GB1014826A - Process and apparatus for producing shaped resistance-welded bimetallic articles - Google Patents

Abstract

1,014,826. Making bimetallic contacts; welding by pressure; shearing; forging. W. RENZ, H. WACKER, and E. SEITZ, [trading as RENZ, WACKER & CO.]. July 31, 1962 [July 31, 1961; May 16, 1962], No. 29393/62. Headings B3A, B3H, B3R and B3W. In making resistance welded shaped articles e.g. bimetallic contacts, from wires of different metals, the ends of two wire elements are buttwelded and the welded wire elements are supplied to a pressing device, a turntable having dies and pressing rods being employed. A turntable 1, Figs. 1, 2, carried in a toothed ring 2 co-operating with a locking pin 4 engaged after each indexing step of the table, has six parting- off dies 3 spaced around its periphery. At station I a copper wire 5 is fed through a stationary guide 6 into a die 3 and as the table is rotated to Station II an end of the wire is sheared. At Station II a silver wire is fed through a guide 8 into the die above the piece of copper wire and as the table is indexed to station III the end of the silver wire is sheared. The table is rotated to Station IV where the pieces of wire are resistance welded by a ram 9 connected to one side of a supply transformer 15 by cam-operated pick-up 14, the other side being connected to the turntable. The table is indexed to Station V where a ram 12 connected also to the transformer 15, finally shapes the welded body which is ejected as a bimetallic contact rivet from the die by a needle 13 at Station VI. A finished rivet is produced at each indexing movement of the table. In a modification using a similar turntable, a copper wire 5 is fed through a guide at Station I, Figs. 3, 6, to be sheared as the table indexes to Station II where a silver wire 7 is fed through a guide 17 into a chamber 18. The copper wire 5 is lifted by a needle 20 until it abuts the silver wire and is clamped by clamp 21. The pieces are resistance welded by current supplied from a transformer 24 under the control of cam-operated pick-up 14. The end of the silver wire is pushed into the die and as the table indexes, is sheared. At station IV the rivet head is shaped by a tool 28 and at Station V a finish pressing foot 29 provides the final shape on the rivet which latter is ejected at Station VI by a needle 30. In a further modification the wires are butt welded in guides outside the turntable, the welded ends are parted from the stock by a knife moving transversely between the guides and are supplied to a die in the turntable which brings them beneath the pressing rods.