GB1458519A - Spot welding gun for an automated machine - Google Patents

Abstract

1458519 Welding by pressure MITSUBISHI JUKOGYO KK 21 Dec 1973 59475/73 Heading B3R A spot welding gun 2 for use on an articulated arm forming part of an automated machine and having a ram in an end member comprises a pair of spaced side plates 18a pivotally connected at their rear ends to arms extending from the end member and pivotally supporting at their forward ends a pair of jaws 13a, 13b carrying welding electrodes 15a, 15b, at their front ends, the jaws being movable to bring the electrodes together by a mechanism which comprises at least two links 9a, 10a pivotally coupled to the jaws and pivotable about a pin 8 passing through a rod 6 connectable to the piston 5 of the ram. Forward motion of the rod closes the jaws and at the forwardmost position of the rod the gun may be rotated about the axis of the pin 8. The jaws are pivoted at 19 between the pair of plates 18a in turn mounted on pivots 20a in arms 3a extending from the end plate 3 secured to the cylinder 4 of the ram. The piston 5 of the cylinder is arranged to move the rod 6 extending between the jaws and carrying the pin 8 to which are pivoted the first ends of a pair of links 9a, 10a on each side of the rod 6. The second ends of the links are pivoted to connectors 11a, 11b engaged in the arms of the jaws with springs between the connectors and the arms. Movement of the rod 6 to the left causes pivoting of the links 9a, 10a to pivot the jaws about pin 19 and close the electrodes 15a, 15b with compression of the springs when the electrodes engage the work. At this stage the pivot pin 8 coincides with the pivots 20a allowing the plates 20a to pivot about 20a if the workpieces are displaced relatively to previously welded workpieces. The piston 5 is returned by a spring 7 to return to the rod 6 and open the electrodes.