Patent attributes
An upper side plate portion (122) of an upper case comprises an insertion hole (122C) for a setscrew (130) and a resilient deformable portion (124) having a rib (125). When the upper case is attached to a lower case using the setscrew (130), the restoring force of resilient deformation of the resilient deformable portion (124) crimps the rib (125) to a lower side plate (112) of the lower case with a pressure force (W10). Accordingly, only the attachment of both cases with the setscrew (130) crimps the rib (125) of the upper case to the lower side plate (112) of the lower case with the pressure force (W10) and reduces the surface resistance value in a contact portion with the rib (125) in the lower side plate (112) below a predetermined value. Thus, the conduction between the upper case and the lower case can be easily and reliably ensured.
