GB2305159A

GB2305159A - A floating device for generating froth, a container for the device, and a method of filling the container

Info

Publication number: GB2305159A
Application number: GB9619282A
Authority: GB
Inventors: Clive Scott Coleman; David Wilson Pennell; David Neil Wragg
Original assignee: Ryford Ltd
Current assignee: Ryford Ltd
Priority date: 1995-09-14
Filing date: 1996-09-16
Publication date: 1997-04-02
Also published as: GB9619282D0

Abstract

A froth generating device 10 comprises a chamber with first and second spaced portions 14 and 25, a first passage 15 for communication between the exterior of the chamber and the interior of the chamber near the second portion 25, and a second passage 31 between the exterior and the interior of the chamber. The second passage 31 may have its inward end near the first portion 14 and the device may float with either portion uppermost. The uppermost passage may have its lower end 41 immersed in beverage which enters the chamber during pressurisation. In a further embodiment, the two passages 120 and 130 may be coaxial, and the device, which may be spherical, may float with the first portion 110 uppermost (see fig 8). The passages may be cylindrical or conical, and may be formed integrally with or separately from the portions 14 and 25. The device is inserted into a beverage container, flushed with a non-oxidising gas using a probe either before or after insertion, beverage is added and the container is sealed. When the container is depressurised by opening, a froth-generating jet of gas is released from the chamber into the beverage via whichever passage is lowermost.

Description

Title: "Insert" Description of invention This invention relates to inserts for inclusion in containers for liquid under pressure and in particular to inserts which, upon a reduction in pressure within the container when the container is opened, releases substance such as gas into the liquid content of the container, particularly, but not exclusively, to have the effect of causing the formation of a head or frothing of the content of the container.

For example, inserts for inclusion in cans of beer or other beverage subjected to a pressure above atmospheric pressure within the interior of the can with the intention of forming a head, or an enhanced head, of froth, preferably of a creamy nature on beer or other beverage by a jet of gas from the insert.

There have been prior proposals to form, or enhance the formation of such a head, examples are: EP-A-227213, WO-A-91/07326, WO-A-92/00896, WO-A-93/24832-4.

Objects of the invention are to provide a new or improved insert for inclusion in pressurised fluid containers and to provide a container having such an insert therein and to provide a method of producing a closed container having such an insert therein.

According to one aspect of the present invention, we provide an insert, adapted to float on liquid in a container for liquid under pressure, for releasing a substance into the liquid from the insert when the pressure in the container is reduced, comprising a chamber having first and second spaced portions and a first passage for communication between the exterior of the chamber at said first portion and the interior of the chamber adjacent said second portion and a second passage for communication between the exterior of the chamber at said second portion and the interior of the chamber.

The insert may be provided with a receptacle for liquid from the container adjacent said second portion whereby the end of the first passage adjacent the second portion is adapted to be immersed in liquid in said receptacle.

In one more specific aspect of the invention the second passage may provide for said communication between the exterior of the chamber at said second portion and the interior of the chamber adjacent said first portion.

The insert may be adapted to float on the liquid in an orientation in which the first portion is disposed above the surface of the liquid and the second portion is disposed below the surface of the liquid.

Alternatively, the insert may be adapted to float on the liquid in a second, alternative, orientation in which the second portion is disposed above the surface of the liquid and the first portion is disposed below the surface of the liquid.

The insert may be provided with a receptacle for liquid from the container adjacent said first portion whereby the end of the second passage adjacent the first portion is adapted to be immersed in liquid in said receptacle.

In another more specific aspect of the invention the second passage may provide for said communication between the exterior of the chamber at said second portion and the interior of the chamber adjacent the second portion.

The first passage may be provided within a tubular formation which projects from an internal surface of a first wall part of the insert at said first portion towards said second portion and the second passage may be provided within a further tubular formation which projects from an internal surface of a second wall part of the insert at said second portion towards said first portion.

The first and second passages may have a minimum dimension of typically 0.5mm.

The first and second passages may have a part of minimum dimension at the outer end of the passage.

The first and second passages may be of circular cross-section at said outer end.

The passages may have a cylindrical portion extending from said outer end.

The passages may have a frusto-conical portion diverging from the cylindrical portion at the end thereof remote from said outer end. The passages may have a further frusto-conical portion divergent from the larger portion of the frusto-conical portion.

In the first more specific aspect the first and second passages may have the same or substantially the same length. For example, the first and second passages may have an overall length of 16mm.

In the second more specific aspect the first passage may have a length which is about 10 times the length of the second passage. For example the first passage may have a length of 24mm and the second passage a length of 2.4mm.

The tubular formations may be received in and secured to apertures provided in said first and second wall parts or may be produced integrally with said wall parts.

In said one more specific aspect the passages may be disposed to extend within the insert at laterally spaced positions.

One passage may extend axially of the insert on the centre line thereof whilst the other passage may be displaced radially from the axis.

The insert may comprise a cup shaped body part having a side wall and a cap part which is a snap fit on the body part, for example, by virtue of a radially outwardly extending rib formation provided on the body part and an undercut or recess in the skirt which extends from the cup part to overlap an end portion of the side wall of the body part.

Alternatively, in said other more specific aspect the passages may be co-axial or substantially co-axial.

The insert may comprise a generally spherical body part which may be made in two generally hemispherical portions which may snap into fit and the body part being provided with a centre of gravity which is displaced from the centre of buoyancy of the body part so that the body part floats in the liquid so that the first portion is uppermost.

According to a second aspect of the present invention we provide a sealed container having a base and a top, in which an openable closure is provided to permit the contents of the container to be dispensed, and the container having therein a liquid such as a beverage and an insert according to the first aspect of the invention floating on the liquid whereby one of said passages provides communication between a head space above the liquid in the container and the interior of the chamber adjacent a lower end thereof and the other of said passages provides communication between the liquid in the container and the interior of the chamber.

The container and its contents may have been subjected to a pasteurising operation as a result of which liquid has entered the chamber through said other of said passages and liquid within the chamber is above the bottom of the one passage.

As a result, during storage, the presence of liquid above the bottom of the one passage and the presence of the liquid in contact at least with the outer end of the other passage seals the chamber so that gas within the chamber is retained therein, thereby preventing egress of gas from the interior of the chamber.

According to a third aspect of the invention we provide a method of filling and sealing a container comprising the steps of inserting an insert according to the first aspect of the invention and containing a gas into the container, filling the container with liquid and sealing the container, whereby the insert floats on the liquid and one of said passages provides communication between a head space above the liquid in the container and the interior of the chamber and the other of said passages provides communication between the liquid in the container and the interior of the chamber, subjecting the sealed container to a subsequent pasteurisation operation in which the container is heated, and pressure therein thereby being increased above atmospheric pressure to cause liquid to enter the chamber through said other of said passages to provide a volume of liquid within the chamber having an upper surface above the lower end of said one passage and, when the container is opened to reduce the pressure inside the container, the pressure differential between the interior and the exterior of the chamber causes gas to flow out of the other passage in preference to forcing liquid upwardly through said one passage.

The method may include the step of flushing air from the interior of at least the insert and preferably the insert and the container with nitrogen, carbon dioxide or other non-oxidising gas.

The flushing step may be performed after the insert has been introduced into the container or prior to the insert being introduced into the container.

The flushing step may be performed by introducing a probe into engagement with the outer end of the uppermost passage of the insert to flush non-oxidising gas through the insert and thus also to flush the can with nonoxidising gas which is passed through the insert.

Two embodiments of the invention will now be described by way of example with reference to the accompanying drawings, wherein: FIGURE 1 is a longitudinal section through an insert embodying the invention; FIGURE 2 is a fragmentary cross-section, to an enlarged scale, of part of the insert of Figure 1; FIGURE 3 is an end view of the insert of Figure 1; FIGURE 4 is an opposite end view of the insert of Figure 1; FIGURE 5 is a diagrammatic longitudinal cross-section through a container having an insert embodying the invention disposed therein at a first stage of a filling and sealing method embodying the invention;; FIGURES 6 and 7 are similar views to that of Figure 5 showing subsequent stages in the method, and FIGURE 8 is a diagrammatic cross-section through a container having another insert embodying the invention disposed therein at a stage of a filling and sealing method corresponding to that of Figure 6.

Referring to the Figures, an insert is shown at 10 and comprises a body part 11 and a cap part 12 which are made, in the present example, by injection moulding in a suitable synthetic plastics material such as polypropylene.

The body part 11 comprises a cylindrical side wall 13 and a circular flat disc shaped end wall 14. The end wall 14 comprises a first portion of the insert and has a first passage 15 therethrough disposed centrally of the end wall 14.

The cap part 12 has a transversely extending wall part 25 of generally flat circular disc configuration having a raised circular central part 26 and a raised circumferentially extending part 27. The cap part 12 also has a peripheral skirt 28 which overlies an end portion of the side wall 13 and which is provided with an undercut or recess 29 which snap fits with an outwardly extending rib 30 at the free end of the wall 13 to retain the cap and body parts together in gas tight relationship.

If desired, a suitable sealant and/or adhesive may be provided between the cap and body parts to ensure that the parts are thus retained in gas tight relationship.

The wall part 25 comprises a second portion of the insert and has a second passage 31 therethrough disposed radially offset from the centre of the insert.

Referring now to Figure 2, the first and second passages 15, 31 are conveniently provided in identical tubular elements having the configuration shown at 32 in Figure 2. Each tubular element 32 has a frusto-conical external surface 33 extending over the majority of its length having a diameter, in the present example, of 5.5mm at its larger diameter end and Smm at its smaller diameter end. A further frusto-conical mounting portion 34 converges from the smaller diameter end of the frusto-conical portion 33 with a step or shoulder 35 therebetween. The further frusto-conical portion 34 is received in a correspondingly shaped aperture 36, or 37 provided in the end walls 14, 25 of the insert. The mounting portions 34 are secured in the associated aperture 36, 37 by an adhesive melt welding or by any suitable means.Alternatively, the first and second passages may be provided in tubular elements which are moulded integrally with the respective insert portion.

Each tubular element 32 has a central bore which provides the respective passage 15, 31. Each bore has a frusto-conical portion 38 which has an included angle of 20 and a diameter of 2mm at its smaller diameter end.

Converging from the smaller diameter end is a frusto-conical portion 39 of the bore which has an included angle of 10 and a smaller diameter end of lmm diameter. A cylindrical outer end part 40 of the bore is provided and has a diameter of 0.5mm. If desired the passage may be non-circular at least at one position along its length and it is preferred that the minimum cross-sectional dimension is typically 0.5mm.

The tubular elements are arranged to have a length so that their larger diameter ends 41 are spaced from an associated inwardly facing surface 14, 25a respectively of the end walls 14, 25 by a short distance of, in the present example, 1.4mm, the spaces between the inwardly facing walls 14, 25a being 15.2mm.

In use, an insert 10 can conveniently be assembled together from the body and cap parts off site and transported to a container filling line as desired.

The insert contains air at ambient pressure and thus can be transported and stored for any desired period of time.

Such an insert is then introduced into the interior of a container 50 which in the present example is a conventional beer can made of pressed aluminium of conventional shape and having a generally dome shaped base wall 51 and an open mouth 52 which is of smaller cross-section than the cross-section of the main cylindrical wall 53 of the container.

The insert is simply dropped into the interior of the container and may lie, at the base of the container, with either the wall 14 or the wall 25 uppermost.

A suitable probe is then passed through the mouth of the container into gas tight engagement with the outer end of either the passage 15 or the passage 31 depending upon the orientation of the insert in the container. The interior of the insert is then flushed with nitrogen to remove the air and in particular to remove oxygen from the air so that no oxidising gas remains in the insert sufficient deleteriously to affect the beverage to be stored in the container.

The nitrogen is introduced into the chamber of the insert through the uppermost passage and air and nitrogen leaves the insert through the other passage. This operation is carried out until adequate flushing has been performed to reduce the oxidising gas content of the insert to a desired level. In the present example this flushing of nitrogen through the insert also causes the container itself to be similarly flushed with nitrogen which is passed through the insert. If desired, however, the container may be flushed with nitrogen separately from the insert.

Furthermore, other non-oxidising gas such as carbon dioxide may be used to flush the insert and/or the container.

Figure 5 illustrates the container prior to or at the end of the flushing operation.

The container is then filled with beverage such as beer and a dose of liquid nitrogen is added and a lid having an operable closure, such as by means of a ring pull, is fitted and sealed to the upper end 51 of the container in conventional manner.

The nitrogen gas in the insert is at atmospheric pressure after flushing and substantially at atmospheric pressure during the filling and container sealing operations.

The container containing the beverage may at this stage be inverted since the pressure inside the insert is substantially the same as the pressure outside the insert and because of the small diameter of the passages 15 and 31 the nitrogen gas is retained in the container since one of the passages 15 or 31 which communicates with a head space above the beverage in the container is already in communication with nitrogen at substantially the same pressure as the pressure within the insert, whilst the other passage 15 or 31, whilst in communication with the beer extends to a position above the level of the beverage in which the insert is floating and therefore beverage does not enter the interior of the insert through the other passage.

The thus filled and sealed container is then subjected to a conventional pasteurising operation where the can is heated to an elevated temperature of, for example, 62"C which causes the pressure inside the container to increase to, for example, 6 atmospheres and this causes the beverage in the container to enter the interior of the insert through the lower of the passages. Figure 6 illustrates the container after pasteurisation. The first passage 15 is shown uppermost but depending on how the insert happens to become oriented the second passage 31 may be uppermost. In either case the interior of the insert provides the insert with a receptacle, for the liquid from the container, adjacent the lower portion of the insert.

The amount of beverage B which enters the insert is relatively small and forms a layer having a depth of typically 2mm, but in any event, such as to cover and extend above the lower end 41 of the tubular element which extends downwardly away from the head space, i.e. the passage 15 in the illustrated example of Figure 6. At the same time nitrogen in the head space passes through the passage 15 at a faster rate than beverage through the passage 31 and so a relatively small amount of beverage enters the insert but sufficient to rise above the lower end of the passage 15.

After pasteurisation the pressure within the container has fallen but still remains above atmospheric pressure, for example at a pressure of about 3 atmospheres. The interior of the insert is sealed from the head space by virtue of the beverage within the insert being above the lower end of the passage 15 and by virtue of the beverage in contact with the lower end of the passage 31 and contained in the passage 31 and thus nitrogen does not exit from within the insert.

The container can thus be stored for any normal length of time and may be refrigerated or stored at ambient temperature as desired.

When the closure of the container is opened, as shown in Figure 7 for example by pulling the ring pull, the pressure inside the container is reduced to atmospheric pressure and thus the nitrogen within the insert is at a relatively high pressure differential so that the gas in the insert escapes by the easiest route which is downwardly into the beverage in the container through the passage 31 as opposed to forcing the beverage on the bottom of the insert upwardly through the passage 15. The gas thus flowing through the passage 31 aids the formation of head in conventional manner.Although in the example described and illustrated with reference to the drawings the insert has been described with the passage 15 having its outer end in communication with the head space, if desired the insert may be oriented upside down in the container so that the passage 31 is in communication with the head space, but the operation is exactly the same as the operation described hereinbefore.

The top closure of the container has an openable closure, for example by means of a ring pull, and in normal storage and use the can is disposed with the openable closure uppermost.

Because the insert is configured so that it is substantially bi-stable it can float on the beverage either with the wall 14 uppermost or the wall 25 uppermost and can function identically in either orientation. It does not matter which way the insert is originally introduced into the container, nor does it matter whether the insert turns over during storage or transport of the container.

If desired, the insert could be arranged so as to float in only one or other of said positions by suitable disposition of the centre of gravity and floatation or could be mounted in a container in only one of said positions but such options do not have the flexibility of bi-stability mentioned above.

Referring now to Figure 8, a second embodiment is illustrated floating in a container at a stage in a filling and sealing method similar to that described hereinbefore with reference to Figures 1 to 7 and which is equivalent to the stage illustrated in Figure 6. In this embodiment the insert is shown at 110 and comprises a generally spherical insert comprising two generally hemispherical body parts 111, 112 which are made, in the present example, by injection moulding a suitable synthetic plastics material such as polypropylene. The body part 111 is provided with a peripherally extending rib 113 adapted to snap interfit with a socket part 114 provided on the body part 112. The body part 112 has a greater wall thickness so as to dispose the centre of gravity of the insert at a position spaced from the centre of buoyancy so that the insert always floats with the body part 112 lowermost. If desired a suitable sealant and/or adhesive may be provided between the body parts to ensure that all the parts are in thus retaining gas-tight relationship.

The body part 111 has a first passage 115 extending through the wall of the body part 111 at a first portion 116 thereof. The body part 112 has a second passage 117 extending therethrough at a second portion 118 of the insert.

The first passage 115 is provided in a tubular element 120 having the configuration shown in Figure 8. Each tubular element 120 has a frusto-conical external surface 121 extending over a majority of its length having a diameter, in the present example of 4mm at its smaller diameter end and 4.5mm at its larger diameter end. The element 120 is formed integrally with the remainder of the body part 110 but, if desired, may be formed separately therefrom and secured thereto analogously to the mounting arrangement described in connection with the first embodiment.

Each tubular element 120 has a central bore which provides the passage 115. The bore has a first frusto-conical part 122 having a relatively small included angle and having an internal diameter of 3mm at its larger diameter end and an internal diameter of 2.5mm at its smaller diameter end. Converging from the smaller diameter end is a further frusto-conical portion 123 having a diameter, at a smaller diameter end, of 0.5mm. A cylindrical outer end part 124 of the bore is provided and likewise has a diameter of 0.5mm. A recess 125 is provided in the wall of the body part 111.

The tubular element terminates adjacent the second portion 118 of the insert at a distance which is just under 2mm from the internal wall surface 126 of the second portion 118.

The second passage 117 is provided in another tubular element 130 which has a first part 131 of a frusto-conical external and internal configuration but which terminates at a position spaced about lmm above the surface 126 referred to above. The element 131 has a central bore which provides the passage 117. The bore has a first frusto-conical part 132 of about 2mm diameter and converging from the small diameter end is a second frusto-conical portion 133 having a smaller diameter end of 0.5mm diameter. A cylindrical outer end part 134 of the bore is provided and also has a diameter of 0.5mm.

A cylindrical wall 135 provides a dam around the co-axially disposed tubular elements thereby providing a receptacle for liquid from the container adjacent the second or lower portion of the insert.

In use, an insert 1 10 is assembled and inserted into a container in a manner analogous to that described hereinbefore in connection with the first embodiment and a suitable probe is again introduced into gas-tight engagement with either passage. The interior of the insert is then flushed with nitrogen in a manner analogous to that described previously. Thereafter the container is filled with beverage and sealed and pasteurised as described hereinbefore.Because of the relative dispositions of the centre of gravity and the centre of buoyancy the insert will float in the orientation shown in Figure 8 and the increase in pressure within the container on pasteurisation described hereinbefore causes the beverage in the container to enter the insert through the lower of the passages, i.e. the passage 117 and the receptacle provided by the wall of the insert and the dam 134 retains this liquid therewithin to provide a depth of approximately 2mm and thus the liquid covers and extends above both the upper end of the tubular element 130 and the lower end of the tubular element 121. At the same time nitrogen in the head space passes through the passage 122 at a faster rate than beverage through the passage 117 and so a relatively small amount of beverage enters the insert but sufficient to rise to the above described level.

After pasteurisation the pressure within the container has fallen but still remains above atmospheric pressure as described hereinbefore. The interior of the insert is sealed from the head space by virtue of the beverage within the insert being above the lower end of the passage 115 and thus nitrogen does not exit from within the insert.

When the closure of the container is opened, for example by pulling the ring pull, the pressure inside the container is due to atmospheric pressure and thus the nitrogen within the insert is at a relatively high pressure differential and there is an initial surge which pushes beverage up the passage 115 and down the passage 117. Accordingly, the gas in the insert escapes by the easiest route, which is downwardly into the beverage in the container through the passage 117 as opposed to forcing beverage within the passage 117 upwardly into the head space. Gas thus flowing through the passage 117 aids the formation of head in conventional manner.

Although the substance released when the can is opened is gas, if desired other substance may be released.

The features disclosed in the foregoing description, or the accompanying drawings, expressed in their specific forms or in terms of a means for performing the disclosed function, or a method or process for attaining the disclosed result, or a class or group of substances or compositions, as appropriate, may, separately or in any combination of such features, be utilised for realising the invention in diverse forms thereof.

Claims

1. An insert adapted to float on liquid in a container for liquid under pressure, for releasing a substance into the liquid from the insert when the pressure in the container is reduced, comprising a chamber having first and second spaced portions and a first passage for communication between the exterior of the chamber at said first portion and the interior of the chamber adjacent said second portion and a second passage for communication between the exterior of the chamber at said second portion and the interior of the chamber.

2. An insert according to claim 1 wherein the insert is provided with a receptacle for liquid from the container adjacent said second portion whereby the end of the first passage adjacent to the second portion is adapted to be immersed in liquid in said receptacle.

3. An insert according to claim 1 wherein the second passage provides said communication between the exterior of the chamber at said second portion and the interior of the chamber adjacent said first portion.

4. An insert according to claim 3 wherein the insert is adapted to float on the liquid in an orientation in which the first portion is disposed above the surface of the liquid and the second portion is disposed below the surface of the liquid.

5. An insert according to claim 4 wherein the insert is provided with a receptacle for liquid from the container adjacent said second portion whereby the end of the first passage adjacent to the second portion is adapted to be immersed in liquid in said receptacle.

6. An insert according to any one of claims 3 to 5 wherein the insert is adapted to float on the liquid in an orientation in which the second portion is disposed above the surface of the liquid and the first portion is disposed below the surface of the liquid.

7. An insert according to claim 6 wherein the insert is provided with a receptacle for liquid from the container adjacent said first portion whereby the end of the second passage adjacent to the first portion is adapted to be immersed in liquid in said receptacle.

8. An insert according to claim ] wherein the second passage provides for said communication between the exterior of the chamber at said second portion and the interior of the chamber adjacent to the second portion.

9. An insert according to claim 8 wherein the insert is adapted to float on the liquid in an orientation in which the first portion is disposed above the surface of the liquid and the second portion is disposed below the surface of the liquid.

10. An insert according to claim 9 wherein the insert is provided with a receptacle for liquid from the container adjacent said second portion whereby the end of the first passage adjacent to the second portion is adapted to be immersed in liquid in said receptacle.

11. An insert according to any one of the proceeding claims wherein the first passage is provided within a tubular formation which projects from an internal surface of a first wall part of the insert at said first portion towards said second portion and the second passageway is provided within a further tubular formation which projects from an internal surface of a second wall part of the insert at said second portion towards said first portion.

12. An insert according to claim 11 wherein the first and second passages have a minimum cross-sectional dimension of typically 0.5 millimetres.

13. An insert according to claim 11 or claim 12 wherein the first and second passages have a part of minimum cross-sectional dimension at the outer end of the passage.

14. An insert according to claim 13 wherein the first and second passages are of circular cross-section at said outer end.

15. An insert according to claim 14 wherein the first and second passages have a cylindrical portion extending from said outer end.

16. An insert according to claim 15 wherein the first and second passages have a frusto-conical portion diverging from the cylindrical portion at the end thereof remote from said outer end.

17. An insert according to claim 16 wherein the first and second passages have a further frusto-conical portion divergent from the larger portion of the frusto- conical portion.

18. An insert according to any one of claims 11 to 17 where dependent directly or indirectly on claim 3 wherein the first and second passages have the same or substantially the same length.

19. An insert according to claim 18 wherein the first and second passages have an overall length of sixteen millimetres.

20. An insert according to claims 11 to 17 where dependent directly or indirectly on claim 8 wherein the first passage has a length which is about ten times the length of the second passage.

21. An insert according to claim 20 wherein the first passage has a length of 24 millimetres and the second passage has a length of 2.4 millimetres.

22. An insert according to claim 11 or any one of claims 12 to 21 where dependent directly or indirectly on claim 11 wherein the tubular formations are received in and secured to apertures provided in said first and second wall parts.

23. An insert according to claim 11 or any one of claims 12 to 21 where dependent directly or indirectly on claim 11 wherein said tubular formations are produced integrally with said first and second wall parts.

24. An insert according to any one of claims 11 to 23 where dependent directly or indirectly on claim 3 wherein the passages are disposed to extend within the insert at laterally spaced positions.

25. An insert according to claim 24 wherein one passage extends axially of the insert on the centreline thereof while the other passage is displaced radially from the axis.

26. An insert according to claim 3 or any one of claims 4 to 25 when dependent directly or indirectly on claim 3 wherein the insert comprises a cupshaped body part having a side wall and a cap part which is a snap fit on the body part.

27. An insert according to any one of claims 11 to 23 where dependent directly or indirectly on claim X wherein the passages are coaxial or substantially coaxial.

28. An insert according to claim 8 or any one of claims 9 to 27 when dependent directly or indirectly on claim 8 wherein the insert comprises a generally spherical body part, said body part being provided with a centre of gravity which is displaced from the centre of buoyancy of the body part so that the body part floats on the liquid such that the first portion is uppermost.

29. An insert according to claim 28 wherein said generally spherical body part comprises two generally hemispherical portions which snap inter-fit.

30. An insert substantially as hereinbefore describe with reference to the accompanying drawings.

31. A sealed container having a base and a top, in which an openable closure is provided to permit the contents of the container to be dispensed, and the container having therein a liquid such as a beverage and an insert, according to any one of claims 1 to 30, floating on the liquid whereby one of said passages provides communication between a head space above the liquid in the container and the interior of the chamber adjacent a lower end thereof and the other of said passages provides communication between the liquid in the container and the interior of the chamber.

32. A sealed container according to claim 31 wherein the container and its contents have been subjected to a pasteurising operation as a result of which liquid has entered the chamber through said other of said passages and liquid within the chamber is above the bottom of the one passage.

33. A sealed container according to claim 32 wherein during storage, the presence of the liquid above the bottom of the one passage and the presence of the liquid in contact with at least the outer end of the other passage seals the chamber so that gas within the chamber is retained therein, thereby preventing egress of gas from the interior of the chamber.

34. A sealed container substantially as herein before described with reference to the accompanying drawings.

35. A method of filling and sealing a container comprising the steps of inserting an insert according to any one of claims 1 to 30 and containing a gas into the container, filling the container with liquid, and sealing the container, whereby the insert floats on the liquid and one of said passages provides communication between a headspace above the liquid in the container and the interior of the chamber and the other of said passages provides communication between the liquid in the container and the interior of the chamber, subjecting the sealed container to a subsequent pasteurisation operation in which the container is heated and pressure therein being increased above atmospheric pressure to cause liquid to enter the chamber through said other of said passages to provide a volume of liquid within the chamber having an upper surface above the lower end of said one passage and, when the container is opened to reduce the pressure inside the container, the pressure differential between the interior and the exterior of the chamber causes gas to flow out of the other passage in preference to forcing liquid upwardly through one passage.

36. A method according to claim 35 wherein the method includes the step of flushing air from the interior of at least the insert and preferably the insert and the container with nitrogen, carbon dioxide or other non-oxidising gas.

37. A method according to claim 36 wherein the flushing step is performed after the insert has been introduced into the container.

38. A method according to claim 36 wherein the flushing step is performed prior to the insert being introduced into the container.

39. A method according to claim 37 or 38 wherein the flushing step is performed by introducing a probe in to engagement with the outer end of the upper most passage of the insert to flush non-oxidising gas through the insert.

40. A method according to claim 39 where dependent on claim 37 where the container is flushed with non-oxidising gas which is passed through the insert.

41. A method of filling and sealing a container as herein before described with reference to the accompanying drawings.

42. Any novel feature or novel combination of features as described herein, with reference to the accompanying specification and/or figures.