made from stainless steel as shown in fig7 too the rotating section 162 includes disk attaching section 163 and penetrating hole 164 the disk attaching section 163 is located at the top of rotating section 162 and the diameter is smaller than the rotating section 162 and is notched at a section the penetrating hole 164 crosses to the rotating axis of rotating section 162 at a right angle the cross bar member 165 is inserted into penetrating hole 164 and is detachable the pedestal section 161 includes projecting pieces 166 a 166 b and circle section 167 which connects between the bases of projecting pieces 166 a 166 b the bottom of projecting pieces 166 a 166 b is flat and is fitted into step section 149 of chassis 141 the projecting pieces 166 a 166 b are located at a point of symmetry to the center of rotating section 162 and extend to the diameter direction and the ends are semi circle like in shape also projecting pieces 166 a 166 b can be established as only one screw holes 169 for screws 168 are located at each of the projecting pieces 166 a 166 b the screws 168 are screwed into one of screw holes 151 at grooves 150 a 150 h therefore pedestal section 161 is fixed at the step section 149 of chassis 141 the pedestal section 161 is not moved upwards despite the received pushing force from rotating shaft member 160 which is moved by disk 102 un rotating surface 163 a is notched at a section of disk attaching section 163 and screw hole 163 c are located at disk attaching section 163 un rotating surface.