Arc welding head and a welding arrangement

Abstract

An arc electric welding head comprising a first contact device housing a first duct for feeding a first electrode and providing electrical contact between a first power source and said first electrode, a second contact device housing a second duct for feeding a second electrode and providing electrical contact between a second power source and said second electrode, said first and second contact devices being electrically insulated from each other, said first and second ducts being parallel.

1 . An electric arc welding head comprising:
 a first contact device housing a first duct for feeding a first electrode to a weld puddle while providing electrical contact between a first power source and the first electrode;   a second contact device housing a second duct for feeding a second electrode to the weld puddle while providing electrical contact between a second power source and the second electrode, wherein the first contact device and the second contact device are electrically insulated from each other, the first and second ducts are parallel to each other, and the first duct is separated from the second duct by a distance which allows a first arc formed between the first electrode and a workpiece on which the weld puddle is formed and a second arc formed between the second electrode and the workpiece to have an overlapping region; and   an insulated third duct arranged to feed a cold wire into the overlapping region so that the first electrode, the second electrode, and the cold wire each operate in the weld puddle.   
     
     
         2 . The electric arc welding head of  claim 1 , wherein the first contact device is connected to a first retainer element comprising:
 a first retaining part carrying a first contact plate; and   a second retaining part carrying a second contact plate, the first retaining part and the second retaining part being movable with respect to each other so that a dimension of a gap between the first contact plate and the second contact plate is adjustable.   
     
     
         3 . The electric arc welding head of  claim 2 , wherein the second contact device is connected to a second retainer element comprising:
 a third retaining part carrying a third contact plate; and   a fourth retaining part carrying a fourth contact plate, the third retaining part and the fourth retaining part being movable with respect to each other so that a dimension of a gap between the third and fourth contact plates is adjustable.   
     
     
         4 . The electric arc welding head of  claim 3 , wherein the first and second retainer elements are separated by an insulating body housing the third duct, and the first and second retainer elements being connected via an insulated connection to form an integrated unit. 
     
     
         5 . The electric arc welding head of  claim 4 , wherein the insulated connection is a pipe extending through the first and second retainer elements and the insulating body. 
     
     
         6 . The electric arc welding head of  claim 1 , wherein the first duct, the second duct, and the third duct are arranged in parallel. 
     
     
         7 . The electric arc welding head of  claim 1 , wherein the first duct and the second duct lie in a first plane and the third duct lies in a second plane which is orthogonal to the first plane. 
     
     
         8 . The electric arc welding head of  claim 1 , wherein the first duct, the second duct, and the third duct all lie in a first plane. 
     
     
         9 . The electric arc welding head of  claim 1 , wherein the third duct is positioned between the first duct and the second duct. 
     
     
         10 . The electric arc welding head of  claim 1 , wherein the first duct and the second duct have different diameters for feeding respective electrodes having different diameters. 
     
     
         11 . The electric arc welding head of  claim 1 , wherein the first contact device comprises a metallic body in which the first duct is formed, the second contact device comprises a metallic body in which the second duct is formed, and the third duct is formed in a body of insulating material separates the first contact device from the second contact device. 
     
     
         12 . The electric arc welding head of  claim 11 , wherein the first contact device and the second contact device each abut a respective side of the body of insulating material to form an integral body. 
     
     
         13 . The electric arc welding head of  claim 12 , wherein the first contact device and the second contact device each include a first essentially semi cylindrical envelope surface forming an outer surface of the electric arc welding head, a second essentially flat side abutting the body of insulating material, and an end face at which a duct aperture of its respective duct is positioned. 
     
     
         14 . The electric arc welding head of  claim 12 , wherein the first contact device and the second contact device are clamped together with the body of insulating material to form a cylindrical body in a lower portion of the electric arc welding head at which apertures of the first duct, the second duct, and the third duct are located. 
     
     
         15 . A welding system comprising:
 a first wire feeder for feeding a first electrode,   a second wire feeder for feeding a second electrode,   a third wire feeder for feeding a cold wire,   a first power source connected to a first contact device for providing electrical contact between the first power source and the first electrode, and   a second power source connected to a second contact device for providing electrical contact between the second power source and the second electrode,   wherein the welding system further includes a welding head of  claim 1 .   
     
     
         16 . A welding system comprising:
 a first wire feeder for feeding a first electrode to a weld puddle;   a second wire feeder for feeding a second electrode to the weld puddle;   a third wire feeder for feeding a cold wire to the weld puddle;   a first power source connected to a first contact device housing a first duct and providing electrical contact between the first power source and the first electrode;   a second power source connected to a second contact device housing a second duct providing electrical contact between the second power source and the second electrode; and   an insulated duct for feeding the cold wire;   wherein the first contact device, the second contact device, and the insulated duct are arranged in an integral welding head so that a first arc formed between the first electrode and a workpiece on which the weld puddle is formed and a second arc formed between the second electrode and the workpiece generate an overlapping region into which the insulated duct feeds the cold wire, so that the first electrode, the second electrode, and the cold wire each operate in the weld puddle.   
     
     
         17 . The welding system of  claim 16 , wherein the first duct, the second duct, and the insulated duct are arranged in parallel. 
     
     
         18 . The welding system of  claim 16 , wherein the first duct and the second duct lie in a first plane and the insulated duct lies in a second plane which is orthogonal to the first plane. 
     
     
         19 . The welding system of  claim 16 , wherein the first duct, the second duct, and the insulated duct all lie in a first plane. 
     
     
         20 . The welding system of  claim 16 , wherein the first contact device comprises a metallic body in which the first duct is formed, the second contact device comprises a metallic body in which the second duct is formed, and the insulated duct is formed in a body of insulating material that separates the first contact device from the second contact device.