Can end

Abstract

A can end having a countersink bead, an inclined chuck wall and a strong seam, resists distortion from its circular profile when subjected to thermal processing or when packaging carbonated beverages. This high hoop strength affects the manner in which the can end ultimately fails when placed under extreme abuse conditions, even if buckle pressure performance is within industry specified standards. The can end of the invention has control features introduced which control the failure mode whilst maintaining specified buckle pressure performance. In one embodiment, the control feature comprises expansion of the countersink bead to act as a trigger for local peaking, together with a groove in the chuck wall which prevents the peaking force from being concentrated at a single point which could result in leaking by the production of a pin hole.

1 . A can end shell comprising a center panel, a countersink bead, a chuck wall portion, a seaming panel, and one or more control features, each control feature extending around an arc of at least part of the countersink bead and/or the chuck wall, whereby the failure mode of the can end, when seamed to a can body, is controlled, and in which the or each control feature comprises one or more of: an expansion of the countersink bead, a shelf in the outer wall of the countersink, an indentation in the chuck wall, and/or coining.  
     
     
         2 . An end shell according to  claim 1 , in which the control feature includes at least one feature which extends around the whole circumference of the end shell.  
     
     
         3 . An end shell according to  claim 1 , in which the control feature extends over an arc behind the heel of a tab fixed to the can end, and centered on a diameter through a tab central axis.  
     
     
         4 . An end shell according to  claim 1 , in which a control feature is disposed on each side of a diameter through a tab central axis and each extending around an arc of the can end.  
     
     
         5 . An end shell according to  claim 3 , in which the arc length is 90° or less.  
     
     
         6 . An end shell according to  claim 1 , in which said end shell includes a combination of different types of control features extending around an arc centered on the same diameter of the can end.  
     
     
         7 . An end shell according to  claim 1 , in which each control feature comprises at least an expansion of the countersink bead and an indentation in the chuck wall, extending around an arc centered on the same can diameter.  
     
     
         8 . An end shell according to  claim 7 , in which the arc length of the bead expansion is less than the arc length of the chuck wall indentation, such that the bead expansion acts as a trigger.  
     
     
         9 . An end shell according to  claim 1 , in which an indentation or coined region is positioned at least partially in the upper half of the chuck wall, extending either internally or externally, or a combination of these.  
     
     
         10 . An end shell according to  claim 1 , further comprising coining of a shoulder between the inner wall of the countersink and the center panel over an arc or pair of arcs.  
     
     
         11 . An end shell according to  claim 1 , in which the control feature is made in either a shell press or a conversion press or a combination of these.  
     
     
         12 . An end shell according to  claim 4 , wherein the arc length is 90° or less.  
     
     
         13 . An end shell capable of being double seamed to a can body, said end shell comprising a center panel, a countersink bead disposed radially outwardly from the center panel, a wall portion disposed radially outwardly from the countersink, a seaming panel disposed radially outwardly from the wall portion, and failure control means for controlling eversion of the countersink bead.  
     
     
         14 . The end shell according to  claim 13 , in which the countersink bead extends from the center panel.  
     
     
         15 . The end shell according to  claim 14 , in which the wall portion extends from the countersink bead.  
     
     
         16 . The end shell according to  claim 15 , in which the seaming panel extends from the wall portion.  
     
     
         17 . The end shell according to  claim 13 , in which controlling eversion includes diminishing a propensity of the end to leak upon eversion of the counter sink bead.  
     
     
         18 . The end shell according to  claim 17 , in which controlling eversion diminishes the strength of the end.  
     
     
         19 . A combination beverage can body and end seamed to said can body in a double seam, said end comprising a center panel, a countersink bead disposed radially outwardly from the center panel, a wall part disposed radially outwardly from the countersink, a seam disposed radially outwardly from the wall part, and failure control means for controlling eversion of the countersink bead.  
     
     
         20 . The combination according to  claim 19 , in which the countersink bead extends from the center panel.  
     
     
         21 . The combination according to  claim 20 , in which the wall part extends from the countersink bead.  
     
     
         22 . The combination according to  claim 21 , in which the seaming panel extends from the wall part.  
     
     
         23 . The combination according to  claim 19 , in which controlling eversion includes diminishing a propensity of the end to leak upon eversion of the counter sink bead.  
     
     
         24 . The combination according to  claim 23 , in which controlling eversion diminishes the strength of the end.  
     
     
         25 . An end shell capable of being double seamed to a can body, said end shell comprising a center panel, a countersink bead disposed radially outwardly from the center panel, a wall portion disposed radially outwardly from the countersink, a seaming panel disposed radially outwardly from the wall portion, and a weakening deformation in the countersink bead, whereby said weakening deformation is capable of affecting eversion of the countersink to reduce leaking upon eversion.  
     
     
         26 . The end shell of  claim 25 , in which said weakening deformation is formed in a continuous circumference.  
     
     
         27 . The end shell of  claim 25 , in which said weakening deformation is formed in an arcuate region less than 360 degrees.  
     
     
         28 . The end shell of  claim 25 , in which said weakening deformation is substantially formed by point indentations.  
     
     
         29 . The end shell of  claim 25 , in which said weakening deformation comprises an expansion of the countersink bead.  
     
     
         30 . The end shell of  claim 25 , in which said weakening deformation comprises a shelf in the outer wall of the countersink.  
     
     
         31 . The end shell of  claim 26 , in which said weakening deformation comprises a shelf in the outer wall of the countersink.  
     
     
         32 . The end shell of  claim 25 , in which said weakening deformation comprises coining.  
     
     
         33 . The end shell of  claim 32 , in which said coining is disposed at least on an inside shoulder of said countersink.  
     
     
         34 . The end shell of  claim 33 , in which additional coining is disposed at least on an outside shoulder of said countersink.  
     
     
         35 . The end shell of  claim 33 , in which additional coining is disposed at least on an outside shoulder of the wall portion.  
     
     
         36 . The end shell of  claim 26 , in which said weakening deformation comprises coining.  
     
     
         37 . The end shell of  claim 30 , in which said weakening deformation comprises coining.  
     
     
         38 . The end shell of  claim 31 , in which said weakening deformation comprises coining.  
     
     
         39 . The end shell of  claim 25 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         40 . The end shell of  claim 26 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         41 . The end shell of  claim 30 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         42 . The end shell of  claim 31 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         43 . The end shell of  claim 32 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         44 . The end shell of  claim 36 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         45 . The end shell of  claim 37 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         46 . The end shell of  claim 38 , in which said can end further comprises another weakening deformation formed in the end wall portion.  
     
     
         47 . The end shell of  claim 25 , in which said weakening deformation triggers the eversion.  
     
     
         48 . A combination beverage can body and end seamed to said can body in a double seam, said end comprising a center panel, a countersink bead disposed radially outwardly from the center panel, a wall part disposed radially outwardly from the countersink, a seaming panel disposed radially outwardly from the wall part, and a weakening deformation in the countersink bead, said weakening deformation capable of affecting eversion of the countersink to reduce leaking upon eversion.  
     
     
         49 . The combination of  claim 48 , in which said weakening deformation is formed in a continuous circumference.  
     
     
         50 . The combination of  claim 48 , in which said weakening deformation is formed in an arcuate region less than 360 degrees.  
     
     
         51 . The combination of  claim 48 , in which said weakening deformation is substantially formed by point indentations.  
     
     
         52 . The combination of  claim 48 , in which said weakening deformation comprises an expansion of the countersink bead.  
     
     
         53 . The combination of  claim 48 , in which said weakening deformation comprises a shelf in the outer wall of the countersink.  
     
     
         54 . The combination of  claim 52 , in which said weakening deformation comprises a shelf in the outer wall of the countersink.  
     
     
         55 . The combination of  claim 48 , in which said weakening deformation comprises coining.  
     
     
         56 . The combination of  claim 55 , in which said coining is disposed at least on an inside shoulder of said countersink.  
     
     
         57 . The combination of  claim 56 , in which additional coining is disposed at least on an outside shoulder of said countersink.  
     
     
         58 . The combination of  claim 56 , in which additional coining is disposed at least on an outside shoulder of the wall part.  
     
     
         59 . The combination of  claim 52 , in which said weakening deformation comprises coining.  
     
     
         60 . The combination of  claim 53 , in which said weakening deformation comprises coining.  
     
     
         61 . The combination of  claim 54 , in which said weakening deformation comprises coining.  
     
     
         62 . The combination of  claim 48 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         63 . The combination of  claim 52 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         64 . The combination of  claim 53 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         65 . The combination of  claim 54 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         66 . The combination of  claim 55 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         67 . The combination of  claim 59 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         68 . The combination of  claim 60 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         69 . The combination of  claim 61 , in which said can end further comprises another weakening deformation formed in the end wall part.  
     
     
         70 . The combination of  claim 48 , in which said weakening deformation triggers the eversion.  
     
     
         71 . An end shell capable of being double seamed to a can body, said end shell comprising a center panel, a countersink bead disposed radially outwardly from the center panel, a wall portion disposed radially outwardly from the countersink, a seaming panel disposed radially outwardly from the wall portion, and a weakening deformation in the wall portion, whereby said weakening deformation is capable of affecting eversion of the countersink to reduce leaking upon eversion.  
     
     
         72 . The end shell of  claim 71 , in which said weakening deformation is formed in a continuous circumference.  
     
     
         73 . The end shell of  claim 71 , in which said weakening deformation is formed in an arcuate region less than 360 degrees.  
     
     
         74 . The end shell of  claim 71 , in which said weakening deformation is substantially formed by point indentations.  
     
     
         75 . The end shell of  claim 71 , in which said weakening deformation comprises an indentation.  
     
     
         76 . The end shell of  claim 71 , in which said weakening deformation comprises coining.  
     
     
         77 . The end shell of  claim 71 , in which said weakening deformation comprises a shelf.  
     
     
         78 . The end shell of  claim 71 , in which said can end further comprises another weakening deformation formed in the countersink bead.  
     
     
         79 . The end shell of  claim 78 , in which said can end further comprises coining disposed at least on an inside shoulder of the wall portion.  
     
     
         80 . The end shell of  claim 78 , in which said can end further comprises coining disposed at least on an outside shoulder of the wall portion.  
     
     
         81 . The end shell of  claim 71 , in which said weakening deformation triggers the eversion.  
     
     
         82 . A combination beverage can body and end seamed to said can body in a double seam, said end comprising a center panel, a countersink bead disposed radially outwardly from the center panel, a wall part disposed radially outwardly from the countersink, a seaming panel disposed radially outwardly from the wall part, and a weakening deformation in the wall part, whereby said weakening deformation is capable of affecting eversion of the countersink to reduce leaking upon eversion.  
     
     
         83 . The end shell of  claim 82 , in which said weakening deformation is formed in a continuous circumference.  
     
     
         84 . The end shell of  claim 82 , in which said weakening deformation is formed in an arcuate region less than 360 degrees.  
     
     
         85 . The end shell of  claim 82 , in which said weakening deformation is substantially formed by point indentations.  
     
     
         86 . The end shell of  claim 82 , in which said weakening deformation comprises an indentation.  
     
     
         87 . The end shell of  claim 82 , in which said weakening deformation comprises coining.  
     
     
         88 . The end shell of  claim 82 , in which said weakening deformation comprises a shelf.  
     
     
         89 . The end shell of  claim 82 , in which said can end further comprises another weakening deformation formed in the countersink bead.  
     
     
         90 . The combination of  claim 89 , in which said can end further comprises coining disposed at least on an inside shoulder of the wall part.  
     
     
         91 . The combination of  claim 89 , in which said can end further comprises coining disposed at least on an outside shoulder of the wall part.  
     
     
         92 . The combination of  claim 82 , in which said weakening deformation triggers the eversion.