Gas shielded metal arc welding torch for limited access welding

Abstract

A gas shielded metal arc welding torch for joining internal walls in a workpiece such as a compressor impeller having limited access to the internal joint to be welded. A torch body is provided for remote feeding of consumable electrode wire, electric welding power, shielding gas, and a supply of cooling water to and from a small torch head. The exterior of the torch head is adpated to contact the internal walls to be joined while electrically insulating the current carrying parts from the workpiece, and to direct the consumable electrode wire and shielding gas toward the joint to be welded. The torch head is supported from the torch body by an assembly of at least three mutually coaxial fluid conducting tubes carrying shielding gas and supplying and discharging cooling water to and from the torch head. Means are provided to spring bias the torch head toward the workpiece walls and guide the torch head while movement takes place between it and the workpiece. Such spring biasing means may include one or more of the mutually coaxial tubes or may include additional spring devices between the torch body and the torch head.