GB887097A - Method of and apparatus for the continuous production of bimetal articles - Google Patents

Abstract

887,097. Making bi-metal contacts; welding by pressure. DURRWACHTER, E. Jan. 5, 1960, No. 296/60. Classes 83 (2) and 83 (4). [Also in Group XXV] A method of making bi-metal contact rivets or studs comprises shearing off sections of wire from two separate supplies and buttwelding the wires by pressure. The apparatus comprises a pair of wire guides 4 and 5 through which the wires 2 and 3 are fed, and two dieblocks 6 and 7. The wires are sheared by transverse movement of the dies and the guides 4 and 5 then move together and produce welding and enlargement of the adjacent wire ends (Fig. 3). The head of the contact is formed by a separate die (Fig. 6). In a modification, the die 9 is a single block and after the shearing operation the block moves under a heading die 10, the wire sections are pushed up by a pin 13 and the welding and heading operations occur simultaneously. In a second modification (Fig. 17) a solid die is mounted on a turntable, a wire is pushed into the die and is sheared off when the turn-table rotates and carries the die to a second station where a further wire is inserted and is similarly sheared off when the turn-table rotates and carries the die block under a heading die 10. The wires are supported by a pin 13 during the heading operation. In a third modification a split die 9a and 9b is used on a turn-table. Wires are inserted and sheared off at each of two stations and at a later station pins 13a and 13b enter the die and effect welding of the parts. The flash enters a recess 21 in the die parts and at the next station a pin 13c pushes the contact upwards, shears off the flash 22 and acts as a support for the heading operation. The strength of the joint is increased by annealing. In the case of a silver-copper joint the maximum increase in strength is achieved by annealing in the range 300-500‹ C., in the case of other materials the increase in strength is proportional to the annealing temperature.