A normally engaged parking brake system for a mower that automatically disengages a parking brake when a steering arm is moved from a park position. During the acquisition of the measured values for the scannogram, the scanning unit or the radiation source rotates about the examination zone and a 3D data set is reconstructed from the measured values acquired during the acquisition. A first group of connecting pads for the first trunk line is located near the second trunk line such that each line of the first group is electrically connected to the first trunk line at an associated one of the connecting pads belonging to the first group near the second trunk line.