US 6,386,013 B1 · Container end with thin lip

Abstract

A container end is provided with a suitable stock thickness for necessary strength and pressure resistance over its selected areas of its central portion while employing a substantially thinner peripheral wall. A method of forming thins the peripheral wall by drawing and ironing in a single workstation using compound die that also shears the blank from sheet stock. Optionally, multi-layers or laminates form the central portion of a lid, with a reduced number of layers forming the peripheral wall. Alternatively, the peripheral wall is thinned by ironing, spinning, or roll forming after the blank is formed into a shell. A forming apparatus clamps a planar peripheral wall of a blank with a clamping element that includes a thining tool. The apparatus oppositely offsets the center of the blank from the peripheral wall to draw the peripheral wall over the thinning tool on the clamping element.

Claims9

Dependent claims

A method of forming a container lid with a thinned peripheral lip, comprising the steps of:

first, performing a blanking step by shearing a blank from planar sheet stock of generally predetermined stock thickness, wherein the blank is composed of at least a central portion and a peripheral annular lip portion circumferentially bounding the central portion and lying generally in a plane;
second, performing a clamping step by clamping the peripheral annular lip portion between first and second clamping elements, one against each face of the blank, wherein at least the first clamping element carries a thinning means for thinning the peripheral lip portion by relative movement between the thinning means and peripheral lip portion;
third, performing a thinning step by oppositely relatively displacing the central portion of the blank and the peripheral lip portion, transversely to the plane of the peripheral lip, while applying through the clamping elements a predetermined clamping force of a magnitude allowing relative movement between the peripheral lip portion and the thinning means with resultant thinning of the lip portion to less than said generally predetermined stock thickness.

Dependencies are inferred from the claim text.

Container end with thin lip

Life of this patent

Container end with thin lip

Life of this patent

Abstract

Claims9