JPS57190742A - Manufacture of l-ring for packaging steel sheet coil - Google Patents

Abstract

PURPOSE:To fit the L-ring firmly to a steel sheet coil end fit it easily and simply by making the central tubular body of an L-ring smaller in diameter than inner diameter of the steel sheet coil to be packed and forming this using a forming pressure die. CONSTITUTION:A steel sheet of required thickness is cut to a steel strip of required width, and specified width at one end of the steel strip is bent at right angles to form a long L-shaped material, and the long L-shaped material is formed to ring-shape. Both ends of the L-shaped material are welded to form an L-shaped ring 5 in which a flangelike disk 4 is fitted to the bottom outer periphery of a tubular body 3. The diameter of the central tubular body 3 is made slightly smaller than inner diameter of the steel sheet coil A. The central tubular body 3 of the L-ring 5 is fitted to a female die B using a forming pressure die consisting of a female die B having inner diameter that coincides with inner diameter of the steel sheet coil A and a male die C having diameter that coincides with inner diameter of the female die B and thinned at the tip. The male die C is fitted and pressed and formed so that the tubular body 3 at the center of the L-ring makes a right angle to the flangelike disk 4 and the thinned tip part is bent slightly to inside. Then, it is fitted firmly to the steel sheet coil A.