Abstract: An apparatus for safeguarding a welding pool in mechanized welding in a constrained position, for example a vertical position, comprises sliding blocks pressed against the surfaces of the work pieces to be welded and supplying the welding current and the welding electrode and moving at the welding rate. The sliding blocks comprise two segments which are closely adjacent in the perpendicular center plane of the welding gap between the work pieces and are mutually movable. The sliding block segments are pressed in a yielding manner against the surface of each work piece and are individually and independently movable.

Abstract: A method of improving the reproducibility of the welds in an electric spot welding machine comprises prior to the initiation of a welding operation passing a preheating current of lower magnitude than the welding current through the parts to be welded. When either the total electrical workpiece resistance of the parts to be welded has fallen below a given limit or when its rate of decrease is slower than a predetermined limit the changeover from preheating current to welding current is effected.

Abstract: In an apparatus for electroslag welding of steel sheets with the aid of at least one wire electrode pair, a welding gap defined between the electrodes of the electrode pair, current-carrying conduits for the electrode pair, and a supply tube for supplying metal in a powdered state, and welding flux into the welding gap, the improvement includes a shielding device creating a duct along the current-carrying conduits. The duct, owing to the shielding device, is substantially free of any magnetic field, and the supply tube is positioned in the duct.

Abstract: A method of and apparatus for welding sheet steel panels by submerged arc welding is described. By providing one or, depending on the thickness of the sheet steel panels, more than one pair of closely spaced wire electrodes in the weld gap with the simultaneous introduction of additional filler metal carrying no current, preferably in the form of a metal powder, disadvantages associated with known methods may be avoided.