Pinch weld gun

Abstract

A pinch type weld gun wherein the weld arms are pivotally mounted on the frame structure via a ball bearing structure including annular members of insulative material positioned in apertures in the weld arms, inner races fixedly mounted on a common pivot pin, outer races positioned within the respective insulative annular members, and ball races positioned between the respective inner races and respective outer races. A shunt is fixedly secured at one end thereof to a gun electrode and fixedly secured at another end thereof to the gun transformer, and the other end of the shunt defines a coolant passage communicating with the transformer coolant passage system whereby coolant may be delivered to the transformer coolant passage system through the coolant passage in the other end of the shunt. A second shunt fixedly secured at one end thereof to a further electrode and fixedly secured at another end thereof to the transformer defines a further coolant passage in the other end thereof communicating with the transformer coolant passage system so that the coolant may be delivered to the transformer coolant passage system through the coolant passage in the other end of the first shunt and discharged from the transformer coolant passage system through the coolant passage in the other end of the second shunt to provide a continuous flow of coolant through the transformer coolant passage system. A cooling liquid distribution block is mounted on the gun frame at a location remote from the electrodes and concentric tubing extends from the distribution block to the electrodes for respective connection to concentric passageways defined in the electrodes.