Abstract: An improved method and arrangement for cutting non-metallic materials by means of a plasma arc which is formed between a plasma torch and a confronting non-melting electrode-anode. The arrangement includes an arrangement for rotating the electrode-anode during and/or prior to cutting and an arrangement for forcibly elongating the plasma arc prior to cutting by increasing the distance between the plasma torch and electrode-anode prior to cutting. The arrangement includes a support for jointly supporting the plasma torch and electrode-anode. This support is adapted to be partly or completely moved relative to the non-metallic material to be cut. Conduits for a cooling medium are incorporated in the support and the non-melting electrode-anode.

Abstract: Device for the manual start-up of a plasmotron. The device has a spring biased plunger which constitutes an electrode which selectively bridges the anode and cathode of the plasmotron and creates an arc between the anode and cathode when it is released so as to be retracted by the spring. The device is provided with an automatic lock which secures the plunger in its outer, retracted position and must be released manually to prevent unintended operation of the start-up device.

Abstract: Plasma torch or plasmotron for processing metals in the air or under water. The plasma stream issuing from the torch is shielded by a conical spray of water issuing from the torch. The water spray is given a rotary or whirling motion, thereby increasing its effectiveness in shielding the plasma stream, and insuring outer water shielding of the plasma stream with its changing shape and movement in accordance with changes in the medium wherein the processing is carried out.