GB139455A - A new or improved method and apparatus for drawing metal tubes - Google Patents

Abstract

139,455. Ball Rolled Tube Corporation, (Assignees of Brinkman, L. H.). Feb. 10, [Convention date]. Axial rolling; rolling tubes; rolling- mandrels.-In drawing metal tubes, heat is communicated to the articles by heated walls such as a tube, between which the articles are passed, so as to distribute the heat more evenly and to prevent too intense heating and scaling, which is caused when the gases from an oil or gas furnace impinge directly on the work. In the form shown, in which a tube 5 is drawn through a rotating ball die 8, as described in Specification 110,598, the tube passes through and is heated by a tube 4 extending through a furnace 1 having fuel or fuel and air pipes 2 and 3. The inner end of the tube 4 extends up to the die to prevent cooling of the tube 5 after leaving the furnace. The mandrel has a head 11 of high-speed steel screwed to a member 12 which is screwed to a tube 10, a space 16 being provided to reduce heating of the member 12. To avoid damage to the threads on the portion 14 of the member 12, water is forced from a pipe 19 into a closed passage 17 therein. The water passes back through and cools the tube 10 and is drained out of the opening 20. The tube 10 is surrounded by a heat-insulating covering 21 such as asbestos, held in place by a metal sleeve 22. The Specification as open to inspection under Sect. 91 (3) (a) states that the apparatus is applicable for drawing rods. This subject-matter does not appear in the Specification as accepted.