Metal Containers and Methods of Manufacture

Abstract

A method of reducing a thickness and increasing a height of a cylindrical wall of a metal cup to form a can body comprises positioning a wall-ironing punch inside the cup, moving an annular wall-ironing die axially over the closed end of the cup towards the open end of the cup, but not beyond the open end of the cup, in order to iron the cylindrical wall from the closed end up to a position axially spaced from the open end and moving the wall-ironing die back in an opposite direction to remove the can body from the die. Methods of altering a diameter of one or more regions of a can body are also disclosed.

1 - 19 . (canceled) 
     
     
         20 . A metal cup comprising:
 a base defining a bottommost end of the metal cup;   a curl disposed at an uppermost end of the metal cup;   a circumferential body-wall disposed between the curl and the base, the body-wall including a plurality of circumferential wall regions; and a plurality of circumferential transition portions;   adjacent pairs of the wall regions having one of the transition portions disposed therebetween; each one of the transition portions having a transition portion upper diameter and a taper portion lower diameter, the transition portion upper diameter being greater than the taper portion lower diameter; and   a wall thickness of the body-wall proximate the base being greater than a wall thickness of the wall region proximate a mid-point of the body-wall;   wherein the metal cup is nestable with other ones of the metal cups.   
     
     
         21 . The metal cup of  claim 20 , wherein the transition is a taper. 
     
     
         22 . The metal cup of  claim 20 , wherein the metal cup is formed of a pre-coated aluminum. 
     
     
         23 . The metal cup of  claim 21 , wherein the plurality of wall regions is a first-wall region, a second-wall region, and a third-wall region, and wherein the plurality of taper portions is at least a first-taper portion and a second-taper portion. 
     
     
         24 . The metal cup of  claim 20 , wherein at least one of the wall regions defines a cylinder. 
     
     
         25 . The metal cup of  claim 23 , wherein each one of the wall regions defines a right-angle cylinder. 
     
     
         26 . The metal cup of  claim 25  wherein the right-angle cylinder defined by each one of the wall regions has the same diameter of other ones of the right-angle cylinders. 
     
     
         27 . The metal cup of  claim 20 , wherein each one of the taper portions is configured such that an angle between each pair of adjacent wall regions is at least 10 degrees. 
     
     
         28 . The metal cup of  claim 27 , wherein the angle between each pair of adjacent wall regions is at least 15 degrees. 
     
     
         29 . The metal cup of  claim 20 , wherein an upper one of each of the adjacent pairs of the wall regions blends into the taper portion therebelow. 
     
     
         30 . The metal cup of  claim 28 , wherein a lower one of each one of the adjacent pairs of the wall regions blends into the taper portion thereabove. 
     
     
         31 . The metal cup of  claim 29  wherein a diameter of the upper one of each of the adjacent pairs of wall regions measured proximate the taper portion therebelow is greater than a diameter of the lower one of each of the adjacent pairs of the wall regions measured proximate the taper portion thereabove. 
     
     
         32 . The metal cup of  claim 29 , wherein at least one taper portion is angled such that an angle between each pair of adjacent wall region of the plurality of wall regions is at least 10 degrees. 
     
     
         33 . The metal cup of  claim 21 , wherein the plurality of wall regions is at least a first-wall region, a second-wall region, and a third-wall region, and wherein the plurality of taper portions is at least a first-taper portion and a second-taper portion. 
     
     
         34 . The metal cup of  claim 33  wherein:
 the first-wall region blends into an upper portion of the first-taper portion from a first-wall-region lower diameter, 
 a lower portion of the first-taper portion blends into the second-wall region to a second-wall region upper diameter; 
 the second-wall region blends into an upper portion of the second-taper portion from a second-wall-region lower diameter; and 
 a lower portion of the second-taper portion blends into the third-wall region to a third-wall-region upper diameter. 
 
     
     
         35 . The metal cup of  claim 34  wherein the first-wall region lower diameter is greater than the second-wall region upper diameter, and wherein the second-wall region lower diameter is greater than the third-wall region upper diameter. 
     
     
         36 . The metal cup of  claim 35 , wherein every diameter of the first-wall region is greater than every diameter of the second-wall region, and wherein every diameter of the second-wall region is greater than every diameter of the third-wall region. 
     
     
         37 . The metal cup of  claim 36  further comprising a third-taper portion, the third-taper portion blending into the body-wall proximate the base. 
     
     
         38 . The metal cup of  claim 37  wherein the body-wall proximate the base defines a right-angle cylinder. 
     
     
         39 . The metal cup of  claim 20 , wherein the base includes a base center portion that is approximately planar. 
     
     
         40 . The metal cup of  claim 39 , wherein the base includes a standing ring disposed radially outwardly relative to the base center portion. 
     
     
         41 . The metal cup of  claim 20 , wherein a thickness of a portion of the body-wall proximate the curl is greater than the wall thickness of the body-wall at the mid-point. 
     
     
         42 . The metal cup of  claim 20 , wherein a height of each one of the plurality of wall regions is approximately equal to a height of other ones of the plurality of wall regions.