GB447200A - Brake drum and method of forming same - Google Patents

Abstract

447,200. Making brake drums. KELSEYHAYES WHEEL CO., 3600, Military Avenue, Detroit, Michigan, U.S.A. Nov. 13, 1934, No. 32707. Convention date, Dec. 11, 1933. [Classes 83 (ii) and 83 (iv)] Stamping; spinning; working at specified temperatures. - Blanks for brake drums, which have been cupped either in stamping dies or by spinning, are heated to a temperature of 1600 to 1700‹ F., after which they are gripped at the central portion and fashioned by spinning. As shown, a rotatable spindle E, Fig. 5, carries a head F shaped suitably to the form of the finished article but of slightly smaller diameter so as not to contact therewith except at the centre part of the cupped blank which is gripped between it and a clamping head G<1> moved upwardly by an hydraulic plunger. A pilot pin H engages a recess H<1> in the head F and an aperture D<1>, Fig. 4. In the blank, successive operations on the blank take place with the aid of a roll I which moves upwardly and acts on the part J followed by a roll K which acts upwardly against the part F<2>. A roll moving inwardly shapes the part J to a further extent and this may be ribbed by a correspondingly shaped roller. The blank may be trued and keyed by expanding dies. The flange J<1> may be acted on by a conical roller and may be set obliquely by dies. The material from which the drum is made is sheet steel containing for example, carbon À65 to À75, manganese À65 to À85 and silicon À15 to À30.