder;A cup-shaped power piston one open end of which receives the outer periphery of the projecting portions slidably and sealingly relative thereto, and the other closed end of which is adapted to actuate a piston of the master cylinder;A working chamber defined between the power piston and the projecting portion;A bore extending through the body and coaxial with the piston of the master cylinder;A valve member slidably fitted in the bore and having one end extending into the working chamber;A spring urging the valve member in the direction away from the working chamber;A bore provided in the valve member coaxially therewith and communicating with the working chamber;A first pressure chamber defined between the bore of the body and the outer periphery of the valve member and normally communicating with a pressure source;A normally closed first v

Abstract: The brake system includes a tandem master cylinder and a control valve for introducing pressure supplied from a power source. The main feature of the present invention is that the pressure from the power source is first introduced into annular chambers behind the sleeve seals of both the tandem master-cylinder pistons. This makes it possible for the pistons to travel only a small distance if power from the power source is available. Thus, the pistons can be dimensioned in accordance with the force the driver is able to exert with his foot in the event of failure of the power source.

Abstract: A vehicle brake booster and master cylinder assembly has a vacuum suspended booster section which is controlled by movement of the vehicle brake pedal. A hydraulic booster section is in series with the vacuum suspended booster section, and a master cylinder unit is in series with the hydraulic booster section. The assembly is so arranged that in normal operation the vehicle operator obtains booster brake actuating pressures by operation of the vacuum suspended booster which acts through the hydraulic booster mechanism without operating the hydraulic booster. When greater brake actuating pressures are required, as indicated by increased brake pedal force exerted by the operator, the vacuum booster reaches its limit or run-out condition and the hydraulic booster is operated so as to continue the increase in master cylinder output pressure.