Patent ID: 6657161
Filing Date: 2003-12-02
Classification: B23K

Abstract:
An apparatus for welding abutting pipe sections along a weld seam, said apparatus comprising:a motorized main carriage for travelling circumferentially about one of the pipe sections to be welded; a welding torch connected to the main carriage, the welding torch being movable relative to the main carriage; a first motorized transport mechanism connected to the main carriage for vertically displacing the welding torch relative to the weld seam; a second motorized transport mechanism connected to the main carriage for pivotally moving the welding torch transversely of the weld seam; and a controller for actuating the second transport mechanism so as to pivotally oscillate the welding torch transverse of the weld seam, wherein the controller actuates the first and the second transport mechanisms simultaneously so as to change a vertical position of a pivoting point of the torch in accordance with a pre-determined trajectory; and wherein the controller receives feedback as to a welding current, a welding voltage and actuating the first transport mechanism so as to effect a pre-determined minimum heat input into the weld seam.