Plasma torch with axial supply of the stabilizing gas

Claim 1

Plasma torch with axial supply of a stabilizing gas comprising in combination: a torch head comprising a sleeve, a cover and a nut connecting both the sleeve and cover, the nut enabling an adjustment of the axial distance between the cover and the sleeve, a nozzle forming the anode of the torch, connected by an internal tube and an external coaxial mantle with the sleeve, a coaxial separating tube fixed to the sleeve, dividing the space between the internal tube and the external mantle into two coaxial annular spaces, communicating near the front face of the nozzle, means for supply and removal of a cooling liquid to and from said annular spaces, the separating tube extending into a distributing insert, leaving a narrow space at places adjacent to the operating surfaces of the nozzle, means for securing the position of the distributing insert with respect to the nozzle while leaving free passages for the cooling liquid, a distribution chamber arranged axially slidable within the torch head, a tubular holder fixed to this distribution chamber and extending into the space of the internal tube, a cathode fixed to the extremity of this holder, an inlet tube for a cooling liquid for the cathode inserted into this holder dividing its space into two annular spaces communicating near the head of the cathode, means for supply and removal of the cooling liquid to and from these annular spaces, a tube of electrically insulating material fixed to said distributing chamber and engaging into the space between the internal tube and the holder of the cathode, means for supplying a stabilizing gas into the space between the holder of the cathode and the tube of electrically insulating material, the external surface of the cathode provided with longitudinal grooves limiting the passage of the stabilizing gas through the nozzle, spring means urging the distributing chamber against the bottom of the cover of the torch head.