Second generation low gauge crown cap

Abstract

A lightweight, crimp-type crown cap for application to a glass beverage bottle, comprises a shell formed of a material comprising steel tinplate. The shell includes a round panel having an upper surface, a lower surface and a peripheral edge. A skirt depends downwardly from the peripheral edge of the panel, the skirt having fewer than 21 corrugations, wherein the corrugations are adapted to be crimped to affix the crown cap to a rim of a bottle opening. A circular groove is formed in the panel, defining a downwardly concave portion on the upper surface of the panel and a corresponding downwardly convex portion on the lower surface of the panel, and the circular groove is arranged to align with the rim of the bottle. A liner is disposed on the lower surface of the panel.

1 . A lightweight, crimp-type crown cap for application to a glass beverage bottle having a body, a neck extending up from the body and a rim formed at a top of the neck, the crown cap comprising:
 a shell formed of a material comprising steel tinplate, the shell including:   a round panel having an upper surface, a lower surface and a peripheral edge;   a skirt depending downwardly from the peripheral edge of the panel, the skirt having fewer than 21 corrugations, wherein the corrugations are adapted to be crimped to affix the crown cap to the bottle;   a liner disposed on the lower surface of the panel; and   a circular groove formed in the panel defining a downwardly concave portion on the upper surface of the panel and a corresponding downwardly convex portion on the lower surface of the panel, wherein the circular groove is arranged to align with the rim of the bottle and the liner.   
     
     
         2 . The crown cap of  claim 1 , wherein said skirt has 10 to 19 corrugations. 
     
     
         3 . The crown cap of  claim 1 , wherein corrugations define alternately disposed contact zones and non-contact zones, the contact zones being adapted to make sealing contact with the neck of the bottle when the crown cap is affixed to the bottle. 
     
     
         4 . The crown cap of  claim 2 , wherein a ratio of a circumferential length of said contact zones to a radial width of said non-contact zones is greater than 1. 
     
     
         5 . The crown cap of  claim 1 , wherein a ratio of a circumferential length of said contact zones to a radial width of said non-contact zones is 1.27. 
     
     
         6 . The crown cap of  claim 1 , wherein said round panel is a flat planar panel. 
     
     
         7 . The crown cap of  claim 1 , wherein said steel tinplate has a thickness of less than 0.17 mm. 
     
     
         8 . The crown cap of  claim 1 , wherein said steel tinplate has a thickness of less than 0.14 mm. 
     
     
         9 . The crown cap of  claim 1 , wherein said steel tinplate has temper of at least DR9. 
     
     
         10 . The crown cap of  claim 1 , wherein the groove presses the liner against the top surface rim the rim to increase the contact surface between the liner and the bottle. 
     
     
         11 . A die for forming a crown cap for application to a glass beverage bottle, comprising:
 a substantially cylindrical die body having a top, a bottom and a substantially cylindrical inner wall defining a hollow interior;   a plurality of alternately disposed teeth and notches formed around an inner circumference of a top rim of the die body; and   wherein the teeth and notches are configured for forming in a pressing operation, in conjunction with the top rim and cylindrical inner wall, a crown cap having a substantially planar top surface, a circular notch formed proximately to an outer periphery of the planar top surface, and a skirt depending downwardly from the planar top surface and having a plurality of flutes and lands defined by the plurality of teeth and notches;   wherein the plurality of teeth and notches consists of fewer than  21  teeth and notches.   
     
     
         12 . The die according to  claim 11 , wherein the plurality of teeth and notches consists of 10 to 19 teeth and notches. 
     
     
         13 . The die according to  claim 11 , wherein a ratio of a circumferential length of said teeth to a radial width of said non-contact notches is greater than 1. 
     
     
         14 . A method of forming a crown cap for application to a glass beverage bottle, comprising:
 providing a material blank;   forming in said blank a substantially planar circular crown top;   forming in said crown top a circular groove disposed proximately to an outer periphery of said crown top;   forming in said blank a circular skirt depending downwardly from a periphery of the crown top, and a downwardly and radially outwardly extending flange extending from a periphery of the skirt;   forming in said skirt a plurality of corrugations, the plurality of corrugations consisting of fewer than 21 corrugations; and   cutting from said blank a formed crown top comprising the circular crown top, skirt and corrugated flange.   
     
     
         15 . The method of  claim 14 , further comprising affixing a liner to an inner surface of the circular crown top. 
     
     
         16 . The method of  claim 14 , wherein said corrugations define alternately disposed contact zones and non-contact zones, the contact zones being adapted to make sealing contact with the neck of the bottle when the crown cap is affixed to the bottle. 
     
     
         17 . The method of  claim 16 , wherein a ratio of a circumferential length of said contact zones to a radial width of said non-contact zones is greater than 1. 
     
     
         18 . The method of  claim 14 , wherein said plurality of corrugations consists of 10 to 19 corrugations. 
     
     
         19 . The method of  claim 14 , wherein said circular crown top, said skirt and corrugated flange are formed in said blank by a corrugating die in a pressing operation.