Abstract: In resistance forge welding, the heat for the welding point is produced by simultaneous action of an electrical current and the force of the electrode as well as the electrical resistance of the materials to be welded in the region of the point of contact of the electrodes. The workpieces generally lie flat on each other and are welded under considerable pressure at individual points by the force of the electrode. The current and the electrode force are supplied via the electrodes.In order to increase the controllability and dynamics of the electrode movement, according to the invention a controllable electromotive drive (13), which has a drive spindle (16) or a toothed rack, is used.

Abstract: The invention relates to a coordinate thermal-cutting machine with a means for automatically setting the initial height of a torch, in particular a plasma torch, above a workpiece surface. In order to achieve a fast and exact setting of the igniting distance above the workpiece surface, the torch (28) is at least partially surrounded by an inner tubular enclosure (7), which is at least partially surrounded by an outer tubular enclosure (10), bearing elements (8, 9 and 29, 30) being arranged between the tubular enclosures (7, 10) in such a way that the inner tubular enclosure (7) is at least longitudinally displaceable with the torch (28), there also being provided a position sensor which senses the longitudinal displacement and, furthermore, the inner enclosure (7) is connected to a compensation device (35) which reduces the weight of the inner enclosure (7) with the torch (28).