GB1293229A - Plasma generating method and means - Google Patents

Abstract

1293229 Welding by fusion; cutting by fusion NORTH AMERICAN ROCKWELL CORP 1 May 1970 50036/70 Divided out of 1293228 Headings B3R and B3V [Also in Division H5] A plasma generating torch comprises a nozzle, an electrode 10 protruding from the nozzle, in use to create an unconfined arc, the nozzle having at least one aperture 50 which is inclined so as, in use, to create a jet of ionizable gas which intersects the axis of the electrode 10 beyond its tip, and means for providing a protective gas shield around the jet(s) and arc. In the embodiment shown in Fig. 3 replace- able rings 82, 84 allow adjustment of the shield- ing gas outlet size. The gas may be helium; and the electrode may be consumable or non- consumable. In the embodiment shown in Fig. 5 the tip of the torch extends at 90 degrees to the axis of the main part of the torch, for weld- ing in areas of restricted access. The torch may be used for seam welding or cutting. Several arrangements of circuits including one or more such torches are described. In one form (Fig. 7, not shown), two torches oppose each other across the weld seam; in another form (Fig 9, not shown), a pair of adjacent torches have an arc struck between them, the arc then being supplied with high pressure gas streams which are directed towards the work. In yet another form (Fig. 8, not shown), a liquid-cooled body (112) is placed behind and spaced from the weld seam and acts as one ter- minal of the welding circuit. Filler wire can be used in forming weld seams using the torch.