초록 ▼

A method of forming a smooth shoulder (16, 14b, 19b), neck (17, 37) and flange (18, 38) at the open end of the cylindrical side wall (12) of a can body (10) comprises the steps of forcing a marginal edge portion (13) of the side wall into at least a first die to form a first portion of reduced diame

A method of forming a smooth shoulder (16, 14b, 19b), neck (17, 37) and flange (18, 38) at the open end of the cylindrical side wall (12) of a can body (10) comprises the steps of forcing a marginal edge portion (13) of the side wall into at least a first die to form a first portion of reduced diameter having a first shoulder portion (14) and a first cylindrical portion (15); and optionally applying at least one rolling operation to the first portion of reduced diameter, and any further die formed portions of reduced diameter subsequently formed, to generate a smooth shoulder (16, 14, 19b), neck (17, 37) and flange (18, 38). Reference is made to the roll forming process described and claimed in British Pat. No. 1,534,716 as being particularly suitable. The margin-portion (13) is preferably thicker than the rest of the side wall (12).

대표청구항 ▼

A method of forming a shoulder, neck and flange at an open end of the cylindrical side wall of a can body, comprising a die necking operation followed by a rolling operation, wherein the die necking operation includes a static die necking step in which a marginal edge portion defining the open end o

A method of forming a shoulder, neck and flange at an open end of the cylindrical side wall of a can body, comprising a die necking operation followed by a rolling operation, wherein the die necking operation includes a static die necking step in which a marginal edge portion defining the open end of the side wall is forced into a die to make a portion of reduced diameter having a shoulder portion supporting a cylindrical portion, the rolling operation includes a rolling step in which the portion of reduced diameter is rolled so as to further reduce the diameter of the cylindrical portion and generate a rereduced shoulder supporting said neck, and forming a flange at a terminal end portion of said cylindrical portion.