Abstract A method for producing a tinplate cylindrical container with a bottom end having a thick walled upper portion by drawing and ironing in which the wall of the main part of the container body near the bottom end is made thick while the wall thereof near the upper portion is made thin, and in which the gradient angle or taper representing the variation of the wall thickness of the container main body part is made smaller than that of the punch core of the ironing means so as to make it possible to readily strip said container from said punch core. There is also provided a container of that kind in which the upper portion of said container is not subjected to the final ironing so that the hardness thereof is lower than that of the middle part of the body of the container to prevent the cracking of the flange which would otherwise be encountered.
A tinplate container comprising a relatively deep drawn cupshaped body having a bottom of substantially uniform thickness and an integral encircling wall upstanding therefrom, said upstanding wall having a cylindrical outer surface of substantially uniform diameter and an inner surface in the form of an inverted truncated cone, said upstanding wall further being characterized by having a short portion adjacent said bottom and which extends upwardly therefrom from an initial thickness substantially greater than said bottom in a course of decreasing thickness to joinder with a wall main body portion, said upstanding wall further having an upper portion joined to said main body portion, the thickness of said main body portion gradually decreasing in a direction away from said short portion to a point of minimum thickness at its joinder with said upper portion, said upper portion having a substantially uniform thickness which is greater than that of said main body portion for providing material for a container flange, the upper portion of said wall having a Rockwell hardness which is lower than that of said wall main body portion.
Claim 2
Dependent Claim
180 words
A tinplate container comprising a relatively deep drawn cupshaped body having a bottom of substantially uniform thickness and an integral encircling wall upstanding therefrom, said upstanding wall having a cylindrical outer surface of substantially uniform diameter and an inner surface in the form of an inverted truncated cone, said upstanding wall further being characterized by having a short portion adjacent said bottom and which extends upwardly therefrom from an initial thickness substantially greater than said bottom in a course of decreasing thickness to joinder with a wall main body portion, said upstanding wall further having an upper portion joined to said main body portion, the thickness of said main body portion gradually decreasing in a direction away from said short portion to a point of minimum thickness at its joinder with said upper portion, said upper portion having a substantially uniform thickness which is greater than that of said main body portion for providing material for a container flange, the upper portion of said wall having a Rockwell hardness which is lower than that of said wall main body portion.