GB1145519A - Method and machine for welding with driven electrodes - Google Patents

Abstract

1,145,519. Welding by pressure. P. OPPRECHT. 21 Dec., 1966 [22 Dec., 1965], No. 57245/66. Heading B3R. A welding machine having one or more driven electrodes arranged to move work forwards is provided with means for accelerating the work before the work enters the welding station to a velocity corresponding to that of the electrode or electrodes. In an embodiment the machine comprises a fixed lower arm 3 carrying a roller electrode 9 and a pivoted upper arm carrying a roller electrode 7, electrode wires passing over the roller electrodes being driven by rollers 41, 57. Rails 13 on the arm 3 support a carriage 11 having a holder 15 for the work and a belt 17, connected to the frame of the machine and the carriage, normally urges the carriage to its position shown in Fig. 1. An abutment 19 on the carriage engages a buffer 21 on a bar 23 adjustably secured in a tube 25. The tube 25 carries a control member 29 controlling a limit switch 31 and an abutment plate 35 for movement between two stops 33, 36 fixed to the machine frame. A control bar 37 of triangular crosssection is secured to the plate 35 and is arranged between a roller 43 movable vertically by a piston/cylinder device 47, 49 and the roller 41 for driving the lower wire electrode. With the machine in its start position as in Fig. 1, the work (sheets 59, 61) are secured to the carriage 11 spaced from the rollers 7, 9, the plate 35 contacts the stop 36 and the bar 37 is spaced from the wire driving roller 41. The upper arm 5 is lowered to bring the rollers 7, 9 together and when welding pressure is obtained the rollers 41, 57 drive the wires 53, 55. When the welding pressure is reached air is forced through a conduit 51 to raise the roller 43 and thus the bar 37 against the roller 41. The bar 37 and thus the carriage 11 is moved towards the rollers 7, 9 the plate 35 strikes the stop 33 and the carriage continues towards the rollers 7, 9 to advance the work between the wire electrodes and roller electrodes. The welding current may be reduced to 50-80% e.g. 70-75% of normal as the work initially comes between the roller electrodes and as it leaves the electrodes.