Robert Boschgmbh

Gerd Bassler

Arno Altpeter

Franz Armbruster

Gunter Schmidt

Hans-Peter Sitka

Albano Paoli

A method for producing strong resistance-welded joints between wires and massive workpieces, especially welded joints between nickel-plated copper wires and steel workpieces. The melting of the nickel coating is insured by producing locally high temperatures and pressures, due to the special configuration of the surface of the workpiece. The work surface is provided with bulges or protrusions which cause a concentration of electrical current and electrode pressure.

Method of resistance welding wires to a massive workpiece

A plurality of conductors forming the armature windings are arranged in a superimposed stack, with their end faces aligned and located over the respective commutator strip or lamella. An electrode presses the stack against the lamella, another electrode, preferably liquid cooled, is applied to the lamella and solder, for example in form of a ribbon, placed against the end faces of the conductors forming the stack. Upon application of current, the solder will melt and flow between the commutator lamella and the conductor strips forming the armature winding to simultaneously, in one step, secure together the conductors and the commutator lamella. The method is particularly applicable to forming the armature windings in d-c motors for example in electric-car driving motors.

Method to secure armature conductors to the commutator strips in dynamo

To prevent flowing of coating material on corrosion-protected sheet steel, such as a zinc coating, when making overlap weld seams, the end portion of at least one of the steel sheets is formed with openings which extend from adjacent the outer edge of the end portion inwardly, to leave projections between the openings, the projections being entirely within the overlap and leaving a short strip of solid material in the overlap region, so that the weld will occur at concentrated hot spots of the material, and contamination of the welding electrodes by the zinc coating material is prevented. The openings may extend clear to the edge in the form of notches, leaving intervening teeth, or they may be punched holes.

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Kornwestheim, Germany

Gerd Bassler