Abstract: A continuous and optimum weld is provided in the weld space between the attachment end of a secondary pipe and the outer surface of a primary pipe by means of a downwardly extending electric welding burner, the secondary pipe being oriented to extend at an angle to an imaginary central axis line extending through the primary pipe, by coordinating the vertical and horizontal positioning of the welding burner as the primary pipe is rotated, both around its imaginary central axis and end over end, so that the welding burner will be continuously aimed at the weld space and will operate at a constant current strength as the primary pipe rotates.

Abstract: An apparatus for performing a work function on a tubular workpiece includes a support frame movable along an X-axis, a bracket on the frame movable toward and away from the workpiece along a Z-axis, a support arm mounted on the bracket for movement about a swival axis lying in the Z-direction, a carriage mounted on the arm for movement therealong in a Y-direction, a workpiece implement mounted on the carriage for movement together therewith and about a tilting axis lying in the X-direction, and the workpiece implement being capable of adjustment along its central axis, the support arm lying in a plane containing the swivel axis and perpendicular to the tilting axis.

Abstract: The cutting apparatus is used to cut a hole in a workpiece such as a pipe of relatively large thickness. The burner is mounted on a carriage which is reciprocated along a radially directed carrier which rotates about an axis perpendicular to the carrier. Reciprocation of the carriage is controlled as a function of the rotation of the carrier about the axis. In addition, a cam causes pivoting of the burner in accordance with the reciprocation of the carriage along the carrier. Operation of the apparatus is such that the tip of the burner is held at a constant distance from the surface of the workpiece. A motor is also provided for moving the burner longitudinally of its axis.