Patent GB-1462825-A (GB)
Title: Method and apparatus for producing a chain
IPC: F16G15/02
Filed: 1974-09-20
Abstract: 1462825 Welding by pressure WAFIOS WAGNER FICKER & SCHMID GmbH 20 Sept 1974 [22 Sept 1973] 41074/74 Heading B3R In making a chain the ends of interengaged C-shaped bent wire links are electrically resistance butt welded, link by link, and the unwelded chain is drawn over the apex of a saddle with the plane of each link inclined to the plane of the next link such that the angle included between the plane of each link and the vertical central plane containing the longitudinal axes of the links has a maximum of substantially 45 degrees, and the link at the apex to be welded is rotated to bring it into an upright position on the saddle. An apparatus, in an embodiment, comprises a vertical plate 4 in front of which is carried a saddle 6 which as viewed in Fig. 1 is substantially triangular with a flattened top over which the chain is drawn, pressure applying tools 16, 16 being arranged horizontally on each side of the saddle and electrodes 18, 18 being arranged above the saddle. Guides 20, 20 for the chain are provided one on each side of the saddle at 45 degrees to the horizontal. Each guide includes two opposed strips 22, Fig. 7, each having a tapered edge formed by surfaces 26, 28, the tapered edges together forming guide surfaces for the chain links which are inclined at 45 degrees to a vertical plane parallel to the plate 4. The lower strip 22 in each guide extends beyond the other and is secured adjustably to the plate 4 by a screw and slot connection 32, 34 and the upper strip 22 is secured adjustably to the lower strip. The saddle has a guide surface on each of its larger sides and on its upper side formed as a part circular groove and in each of its front and rear surfaces a vertical recess 44 is formed and below the grooves two bores 46 are provided. Leaf springs 48 carrying at their upper ends opposed blocks 50 are located one in each recess 44, the springs 48 being coupled to a lever mechanism 52 operated by a cam 72. A double acting piston and cylinder device 86 has a piston-rod head 87 for engagement with the front spring 48 and the cylinder of the device is carried on a plate 92 secured to the outer ends of two rods 90 passing through the bores 46 in the saddle, the other ends of the rods being connected to a plate 92 carrying an adjustable bolt 96. In operation with a link to be welded resting in the upper groove of the saddle and inclined at 45 degrees to the vertical, the cam 72 is rotated so that the linkage 52 raises the leaf springs 48 to the position shown in Fig. 3 and then the piston cylinder device 86 is operated so that the piston-rod head 87 moves forwards to press the block 50 on the front leaf spring against the link and the bolt 96 is moved to press the block 50 on the rear leaf spring against the link. The blocks together tilt the link into a vertical position and the tools 16 are applied to the link's rounded ends. The device 86 is then operated to withdraw the piston head 87 and bolt 96 from the link and the electrodes 18 are lowered on to the link and welding is effected. After welding the electrodes and tools 16 are released and the link falls back to its original position. The chain is advanced to bring a new link on to the saddle top and it is tilted in the opposite direction into a vertical plane and the welding process repeated. In a modification the blocks 50 are replaced by bodies shaped to grip the link to be welded and to engage the adjacent ends of the next adjacent links to move them apart.