Apparatus for welding with preheated filler material

An apparatus comprising:

• first and second components to be welded, said first and second components forming a groove having a bottom;
• a welding electrode having an electrode tip at an end thereof, said electrode tip being located in said groove;
• a hot-wire nozzle for guiding filler material to a location in the path of an arc from said electrode tip, said hot-wire nozzle comprising a contact tube made of electrically conductive material and having a channel with an outlet at a distal end thereof, said outlet being located in said groove, and an outer sheath surrounding said contact tube;
• and
• first and second layers of electrically insulating material arranged between said contact tube and said outer sheath, wherein each of said first and second layers of electrically insulating material comprises a sheet of mica.

An apparatus comprising:

• first and second components to be welded, said first and second components forming a groove having a bottom;
• a welding electrode having an electrode tip at an end thereof, said electrode tip being located in said groove;
• and
• a hot-wire nozzle for guiding filler material to a location in the path of an arc from said electrode tip, said hot-wire nozzle comprising a contact tube made of electrically conductive material and having a channel with an outlet at a distal end thereof, said outlet being located in said groove, and an outer sheath surrounding said contact tube, wherein said outer sheath comprises first and second sheets of material joined along first and second edges to form a structure having a lenticular cross section.

A hot-wire nozzle for guiding filler material into a welding groove, comprising:

• a contact tube made of electrically conductive material and having a channel with an outlet at a distal end thereof, said channel having a non-circular cross section;
• an outer sheath surrounding said contact tube and having a non-circular cross section;
• and
• first and second layers of electrically insulating material arranged between said contact tube and said outer sheath, wherein each of said first and second layers of electrically insulating material comprises a sheet of mica.

A hot-wire nozzle comprising:

• a contact tube made of electrically conductive material and having a channel with an outlet at a distal end thereof;
• a outer sheath made of structural material and surrounding at least said distal end of said contact tube, said outer sheath comprising first and second walls which exert compressive force on first and second sides of said contact tube;
• and
• first and second layers of electrically insulating material, said first layer of electrically insulating material extending between and in contact with said first side of said contact tube and said first wall of said outer sheath, and said second layer of electrically insulating material extending between and in contact with said second side of said contact tube and said second wall of said outer sheath.