Head tube assembly having insulated mechanical interface with welding gun body

摘要

A welding gun comprising: an electrically conductive gun body having a passageway; a head tube assembly having one end inserted in the passageway of the gun body; a rotation nut that retains the head tube assembly in the inserted state when the rotation nut is threadably coupled to the gun body; and an electrically insulative ring installed between a portion of the gun body and an electrically conductive part of the head tube assembly. The electrically conductive gun body has a frusto-conical inner peripheral surface that is in contact with a frusto-conical outer peripheral surface of the electrically insulative ring. The rotation nut comprises an electrically conductive part that is threadably engaged to the electrically conductive gun body and that is in electrical contact with the electrically conductive portion of the head tube assembly. Electric current for welding is transmitted around the electrically insulative ring, through the electrically conductive portion of the rotation nut and into the electrically conductive part of the head tube assembly.