point 46 is configured as a fastening bolt that is arranged in the blade cover 4 and that passes with a precise fit through an opening in the blade cover 4 for purposes of the final fastening the blade cover 4 is locked by means of a bar 47 that can be pivoted around an axis 48 the connection lines of the three fastening points 44 45 46 form a triangle and thus a stable triangular mount for the blade cover 4 the blade cover 4 is removed in the opposite order starting with the unlocking of the bar 47 the bar 47 has a slanted ramp so that when the blade cover 4 is locked it is pulled against the blade protection ring 22 where it is in close contact and is thus fastened without play the bar 47 is arranged behind the blade protection ring and consequently for operating purposes there is a need to reach around the blade protection ring 22 fig3 a and 3 b show a variant of the fastening point 46 unlike the variant shown in fig2 to 2 b the bar needed to lock the blade cover is now operated by a knob 57 that is pivoted around an axis 58 and that is arranged in front of the blade cover 4 with this variant there is no need to reach around the blade cover fig4 a and 4 b show another variant of the fastening point 46 the pivoting bar 67 is configured here as a u shaped bar that is mounted on the blade protection ring 22 so as to pivot around an axis 68 all of the embodiments of the pivoting bar 47 57 67 shown have in common that they have a.