GB2162158A - Closure - Google Patents

Abstract

A closure for a pressurised container, such as a beverage bottle, comprises a housing 12 within which is located a resilient sealing insert 22 to press and seal against the top of the bottle. Access to the sealing insert is provided through an aperture 18 in the top wall of the housing. The insert is resiliently and resealable puncturable by means of an injection needle. Thus, the container and its contents can be pressurised with gas supplied from a pressurised source through the injection needle which punctures the sealing insert. On withdrawal of the needle, the puncture seals against the gas pressure within the container to hold the gas therein. The top wall 14 of the housing may bear on its inner surface two concentric annular projections against which the insert 22 abuts. <IMAGE>

Description

SPECIFICATION Closure This invention relates to closures and, more particularly, to closures for use with pressurisable containers.

Valve systems have been proposed which permit introduction of a pressurised gas into a container on which the valve is attached, such as on tyres and the like. Once the desired pressure has been attained in the container, the feed of pressurised gas is halted and the valve prohibits escape of gas therethrough.

Such systems often include an intricate and relatively expensive valve system which is susceptible to malfunction.

A specific example of the need for simple, inexpensive valve systems on pressurised containers is in connection with carbonated beverages. It is desirable to carbonate a beverage in a container, after the beverage has been prepared, e.g. in preparation of soda water, beer, sparkling wines, etc., at the domestic or consumer level.

it is an object of the present invention to provide a simple and inexpensive novel closure system for pressurised containers.

The present invention provides a system comprising a resilient and puncturable insert which allows penetration by means for supplying the pressurised gas into the container, such as an injection needle, and which, owing to the resiliency of the insert, reseals the puncture once the said means is withdrawn, so as to maintain the gas pressure within the container.

In order to retain the insert in sealing arrangement over the mouth of the container to be pressurised, means are provided for releasably attaching the insert on to the container, said means defining an aperture which permits access to the insert.

Thus, in accordance with the present invention, there is provided a closure comprising a puncturable and resiliently resealable sealing insert, and a housing therefor, said housing comprising means for attachment thereof to a container and defining an aperture therethrough, said aperture permitting access into the container via said insert.

In the preferred arrangement, the sealing insert is disc-shaped so as to seal the mouth of the more common cylindrical container spout, such as a bottle neck. The housing for the preferred shape of the insert is, consequentially, comprised of a circulartop wall having an integral depending skirt. The top wall defines an aperture which allows introduction of the pressurised gas-mediating device through the sealing insert and into the container. Suitably, the top wall aperture is only slightly larger than the size of the gas-mediating device to be passed therethrough.

It will be appreciated that, although the external clamping systems may be employed to maintain the housing in a position in which the insert is in sealing arrangement over the mouth of the container, the preferred means allowing attachment of the housing to the container is screw threading of the interior of the depending skirt to complement screw threading provided on conventional container spouts.

In orderto locate the sealing insert in a relatively fixed position within the housing, the insert is provided with a diameter of a magnitude that permits it to be an interference fit within the housing.

The insert of the present invention is preferably composed of a resilient rubber compound which is penetrable by a sharply pointed device used to mediate pressurised gas from a stored position into the container via the sealing insert. For use in connection with beverage bottles, the preferred application of the closure according to the invention, the insert should, of course, be made of food grade material, since it is likely to contact the beverage.

Butyl rubber and natural rubber are examples of suitable materials. The closure housing for use in such applications is suitably of food grade plastic, e.g. polyethylene. The insert is suitably of thickness about 1/32" to about 1/4".

The gas-mediating device is preferably an injection needle having a channel extending therethrough, such as, for example, a hypodermic-type needle.

In practice, the closure is placed on to the spout of a container into which pressurised gas is to be introduced, and to a position where the perimeter of the insert is pressed between the top of the spout of the container and the perimeter of the under surface of the top wall of the housing. In this way, the insert acts as a seal between the interior of the container and the environment.

Alternatively, the ability of the closure to maintain pressure within the container may be supplemented by providing an annular projection on the under surface of the top wall of the housing circumjacent the perimeter and, if desired, circumjacent the aperture. Inclusion of the annular projection(s) affords an improved seal between the housing and the container via the insert by providing a localised area on which the insert may be sealably deformed.

After connecting the closure over the spout, gas stored under pressure is fed from a storage tank through a hose adapted at one end to accommodate a hollow needle. The needle is used to pierce the insert in the area exposed by the housing aperture and the pressurised gas is allowed to flow into the container until the desired pressure is attained within the container, normally regulated by the presence of a pressure relief valve in the gas supply line. Once the desired pressure has been attained, the needle is removed. The insert self-seals the puncture created by the passage of the needle.

A correctly dimensioned such needle will readily penetrate the rubber sealing insert. Upon removal of the needle therefrom, the puncture caused by the passage of the needle is substantially spontaneously sealed owing to the characteristic resilience of the rubber insert. Effectively, the needle may penetrate the insert by tearing it, in the preferred arrangement rather than creating a void, so that a flap of material remains to reseal the insert when subject to pressure from within the container. In this way, gas is prevented from flowing back through the puncture and the pressure may be maintained within the container.

It will be appreciated that the self-sealing capabil ity of the insert is, inter alia, related to the diameter of the needle used to puncture the insert. A needle which is too thick may have a tendency to remove portions of the rubber insert during penetration. A needle of diameter about 1/16" is suitably used, with an insert of thickness about 1/16".

Also, it has been found that best results are obtainable when the needle is inserted obliquely relative to the planar surface of the insert. Thus, the preferred form of needle has an obliquely angled tip to provide a puncture through the seal which is obliquely angled with respect to the surface thereof.

Such a puncture arrangement is readily sealed by gas pressure from within the container exerted against the underside of the resilient insert.

Preferably, the rubber insert is removable from the closure housing, so that it can be replaced on re-use of the closure. The insert may thus be a throw-away item, to avoid problems of its deterioration through repeated puncturing bacterial contamination, etc., whereas the housing may be re-usable.

In the accompanying drawings which illustrate embodiments of the invention, Figure 1 is a perspective view of a closure partially in section; Figure 2 is a sectional view of the closure, with a container indicated in broken lines; Figure 3 is a sectional view of an alternative embodiment of a closure according to the present invention; Figure 4 is a view, similar to Figure 3, showing the insert after the container has been pressurised; and FigureS is a perspective view of a system suitable for use with the closure as illustrated in Figures 1 through 4.

With reference to Figures 1 and 2, the closure 10 comprises a generally cylindrical housing 12 formed from rigid plastic, e.g. polyethylene, and having a generallycirculartopwall 14and an integral de- pending skirt 16. An aperture 18 is defined by the top wall 14 in a generally central position thereon. Screw threads 20 are present on the inner surfaces of the depending skirt 16.

Within the housing, and in sealing arrangement with the aperture 18, is a circular puncturable insert 22 of natural rubber.

As shown in Figure 2, in use, the closure 10 is threaded on to a complementarily threaded spout 24 of a container 40 to a position at which the perimeter of the insert 22 is trapped between the upper edge 26 of the container spout 24 and the perimeter of the under surface of top wall 14 of the housing 12. In this position, the rubber insert 22 acts as a seal between the interior of the container 28 and the environment.

To enhance the sealing function of the rubber insert 22, annular ribs may be provided on the under surface of the top wall of the housing, as depicted in Figure 3 to which reference is now made. By providing a first rib 17 circumjacentthe perimeter of the under surface of the top wall 14 of the housing 16, the insert may be sealably deformed between the lip 19 of the container spout and the annular rib 17.

Furthermore, a second annular rib 15 may be provided circumjacent the aperture 18, the function of which is realised after pressurisation, as illustrated in Figure 4. When under pressure, as indicated by arrow A, the sealing of a puncture through the insert 22 in the area below the aperture 18 is assisted by the second annular rib 15 which defines a space below the aperture so that the force of the pressurised gas seeking exit through the puncture urges the sides of the tear into sealing engagement.

The annular ribs described above are integral with the housing and are formed during the moulding process used to produce the housing.

Reference is now made to Figure 5 of the drawings to illustrate a preferred method of pressurising a container bearing a closure according to the invention. Carbon dioxide gas under pressure is fed from a cylinder 30 via polyethylene tubing 32 and elbow connectors 33 to an injection needle 36 having a lowermost oblique tip-aperture 37. The CO2 cylinder 30 is provided with a standard manually operated trigger on-off valve 38 and a pressure relief valve 39, set to the maximum desired pressure for container 40, e.g. 50 psi.

To carbonate the liquid contents 42 in the container 40, the needle 36 is passed through the aperture 18 and punctures the insert 22 at an acute angle relative to the surface of the insert 22, to protrude into the interior 28 of the container 40. Because of the design of the needle 36 and the nature of the insert 22, the puncture path is oblique to the surface of the sealing insert 22, so as to assist in resealing of the puncture by pressure from within the container 40. Valve 38 is opened to allow the CO2 under pressure to flow through the needle 36 and into the beverage liquid contents 42 in the container 40. Once the desired pressure has been attained in the container 40, e.g. 25 - 50 psi, the valve 38 is closed and the needle 36 is withdrawn along generally the same path in which it entered. No effective amount of gas leaks from the container after withdrawal of the needle.

Claims (14)

1. A closure comprising, in combination, a puncturable and resiliently resealable sealing insert, and a housing therefor, said housing comprising means for attachment thereof to a container and having an aperture therethrough, said aperture permitting access into said container via said insert.

2. A closure for releasable attachmentto a bottle to seal gas pressure therein comprising, in combination, a generally cylindrical housing, said housing having a generally circular top wall defining an aperture therein and an integral depending skirt adapted for releasable attachementto a bottle neck, and a puncturable and resiliently resealable sealing insert disposed within said closure so as normally to seal the aperture therein, said insert being puncturable by passage of a gas injection needle therethrough, but resiliently resealable effectively to prevent gas passage therethrough upon withdrawal of said gas injection needle.

3. A closure according to claim 2, wherein the inner surface of said skirt is screw-threaded.

4. A closure according to any one of claims 1,2 or 3, wherein said sealing insert is formed from butyl rubber or natural rubber.

5. A closure according to any preceding claim, wherein the sealing insert has a thickness of from about 1/32" to about 1/4".

6. A closure according to any of claims 2 - 5, wherein the sealing insert abuts against the lower surface of the top wall of said housing and constitutes an interference fit within the skirt thereof.

7. A closure according to any of claims 2 - 5, wherein said top wall bears an annular projection on its under surface for contact with said insert.

8. A closure according to any of claims 2 - 5, wherein said top wall bears two concentric annular projections, the inner of which is disposed circumjacent the aperture therein.

9. A closure according to claim 7, wherein the insert abuts against said projection and constitutes an interference fit within said skirt.

10. A method of pressurising a container, having a spout defining a mouth, said mouth having a resilient sealing insert fixed thereover, said method comprising the steps of a) puncturing the resilient sealing insertwith a hollow needle, b) feeding pressurised gas through the needle into the container, and c) removing said needle whereby said insert resealsthe puncture made by the needle so as to prevent gas from escaping therethrough.

11. The method of claim 10, wherein said insert is composed of butyl rubber.

12. In combination: a bottle having an externally screw threaded neck; a closure for said bottle comprising a cylindrical, internally screw threaded skirt complementing the screw threaded neck; an apertured top end wall, and a resilient sealing insert disposed within the skirt and in sealing abutment with the top wall; said sealing insert being resiliently puncturable; a source of pressurised gas for supply to said bottle; gas supplying means connected to said source and comprising a hose for passage of gas therethrough; a pressure relief valve operatively associated with said hose to allow gas to escape from said hose when a predetermined maximum gas pressure therein is exceeded, and a hollow injection needle connected to the downstream end of said hose; ; the sealing insert being puncturable by said injection needle to feed gas into the container up to said predetermined maximum pressure, the insert being resiliently resealable to close said puncture and retain gas pressure within the container up to said predetermined maximum upon withdrawal of the needle therefrom.

13. The combination of claim 12, wherein the under surface of said end wall of said closure bears an annular rib circumjacentthe perimeter of said under surface for contact with said insert.

New or amended claims:

14. A closure substantially as hereinbeforede- scribed with reference to the accompanying drawings.