segment 21 of the lifting lever in order to obtain an appropriate resilient presser foot pressure a tension spring 22 is provided which extends between the pin 14 of the presser bar and a horizontal pin 23 provided on the lifting lever 15 the presser foot pressure can thereby be controlled by means of the lifting lever as will be described in more detail in the following in order to determine the position of the presser bar and the presser foot the arrangement comprises a code disc 24 one end of which is rotatably journalled on the shaft 16 and the other end of which is movably connected to the presser bar by means of an elongated opening 25 through which the pin 14 extends with a close fit by means of a differential gauge comprising optical position sensors 26 attached to the lifting lever 15 and cooperating with a toothed segment 27 of the code disc the mutual positions of the lifting lever and the code disc are determined when the presser foot is in its elevated position and thus not engaging the cloth below no mutual movement of the lifting lever and the code disc takes place when the presser foot is lowered and engages the cloth whereby its descending movement is stopped the continuing downward movement of the lifting lever 15 will result in tensioning the spring 22 and a corresponding increase of presser foot pressure with a knowledge of the spring constant the position.