Patent ID: 8674264
Filing Date: 2014-03-18
Classification: B08B,B23K

Abstract:
1. A method for cleaning a contact tube of a welding torch, via which contact tube a welding wire is supplied with electrical energy, the contact tube having a length and an internal bore, the method comprising steps of: moving said welding wire from a starting position and to the welding torch by a wire reel or a welding drum via a wire feeder, wherein friction against said welding wire during the moving of said welding wire forms abrasion particles from said welding wire, the abrasion particles accumulating in the internal bore of the contact tube, melting an end of the welding wire to form a welding wire end region of increased diameter, subsequently at least once moving the welding wire backwards to a pulled-back position in the direction of the wire reel or the welding drum until an end of the welding wire is at least within a selected portion of the length of the contact tube and such that the abrasion particles accumulated in the internal bore of the contact tube are detached from the welding wire, are partly carried away, and are fed to rest behind the contact tube, and subsequently moving the welding wire forwards again in a subsequent forward movement such that the abrasion particles in the contact tube are fed outwards via the internal bore of the contact tube, wherein the abrasion particles are also fed outwards from the contact tube via at least one radial opening in the contact tube during at least one of the backwards movement of the welding wire and the subsequent forwards movement of the welding wire, and wherein the welding wire end region of increased diameter acts as a piston within the internal bore of the contact tube during the backwards movement of the welding wire and during the subsequent forwards movement of the welding wire.