GB795665A - Wire and method and apparatus for its production - Google Patents

Abstract

795,665. Drawing; making nails, reinforcing bars and gratings. STEEL CO. OF CANADA, Ltd. Sept. 22,1954, [Oct. 1, 153 ; June 2, 1954], No. 27458/54. Classes 83 (2) and 83 (4). Wire of non-circular cross-section and generally helical configuration is drawn through a rotary die having a helically twisted non-circular passage. In one example round wire 37, Fig. 7, is drawn to helical square section through a die 23 having a flared entry portion leading to tapering helically twisted square section near the exit end 40. The section may alternatively be triangular or polygonal or any non-circular section such as an oval. In another example wire which is initially of circular or polygonal section with or without helical twist is drawn through the dies which have maximum radial dimensions greater than the minimum radial dimensions of the initial wire so that various irregular surface formations may be obtained such as a square section with round corners or a bar, Fig. 18, with opposite helical formations as a result of which the bar section changes alternately from square section as at the end 20 to octagonal as at the section 19. A similar effect may be obtained by drawing a square section wire initially formed with a helical twist through an ordinary square section die. The die may be rotatably driven or may rotate freely, the work being held against rotation. Variation in the helical angle along the length of the work may be obtained by intermittently restraining the rotation of the die or periodically increasing the tension of the drawn wire as by passing the wire over a rotating eccentric. Apparatus suitable for carrying the die 9, Fig. 1, comprises a die holder 10 rotatably mounted on a ball bearing 7 in a supporting wall 2 to which a soap box 8 is attached. A radial flange 13 with a peripheral bead 14 protects the bearing 7 from being reached by the soap. An annular chamber 17 supplied with cooling fluid through pipes 18, 19 is provided in the wall 2 to cool the bearing 7. The wire produced may be used for threaded nails or reinforcing bars and for making non-slip gratings by assembly to cross members. Barbed wire may also be made using the helixed wire for the barbs to be wrapped round the line wire and also for the line wire itself.