Device for plasma arc working of metals - e.g. welding, cutting or microwelding

• Main Author: V. K. LEBEDEV, V. A. TROITSKY, B. I. SHNAIDER, D. M. TUZOV, P. G. ZHUKOVSKY, L. N. KOZLOV, J. E. GODLIS, A. S. SVETSINSKY, V. V. SHERBAK, J. F. SHEVCHENKO, N. G. BELY, V. A. NAGAITSEV, V. D. YARESHKO, J. A. ZHUK ET V. D. BORISENKO
• Format: Patent
• Language: English; French
• Published: 08.04.1977
• Subjects: BASIC ELECTRIC ELEMENTS; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; ELECTRICITY; INDUCTANCES; MACHINE TOOLS; MAGNETS; METAL-WORKING NOT OTHERWISE PROVIDED FOR; PERFORMING OPERATIONS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES; SOLDERING OR UNSOLDERING; TRANSFORMERS; TRANSPORTING; WELDING; WORKING BY LASER BEAM

Device for the plasma arc working of metals uses a symmetrical, three phase power transformer with adjustable short circuit resistance and legs at 120 degrees intervals. Each phase has one prim. and two sec. windings, one sec. feeding a rectifier providing direct polarity between electrode and workpiece, the other sec. feeding a rectifier providing inverse polarity between the workpiece and the plasma nozzle. A thyristor switch is fitted. The novelty is that the transformer has a shunt with premagnetising coils, and each sec. winding consists of two parts connected in series between the transformer and the rectifiers. Ten figs. are provided. The device is used for plasma welding, cutting or microwelding, for stepless control of the direct or inverse currents, e.g. in welding sheet 0.5-5 mm thick using direct polarity 16-100 amps and indirect polarity 8-50 amps.