Patent ID: 6815632
Filing Date: 2004-11-09
Classification: H05H

Abstract:
A contact start plasma torch, wherein it comprises, inside a torch body extending mainly longitudinally:a hollow shaft, connected on one side to a first supply pipe for a flow of a first gas and, on the other side, to an electrode which is hollow so that it surrounds part of the shaft and forms, close to the internal end of the electrode, a first, internal chamber for cooling the inside of the electrode and for outfeed of the first gas; a nozzle body, which is electrically connected to a positive pole, surrounding the electrode and forming: a second chamber, for receiving the first gas for generating plasma; a third, intermediate chamber, for the passage of the first gas, said first gas arriving from the first, cooling chamber through third pipes made in the shaft and the nozzle body, to at least the second, plasma generation chamber through second pipes passing through the nozzle body; first sealing parts, being inserted between the shaft and the nozzle body and on both sides of the third pipes, forming a sealed zone close to the third pipes; shaft drive means, consisting of a cylinder, connected to the shaft and acting on the shaft by means of an inflow and, respectively, an outflow of a second operating fluid in a fourth chamber of the cylinder, said second operating fluid being separate from the first gas, in a fourth chamber of the cylinder, to provide a forward starting position, in which the electrode is in contact with the nozzle body, and a back torch operating position, in which the electrode is distanced from the nozzle body, in the presence of the first gas.