Abstract: Automatic welding apparatus for making uniform welds around the perimeter of a polygonal shape made up of a succession of flats and arcuate corners is described in connection with a tubular hexagonal workpiece which is rotated about its longitudinal axis beneath a welding torch assembly. The distance of the welding electrode above the workpiece is maintained as preselected by automatic voltage control means. The welding electrode is automatically maintained perpendicular to a tangent to the surface of the workpiece and extending in the plane of the weld line by oscillating the welding torch assembly so that its longitudinal axis describes an arc having its center on the longitudinal axis of rotation of the workpiece in synchronization with the rotation of the workpiece. Synchronization is provided by means of an annular cam surface which is rotated in predetermined relation to the workpiece and which controls the oscillation of the welding torch assembly.

Abstract: An ultrasonic measuring system particularly suited for measuring the wall thickness of large tubing of widely different shapes and sizes. An ultrasonic transducer is adjustably supported in an ultrasonic head assembly so as to provide precise focusing of the energy across a gap to the surface of the part being measured. The head assembly is urged against the surface of the part while the two are displaced relative to one another so that the transducer scans a predetermined path along the part. Freely rotatable balls carried by the head assembly engage the surface of the part while a column of water is maintained to fill the gap between the transducer and the surface of the part. Provision is made for rotating circular parts so that the transducer sweeps out a spiral path over the surface of such parts.