Patent attributes
A receiving member is provided on a face of a casing and includes an insertion port and first and second abutment portions. An insertion portion of each of the brackets is inserted through the insertion port. The insertion port is shaped to have at least one step varying in a width of the insertion port such that the width is narrower as the at least one step is farther away from the face of the casing. Each of the first and second abutment portions has such an inner shape that, when the insertion portion is inserted through the insertion port, the abutment portion abuts against the leading end of the insertion portion in the insertion direction to restrict a movement of the leading end in association with the corresponding one of different widths of the insertion portions.