Patent GB-1460365-A (GB)
Title: Electric resistance chain link welding machine
IPC: B23K11/00
Filed: 1974-03-22
Abstract: 1460365 Welding chains by pressure WATIOS WAGNER FICKER & SCHMID GmbH 22 March 1974 [7 April 1973] 12921/74 Heading B3R An electric resistance chain link welding machine for welding interlinked C shaped chain links in which each link to be welded is compressed by two reciprocatory upsetting tools 30 to bring its free ends together, comprises separate drive devices for the positioning and compressing portions of the upsetting movement of the upsetting tools, the motion of the positioning portion being more rapid than that of the compressing portion and the drive device for the positioning portion comprising a pair of toggle joints each connected at one end to a respective upsetting tool and mounted at the other end on the machine frame, the middle pivot of each toggle joint being connected to actuating mechanism of the machine for operation in timed relation with operation of the drive device for the compressing portion. The chain welding machine in an embodiment comprises a saddle 6 for supporting a link to be welded, two guide supports 8, 10, inclined to the horizontal, for supporting the chain, two levers 100 pivoted about parallel axes 102 and two tool carriers 28, carrying chain link comprising tools 30, coupled to the levers 100 and guided for horizontal opposed movements, the end of each tool carrier remote from its tool carrying end being pivoted to one lever 38 forming with another lever 42 a toggle lever 40 and the knee joint of the toggle lever being coupled to a rod 60 in operative relationship with an operating cam 84 on a control shaft 86. Each tool carrier is mounted in a horizontal guide 72 formed by a U section member and a plate closing the U section, the tool 30 carried by the carrier extending on one side of the guide 22 and the end 32 of the carrier remote from the tool being pivotally connected to the H-shaped toggle lever 38 on the other side of the guide. The other lever 42 of the toggle lever 40 is pivoted at its end 50 remote from the carrier 28 on a pin 54 in an elongated hole 56 in a bearing 52 secured to the frame and the rod 60 connected to the knee joint of the toggle lever is of adjustable length and ball-and-socket joints 66, 68 are provided between the knee joint and the lever 80, 82 operatively connected to the cam 84. Each lever 100 is formed of two spaced parallel members pivoted at upper ends to two bars 110 mounted on the pivot pin 54 of the bearing 52. The lower end of each lever 100 is pivoted to one end of a rod 120 pivoted at its other end to a slide member 126 guided on rails 132, the slide being pivotally connected to a lever 142, Fig. 5, connected at one end by a chain 158 to a spring 156 and at its other end coupled to a cam 148 on the shaft 86. The spring force is adjustable by a device 160 and 162. In operation the legs 38, 42 of the toggle levers 40 which are initially in the dotted line position at the right hand side of Fig. 1 are caused to assume the full line position of the left hand side of Fig. 1 by means of the cam 84 and rod 60 raising the knee joints of the toggle levers this moving the tools 30 against a chain link on the saddle. During this movement the springs 156 are tensioned by operation of the cam 150 and the welding electrodes 30 are applied to the link. Then the cam 150 causes the levers 100 to move from the dotted line position at the right hand side of Fig. 1 to the full line position at the left hand side of Fig. 1 to force the tools 30 against the link, the holes 56 allowing the carriers 28 to be moved forwards a small amount. In a modification a safety device is fitted to the toggle lever knee joint operating devices which cause the cam followers to be lifted clear of the cams if the knee joints cannot reach their desired position.