Head tube assembly having insulated mechanical interface with welding gun body

A welding gun comprising an electrically conductive gun body and a head tube assembly supported by said gun body, said gun body comprising a threaded outer peripheral surface and a cavity defined in part by a frusto-conical inner peripheral surface, and said head tube assembly comprising:

• an electrically conductive fitting comprising an end that is received in said cavity of said gun body;
• an electrically conductive tube comprising an end supported by said fitting;
• a rotation nut comprising an electrically conductive portion that is in contact with said gun body and said fitting, said electrically conductive portion comprising a threaded inner perlpheral surface that threadably engages said threaded outer peripheral surface of said gun body, said rotation nut fastening said fitting to said gun body when said rotation nut is threadably engaged with said gun body;
• and
• an electrical insulator disposed between and in contact with said fitting and said frusto-conical inner peripheral surface of said gun body.

A welding gun comprising:

• an electrically conductive gun body comprising a passageway, said passageway comprising a circular cylindrical inner peripheral surface and a frusto-conical inner peripheral surface;
• an electrically conductive fitting comprising a passageway, a collar and a circular cylindrical outer peripheral surface located inside said circular cylindrical inner peripheral surface of said gun body;
• an electrically conductive tube having one end supported in said passageway of said fitting and projecting forward of said fitting;
• an electrically insulative ring comprising a frusto-conical outer peripheral surface in contact with said frusto-conical inner peripheral surface of said gun body and a circular cylindrical inner peripheral surface in contact with said circular cylindrical outer peripheral surface of said fitting;
• and
• a retaining device comprising an electrically conductive portion that is in contact with and coupled to said gun body and in contact with said fitting, said retaining device retaining said fitting in engagement with said gun body when said retaining device is coupled to said gun body.

A welding gun comprising:

• an electrically conductive gun body comprising a passageway;
• an assembly comprising a sequence of electrically conductive components connected in series to form a conductive path for electric current and a passageway for welding wire, one end of said assembly being inserted in said passageway of said gun body;
• a rotation nut that retains said assembly in said inserted state when said rotation nut is threadably coupled to said gun body;
• and
• an electrically insulative ring installed between an electrically conductive portion of said gun body and an electrically conductive portion of said assembly, wherein said ring comprises a frusto-conical outer peripheral surface.

A method of assembling a welding gun, comprising the following steps:

• sliding a ring of electrically insulative material onto an end portion of a head tube assembly until said ring is proximal to a first portion of said end portion of said head tube assembly having a maximum dimension greater than an inner diameter of said ring, said ring having a frusto-conical outer peripheral surface;
• inserting a second portion of said end portion of said head tube assembly into a cavity of a gun body until said frusto-conical outer peripheral surface of said electrically insulative ring engages a frusto-conical inner peripheral surface of said gun body cavity;
• and
• fastening said head tube assembly to said gun body.

A welding gun comprising:

• an electrically conductive gun body comprising a passageway;
• an assembly comprising a sequence of electrically conductive components connected in series to form a conductive path for electric current and a passageway for welding wire, one end of said assembly being inserted in said passageway of said gun body, and a component of said assembly comprising an electrically conductive frusto-conical outer peripheral surface;
• and
• an electrically conductive rotation nut that retains said assembly in said inserted state when said rotation nut is threadably coupled to said gun body, said rotation nut comprising an electrically conductive frusto-conical inner peripheral surface that engages said electrically conductive frusto-conical outer peripheral surface of said assembly component.