Patent ID: 8684147
Filing Date: 2014-04-01
Classification: F16D,F16H

Abstract:
1. Combined vehicle brake comprising: a hydraulically actuable service brake, an electromechanically actuable parking brake device, a hydraulic service pressure space being delimited in a brake housing by a brake piston which can be acted upon by hydraulic pressure medium in order to execute service braking operations, so that the brake piston can be actuated along a piston longitudinal axis in order to achieve a braking action, said parking brake device acting on the brake piston by a gear, wherein the gear converts a rotational movement of an electromechanical actuator into a translational movement and causes an actuation of the brake piston in order to execute parking braking operations and holds the brake piston in the actuated position, said gear having a threaded spindle that is rotatable and a threaded nut which are in contact with one another via a plurality of rolling bodies, wherein the rolling bodies are arranged so as to be movable to a limited extent in a thread flight between two stops, wherein rotational movement of the threaded spindle is transmitted via the rolling bodies to the threaded nut to execute a translational movement of the threaded nut, a first spring element arranged between the rolling bodies and one of the two stops and allowing a slipping of the rolling bodies in an event of a load-free actuation of the gear and causing a rolling of the rolling bodies in an event of an actuation of the gear under load, and one or more intermediate spring elements provided between the rolling bodies which reduces a frictional force of the rolling bodies with respect to one another when the gear is actuated, wherein a second spring element is provided, which is arranged between the rolling bodies and the other of the two stops, and wherein the threaded nut is not biased by a spring along the piston longitudinal axis toward the actuated position of the brake piston.