Patent ID: 8322799

Claim:
A power brake system for a motor vehicle, comprising: one or more brake circuits, each brake circuit having at least one or more brakes that are each assigned to a respective wheel of the vehicle; and a separate brake servo assigned to each brake of the one or more brake circuits of the power brake system, said separate brake servos being activatable by way of a brake pedal operatively coupled to the brake servos, wherein each brake servo comprises an electromechanical drive including a ball screw spindle, around which an electrically drivable spindle nut engages, said ball screw spindle communicates with a hydraulic cylinder by which a respectively assigned brake is hydraulically activatable, each brake servo is operatively configured such that braking occurs via the ball screw spindle upon actuating the brake pedal even if the electrically drivable spindle nut is inoperative, a foot pedal of the brake pedal is connected to a hydraulic piston by which the ball screw spindle of the electromechanical drive is activatable via a connected piston by hydraulic pressure generated solely by the hydraulic piston by direct transfer of a force applied to the foot pedal to the hydraulic piston in response to application of the foot pedal, and the hydraulic pressure generated solely by the hydraulic piston acts on the connecting piston directly on an end of each ball screw spindle.