GB774945A - Method of, and apparatus for, electrically butt welding studs and the like - Google Patents

Abstract

774,945. Welding by pressure; shearing. ALLMANNA SVENSKA ELEKTRISKA AKTIEBOLAGET. May 13, 1955 [May 15, 1954], No. 13848/55. Class 83 (4). In electrically butt - welding studs &c. to a plane or curved workpiece, a length of wire is cut from the leading end of a continuous wire and is moved into a line parallel with the continuous wire, the cut-off length is advanced into contact with the workpiece for butt-welding, advancing at the same time the continuous wire a distance equal to the cutoff length and butt-welding the cut-off length to the workpiece. In an embodiment a wire straightener 2, a device 3 comprising two fluid-pressure cylinders, a fluidpressure wire-holding device 4 and a fluid-pressure cylinder 16 are secured to a frame 1. The piston of the upper cylinder in the device 3 is hollow and has tubular extensions, the forward one 5 of which carries a fluid-pressure operated wire clamping device 6, the continuous wire being fed through the tubular extensions. The piston of the lower cylinder has a rod 7 which is connected through a spring 8 with a sliding member 9 having a vertically slidable member 14 mounted therein, a nozzle 12 and a tubular extension 13 in line with the wire feed path. With the apparatus in the position shown in Fig. 1, the continuous wire p having its end in a bore 17 in the slide 14 and abutting a stop 18, the piston 15 of the cylinder 16 is operated to press the slide 14 downwardly against a spring 21, thus shearing off the end of the wire and bringing it into line with the nozzle 12. A piston 10<SP>1</SP> in a fluid-pressure cylinder in the member 9 is operated so that its extension 11 moves the sheared off end into the nozzle 12 and locks the slide against upward movement. The device 4 is released and the device 6 is clamped on the wire and simultaneously the cylinders of the upper and lower cylinders of the device 3 are supplied with fluid. Thus, as shown in Fig. 2, the wire is drawn to the left and the cut length in the nozzle 12 is pressed against the workpiece to be welded thereto, current being supplied to the nozzle and to the work. After welding the extension 11 is withdrawn to allow the slide to rise and then the pistons in the device 3 are retracted, the device 6 having been released and the device 4 clamped on the wire. The wire is received in the bore of the slide 14 in readiness for another operation. A plurality of wires may be fed and welded. Specification 676,069 is referred to.