Abstract: A drilling head of a rock drill for use with a hand-held power tool is formed completely of a hard material and includes a main bit (2) and at least one auxiliary bit (3a, 3b). The at least one auxiliary bit (3a, 3b) is provided exclusively in a radially outer region of the drilling head and has an arcuate cutting edge (4a, 4b).

Abstract: Electromechanical brake with zero backlash actuation The invention relates to an electromechanical brake (10), especially for vehicles, comprising an electrical actuator generating an actuation force and acting upon at least one friction member (16) in order to press said member to elicit a frictional force against a rotational component (14), which is to be braked, of the brake. The invention also comprises a self-boosting device arranged between the friction member (16) and the electrical actuator, said device serving to self-boost the actuation force generated by the electrical actuator. The invention further comprises at least one wedge (18) with an angle of inclination &agr; that is supported on a corresponding counter bearing (22).

Abstract: An electromechanical brake has an electrical actuator which generates an actuation force and acts on at least one friction member in order to press said member to elicit a friction force against a rotational component, which is to be braked, of the brake. A self-boosting device is arranged between the friction member and the electrical actuator, said device serving to self-boost the actuation force generated by the electrical actuator, and having at least one wedge (12), which has a wedge surface (14) arranged at a wedge angle a and supported on a corresponding counter bearing (16). When the brake is actuated, the electrical actuator displaces the wedge (12) relative to the counter bearing (16) in an actuation direction (x) to press the friction component against the component, which is to be braked, of the brake.

Abstract: A drilling head of a rock drill for use with a hand-held power tool and formed completely of a hard material and including a main bit (2), and at least one auxiliary bit (3a, 3b) provided exclusively in a radially outer region of the drilling head and having an arcuate cutting edge (4a, 4b).