Cartwright's Pipe-weding Machine.—Figs. S and 9 represent a machine designed by Robert Cartwright, of Rochester, N. Y., for welding the longitudinal seems of steel pipes of huge diameter. The general features of the machines are two compound air and gas furnaces, one internal and one external, immediately in advance of internal and external rolls, all being mounted on a frame to which a reciprocating motion is imparted by a crank, the seam of the sheet being welded being drawn between the furnaces and rolls as the weld is made. The gas and air are supplied through pipes attached to the reciprocating frame; and as their rear ends are joined to rubber hose, the movement of the frame is made possible.
The sheet l aviugbeer,tolledtothe required diameter, is held rigidly in shape by suitably designed re movable clamps on the outside, and compression rings on the inside immediately under the clamps. These clamps and rings are quickly removed as the weld advances and without requiring the stoppage of the work, in starting to weld a seam the blow pipe jets of the furnaces heat the material, and as the pipe is drawn in the part longest in the flame comes to welding heat and is brought between the rolls and closed down to a perfect weld, the rolls being adjd.stable to suit different thicknesses of material. The machine consists of a base, A. formed with horizontally projecting arms, B C, so arranged as to create an don gated slot-way opening into the body of the machine. On the rear of the machine is mounted a crank pulley, connected by means of a pitman to a slide arranged as shown. To this slide
are connected parallel bars, reciprocating in suitable guideways and carrying at their extreme outer ends the welding rolls and heating furnaces. The welding roll is guided on the frame of the machine. The sides of the frame in which the welding roll is journaled are recipro cated by means of the crank motion. Alounted in this frame is the main arbor, mounted upon which is the central welding roll, and two supporting rolls, all of which have friction bear ings. These operate entirely independent of each other, and by their friction upon the main arbor they cause that to rotate more or less, the result being that when in operation each roll is constantly wearing against a different part of the main ar bor, so that the latter is never worn out of trite. The sup porting rolls travel upon a track held adjustably to the frame by means of bolts. By adjusting in a vertical direc tion the rolls may be adapted to work upon thick or thin work, especially when welding the joint of a pipe, in which case one welding roll is used inside and one outside of the pipe, both being in the same vertical line. It is evident that this construction trans fers all the strain of the weld ing pressure upon the roll to the arbor, and thence to the supporting rolls and track way, and that the reciprocat ing movement of the roll does not abrade the metal at the weld, the operation being more nearly allied to that of annealing the hot metal at the joint. thereby preserving the fibre intact.