Abstract: The present invention provides a booster of the gaseous pressure type.

Abstract: A reaction mechanism for use in a vacuum brake booster (10). A lever (86) transfers a reaction force from a first plunge (64) into a second plunger (110) to provide an operator with an indication of the output force being produced in response to an input force. A resilient member (118) urges a first connecting member (116) into engagement with the lever (86). When a predetermined input force is applied, the reaction force overcomes the resilient member (118) and thereafter allows the input force to be directly transmitted through a second connecting member (122) and added to the output force.

Abstract: A fluid-assisted electromagnetic valve comprises an element movable in a working chamber as a function of a fluid pressure differential applied by an electromagnetic control. The movable element has inlet and exhaust nozzles in the working chamber which are selectively obturated by respective spring-biased plungers mounted on an extension of a mobile core of the electromagnetic control, according to the direction of movement of the core, to provide the pressure differential. Said extension comes to bear directly against the respective nozzle to ensure movement of the element even when the pressure differential is insufficient.