GB2146304A

GB2146304A - Container for pressurised liquid

Info

Publication number: GB2146304A
Application number: GB08416036A
Authority: GB
Inventors: Arthur John Riley
Original assignee: TPT Ltd
Current assignee: TPT Ltd
Priority date: 1983-09-08
Filing date: 1984-06-22
Publication date: 1985-04-17
Also published as: JPS6090158A; AU3275984A; DK408784A; ZA846868B; ES289837Y; ES289837U; GB8324127D0; GB8416036D0; DK408784D0; GB2146304B; EP0134147A2; EP0134147A3

Abstract

A flexible bag 10 adapted for reception of a pressurised liquid, e.g. a carbonated beverage, sparkling wine or beer, and having a tap 15 whereby the liquid may be dispensed is enclosed within a cylindrical, plastics or paperboard casing 11 at each end of which is a respective end cap 12, 13. To minimise head space in the bag 10 as the liquid is dispensed so that the liquid does not go flat or stale, one end cap 13 is movable inwardly of the casing 11. This may be achieved simply by pushing downwards on the end cap 13. The movable end cap is preferably part spherical in form and has an auxiliary resilient plate 20, the plate being screw threadedly connected to a handle 30 via an aperture in the end cap. Tightening of the screw threaded connection causes plate 20 to press against convex lower face of the cap so flattening it and expanding its rim into tight engagement with the casing. In this tight fitting position the cap cannot be pushed further into the casing but the entire container can be moved around. To prevent accidental removal of cap 13, e.g. when temperature is high, protrusions may be provided on the inner surface of the casing. Alternatively the cap and casing may have co-operating screw threads (Fig. 4) or ratchet formations to hold the cap in a desired position. <IMAGE>

Description

1 GB 2146 304A 1

SPECIFICATION

Container for pressurised liquid This invention relates to a container for pres- 70 surised liquid, particularly but not exclusively a carbonated beverage such as beer or spark ling wine or a soft drink.

So-called bag-in-box containers are already well known for still table wine. Such contain- 75 ers consist of a substantially impermeable bag, usually of metalised polyester, disposed within a box of cardboard or similar material, the bag being filled with wine and having a tap projecting through the box material so that the wine can be easily dispensed. The great advantage of such a container over a conventional bottle, carafe or the like is that the bag is made of flexible material so that as liquid is dispensed the bag collapses by a corresponding amount and virtually no air is allowed to enter to cause oxidation of the liquid. Progressive oxidation of a beverage such as wine leads, of course, to the beverage firstly becoming stale and subsequently spo- 90 iled. Accordingly the bag-in-box packaging keeps the product fresh for an extended per iod.

A further advantage of bag-in-box contain ers is that they are lighter than most conven- 95 tional containers and are therefore more suit able for transporting liquids and/or for hold ing larger quantities of liquid. Moreover, they are inexpensive enough to be sold as disposa ble containers.

The integral tap is also particularly conve nient for dispensing the contained liquid and there is no difficulty in the consumer opening the container, as may be the case with bottles or cans.

It is desirable to extend bag-in-box packag ing to pressurised liquids, particularly carbo nated beverages such as beer, sparkling wine and soft drinks, so as to achieve, in relation to these liquids, the above-mentioned advan tages. However, when such liquids are filled into flexible bags within semi-rigid casings in the form of boxes, the latter have been found to sag or bulge outwardly because of the additional pressure of gas from the liquid. 115 This is clearly unsatisfactorily as it makes the overall container unstable and likely to topple over and it is not possible to stack the containers for storage or transportation.

A further problem in relation to carbonated beverages is that when there is a space above a quantity of the liquid (a so-called -head space---) carbon dioxide tends to come out of the liquid into the space and the liquid be- comes increasingly flat. This will tend to occur when a bag of the aforementioned type is only partially filled with liquid, (e.g. when a portion of the original volume has been dispensed) since the bag, being flexible, can be forced outwards as far as the walls of the box 130 by gas coming out of the liquid.

An object of the present invention is to provide a container based on the bag-in-box principle of a flexible bag within an outer casing, which container will not sag or bulge outwardly when filled with a pressurized liquid and which also has means to minimize the head space above such liquid.

With this object in view, the present invention provides a container for pressurized liquid comprising a flexible bag adapted for reception of liquid and having a tap whereby the liquid may be dispensed, the bag being enclosed within a casing of plastics or paper- board through which the tap projects, characterised in that the casing is in the form of a cylinder with a respective end cap arranged at each end, at least one end cap being movable from an initial position adjacent its end of the cylinder towards the other end cap.

The cylindrical shape is better than any other at resisting sagging or bulging due to pressure of liquid.

The most convenient construction of container has been found to include only one movable end cap. The other end cap is firmly fixed in position and the tap projects through the casing adjacent to the fixed end cap. In some instances, however, the tap could project through the fixed end cap.

The movement of the other end cap may be brought about in one of three ways.

Firstly, the movable end cap may be partspherical in form so as to present a concave outer face and a convex inner face. Such a cap must be made of resilient material, such as rigid or flexible plastics. Because of its shape and resilience it may be capable of simply being pushed inwardly from its end of the casing while maintaining a tight fit within the casing when force is not applied to its concave outer face. However, in practise it has been found preferable to provide means for application of force to the convex inner face of the movable end cap to ensure that said cap maintains a tight fit in the cylinder when it is not being pushed inwardly. Said means preferably comprises an auxiliary plate of resilient material located inside the movable end cap, the plate being screw-threadedly connected to a handle outside the end cap by way of an aperture in said end cap such that tightening of the screw-threaded connection causes application of force to the convex inner face of the movable end cap.

Alternatively, the cylinder may be internally screw-threaded while the movable end cap has an externally screw threaded rim so that it can be screwed inwardly from its end of the casing either manually by means of a hand grip on its outer face or by means of additional machinery. From a practical point of view, this is not as favourable as the abovementioned arrangement due to the difficulty of providing an internal screw-thread in the 2 GB 2146 304A 2 cylinder.

Finally, a number of ratchet devices may be provided on the internal surface of the cylinder and the movable end cap, which in this case is not part-spherical, may be pushed inwardly of the cylinder in engagement with these devices.

In all the above-mentioned methods of achieving movement of the end cap force may be applied manually or mechanically. It will, of course, be understood that in practice the end cap is intended to be moved inwardly of the casing when a volume of liquid has been dispensed from the bag so as to minimize the head space in the bag and prevent gas escaping from the pressurized liquid. The end cap should therefore be moved inwardly until further movement is prevented by counterpressure from the liquid in the bag.

A number of protrusions are preferably provided around the inner surface of the cylinder outside the movable end cap to prevent removal of the end cap from the casing when the pressure of the liquid inside the bag increases, e.g. in hot weather.

The fixed end cap, which is generally circular or part-spherical in shape with a rim directed outwardly of the casing, may be fixed in position in any one of a variety of manners which may be found most suitable in any particular circumstances. For example, it may be glued in position, or form an inference fit in the end of the cylinder or be held by catch means such as beading or lugs on the end cap or on the internal surface of the cylinder. Advantageously, however, this end cap has a turned over rim providing a circumferential slot into which the end of the cylinder fits.

The base of the tap or an outlet member connecting the tap to the bag conveniently engages in a slot provided in the cylinder adjacent to the fixed end cap, or provided in the fixed end cap itself, so that the bag is correctly positioned within the casing. This also ensures that the tap is held securely in an appropriate dispensing position.

The bag is preferably formed of two layers of material, namely an inner layer of polyethylene and an outer covering of nylon/alu- min ium/ polyethylene laminate. The latter ma- 115 terial has been found to be particularly effective in preventing escape of carbon dioxide from carbonated liquids within the bag, and preventing the ingress of oxygen into the bag.

In embodiments where the tap projects through the end cap and the container is intended to be laid on its side when liquid is dispensed therefrom, anti-roll means, such as longitudinal ribs, are advantageously provided on the outer surface of the cylindrial casing.

The invention will be described further, by way of example, with reference to the accom panying drawings, in which:

Figure 1 is an exploded perspective view of a preferred practical embodiment of the con- 130 tainer of the invention; Figure 2 is a vertical cross-section of the same embodiment to a somewhat larger scale; Figure 3 is a fragmentary cross-section of one end of a slightly modified embodiment of the container of the invention; Figure 4 is a fragmentary cross-section of one end of another embodiment of the container of the invention; and Figure 5 is a side view, to a reduced scale, of a container in accordance with the invention in which the tap projects through a fixed end cap.

In carrying out a first practical embodiment of the invention, as shown in Figs. 1 and 2, a flexible bag 10 is located within a casing in the form of a paperboard cylinder 11 having respective end caps 12, 13. The bag is formed of two inner sheets of linear low density polyethylene and two outer sheets of nylon /aluminium /low density polyethylene laminate bonded together adjacent their periphery. The bag also has a short cylindrical outlet member 14 with annular ridges and a tap 15 which fits into the outlet member 14.

The outlet member 14 fits into a slot 16 (Fig. 1) at one end of the cylinder 11 so that the tap 15 is positioned outside the cylinder 11 while the bag 10 remains inside the cylinder 11.

Each end cap 12, 13 is made of resilient plastics material and is part spherical in shape, having a convex inner face 1 2a, 1 3a and a concave outer face 12b, 1 3b with a rim 22, 23 respectively directed outwardly of the casing towards the respective end of the cylinder 11.

One end cap 12 (hereinafter referred to as "the first end cap") fixed firmly and immov- ably onto the cylinder 11. Its rim 22 is turned over, as shown in Fig. 1, to provide a circumferential slot 17 into which the end of the cylinder 11 fits and in which it is secured by means of rivets 18. On its outer concave face 1 2b, the first end cap 12 has a number of cross-walls 19 extending between points on the rim 22. These cross-walls 19 serve to strengthen the first end cap 12. The rim 22 is specially formed with a recess 24 in a raised portion to support the outlet member 14 of the tap 15 and the slot 17 is blocked in this region to further support the tap 15 and strengthen the cylinder 11.

The other end cap 13 (hereinafter referred to as "the second end cap") is movable from an initial position adjacent its end of the cylinder 11 towards the first end cap 12. The second end cap 13 has shallow radial crosswalls 25 and a central aperture 26. Its rim 23 is cylindrical and is a friction fit inside the paperboard cylinder 11. An auxiliary plate 20 also of resilient plastics material and having a convex inner face and a concave outer face is located in the cylinder 11 just inside the second end cap 13. It has four radial slots 27 3 GB 2 146 304A 3 for enhanced flexibility and a central internally screw threaded bush 28 which projects into the aperture 26 of the second end cap 13.

A T-shaped handle 30 is connected to the auxiliary plate 20 by way of the aperture 26 by means of a screw threaded shaft 29 which engages the bush 28.

In use, with the bag 10 filled with a suitable liquid such as beer, the second end cap 13 will be in positioned closely adjacent the end of the cylinder 11 and the handle 30 will be screwed into the bush 28 as far as possible. This means that the auxiliary plate 20 will be pressed against and apply a force to the convex face 13 a of the second end cap 13. The end cap 13 is thus slightly flattened and sufficiently expanded in diameter to make its rim 23 an extremely tight fit in the cylinder 11. In this condition the second end cap 13 cannot be pushed inwardly of the cylinder 11. 85 The container can conveniently be carried by means of the handle 30 and when set down on an appropriate surface the beer can be dispensed simply by turning the tap 15.

When a certain portion of the initial volume of 90 beer has been dispensed and the remaining beer is to be kept for some time, e.g. for the next day or a few days hence, the user turns the handle 30 to loosen its screw-threaded engagement with the auxiliary plate 20 and thus decrease the pressure of the auxiliary plate 20 against the inner face 1 3a of the end cap 13. The user can then push the second end cap 13 downwards and into the cylinder 11 as far as possible, that is to say until the counter-pressure of the remaining liquid prevents its further movement. At this point the head space in the bag will be at a minimum and the beer will remain fresh and its ten- dancy to go flat will be minimised. The handle 105 30 is then turned in the opposite direction so that the auxiliary plate 20 again presses firmly against the inner face 1 3a of the second end cap 13 and ensures that the end cap 13 is a tight fit in the cylinder 11.

Due to its special part-spherical shape and the presence of the auxiliary plate 20, the second end cap 13 does not readily move outwardly of the cylinder 11 away from the first end cap 12 even when considerable outward force is applied to the handle 30. Nevertheless, there may be a tendancy for the second end cap 13 to move outwards when the temperature is high and the pressure of liquid in the bag 10 is increased. To prevent removal of the second end cap 13 from the cylinder 11 in this way, protrusions may be provided around the inner surface of the cylinder adjacent the outer face 1 3b of the second end cap 13. Fig. 3 shows a modification in which a number of rivets 31 are positioned around the cylinder 11 adjacent its end to provide such protrusions. A number of re cesses 32 are provided around the rim 23 of 6 5 the end cap 13 to accommodate the rivet 130 shafts in the initial position of the end cap 13.

In a second embodiment of the container of the invention, as illustrated in Fig. 4, the cylinder 11 is formed of plastics material and is screw-threaded on its internal surface, as indicated at 41. The end caps are circular in shape with rims directed towards their respective ends of the cylinder. The first end cap (not shown) is fitted firmly and immovably into the cylinder 11 by an interference fit or by Jugs on the outside of the rim engaging with corresponding L-shaped recesses formed on the internal surface of the cylinder. The second end cap 43 has a cross wall or flange 44 extending across its outer face between appropriate locations on the inside of the rim 42. The outer surface of the rim 42 is screwthreaded and engages with the internal threading of the cylinder 11. The cross wall or flange 44 serves as a hard grip whereby the second end cap 43 can be turned and moved inwards or outwards of the cylinder 11.

A flexible plastics handle (not shown) in the form of a strip extending between opposing points on the outside of the cylinder or formed integrally with either the first or second end caps may be provided for carrying this container.

In a further embodiment, which is not illus- trated and is probably not of much practical significance, a number of ratchet devices may be provided on the internal surface of the cylinder, one of the end caps being movable inwardly of the cylinder in engagement with said devices.

The foregoing are, of course, illustrative and not limitative of the scope of the invention and many variations are possible. For example, in the first described, preferred, embodiment the auxiliary plate need not be partspherical in shape and its engagement with the handle may be by way of a screw threaded shaft on the plate and an internally screw- threaded bush or the handle, i.e. oppo- site to the previously described manner of engagement. Moreover, alternative means of selectively pressing the auxiliary plate against the inner face of the movable end cap may be provided.

The tap has been particularly described as projecting through a slot in the cylinder adjacent the fixed end cap. This is preferred as it allows the cylinder to be placed upright on a surface for dispensing the liquid, usually a beverage. However, the tap may alternatively project through a slot in the fixed end cap, as shown in Fig. 5. In this case, a pair of ribs (not shown) may be provided extending longitudinally, a short distance apart, on the exter- nal surface of the cylinder. When the cylinder is disposed horizontally for dispensing of liquid it rests on these ribs which prevent it from rolling.

Other variations are possible within the scope of the invention. It will, of course, be 4 GB 2 146 304A 4 appreciated that containers in accordance with the invention may be produced in a wide range of sizes to accommodate differing volumes of liquid, for example from considerably less than a litre to tens of litres. Also, for storage and marketing the entire container may be shrink-wrapped with transparent film so that the tap cannot be tampered with prior to sale.

Claims

1. A container for pressurised liquid comprising a flexible bag adapted for reception of liquid and having a tap whereby the liquid may be dispensed, the bag being enclosed within a casing of plastics or paperboard through which the tap projects, characterised in that the casing is in the form of a cylinder with a respective end cap arranged at each end, at least one end cap being movable from an initial position adjacent its end of the cylinder towards the other end cap.

2. A container as claimed in claim 1 wherein only one end cap is movable and the other end cap is firmly fixed in position, and the tap projects through the casing adjacent to the fixed end cap.

3. A container as claimed in claim 2 wherein the movable end cap is formed of resilient material, has a convex inner face and a concave outer face, and is capable of being pushed inwardly from its end of the casing.

4. A container as claimed in claim 3 wherein means are provided for application of force to the convex inner face of the movable end cap so that said cap maintains a tight fit in the cylinder.

5. A container as claimed in claim 4 wherein said means comprise an auxiliary plate of resilient material located inside the movable end cap, the plate being screwthreadedly connected to a handle outside the movable end cap by way of an aperture in said end cap such that tightening of the screw-threaded connection causes application of force to the convex inner face of the movable end cap.

6. A container as claimed in claim 2 wherein a number of ratchet devices are pro- vided on the internal surface of the cylinder and the movable end cap is capable of being pushed inwardly from its end of the casing in engagement with these devices.

7. A container as claimed in claim 2 wherein the cylinder is internally screwthreaded and the movable end cap is capable of being screwed inwardly from its end of the casing.

8. A container as claimed in any of claims 2 to 7 wherein a number of protrusions are provided around the inner surface of the cylinder outside the movable end cap to prevent removal of that end cap from the casing.

9. A container as claimed in any of claims 2 to 8 wherein the fixed end cap has a rim directed outwardly of the casing, the rim being turned over to provide a circumferential slot into which the end of the cylinder fits.

10. A container for pressurised liquid sub- stantially as hereinbefore described with reference to and as illustrated in Figs. 1 and 2, or in Fig. 3, or in Fig. 4, or in Fig. 5 of the accompanying drawings.

Printed in the United Kingdom for Her Majesty's Stationery Office. Dd 8818935, 1985. 4235 Published at The Patent Office, 25 Southampton BuddingsLondon, WC2A 1 AY. from which copies may be obtained