Closure having tapered sealing plug

Abstract

A plastic closure for a container includes an upper wall and a generally cylindrical sidewall that depends downwardly from the upper wall: The generally cylindrical sidewall has a threaded internal surface so that it may be screwed onto a container neck. The closure further includes an annular sealing plug that depends downwardly from a lower surface of the upper wall. The annular sealing plug has an inner annular surface that when viewed in longitudinal cross-section extends at a first angle with respect to a longitudinal axis of said closure and an outer annular surface that when viewed in longitudinal cross-section extends at a second angle with respect to the longitudinal axis. The first angle is advantageously greater than the second angle, creating a tapered profile that improves moldability of the closure.

1 . A plastic closure for a container, comprising: 
 an upper wall;    a generally cylindrical sidewall depending downwardly from said upper wall, said sidewall having a threaded internal surface; and    an annular sealing plug depending downwardly from a lower surface of said upper wall, said annular sealing plug having an inner annular surface that when viewed in longitudinal cross-section extends at a first angle with respect to a longitudinal axis of said closure and an outer annular surface that when viewed in longitudinal cross-section extends at a second angle with respect to said longitudinal axis, and wherein said first angle is greater than said second angle.    
   
   
       2 . A plastic closure for a container according to  claim 1 , wherein said inner annular surface is oriented to angle downwardly and radially outwardly toward said sidewall.  
   
   
       3 . A plastic closure for a container according to  claim 2 , wherein said outer annular surface is also oriented to angle downwardly and radially outwardly toward said sidewall.  
   
   
       4 . A plastic closure for a container according to  claim 2 , wherein said first angle is greater than said second angle by at least 2°.  
   
   
       5 . A plastic closure for a container according to  claim 2 , wherein said first angle is at least 2°.  
   
   
       6 . A plastic closure for a container according to  claim 5 , wherein said first angle is at least 10°.  
   
   
       7 . A plastic closure for a container according to  claim 6 , wherein said first angle is at least 15°.  
   
   
       8 . A plastic closure for a container according to  claim 1 , wherein said outer annular surface comprises a portion that is substantially linear in longitudinal cross-section, and wherein said linear portion intersects said upper wall.  
   
   
       9 . A plastic closure for a container according to  claim 1 , wherein said inner annular surface comprises a portion that is substantially linear in longitudinal cross-section, and wherein said linear portion intersects said upper wall.  
   
   
       10 . A plastic closure for a container according to  claim 1 , wherein said annular sealing plug is downwardly tapered.  
   
   
       11 . A method of packaging a carbonated beverage, comprising steps of: 
 filling a container with a carbonated beverage; and    sealing the container by applying a plastic closure having 
 an upper wall;  
 a generally cylindrical sidewall depending downwardly from said upper wall, said sidewall having a threaded internal surface; and  
 an annular sealing plug depending downwardly from a lower surface of said upper wall, said annular sealing plug having an inner annular surface that when viewed in longitudinal cross-section extends at a first angle with respect to a longitudinal axis of said closure and an outer annular surface that when viewed in longitudinal cross-section extends at a second angle with respect to said longitudinal axis, and wherein said first angle is greater than said second angle.  
   
   
   
       12 . A method of packaging a carbonated beverage according to  claim 11 , wherein said inner annular surface is oriented to angle downwardly and radially outwardly toward said sidewall.  
   
   
       13 . A method of packaging a carbonated beverage according to  claim 12 , wherein said outer annular surface is also oriented to angle downwardly and radially outwardly toward said sidewall.  
   
   
       14 . A method of packaging a carbonated beverage according to  claim 12 , wherein said first angle is greater than said second angle by at least 2°.  
   
   
       15 . A method of packaging a carbonated beverage according to  claim 12 , wherein said first angle is at least 2°.  
   
   
       16 . A method of packaging a carbonated beverage according to  claim 15 , wherein said first angle is at least 10°.  
   
   
       17 . A method of packaging a carbonated beverage according to  claim 16 , wherein said first angle is at least 15°.  
   
   
       18 . A method of packaging a carbonated beverage according to  claim 11 , wherein said outer annular surface comprises a portion that is substantially linear in longitudinal cross-section, and wherein said linear portion intersects said upper wall.  
   
   
       19 . A method of packaging a carbonated beverage according to  claim 1 , wherein said inner annular surface comprises a portion that is substantially linear in longitudinal cross-section, and wherein said linear portion intersects said upper wall.  
   
   
       20 . A method of packaging a carbonated beverage according to  claim 11 , wherein said annular sealing plug is downwardly tapered.