| 摘要 |
1,140,258. Making cans. AMERICAN CAN CO. 2 May, 1966 [4 May, 1965], No. 19297/66. Headings B3A and B3Q. A method of forming a cup-shaped container of low-ductility metal, e.g. steel, comprises coating a flat blank with a higher-ductility metal at least on the surface which is to form the outside of the container, deep drawing the blank to form a cup (Fig. 3) having a bottom wall (42) and a cylindrical side wall (40) of substantially equal thickness and subjecting the cup to at least one ironing step for thinning and elongating the side wall. Both sides of the blank are preferably coated, electrolytically, with tin, copper, zinc, brass, nickel, silver, lead or cadmium, and the blank deep drawn and ironed in the matt condition, i.e. without the coating having previously been melted and flow-brightened. In this condition lubricating oil impregnates the matt surfaces and facilitates the drawing and ironing operations. The blank is centred over a drawing die 14 by a recess 34 in a spring-pressed hold-down 24. A punch 20 with a conical, spheroidal, flat &c. end 22 draws the blank through the die 14 to form a cup (Fig. 3), which may be transferred to another press having one or more ironing dies or, as shown, two or more ironing dies 44, 48 may be disposed beneath the drawing die for producing the container in a single operation. The ironing dies burnish and reduce the thickness of the cup-wall, but the end of the container has substantially the same thickness as the starting blank. Spring-pressed strippers 60 remove the container from the punch. |
