WO2017174963A1

WO2017174963A1 - Container closure having means for introducing an additive into a liquid in the container

Info

Publication number: WO2017174963A1
Application number: PCT/GB2017/050872
Authority: WO
Inventors: Bernard D Frutin; Jordan MAGUIRE
Original assignee: Gizmo Packaging Limited
Priority date: 2016-04-04
Filing date: 2017-03-29
Publication date: 2017-10-12
Also published as: WO2017174962A8; GB201816981D0; GB2565454B; WO2017174962A1; GB2565454A

Abstract

A closure device (100), for use with a container having a main liquid compartment and an opening with a container neck, comprises a cap member (102) adapted to be secured to the opening of the container, a plug member (142) having a nozzle (160), and a pressurised fluid chamber (104) slidably mounted relative to the plug member (142). The fluid chamber (104) has a neck (109) and a bottom aperture (108) in the neck sealingly engageable by the plug member (142) and is movable relative to the plug member (142), from a closed position in which the neck of the fluid chamber (104) is sealed closed by the plug member (142), to a firing position in which the plug member (142) is arranged within the neck (109) to provide a fluid communication path from the fluid chamber (104) through the nozzle (160) of the plug member. The fluid chamber (104) and neck (109) comprise a unitary moulded article, giving the advantage that the fluid chamber (104) is pressure resistant and not prone to leaks, while being inexpensive to manufacture as it is made from a single component.

Description

CONTAINER CLOSURE HAVING MEANS FOR INTRODUCING AN ADDITIVE INTO A LIQUID IN THE CONTAINER

The present invention relates to a closure device for use with a container such as a beverage container which can fire a pressurised additive liquid into a liquid in the container by operation of the closure device, and which allows a user to access the mixed liquid and liquid additive, for example drinking a mixed beverage, without removal of the closure device. The invention also relates to a container including such a closure device and to a method of introducing an additive liquid by means of operating such a closure device.

In a number of applications, such as mixtures of different liquids, it may be necessary to release and mix an additive liquid into another liquid shortly before the liquid mixture is used. It may not be possible or desirable to store the liquids in a premixed form, as they may react undesirably with each other when stored as the mixture for a period of time. An example of this may be two component

pharmaceuticals which have a longer shelf life when unmixed than they do when mixed. However, it can also apply to other liquids or to mixtures of liquids and gases, such as water, alcoholic beverages, other beverages, and other solvents or solutions. The term "beverage" when used in this specification includes any liquid, whether or not provided for drinking purposes, which may be mixed with an additive liquid, and is not limited to potable beverages.

A closure device for use with a beverage container which can release an additive liquid into the beverage by operation of the closure device, and which allows a user to drink the beverage without removal of the closure device, is known from the prior art. International Patent Application WO2008/023197 discloses a closure device comprising a cap member defining a fluid chamber and a plug member which sealingly engages an aperture in the bottom of the fluid chamber and also sealingly engages a spout aperture at the top of the fluid chamber. The cap member is raised relative to the plug member by unscrewing the cap member, from a closed position in which the plug member closes both the bottom aperture and the spout aperture, through a first open position in which the plug member still closes the spout aperture but is withdrawn from the bottom aperture to allow pressurised fluid to flow from the fluid chamber to the beverage, to a second open position in which both the bottom aperture and the spout aperture are open, allowing the beverage to flow through the cap member.

The known device has the disadvantage that it is relatively complex to manufacture, requiring separate housing and cap members. The chamber must be formed from two parts, including a separate bottom wall member, which must be joined to the chamber side wall with a pressure resistant seal, and so is complicated and expensive to make. The closure has a larger diameter than conventional closures, since it must accommodate a housing flange between the external thread of the bottle neck and the internal thread of the outer cap wall. The closure must be at least partially unscrewed before the beverage can be accessed, in contrast to conventional sports cap beverage containers, so that the method of operation is not obvious to new users. It is an object of the present invention to overcome one or more disadvantages of the prior art.

According to a first aspect of the present invention there is provided a closure device for use with a container having a main liquid compartment and an opening with a container neck, the closure device comprising:

a cap member adapted to be secured to the opening of the container, a plug member having a nozzle,

a pressurised fluid chamber slidably mounted relative to the plug member, the fluid chamber having a neck and a bottom aperture in the neck sealingly engageable by the plug member,

wherein the fluid chamber is movable relative to the plug member, from a closed position in which the neck of the fluid chamber is sealed closed by the plug member,

to a firing position in which the plug member is arranged within the neck to provide a fluid communication path from the fluid chamber through the nozzle of the plug member,

and wherein the fluid chamber and neck comprise a unitary moulded article.

The use of a unitary moulded article for the fluid chamber results in a fluid chamber which is pressure resistant and not prone to leaks, while being inexpensive to manufacture as it is made from a single component. It can hold an additive liquid under pressure for many weeks or months, until operation of the closure device by moving the fluid chamber relative to the plug member to allow the additive liquid in the fluid chamber to be ejected through the nozzle under pressure into the container, where it is mixed with the liquid in the container as a result of being ejected through the nozzle under pressure.

The plug member may be is fixed relative to the cap member, and the fluid chamber may be movable relative to the cap member and plug member.

Alternatively the closure device may further comprise a housing adapted to be secured to the container neck, wherein the plug member is fixed to the housing. The fluid chamber may be fixed to the cap member. The plug member may have a plurality of nozzles.

Preferably the fluid chamber and neck are cylindrical in cross section. The neck may have a narrower diameter than the fluid chamber. However the neck may be of substantially the same diameter as the remainder of the fluid chamber, and the plug member may be of sufficient diameter to seal the neck in the closed position.

The nozzle may be provided at the lower end of the plug member, opposite the fluid chamber. The plug member may include an internal nozzle passage extending axially upwards in the plug member from the nozzle.

The plug member may include a transverse internal passage extending to the lateral exterior surface of the plug member and in communication with the internal nozzle passage. In the closed position the transverse internal passage may be closed by a seal provided between the internal surface of the neck of the fluid chamber and the lateral exterior surface of the plug member.

In the firing position the transverse internal passage may be located above the a seal provided between the internal surface of the neck of the fluid chamber and the lateral exterior surface of the plug member, such that the fluid chamber is in fluid communication with the transverse internal passage and the nozzle.

The plug member may include sealing means to provide the seal between the internal surface of the neck of the fluid chamber and the lateral exterior surface of the plug member. The sealing means may be a coating of an elastomeric material, such as a soft plastic.

The fluid chamber may be blow moulded. The fluid chamber may be moulded from PET or other suitable plastic material.

The fluid chamber may contain an additive liquid and a pressurised propellant gas.

According to a second aspect of the present invention there is provided a container having a container neck and an opening, wherein the container contains a liquid, and wherein a closure device according to the first aspect of the present invention is secured to the container neck to close the container.

According to a third aspect of the present invention there is provided a method of introducing an additive liquid into a container having a closure device according to the first aspect of the present invention secured to a container neck of the container, wherein the container contains a liquid, the method comprising:

moving the fluid chamber relative to plug member from a closed position in which the neck of the fluid chamber is sealed closed by the plug member, to a firing position in which the plug member is arranged within the neck to provide a fluid communication path from the fluid chamber through the nozzle of the plug member. urging additive liquid from the fluid chamber through the nozzle into the container under pressure of a pressurised propellant in the fluid chamber, and

mixing the additive liquid with the liquid in the container.

The liquid in the container may be a beverage or a chemical or pharmaceutical composition. The liquid may be of any viscosity, for example a gel. The mixing step may be effected through ejection of the additive liquid through the nozzle at a sufficient velocity under pressure of the pressurised propellant in the fluid chamber. Brief Description of the Drawings

The invention will be described, by way of example only, with reference to the drawings in which: Fig. 1 shows a cross-sectional view of a closure device according to a first embodiment of the present invention when the closure device is in a closed position; Fig. 2 shows a perspective cut-away view of a closure device according to an embodiment of the present invention secured to a container when the closure device is in a closed position;

Fig. 3 shows a cross-sectional view of the closure device of Fig. 2;

Fig. 4 shows a cross-sectional view of the closure device of Fig. 2 in the firing position;

Fig. 5 shows a perspective cut-away view of a closure device according to an embodiment of the present invention secured to a container when the closure device is in a closed position;

Fig. 6 shows a cross-sectional view of the closure device of Fig.5;

Fig. 7 shows a perspective cut-away view of the closure device of Fig. 5 in a firing position;

Fig. 8 shows a cross-sectional view of the closure device of Fig. 5 in the firing position;

Fig. 9 shows a perspective cut-away view of the closure device of Fig. 5 in an intermediate dispensing position; and

Fig. 10 shows a cross-sectional view of the closure device of Fig. 5 in the

intermediate dispensing position.

Description of Specific Embodiments

With reference to Fig. 1 there is shown a closure device 100 according to a first embodiment of the present invention. The closure device 100 is depicted in the closed position. The operation of the closure device is similar to the operation of the closure device disclosed in WO2007/129116. The closure device 100 comprises two main parts, a moulded cap member 102 having a blow moulded fluid chamber 104 fixed inside the cap member 102, and a housing 106. An aperture 108 is provided at the lower end of a neck 109 in the bottom of the fluid chamber 104.

The cap member 102 includes a top cap wall 126, an outer cap wall 128, and an inner cap wall 132, which may all be formed as a single moulding from polypropylene or any other suitable plastic. The outer cap wall 128 includes an internal primary thread 130 adapted to engage a corresponding external primary thread on the housing 106, as will be described below. Together the internal and external primary threads form a primary engagement means which allow the cap member 102 to be lifted relative to the housing 106.

The housing 106 may be formed as a unitary polypropylene moulding, or, as illustrated in Fig. 1 , as two components which are snap fitted together. It comprises a plug member 142 arranged on the central axis of the closure device 100, an outer housing wall 144 adapted to fit outside the neck of a container (not shown), a web 145 which sits on top of the container neck, an inner housing wall 146 which extends down from the web 145 inside the container neck and which seals against the container neck, and a frame 148 which extends from the inner housing wall 146 and supports the plug member 142.

The outer housing wall 144 has an external primary thread 150 which engages the internal primary thread 130 on the cap member 102 as part of the primary engagement means. It also has an internal secondary thread 152 which engages an external thread (not shown) on the neck of the container.

Internal sealing means 154 are provided to seal between the inner cap wall 132 and the inner housing wall 144. The internal sealing means 154 prevents the contents of the container passing between the inner cap wall 132 and the inner housing wall 144 during storage and while the cap member 102 is raised relative to the housing 106, as later described.

The plug member 142 has a nozzle 160 extending below it. A nozzle passage 161 is provided to convey pressurised liquid from the fluid chamber 104 when the closure device is opened. The plug member 142 has an upper seal 166 above a transverse internal fluid passage 170 in the plug member. The upper seal 166 may be formed for example by a soft rubber coating, and engages sealingly with an upper portion of the interior wall of the fluid chamber neck 109 at the lower end of the chamber 104 when the plug member 142 is in the closed position, as shown in Fig. 1. The plug member 142 has a lower seal 168 which engages with a lower portion of the interior wall of the fluid chamber neck 109 below the internal fluid passage 170. The lower portion of the interior wall of the fluid chamber neck 109 may have a larger diameter than the upper portion.

To trigger the firing of the additive liquid from the fluid chamber 104 into the main liquid compartment of the container (not shown), the cap member 102 is unscrewed relative to the housing 106 . The primary threads 130, 150 have a relatively large thread angle, so that a relatively large vertical displacement is effected by a relatively small rotation. As the cap member 102 rises, the fluid chamber 104 is lifted relative to the plug member 142. When the upper seal 166 passes below the narrowest part of the fluid chamber neck 109, the upper seal 166 no longer seals between the aperture 108 and the plug member 142, and the main liquid compartment comes into fluid communication with the fluid chamber 104 in the firing position of the closure 100. The pressurised additive liquid is free to pass between the upper seal 166 and the wall of the neck 109 into the internal fluid passage 170 of the plug member 142, along the nozzle passage 161 and out of the nozzle 160 into the main liquid compartment. The lower seal 168 continues to seal between the fluid chamber neck 109 and the plug member 142, so that the additive liquid cannot leak into the main liquid compartment along any other path.

Further rotation of the cap member 102 allows the closure device 100 to be removed from the neck of the container, as described in WO2007/1291 16. Unlike the known fluid chamber of the closure device described in WO2007/129116, the fluid chamber 104 and neck 109 of the closure device of the present invention comprise a unitary moulded article.

The use of a unitary moulded article for the fluid chamber 104 results in a fluid chamber which is pressure resistant and not prone to leaks, while being inexpensive to manufacture as it is made from a single component. It can hold an additive liquid under pressure for many weeks or months, until operation of the closure device 100 by moving the fluid chamber 104 relative to the plug member 142 to allow the additive liquid in the fluid chamber to be ejected through the nozzle 160 under pressure into the container, where it is mixed with the liquid in the container as a result of being ejected through the nozzle under pressure.

In the closed position the transverse internal passage 170 is closed by the upper seal 166 provided between the internal surface of the neck 170 of the fluid chamber and the lateral exterior surface of the plug member 142.

In the firing position the transverse internal passage 170 is located above the lower seal 168 provided between the internal surface of the neck 170 of the fluid chamber and the lateral exterior surface of the plug member 142, but is no longer sealed by the upper seal 166 from the fluid chamber 104, such that the fluid chamber 104 is in fluid communication with the transverse internal passage 170 and the nozzle 160.

Preferably the fluid chamber is blow moulded. The fluid chamber may be moulded from PET or other suitable plastic material.

The closure of Fig. 1 comprises only three separate components, each of which can be manufactured simply: the fluid chamber 104, which can be lightly bonded to the cap member 102; the housing 106, which includes the plug member 142; and the cap member 102.

Because the fluid chamber 104 of the closure device of the present invention is formed as a single part, the fluid chamber can be manufactured using a simple moulding process such as injection blow moulding using PET or other low cost impervious material.

With reference to Figs. 2, 3 and 4 there is shown a closure device 200 according to a further embodiment of the present invention. The closure device 200 is depicted in the closed position in Figs. 2 and 3 and in the open or firing position in Fig. 4. The operation of the closure device 200 is similar to the operation of the closure device 100 described with reference to Fig. 1. The closure device 200 comprises two main parts, a moulded cap member 202 having a blow moulded fluid chamber 204 fixed inside the cap member 202, and a housing 206. An aperture 208 is provided at the lower end of a neck 209 in the bottom of the fluid chamber 204. The cap member 202 includes a top cap wall 226, an outer cap wall 228, and an inner cap wall 232. The outer cap wall 228 includes an internal primary thread 230 adapted to engage a corresponding external primary thread on the housing 206. In this embodiment the wall of the fluid chamber 204 is sufficiently stiff such that the inner cap wall 232 only extends part of the way along the wall of the fluid chamber 204.

The housing 206 comprises a plug member 242 arranged on the central axis of the closure device 200, an outer housing wall 244 adapted to fit outside the neck of a container (not shown), a web 245 which sits on top of the container neck, an inner housing wall 246 which extends down from the web 245 inside the container neck and which seals against the container neck, and a frame 248 which extends from the inner housing wall 246 and supports the plug member 242.

The outer housing wall 244 has an external primary thread 250 which engages the internal primary thread 230 on the cap member 202 as part of the primary engagement means. It also has an internal secondary thread 252 which engages an external thread (not shown) on the neck of the container.

Internal sealing means 254 are provided to seal between the inner cap wall 232 and the inner housing wall 244.

The plug member 242 has a nozzle 260, a nozzle passage 261 , an upper seal 266, a lower seal 268 and a transverse internal fluid passage 270, similar to the plug member 142 of Fig. 1. The operation of the closure device of Figs. 2, 3 and 4 is similar to that of the closure device of Fig. 1 and is not described further.

In the embodiments of Figs. 1 to 4, the housing 106, 206 is adapted to be secured to the container neck, for example by a threaded connection, and the plug member 142, 242 is fixed to the housing 106, 206. The fluid chamber 104, 204 is fixed to the cap member 102, 202, for example by adhesive or by moulding in situ. Although the invention has been illustrated by embodiments in which the fluid chamber or tank 104, 204 is raised relative to the plug member 142, 242 to move from the closed position to the firing position, it is to be understood that the closure device of the present invention may be arranged such that the fluid chamber or tank is raised relative to the plug member to move from the closed position to the firing position. An embodiment with such an arrangement is illustrated in Figs. 5 to 8.

With reference to Figs. 5 to 10 there is shown a closure device 10 in a closed position. The closure device 10 is depicted connected to the upper part of a container 34 that contains a fluid. The container depicted has a neck 38. The container 34 may be, for example, a PET bottle. The container 34 may hold a variety of liquids such as water, or a pharmaceutical or glucose solution. The liquid may be for consumption, but may instead be a chemical composition for other use, such as cleaning, healthcare, hair dye application, painting or household maintenance.

However, for the purposes of this description, the liquid held in the container 34 will hereinafter be referred to as the beverage.

The closure device 10 includes a spout 12 and a cap member 36. The closure device 10 closes an opening 40 in the neck 38 and is attached to the container 34 by the cap member 36. The cap member 36 is detachably attached to the container neck 38 by a threaded arrangement. The threaded arrangement comprises an internal thread 42 located on an outer surface of the container neck 38 that engages with an external thread 46 located on an inner surface of the cap member 36. Thus the cap member 36 can be unscrewed and removed by a user of the closure device 10. All of the aforementioned components may be formed of polypropylene.

Inside the cap member 36 a fluid chamber 60 is located. The fluid chamber 60 may contain an additive pressured fluid. The additive fluid held in fluid chamber 60 may be of significantly greater pressure than the beverage held in the container 34. The fluid chamber 60 is enclosed by a fluid chamber wall 62. The fluid chamber 60 may be formed using plastic injection moulding and may be formed of PET or any other suitable plastic. The fluid chamber 60 is supported by a housing 54 that extends upwards from the bottom of the container neck 38. The housing 54 includes a cylindrical housing wall 56 that extends upwards and substantially parallel to the container neck 38. The top of the housing wall 56 extends over the top of the container neck 38 to form a housing flange 58. The housing flange 58 may be fixed to the underside of the cap member 36. The housing flange 58 and cap member 36 may have a joint formed between them. The joint may be moulded, welded or clipped. If the joint is clipped, the joint may include a seal, as to hermetically seal the joints. The housing 54 may further comprise leg members that extend from the cylindrical wall 56 to a plug member 64. Both the housing 54 and the plug member 64 may be formed by injection moulding or another suitable method. The housing 54 must allow for the fluid communication of fluid through it from the container 34 to the cap member aperture 37, so the legs must be spaced apart. The housing 54 may further include an upper cylindrical portion that is adapted to be fixed to the inside of the container neck 38.

The plug member 64 of the housing is a cylindrical member which extends upwards from the base of the housing 54 and is adapted to engage sealingly with an aperture 66 in the fluid chamber 60. The aperture 66 comprises a neck portion of the fluid chamber 60. The fluid chamber 60 and neck 66 comprise a unitary moulded article. The leg members extend from the plug member 64 to the upper cylindrical portion of the housing 54. The plug member 64 includes a lateral passage 70 that extends between the outer walls of the plug member 64.

The plug member 64 further includes a longitudinal internal nozzle passage 72 that extends downwards from the lateral passage 70 to a nozzle 74. The plug member 64 has a coating 78 of formed of a resilient, soft plastic or rubber material such as mouldable thermo plastic elastomer or nitrile rubber, which acts to form a seal between the plug member 64 and the aperture 66 in the fluid chamber 60.

Alternatively, separate O-ring seals could be utilised to form a seal between the plug member 64 and the aperture 66. The closure device 10 may include anti-tamper means 76 to prevent rotation of the cap member 36 relative to the container neck 38 and vertical lifting of the cap member 36. The anti-tamper means 76 extends circumferentially around the exterior of the container neck 38.

The anti-tamper means 76 includes an anti-tamper flange that is held beneath a detent 52 formed on the container neck 38. If sufficient rotational force is applied by the user of the closure device 10 to the cap member 36, the anti-tamper means 76 dissociates from the cap member 36, meaning that the cap member 36 can be freely rotated and detached by the user.

The spout 12 of the closure device 10 extends upwards from the upper surface of the cap member 36. Both the spout 12 and the cap member 36 may be formed by injection moulding, or another suitable method. The spout 12 includes a cylindrical spout wall 20 extending upwards from the upper surface of the cap member 36 that encloses a spout chamber 30.

The cylindrical spout wall 20 includes positioning means comprising first

engagement portions that comprise first, second and third spout wall ribs 24, 26, 28 that are provided on its outer surface. The spout wall ribs 24, 26, 28 extend circumferentially around the outer surface of the spout wall 20.

The closure device 10 also includes a spout cover 16, which includes a spout cover cylindrical wall 22. The spout cover 16 has one or more spout cover apertures 32 that allows for the fluid communication of fluid.

The spout cover cylindrical wall 22 includes corresponding positioning means comprising second engagement portions that comprise first, second and third spout cover ribs 23, 25, 27. The spout cover ribs 23, 25, 27 are provided on the inner surface of the spout cover cylindrical wall 22 and extend circumferentially around the inner surface of the spout cover cylindrical wall 22. The spout cover ribs 23, 25, 27 are adapted to engage with the spout wall ribs 24, 26, 28, to provide positive positioning of the spout cover 16 relative to the spout 12 when the spout cover 16 is lifted from a firing position to an intermediate dispensing position, as will be described later. The purpose of the positioning means is to provide a positive fit between the spout cover 16 and the spout 12 over which the spout cover 16 fits and slides. The positioning means holds the spout cover 16 in the first closed position (Figs. 5 and 6) until sufficient force is exerted downwardly to move the spout cover 16 to the firing position (Figs. 7 and 8). The positioning means can then lightly hold the spout cover 16 in the firing position until sufficient force is exerted upwardly to move the spout cover 16 to the intermediate dispensing position (Figs. 9 and 10). The positioning means provides a resistance to moving the spout cover upwardly beyond the intermediate dispensing position. However the positioning means allows a user to move the spout cover downwardly again against a small resistance force to the firing position, or a position close to the firing position, in which the cap member aperture is sealed closed by the plunger. In the embodiment of the invention depicted, the positioning means are

circumferential ribs. However, it should be understood that any other suitable engagement means may be utilised such as detent flanges, lips, grooves, abutment means. The spout cover cylindrical wall 22 is adapted to slide up and down along the cylindrical spout wall 20. The furthest extent of the motion upwards is when the first spout wall rib 24 abuts the third spout cover rib 27. The furthest extent of the motion downwards is when the third spout wall rib 24 abuts the third spout cover rib 27, and the spout cover 16 abuts the upper surface of the cap member 36.

A plunger 14 is attached to the spout cover 16. The plunger 14 extends downwards from spout cover 16 through a cap member aperture 37 in the cap member 36 to the upper surface of the fluid chamber 60. The plunger 14 is capable of moving downwards until the spout cover cylindrical wall 22 abuts the upper surface of the cap member 36. The plunger 14 further comprises first and second sealing portions 15a, 15b of a larger diameter. The first and second sealing portions 15a, 15b are separated by a plunger neck portion 16 of a smaller diameter. The first sealing portion 15a is located above the second sealing portion 15b. The first and second sealing portions 15a, 15b are adapted to seal the cap member aperture 37, such that fluid communication from the container 34 to the spout 12 is prevented.

Spout apertures 32 are provided in the spout cover 16. In the illustrated embodiment of the present invention, the portion of the upper surface of the spout cover 16 from which plunger 14 extends is connected to the remainder of the upper surface of the spout cover 16 by two connecting portions 33. The connecting portions 33 separate apertures 32 when the spout cover is viewed in plan. In the embodiment of the present invention depicted, the spout cover 16 has two apertures 32 separated by connecting portions 33. However, it should be

understood that any suitable number, shape or arrangement of apertures 32 and connecting portions 33 may be utilised. In the embodiment of Figs. 5 to 10 the plug member 64 is fixed, or at least does not move, relative to the cap member 36, and the fluid chamber 60 is movable relative to both the cap member 36 and plug member 64.

In the embodiments of Figs. 1 to 10, the neck 66, 109 of the fluid chamber 60, 104 has a smaller diameter than the remainder of the fluid chamber. However the invention is not limited to a fluid chamber 60, 104 of such a shape. The neck 66, 109 may have a diameter similar to the remainder of the fluid chamber, such that the fluid chamber has a substantially uniform, or even tapering, cross-section. In such a case a larger plug member 64, 142 is used, and may have any suitable shape to achieve a sealed closure of the fluid chamber in the closed position.

The invention is not limited to the specific embodiments described, and modifications and alternatives are possible. The shape, material and size of the various components can be modified.

Claims

1. A closure device for use with a container having a main liquid compartment and an opening with a container neck, the closure device comprising:

and wherein the fluid chamber and neck comprise a unitary moulded article.

2. The closure device according to claim 1 , wherein the plug member is fixed relative to the cap member, and wherein the fluid chamber is movable relative to the cap member and plug member.

3. The closure device according to claim 1 , further comprising a housing adapted to be secured to the container neck, wherein the plug member is fixed to the housing.

4. The closure device according to claim 3, wherein the fluid chamber is fixed to the cap member.

5. The closure device according to any preceding claim, wherein the plug member has a plurality of nozzles.

6. The closure device according to any preceding claim, wherein the fluid chamber and neck are cylindrical in cross section, and wherein the neck is of substantially the same diameter as the remainder of the fluid chamber.

7. The closure device according to any preceding claim, wherein the nozzle is provided at the lower end of the plug member, opposite the fluid chamber, and the plug member includes an internal nozzle passage extending axially upwards in the plug member from the nozzle.

8. The closure device according to claim 7, wherein the plug member includes a transverse internal passage extending to a lateral exterior surface of the plug member and in communication with the internal nozzle passage.

9. The closure device according to any preceding claim, wherein the plug member includes sealing means to provide a seal between an internal surface of the neck of the fluid chamber and a lateral exterior surface of the plug member.

10. The closure device according to claim 9, wherein the sealing means is a coating of an elastomeric material.

1 1. The closure device according to any preceding claim, wherein the fluid chamber is blow moulded.

12. The closure device according to any preceding claim, wherein the fluid chamber is moulded from PET or other suitable plastic material.

13. The closure device according to any preceding claim, wherein the fluid chamber contains an additive liquid and a pressurised propellant gas.

14. A container having a container neck and an opening, wherein the container contains a liquid, and wherein the container has a closure device according any preceding claim secured to the container neck to close the container.

15. A method of introducing an additive liquid into a container having a closure device according to any of claims 1 to 13 secured to a container neck of the container, wherein the container contains a liquid, the method comprising:

moving the fluid chamber relative to the plug member from a closed position in which the neck of the fluid chamber is sealed closed by the plug member, to a firing position in which the plug member is arranged within the neck to provide a fluid communication path from the fluid chamber through the nozzle of the plug member. urging additive liquid from the fluid chamber through the nozzle into the container under pressure of a pressurised propellant in the fluid chamber, and

mixing the additive liquid with the liquid in the container.

16. The method of claim 15, wherein the liquid in the container is selected from a beverage, a chemical and a pharmaceutical composition.

17. The method of claim 15 or 16, wherein the mixing step is effected through ejection of the additive liquid through the nozzle at a sufficient velocity under pressure of the pressurised propellant in the fluid chamber.