receiving holes in which the respective bolt part 48 or 50 is held in a secured manner the bolt parts are retained in the exemplary embodiment by ribs 51 and 52 which extend in the axial direction on the bolt parts 48 and 50 and which preferably consist of soft elastic material sprayed onto the brittle base material of the shear bolt 30 however it is also possible to provide for the shear bolt 30 an embrittlement merely in the predetermined break area 49 and otherwise to produce the bolt parts 48 and 50 from a material which inserted into the respective receiving opening retains the bolt because of its elasticity the invention has been illustrated and explained with the cable tensioning element 11 shown as a cable wind up disc 16 which is mounted directly on the brake lever 15 however other solutions lie within the context of the invention for example the cable windup disc may be mounted on a bracket which for its part is mounted on the brake actuating lever in particular concentrically with the latter and its mount on the support plate of the support console furthermore it is also possible to provide the cable tensioning element as a sector of a disc which is supported concentrically with the actuating lever and can be pivoted together with the latter a sector shaped design of this type permits relatively large pivoting radii and taken up a comparable amount of space overall in particular it permits also an articulation for the cable control connection.