Patent ID: 6739234
Filing Date: 2004-05-25
Classification: B60T

Abstract:
Pneumatic brake booster, in particular for motor vehicles, comprising a control valve for controlling a pneumatic pressure difference, a force input element for actuating the control valve, a force output element for transmitting the braking force, a reaction disk of elastomeric material disposed between the force output element and the force input element, and a unit disposed between the reaction disk and the force input element and acting upon the reaction disk for altering the force transmission ratio between the force input element and the force output element in dependence upon the force exerted upon the force input element, the unit comprising an inner piston and an outer piston surrounding a radially outer side of the inner piston and displaceable relative to the inner piston, wherein the inner piston has at the radially outer side or the outer piston at the radially inner side a depression for receiving material particles, which depression is covered by the in each case oppositely located piston.