Closure For A Container

Abstract

A closure for a container having a circular opening defining an axis, the closure being securable to the container so as to close said opening, the closure having an o-ring sealing member mounted thereon so as to provide a seal with a sealing surface of the container, when the closure is secured to the container, the sealing surface extending around an upper surface or an internal surface of the container. The closure may comprise a bore feature which, in use, extends through the opening into the interior of the container and the o-ring seal may be provided on the bore feature. Various forms of closure are described, eg for closing a bottle neck and a wide-mouth closure. The closure may comprise an inner component and an outer component, eg a cap-on-collar closure, and the container preferably has no thread features on the exterior thereof so it is comfortable to drink from.

1 . A closure for closing a container, the container having a sealing surface extending around an internal surface, a plurality of circumferentially spaced apart thread features extending around an external surface, and a substantially circular opening defining an axis, the closure comprising:
 a cap having an upper portion;
 a skirt portion depending from said upper portion, the skirt portion comprising a plurality of circumferentially spaced apart thread features for engagement with the thread features of the container, the thread features selectively(?) spaced to enable fastening the closure to the container with a rotation of less than 360 degrees; 
 a relatively rigid bore member comprising a groove formed in an outer surface; and 
 an o-ring sealing member comprising a toroid formed of resilient elastomer material, the o-ring sealing member received in the groove in the bore member and sized to enable deformation and movement of the o-ring sealing member within said groove, wherein when the bore of the closure is extended through the opening of the container, the closure is securable to the container by rotation about the axis, the rotation engaging the thread features of the skirt with the thread features of the container, drawing the bore member into the container so as to press the sealing member against a side wall of the groove to seal a gap between the side wall and the sealing surface so the o-ring sealing member provides a seal between the bore member and the sealing surface of the container within a rotation of less than 360 degrees. 
   
     
     
         2 . A closure as claimed in  claim 1  in which the groove comprises two or three faces which, together with said sealing surface of the container when the closure is secured to the container, define an enclosure for constraining the cross-section of the torus. 
     
     
         3 . A closure as claimed in  claim 1  in which the o-ring sealing member is able to move axially within said groove or gland in response to an increase in pressure within the container whereby the o-ring sealing member responds to the increase in pressure and adopts a shape and/or position which is better able to withstand the pressure. 
     
     
         4 . A closure as claimed in  claim 1  in which the closure comprises a cap having an upper portion and a skirt portion depending from said upper portion and in which the bore member is integrally formed with the cap. 
     
     
         5 . A closure as claimed in  claim 1  in which an inner edge of the container lip is chamfered so as to provide a lead-in surface for the o-ring sealing member, said lead-in surface leading to said sealing surface. 
     
     
         6 . A closure as claimed in  claim 1  in which said sealing surface is spaced from an upper surface of the container. 
     
     
         7 . A closure as claimed in  claim 1  in which the upper portion and skirt portion of the closure are formed as one-piece and the closure is rotatably securable directly to the container by means of a threaded engagement therebetween. 
     
     
         8 . A closure as claimed in  claim 1  in which the closure comprises an inner component having a collar portion for locating about the exterior of the container and an outer component for fitting over and/or around the inner component and interacting therewith so as to releasably secure the inner component to the container. 
     
     
         9 . A closure as claimed in  claim 1  when secured to a container adapted to be closed by said closure. 
     
     
         10 . A closure as claimed in  claim 9  in which the compression ratio of the o-ring (as herein defined) is in the range 5% to 35% and preferably in the range 20% to 25%. 
     
     
         11 . A closure as claimed in  claim 9  in which the gland fill (as herein defined) is in the range 50% to 90% and preferably in the range 65% to 85%. 
     
     
         12 . A closure as claimed in  claim 9  in which the depth of a groove in which the o-ring is located is at least 50% and preferably at least 60% of the width of the o-ring cross-section in the corresponding direction. 
     
     
         13 . A closure as claimed in  claim 1  made from metal having thread features formed by a pressing operation. 
     
     
         14 . A closure as claimed in  claim 1  in which the thread form is an eight-start thread form that requires a rotation of only about 45 degrees to fasten or release the closure.