Patent GB-1408146-A (GB)
Title: Method and apparatus for finishing a butt welded joint
IPC: B23K11/02
Filed: 1972-08-17
Abstract: 1408146 Upsetting machines; trimming dies INDUSTRIAL RESEARCH & DEVELOPMENT CORP 17 Aug 1972 [5 June 1972] 38441/72 Headings B3H and B3W In treating a butt welded joint between two elongated metal workpieces, an end portion of each workpiece adjacent the weld is enclosed in a die opening having the shape of the workpiece, a further portion of each workpiece is gripped in gripping means, further from the weld than the respective die, the gripping means are thrust together to cause radial upset of the joint area between the dies and the radial upset, containing the weld heat-affected zone, is trimmed away. At one end of a vertical plate 20 projects a fixed support 22 and at the other end bearing blocks 23, 24 are secured in alignment with hydraulic rams 25, 26 carried on the support 22. Pistonrods 29, 30 of the rams extend through the support 22 and have extensions 34, 35 supported in the bearings 23, 24. A crosshead 36, near the bearings 23, 24, is supported on the piston-rods and has seats for collars 42, 43 on the rods and between the crosshead and support 22 two die carriers 47, 48 are mounted on for movement along the piston-rods. The carriers have lower blocks slidably mounted on the piston-rod 30, carrying lower die blocks 64, 64<SP>1</SP> and coupled by frames 49, 491 to slide blocks 95, 95<SP>1</SP> on which carriers 100 for upper die blocks 117, 117<SP>1</SP> are slidable under control of rams 88, 88<SP>1</SP>. The slide blocks 95, 95<SP>1</SP> are slidably mounted on the pistonrod 29. The die blocks have semicircular grooves to receive a round wire and have V-shaped semicircular recesses 204, 204<SP>1</SP> in their opposing ends to provide sharp knife edges encircling the wires. The die carriers are biased apart by springs 133, 134 and a threaded rod 136 is secured to the carrier 48, extends through the carrier 47 and carries a nut 140 beyond the carrier 47. Hydraulic rams 141, 142 extend between the carrier 47 and crosshead 36 and rams 154, 155 extend between the carrier 48 and support 22. Clamp blocks 165, 166 are secured to the crosshead 36 and support 22, the blocks having V-shaped recesses with clamp wedges 173, 174, 173<SP>1</SP>, 174<SP>1</SP> therein, the wedges being urged apart by springs, being connected to the carriers 47, 48 and having serrated gripping surfaces. In operation with the upper die blocks separated from the lower die blocks and with the rams 25, 26, 141, 142, 154, 155 fully extended already electrically welded wires having a flash about the weld are placed in the lower die blocks. The upper die blocks are lowered by the rams 88, 88<SP>1</SP>, the rams 154, 155 are actuated to retract the carrier 48 to close the wedges 173<SP>1</SP>, 174<SP>1</SP> on to the wire and by virtue of the connection 136, 140 to draw the carrier 47 towards the support 22. The crosshead 36 is also drawn towards the support by virtue of the connection of the crosshead 36 with the carrier 47 by the rams 141, 142. The rams 141, 142 are operated to draw the crosshead further and so close the wedges 173, 174 on to the wire. The parts are then in the position of Fig. 15. The rams 25, 26 are then actuated to draw the crosshead further toward the support 22 to cause the carrier 47 to move relatively to the carrier 48 into the position of Fig. 16. The metal of the wires is upset and weld flash is trimmed off by the knife edges of the dies. The wires may be of aluminium, aluminium alloys or copper. The positions of the dies are initially arranged so that they are at the ends of, or slightly beyond, the weld heataffected zone of the wires so that after working and trimming the resultant joint is at least as strong as the parent metal.