Patent GB-202130-A (GB)
Title: Process of manufacturing metal tubing and apparatus therefor
IPC: B21C37/08
Filed: 1922-07-04
Abstract: 202,130. Jackson, W. J. Mellersh-, (Fretz-Moon Tube Co.). July 4, 1922. Tubes.-In making metal tubes, strip is drawn continuously through an elongated enveloping heating medium or furnace maintained at a higher temperature than that to which it is desired to heat the strip so as to heat the strip gradually throughout its entire crosssection and is bent and its edges raised to welding heat and then welded. A metal strip is fed from a reel s through a furnace a provided with heating-burners d, c and a stack b, and is bent and welded by rolls h and sized by two pairs of rolls i, j, which are driven at a greater speed than the rolls h so as to draw the metal through the rolls h and thus form the tube of proper gauge and prevent buckling. The rolls are cooled and the scale blown from the tube during formation by an air blast delivered through a series of nozzles in a pipe. The tube is received in a trough r whereon it is cut into lengths. During its passage through the furnace the strip rests on supports e which are water-cooled to prevent their burning off. The strips may be partly heated in the furnace, and the edges raised to welding heat by blasts of air passing through pipes w. In another modification, the rolls h may bend and the rolls i weld the tube, and, in a further modification, the strips may be preliminarily bent prior to passing into the furnace by vertical or horizontal rolls or a combination thereof, and the heating completed and welding effected after passing through the furnace. Before the reel s is quite exhausted, the strip is unrolled therefrom and bent round so as to be passed on to the table u, whereupon its end is welded by a burner v to the end of a strip on a second reel t, which is then moved to replace the reel s. The ends of the strip may be bevelled, bent into U-shape, and welded in the position shown in Fig. 6 or may be electrically welded together with a straight or inclined bult joint. In the latter cases the burr on the joint is reduced by a pair of rolls or dies driven from a separate source and mounted on the table into which the strip is placed by hand before the slack is taken in by the rolls h. In the former case, the strip before entering the rolls passes through a guide k, Fig. 13, which is moved to place the strip in line with the roll pass. The strip passes through a protecting shield m on its way to the rolls. Between the two pairs of sizing-rolls are mounted a pivoted forked tube guide n having guide-notches and a weighted scraper p, Fig. 15, for removing scale. The front and rear bearings for the spindles of upper rolls i, j are vertically adjustable by pairs of screws and rest on adjustable supporting-screws. The rear bearings 22 for the upper and lower rolls are fixed to the spindles, and are longitudinally adjusted by nuts and fixed screws in their housings so as to align the grooves in the different rolls with each other. The spindles 32, 33 of the rolls hare mounted in split bearings 31 adjustable in a slot in a housing 29 by nuts 37 engaging four fixed screws 35, and are provided with threaded collars 38 to prevent axial movement thereof. The rolls i, j are connected by gearing and driven by a spur-wheel through a pinion 14 on the shaft 13, which is also connected by chain gear 45, bevel gear 41, 40 and spur gear 39 with the spindles of the rolls h. The shaft 13 is driven by spur gear 15, 48 from a shaft 47, which is connected by a belt 49 through pairs of cone pulleys 50, 51 with the driving shaft 52. One pair of pulleys are moved towards each other, and the other pair simul: taneously separated so as to vary the speed of travel of the strip according to the rapidity with which the strip is heated.