GB872237A - Wire drawing die - Google Patents

Abstract

872,237. Drawing-dies. STEEL CO. OF CANADA Ltd. Oct. 6, 1959 [Oct. 7, 1958], No. 33890/59. Class 83 (4). A wire-drawing die is characterized in that the die includes a shaping zone in which a circular wire is formed into a helically-twisted wire of regular polygonal cross-section. Fig. 13 shows a circular cone 30 of continuously decreasing cross-sectional area and a coaxial helically-twisted square, Fig. 3, of the same length as the cone and of uniform crosssectional area throughout its length. The diameter of the cone 30 at its large end is equal to the diagonal of the square, and at its small end the diameter of the cone is equal to the side of the square, Fig. 14, or in the case of a polygon other than a square would be equal to the diameter of the largest circle which could be inscribed within the polygon. The cross-sectional shape of the die at all intermediate planes, such as 37, is such that along any radial line, e.g. 42 or 45, the distance to the inside periphery of the die is the greater of the two distances to the cone 30 or the square 31. Thus in the case of the line 45, the boundary of the figure enclosing the cross-section of the die follows the circular path 44 whereas in the case of the line 42 the boundary follows the square corner 41. The die also has an entry zone 21, Fig. 1, an exit zone of a uniform crosssectional area, and a relief 25. Specification 795,665 is referred to.