GB863037A - Method of manufacturing dished articles - Google Patents

Abstract

863,037. Making wheel discs; forging; rolling; spinning; curling. COX, D. S. Feb. 6, 1958, No. 3976/58. Classes 83 (2) and 83 (4). A method of manufacturing a dished article, e.g. a wheel disc 7, from a flat plate comprises forming the plate into a cylindrical blank which is then die-formed to curl and at the same time to gather at least a major portion of its length inwardly so as to thicken and to provide the blank with a continuous taper as seen in crosssection, the central section of said gathered portion being next formed into a plane and the rest of the blank into a tapered outwardly-flared portion which is spin-formed and axially elongated to a predetermined dished contour. In an embodiment a metal plate is formed into a cylinder and the abutting ends welded together. Curling.-The cylinder 4 is placed between dies 6 and 7 and the ends pre-curled to facilitate later operations. Forging.-The forming operation is effected between dies 12 and 14, the dies 14 having an abutment 17 which engages and limits the expansion of the tapered skirt 18 of the blank and assists the thickening of the inwardlycurled portion 16. Alternatively, the dies may be formed as shown in Fig. 8. A central ejector 24 is provided. In another embodiment the pre-curled blank, is formed between dies 36 and 46 (Fig. 10) the die 36 being surrounded by a spring-loaded confining ring 38 and a guide-ring 44 surrounding the die 46 is provided with a hardened insert 50 which has an abutment 56 for the blank. Rolling.-In a further embodiment the first forming operation is carried out by rollers 84 (Fig. 11) mounted in a rotatable housing 70 carried by a vertically reciprocable ram (not shown). The rollers co-operate with a die 62 around which the cylindrical blank 4 is placed with one end supported on the die block 60. The next forming operation is effected between dies 90 and 92 (Fig. 13) whereby the central section of the blank is formed into a common plane and further work hardened. Spinning.-Finally the preformed and flattened blank is spun on a mandrel 104 by a roller 116 to the desired final shape. A member 108 clamps the blank on the mandrel 104. The metal movement accomplished by the spinning is such that the overall diameter of the blank is not increased and the thinning and tapering action work hardens the spun portion to complement the previously work hardened central section.