Inverted curling method for metal beverage containers and beverage containers with inverted curls

Abstract

Bottles with inwardly curled upper portions at the bottle opening and methods and tooling for producing such bottles. The inwardly curled upper portions impart compressive stresses into the bottle material and can reduce a likelihood of material splitting because the upper portion may not be stretched to a larger outer diameter as with outwardly curled upper portions. The inwardly curled upper portions may be formed using rollers with an entry radius positioned near an outside diameter of the bottle opening. The inward curl is formed as the bottle material enters the rollers near an entry face of the rollers, transitions through a work face of the rollers, and exits the roller at an exit face of the rollers. The resulting inward curl meets the edge of the bottle material near the inner surface of the bottle.

That which is claimed is: 
     
         1 . A bottle with a curled end, the bottle comprising:
 a top end comprising an edge;   an opening at the top end of the bottle;   an outer surface; and   an inner surface, wherein the top end of the bottle comprises an inward curl extending from the outer surface of the bottle to the inner surface of the bottle such that the edge is adjacent the inner surface of the bottle and the inward curl imparts a compressive stress on the top end of the bottle.   
     
     
         2 . The bottle of  claim 1 , further comprising a lip below the top end of the bottle. 
     
     
         3 . The bottle of  claim 1 , further comprising a threaded feature below the top end of the bottle. 
     
     
         4 . The bottle of  claim 1 , further comprising a crown-type closure feature to allow the bottle to be sealed with a crown-type closure by coupling the bottle to the crown-type closure via the crown-type closure feature. 
     
     
         5 . The bottle of  claim 1 , wherein the inward curl has a constant radius. 
     
     
         6 . The bottle of  claim 1 , wherein the inward curl has a variable radius. 
     
     
         7 . The bottle of  claim 1 , further comprising an insert positioned proximate the opening of the bottle, wherein the insert is affixed within the bottle by confining the insert between the inward curl and a constriction of the bottle. 
     
     
         8 . The bottle of  claim 7 , wherein the insert is a liquid flow modifier. 
     
     
         9 . A method for producing a bottle with an inward curl top, the method comprising:
 providing an uncurled bottle with an outer surface, an inner surface, and a bottle opening;   forming an outer diameter with an upper portion and an edge; and   deforming the upper portion inward toward the bottle opening to form an inner diameter such that the edge is adjacent the inner surface of the uncurled bottle and a compressive stress is imparted in the upper portion.   
     
     
         10 . The method of  claim 9 , further comprising trimming the edge during deformation. 
     
     
         11 . The method of  claim 9 , further comprising forming a lip below the bottle opening. 
     
     
         12 . The method of  claim 9 , wherein deforming the upper portion into the bottle opening comprises curling the upper portion with one or more rollers. 
     
     
         13 . The method of  claim 12 , wherein the one or more rollers comprises a plurality of staged rollers positioned proximate to the bottle for curling the upper portion. 
     
     
         14 . The method of  claim 13 , wherein each roller of the plurality of staged rollers is staged proximate to the bottle based on a desired location, a curvature, or contact pressure of the one or more rollers. 
     
     
         15 . The method of  claim 9 , further comprising forming threads below the bottle opening. 
     
     
         16 . The method of  claim 9 , further comprising:
 forming a constriction below the upper portion of the bottle;   installing an insert in the bottle opening above the constriction; and   deforming the upper portion into the bottle opening such that a top end of the insert is below the edge and the insert is confined between the edge and the constriction.   
     
     
         17 . A roller for compressively curling a bottle opening comprising:
 a work face, an entry face, and an exit face, wherein the work face is concave and is located between the entry face and the exit face and wherein the entry face is configured to make initial contact with an upper portion of a bottle to define an outer diameter of the bottle opening and is angled to guide the upper portion into the work face, and wherein the exit face is configured to receive the upper portion from the work face and is contoured to release the upper portion to define an inner diameter of the bottle.   
     
     
         18 . The roller of  claim 17 , wherein the work face has a constant work face radius. 
     
     
         19 . The roller of  claim 17 , wherein the work face has a variable work face radius. 
     
     
         20 . The roller of  claim 17 , further comprising a trimming feature configured to trim the upper portion.