Container Closure Assembly With Pressure Seal

Abstract

The invention provides a container closure assembly comprising: a container neck ( 10 ) having side walls defining an opening at one end thereof and a lip ( 14 ) extending around the opening; a cap ( 12 ) for said neck, the cap having a base portion ( 22 ) and a threaded skirt portion ( 24 ); a first screw thread ( 16 ) on the neck; a second screw thread ( 26 ) on an inner surface of the threaded skirt of the cap; said first and second screw threads being configured to enable a user to secure, remove and resecure the cap into a sealing position on the neck by rotation of the cap on the neck; a sealing plug ( 52 ) extending from said base portion of the cap inside and substantially concentric with said threaded skirt portion of the cap, wherein the sealing plug is an olive sealing plug for forming a seal against an inside surface of the container neck when the cap is secured on the container neck; and a sealing skirt ( 54 ) extending from said base portion of the cap intermediate said sealing plug and said threaded skirt portion of the cap and substantially concentric with said sealing plug and said threaded skirt portion of the cap, wherein said cap can be displaced towards said neck from said sealing position by application of an axial force without rotation of the cap on the neck and substantially without plastic deformation of the cap.

1 . A container closure assembly comprising:
 a container neck having side walls defining an opening at one end thereof and a lip extending around the opening;   a cap for said neck, the cap having a base portion and a threaded skirt portion;   a first screw thread on the neck;   a second screw thread on an inner surface of the threaded skirt of the cap;   said first and second screw threads being configured to enable a user to secure, remove and resecure the cap into a sealing position on the neck by rotation of the cap on the neck;   a sealing plug extending from said base portion of the cap inside and substantially concentric with said threaded skirt portion of the cap, wherein the sealing plug is an olive sealing plug for forming a seal against an inside surface of the container neck when the cap is secured on the container neck; and a sealing skirt extending from said base portion of the cap intermediate said sealing plug and said threaded skirt portion of the cap and substantially concentric with said sealing plug and said threaded skirt portion of the cap, and wherein said cap can be displaced towards said neck from said sealing position by application of an axial force without rotation of the cap on the neck and substantially without plastic deformation of the cap.   
     
     
         2 . A container closure assembly according to  claim 1 , wherein the displacement from said sealing position is a resilient displacement. 
     
     
         3 . A container closure assembly according to any preceding claim, wherein no part of the cap contacts the top surface of the container lip at the sealing position. 
     
     
         4 . A container closure assembly according to any preceding claim, wherein the container lip is substantially fully radiused in longitudinal cross-section. 
     
     
         5 . A container closure assembly according to any preceding claim, wherein the inner and/or the outer surfaces of the container neck adjoining the lip is slightly tapered 
     
     
         6 . A container closure assembly according to any preceding claim, wherein the sealing skirt has a radial thickness at half-height equal to from about 40% to about 80% of the radial thickness of the sealing plug measured at the same height. 
     
     
         7 . A container closure assembly according to any preceding claim, wherein a region of the radially inner surface of the sealing skirt is concave for engagement with an outer surface of the container neck proximate to said lip when the cap is secured on the container neck. 
     
     
         8 . A container closure assembly according to any preceding claim, wherein the inside diameter of the sealing skirt at half-height is from about 0.05 mm to about 0.5 mm less than the outside diameter of the container neck. 
     
     
         9 . A container closure assembly according to any preceding claim, wherein an outer surface of the sealing skirt does not abut against an internal surface of the threaded skirt or the cap base when the cap is in the secured and sealing position on the neck. 
     
     
         10 . A container closure assembly according to any preceding claim, wherein at least one circumferential sealing rib is provided in said concave region of said sealing skirt. 
     
     
         11 . A container closure assembly according to  claim 10 , wherein at least one said circumferential sealing rib has a substantially triangular cross-section. 
     
     
         12 . A container closure assembly according to  claim 11 , wherein at least one of the sealing ribs has a height in the range of from about 10 to about 250 micrometers. 
     
     
         13 . A container closure assembly according to any preceding claim, wherein the cap is a low-profile cap having an axial height from the top of the base to the bottom of the threaded skirt, but excluding any tamper-evident ring attached to the cap, of from about 10 mm to about 15 mm. 
     
     
         14 . A container closure assembly according to any preceding claim, wherein the cap can be secured and resecured on the container neck by a single smooth rotation through 360° or less, preferably through 180° or less, and more preferably through about 90°. 
     
     
         15 . A container closure assembly according to any preceding claim, wherein the first and second threads are multiple start threads. 
     
     
         16 . A container closure assembly according to any preceding claim, wherein the first and second threads are substantially continuous helical threads. 
     
     
         17 . A container closure assembly according to any preceding claim, wherein the container and cap further comprise complementary locking elements on the container neck and the cap that block or resist unscrewing of the cap from the fully secured position on the container neck until a predetermined minimum opening torque is applied. 
     
     
         18 . A container closure assembly according to  claim 17 , wherein said complementary locking elements comprise first and second locking projections on the container neck and the threaded cap skirt, and either said first locking projection is located longitudinally overlapping with and circumferentially spaced from an upper end of a first thread segment, or said second locking projection is located longitudinally overlapping with and circumferentially spaced from a lower end of a second thread segment, whereby the said first or second locking projection defines an extension of the thread path defined by the thread segments on the neck or the cap. 
     
     
         19 . A container closure assembly according to any preceding claim, further comprising a projecting stop surface on one of the container neck and the cap skirt for abutment against a second stop or a thread on the other of the container neck or the cap to block over-tightening of the cap beyond a predetermined angular sealing position of the cap on the container neck. 
     
     
         20 . A container closure assembly according to any preceding claim, wherein the torque required to secure the cap in a sealing position on the container neck is from about 0.7 Nm to about 0.9 Nm. 
     
     
         21 . A beverage container sealed with a container closure assembly according to any preceding claim. 
     
     
         22 . A beverage container according to  claim 21  which contains a carbonated beverage.