GB2211813A

GB2211813A - Compartmented drinks container

Info

Publication number: GB2211813A
Application number: GB8825419A
Authority: GB
Inventors: Ernest James Cameron-Price
Original assignee: E J Price
Current assignee: E J Price
Priority date: 1987-10-29
Filing date: 1988-10-31
Publication date: 1989-07-12
Anticipated expiration: 2008-10-31
Also published as: GB2211813B; GB8825419D0

Abstract

In order to provide a good head on stout a conventional beer can is provided with an internal diaphragm member (2) which divides the can into an upper drink compartment and a lower nitrogen reservoir. The diaphragm (2) is provided with small holes (8) through which nitrogen bubbles into the stout when the top (5) of the can is opened and pressure released in the upper compartment, and the nitrogen bubbles cause a good head to be produced. The diaphragm (2) is desirably an independent metal disc which is a gas-tight fit with the sidewalls (3) of the can, and is inserted in a dished condition effected by a suction tool. The disc may be corrugated in radial cross section and have a skirt. Alternatively the diaphragm may be formed integrally with the can side wall or be a skirted insert which is secured with the can side wall to a first end wall disc, the second end wall including an easy-open pull ring (6). The diaphragm holes may be recesses in the edge of the diaphragm. <IMAGE>

Description

DRINKS CONTAINER This invention relates to a drinks container particularly, but not exclusively, to a beer can.

Nitrogen is valuable in promoting a good head on beer. When the beer is sold in cans there is difficulty in introducing nitrogen into the beer, nitrogen being relatively insoluble in beer as compared with the solubility of carbon dioxide. It has been proposed to provide a plastics nitrogen containing vessel inside a can of stout at the bottom, with a small hole in the vessel through which the pressurised nitrogen escapes when the can is opened. Whilst that proposal is feasible, it requires the manufacture of the special vessel which must then be retained in place at the bottom of the can in some way.

According to one aspect of the invention a drinks container of substantially cylindrical shape comprises a cylindrical wall, first and second end walls at opposed ends of the container, and a partition wall extending substantially parallel to the end walls and being positioned axially closer to the first end wall to provide a gas reservoir between the partition wall and the first end wall, the second end wall comprising an area which is adapted to provide a normally closed pouring opening to enable drink to be poured from the main chamber defined between the second end wall and the partition wall, the partition wall being provided with a passage means of predetermined dimensions to provide restricted communication between the gas reservoir and the main chamber to enable in use gas under super-atmospheric pressure in the reservoir to pass into drink in the main chamber, when the container is opened by opening of the pouring opening.

Thus, instead of providing a container with a separate vessel, we provide a container with a partition wall containing a passage.

There are various ways in which such a container could be constructed. The partition wall could be formed integrally with the side wall of a can, in a manner similar to a conventional can body of the kind commonly having a capacity of 275ml or 440ml, and a metal cup-shaped member could then be secured to that body.

Alternatively, the junction between the side wall and the base of such a body could be extended downwardly as a skirt, and then the first end wall could be a metal disc which is swaged around its periphery to the skirt.

Another, preferred method of producing the container is to insert a diaphragm into a can body.

Thus, according to a second aspect of the present invention a drinks container of substantially cylindrical shape comprises a cylindrical wall integral with a first end wall, a second end wall secured or adapted to be secured to the cylindrical wall to close the container, the second end wall being provided with an area which is adapted to provide a pouring opening, and an impervious diaphragm, inserted, or for insertion, into the container adjacent to the first end wall, the diaphragm being dimensioned to be a close fit with the cylindrical wall to define a gas reservoir between the diaphragm and the first end wall, the diaphragm being provided with a passage means of predetermined dimensions through which in use gas can flow from the reservoir into drink contained in the main chamber of the container following release of pressure in the main chamber.

The passage means is preferably one or more holes extending through the diaphragm, but it might be one or more recesses in the edge of the diaphragm.

Preferably holes are provided in the diaphragm at positions spaced from both the centre and the edge of the diaphragm. Preferably there are at least four holes.

The drinks container need not be made of metal, but the invention is particularly applicable to metal drinks cans of the type commonly having a capacity of 275m1 or 440ml. Such cans have a cylindrical aluminium alloy wall of thickness approximately 0.005 inches with an integral base, the first end wall, of thickness approximately 0.012 inches. A difficulty with such very thin wall cans is that anything forced into the can to be held by engagement with the cylindrical wall may damage the cylindrical wall during insertion and may deform the cylindrical wall of the assembled can at the diaphragm, which could seriously mar the appearance of the can.

It is preferred to insert the diaphragm into the can whilst the diaphragm is held in a dished form, preferably by suction forces against a suction cup, the diaphragm then being permitted to relax, or partially relax, to grip the cylindrical wall of the can in its assembled position.

With this procedure the diaphragm need not engage the cylindrical wall with any significant force during insertion of the cup into the can.

Alternatively, it might be possible to insert the diaphragm by pressure of an inserting tool applied at its centre, the diaphragm being suitably shaped for this purpose.

h7hen using a suction cup, the diaphragm may be substantially flat in its relaxed condition prior to insertion in the container or it may already be of dished form.

The dimensions of the relaxed diaphragm are preferably such that the diaphragm makes an interference fit with the can side wall.

In order to increase the resilience of the diaphragm in the radial direction, to reduce the possibility of fluting of the diaphragm, the diaphragm may be corrugated in radial cross-section.

The dished diaphragm may be convex upward or downward during insertion into the can.

The diaphragm is preferably of aluminium alloy sheet, of thickness 0.010 inch for example, but other materials could be employed.

The diaphragm may be provided with a peripheral skirt to press against the cylindrical wall of the can, to spread the load and thereby reduce the possibility of a ridge being formed on the outer surface of the can.

The passage means in the diaphragm may be produced by any convenient method.

According to a third aspect of the invention a method of constructing a drinks container in accordance with the second aspect of the invention comprises holding the diaphragm in a dished form during insertion of the diaphragm to its assembled position in the container.

Usually it will be preferred to insert the diaphragm in the can just prior to filling with the drink, and then it will be preferable to purge the can with nitrogen prior to insertion of the diaphragm, and the can then being filled under pressure and sealed in the usual way.

After filling it will probablv be advantageous to invert the can and then store it inverted with the nitrogen reservoir at the top, to reduce the chance of nitrogen leaking from the reservoir.

The diameter of the holes in the diaphragm is typically 0.001 - 0.025 inch. It will be appreciated that the meniscus forces associated with the beer-nitrogen boundary at the holes in the diaphragm resist transfer of beer through the holes.

If desired the design on the exterior of the can may be printed upside down as compared with its usual orientation, so that when the can is stored with the ring tag, or other opening device, at the bottom, the appearance of the can is normal.

The user will then invert the can before opening it, and on release of the pressure in the can the nitrogen will escape from the reservoir and quickly bubble through the beer to contribute to the formation of the head on the beer when it is poured from the can.

A drinks can in accordance with the invention will now be described, by way of example only, with reference to the accompanying schematic drawings in which: Figure 1 is a perspective view of the drinks can; Figure 2 is a vertical section of the can; and Figure 3 is a section similar to Figure 2 but showing a modified diaphragm during insertion, the convexity of the suction tool and diaphragm being exaggerated in the drawing.

The metal drinks can 1 is of conventional construction apart from the provision of a metal diaphragm member 2, the can comprising a cylindrical sidewall 3, bottom 4 and top 5. The sidewall 3 and bottom 4 are integral and formed by deep-drawing of the aluminium alloy to a thickness of about 0.005 inches.

The substantially thicker tcp 5 is swaged over the free edge of sidewall 3 and is provided with a ring pull 6 for tearing out a tab 7 to provide a pouring opening in the top 5.

Diaphragm 2 is a disk of aluminium alloy sheet having an downwardly turned peripheral flange 2' which makes firm sealing engagement with the wall 3 around its entire circumference. Diaphragm 4 is of thickness about 0.010 inch and is provided with four small holes 8 of diameter in the range 0.001-0.025 inches.

The diaphragm 2, as shown in Figure 2, is positioned closer to the bottom 4 of the can than to the top 5 so as to define a main, drinks compartment 9 above the diaphragm, and a gas reservoir 10 below the diaphragm.

The modified diaphragm 2 of Figure 3 has substantially no peripheral flange. In order to insert this diaphragm 2 into the can body, the diaphragm can be applied to the convex face of a suction tool 11 to which a vacuum source is connected, in order to reduce the overall diameter of the diaphragm sufficiently to permit it to be inserted to the desired position without distorting the thin can walls 3, which might otherwise affect the appearance of the can.

If desired, a concave suction tool may be employed.

Claims

1. A drinks container of substantially cylindrical shape comprising a cylindrical wall, first and second end walls at opposed ends of the container, and a partition wall extending substantially parallel to the end walls and being positioned axially closer to the first end wall to provide a gas reservoir between the partition wall and the first end wall, the second end wall comprising an area which is adapted to provide a normally closed pouring opening to enable drink to be poured from the main chamber defined between the second end wall and the partition wall, the partition wall being provided with a passage means of predetermined dimensions to provide restricted communication between the gas reservoir and the main chamber to enable in use gas under super-atmospheric pressure in the reservoir te pass into drink in the main chamber, when the container is opened by opening of the pouring opening.

2. A drinks container as claimed in claim 1 in the form of a metal can, in which the partition wall has been formed integrally with that portion of the side wall of the can which extends between the partition wall and the second end wall, and a metal cup-shaped member has the rim thereof secured to said sidewall portion, or to the periphery of the partition wall, such that the first end wall is provided by the base of the cup-shaped member.

3. A drinks container as claimed in claim 1 in the form of a metal can, in which the first end wall is provided by an independently formed disk, the partition wall has been formed integrally with the side wall of the can, the sidewall extending as a double thickness of metal between the partition and the first end wall to provide a skirt which is secured to the periphery of the first end wall disk.

4. A drinks container cf substantially cylindrical shape comprising a cylindrical wall integral with a first end wall, a second end wall secured or adapted to be secured to the cylindrical wall to close the container, the second end wall being provided with an area which is adapted to provide a pouring opening, and an impervious diaphragm inserted, or for insertion, into the container adjacent to the first end wall, the diaphragm being dimensioned to be a close fit with the cylindrical wall to define a gas reservoir between the diaphragm and the first end wall, the diaphragm being provided with a passage means of predetermined dimensions through which in use gas can flow from the reservoir into drink contained in the main chamber of the container following release of pressure in the main chamber.

5. A drinks container as claimed in claim 4 in which the passage means comprises one or more holes extending through the diaphragm.

6. A drinks container as claimed in claim 4 in which the passage means is provided by one or more recesses in the edge of the diaphragm.

7. A drinks container as claimed in claim 5 or claim 6 in which the passage means comprises at least four holes or recesses.

8. A drinks container as claimed in claim 5 or claim 7 as appended to claim 5 in which the holes are provided in the diaphragm at positions spaced from both the centre and the edge of the diaphragm.

9. A drinks container as claimed in any one of claims 4 to 8 in which the dimensions of the relaxed diaphragm are such that the diaphragm makes an interference fit with the can side wall.

10. A drinks container is claimed in any one of claims 4 to 9 in which the diaphragm is corrugated in radial cross-section.

11. A drinks container as claimed in any one of claims 4 to 10 in which the diaphragm is provided with a peripheral skirt which presses against the cylindrical wall of the can.

12. A drinks container as claimed in claim 4 and substantially as described with reference to the accompanying drawings.

13. A method of constructing a drinks container as claimed in claim 4 comprising holding the diaphragm in a dished form during insertion of the diaphragm to its assembled position in the container, and then releasing the diaphragm to allow the diaphragm to expand resiliently in the radial direction so as to grip the cylindrical wall.

14. The method claimed in claim 13 in which the diaphragm is held in dished form during insertion by a suction tool.

15. The method as claimed in claim 13 or claim 14 in which the diaphragm is inserted into the container just prior to filling with the drink, and the container is purged with nitrogen prior to insertion of the diaphragm, the container then being filled under pressure and sealed.

16. The method of claim 13 and substantially as described with reference to the accompanying drawings.