Patent ID: 7127891

Claim:
Braking force generator for a motor vehicle hydraulic brake system comprising a force input element, which is connected to the brake pedal, a housing and a primary piston displaceable in the housing, wherein the primary piston together with the housing encloses a primary pressure chamber for generation of a hydraulic brake pressure, a pedal simulation device connected to the force input element, a pedal actuation detection device for detecting the pedal actuation and an actuating force booster stage for exerting an actuating force on the primary piston, wherein the pedal simulation device comprises a simulation spring arrangement, which upon a pedal actuation is compressible by the force input element, wherein during normal operation the force input element is mechanically uncoupled from the primary piston and the actuating force booster stage in accordance with the detected pedal actuation exerts an actuating force on the primary piston, and wherein in the event of failure of the actuating force booster stage the force input element is workingly connectable to the primary piston, wherein a contact extension extends from the primary piston towards the force input element, wherein during normal operation the contact extension is held by a release gap at a distance from the force input element and in the event of failure of the actuating force booster stage the force input element after travelling the release gap is applied workingly against the contact extension and that the simulation spring arrangement is constructed with a first simulation spring and a serially connected second simulation spring, wherein the first simulation spring has a lower spring hardness than the second simulation spring.