Patent GB-759076-A (GB)
Title: Apparatus for welding contacts onto wires of electrical relay components
Inventor: EINER WILLIAM LARSEN
IPC: H01H11/04
Filed: 1954-03-31
Abstract: 759,076. Welding by pressure; shearing; making electrical relays. WESTERN ELECTRIC CO., Inc. March 31, 1954 [April 7, 1953], No. 9440/54. Classes 83 (2) and 83 (4). In apparatus for weld. ing contacts on to the ends of wires mounted in a row on an electrical relay component, the component is advanced step by step past a plurality of reciprocable welding heads and the contacts held by the welding heads are simultaneously percussively welded on to corresponding successive wires of different groups of wires in the row. Components 27, Fig. 3, comprising two groups of six wires 26 embedded in plastic blocks 29, 30 are intermittently fed into the apparatus on a guideway formed by a lower bar 41 and an upper bar 42. A groove 46 in bar 41 receives pins 36 on the block 30 and a flange 50 on the bar 42 engages a groove 34 in the block 30. A feed bar 57, slidably secured to bar 42, has pawls 60, Fig. 7, on its lower edge for engaging the blocks 30. The bar is reciprocated by rack and gearing 70, 71, Fig. 1, operated by a cam 75 on a shaft 76. The shaft 76 is secured to a disc 82 having eight rollers 83 engaged successively in a helical groove of a cam 84 on a main shaft 85. The cam 84 rotates eight times for one revolution of the shaft 76 during which the bar 57 feeds one component 27 into the welding position 43 while another is removed from it. At the welding station the bar 41 is interrupted and a holder 94 mounted on a slide 101 is provided to receive a part 27. When a part 27 has been fed on to the holder 94 a cam 119, on a shaft 120 rotated by a helical cam 125 in the manner of shaft 76, causes an arm 115, connected to a bell-crank 111 engaging the cam, to engage the block 30 and push the holder 94. downwardly against a spring 102. The block 29 is now supported on a seat 133 on the slide 101 with the first wires 26 of each group in line with welding heads 97 holding contacts 25 to be welded thereto. A cam 143 on the shaft 120 moves an arm 141 and a link 137, Fig. 7, to advance the slide 101 step by step to align successive pairs of wires with the heads 97. Each welding head 97 comprises a head 150, Fig. 5, secured to a member 155 connected at opposite ends to leaf springs 156, 157 to allow the head reciprocating movement. The rear end of the member 155 engages a cam 161 on a disc 163 carried by the shaft 85 and the heads are urged into welding position by a spring 166. Resilient fingers 168, Fig. 18, form a recess 169 for a contact and surfaces 177 on a stationary member 172 form contact positioning surfaces. The contacts 25 are cut from tapes 182 by pairs of cutters 183, Fig. 21, which each slides in die members 206 in a guideway intersecting apertures for the tapes. Each cutter is reciprocated by a cam 215, Fig. 1, on the shaft 85 to sever a contact from a tape and carry it into a recess in a transfer member 185 reciprocated by a lever 195 from a cam 201 on the shaft 85. The members 185 carry the contacts into the recesses 169 in the heads 97, the heads are retracted, the members 185 are retracted and the heads are thrust forward to percussively weld the contacts to the pair of wires. Current is supplied to each wire from a source, preferably employing condensers, through a cam-operated switch and a contact 222, Fig. 5. The other side of the source and the gun are earthed. Devices for selectively feeding one of each set of tapes 182, which may be of nickel silver coated on one or both sides with palladium, each comprises three pairs of feed rollers, the upper rollers being ratchet driven by pawls 273, Fig. 19, mounted on levers 275, pivoted at 276. Three cams 281 are arranged at 90 degrees spacing on each of six members 283 and are also spaced axially thereof. The members 283 are adjustably mounted between discs 284 on the shafts 76 and 120 and are arranged so that the corresponding cam on each is operative to engage one lever 275 to feed a tape. A clutch 297 between the drive means 88 and the main shaft 85 is actuated by a trip lever 299 to stop the apparatus and in so doing stops the shaft 85 in a predetermined position in which the cutter 183 is in the path of movement of the tapes 182.