GB2403212A

GB2403212A - Sealing unit for a drinks can

Info

Publication number: GB2403212A
Application number: GB0313021A
Authority: GB
Inventors: Keith White
Original assignee: Individual
Current assignee: Individual
Priority date: 2003-06-06
Filing date: 2003-06-06
Publication date: 2004-12-29
Also published as: WO2004108548A1; GB0313021D0

Abstract

A sealing unit or stopper or plug or bung, for use on ring pull type drinks cans, which is used for re-sealing the can, once opened. Consists of a driving member 7 and a driven member 8 which co-act to compress and expand a sealing element 4 by applying pressure to said sealing element. A washer 3 may be provided, the driving member 7 may be a cap (fig 2,1) or a wing nut 7 and the mechanism may be a screw thread and nut arrangement. Alternating the mechanism may be a clamp lever (fig 5, 5).

Description

24032 1 2

SEALING UNIT FOR DRINKS CANS

This invention is a sealing unit for re-sealing the conventional type of 'Ring Pull' drinks can.

Many inventions have been proposed in the art for re-sealing the ring pull type of drinks can once it has been opened. It is quite common for the users of such cans to have taken sufficient from the contents long before the can is empty. In such circumstances it is preferable to keep the drink in good condition for later consumption.

One problem with re-sealing systems is that many re-sealing systems do not provide a gas tight container. Vapour pressure cannot build up inside of the can to prevent the boiling off of carbonic acid. This loss of carbonic acid from a drink results is a corresponding loss of the customary fizz due to lack of carbonation. The resulting lack of carbonation presents the drink as 'flat' and unpleasant to the consumer.

Another problem with such cans once opened is that of spillage or alternatively the entry of insects into open cans.

One solution which is typical of many in the art is to construct the can with a built in re-sealing element such as is shown in US 5 810189, the problem with this however is the cost increase which is attributable to the complexity of the : d manufacturing process and that this cost is carried by all purchasers of drinks cans.

Another solution which is typical of the art is taught in WO 02/081321 in which a cap is placed over the entire end of a drinks can in this case with a system included for releasing the gas pressure by deforming the outer rim of the cap.

Such cap is designed to hook on to the top of the can around the top edge with sufficient force to prevent accidental removal of the cap.

A further example v.hich is typical of the art can be found in EP 0934 887 where particular attention has been paid to the design of the inner surface of the sides of the cap in order to ensure a better grip between the cap and the can. Though, in the same way as in previous art it is still necessary to rely on the ability of the cap to grip onto the raised rim at the top edge of the drinks can. This European patent also takes the art a stage further however by providing a re-sealable exit for the liquid inside of the can so as to eliminate the need to remove the cap before taking a drink from the can.

There is a common problem with examples of a can re-sealing unit as taught by the art and it is related to the efficiency of the seal. With the exception of designs which are incorporated into the original design of the can itself other examples rely on a close fit between the can and the cap. To supplement this some detail on the inside of the surface vvhich slides over the can is often provided to increase the interlock betvveen the cap and can. 1 1

Because of the pressures of gas inside of the can it is common for these designs to fail at high pressure thus releasing gas from the can and causing the drink contained inside to go 'flat' and therefore to become unacceptable to the user. It will be understood that such problems defeat the primary object of the invention.

It is the object of the present invention to overcome the difficulties found in the art and to provide a removable re-sealable drinks can resealing unit which can be an effective seal against the escape of gas under pressure.

According to the intention there is provided a sealing unit for drinks cans consisting of a driving member, a driven member, a compression washer and an expanding seal. These elements being assembled together such that the driving member applies force to the driven member. Such force is maintained either by continuous pressure from the driving member onto the driven member or by rotating the driving member along a screw thread of suitable pitch formed between the driving member and the driven member. Pressure applied to the driven member is transferred directly to the compression washer. As the pressure or the compression washer is increased, the distance between the driving surface of the driving member/compression washer and the distal end of the driven member is reduced, thus compressing the expanding seal.

If this action takes place when the expanding seal is placed into the open hole in a drinks can then the expansion seals the hole in the drinks can both from above and below thus preventing the escape of gas from the can.

To increase efficiently the compression washer could be shaped with a tapered neck extending down from the underside of the compression washer into the expanding seal.

Examples of the invention are given in the following drawings in which: Fig.1 Is an illustration of a standard drinks can Fig 2 Is a threaded cap driven sealing unit where 2/1 is the driving member, 2/2 is the driven member, 2/3 is the compression washer, 2/4 is the expanding seal.

Fig 3 1 a wing nut driven sealing unit where 3/7 is the driving member, 3/8 is the driven member, 3/3 is the compression washer and 3/4 is the expanding seal.

Fig4 Is an alternate threaded cap sealing unit where the thread diameter is smaller than Fig 2. In which 4/9 is the driving member, 4/8 is the driven member, 4/3 is the compression washer and 4/4 is the expanding seal.

Fig 5 Is a further sealing unit with a clamp lever action in which 5/5 is the driving member, 5/6 is the driven member, 5/3 is the compression washer and 5/4 is the expanding seal.

Fig 6 Is a further sealing unit of different construction to the previous example where 6/10 is the driving member, 6/11 is the driven member, 6/3 is the compression washer and 6/4 is the expanding seal.

Fig 7 Shows the compression washer.

Fig 8 Shows an alternate view of the compression washer 3 and the expanding seal 4.

The invention will now be more particularly described by way of example with reference to the drawings previously listed.

This invention relates to a sealing unit for a drinks can such as the can 12 shown in Fig 1. These cans typically have a ring pull 1/13 which is pulled upwards breaking off a section of the can 1/14, leaving a hole at 1/14. In some cans the ring pull is retained and in others it is removed completely. It is desirable in the case of the current invention if the ring pull is removed from the can completely, even with those cans intended to retain the ring pull.

Once the can has been opened the invention can be brought into use by placing it on the top of the can 12 and inserting it through hole 14. The distal end of the driven member 2 together with the distal end of the compression washer 4b both extend through the hole 14 in the can. The unit would then come to rest with the shoulder of the compression washer 4a resting on the top of the can.

When the unit is in position the compression washer 3 which is shown in greater detail in Figures 4 and 7 is arranged so that its curved edge is aligned with the curvature of the top of the can 12. In many cans there is formed a trough extending around the whole of the inner periphery of the top edge of the can. This trough has the appearance of a recess and is a by product of the forming process during manufacture of the can. The protrusions 3a formed on the compression washer 3 will fit into the cans peripheral recess thus assisting retention of the unit in the correct position on the top of the can.

Following the example in Figure 1 In use pressure is applied to the compression washer by rotating the driving member 1 on the screw thread which coexists between the driving member 1 and the driven member 2 causing the shoulders 1a to apply pressure to the compression washer 3. The distance between the shoulders 1a and the distal end of the driven member 2a is reduced thus compressing the expanding seal 4.

The expanding seal 4 maybe assisted by the compression washer, which can be equipped with a conical flange 3a designed to enter the expanding seal 4 and assisting in its expansion. The expanding seal 4 deforms in a number of directions but essentially it expands to fill the hole 14 in the drink can. It becomes a barrel shape inside the can where the waist of the barrel grips the underside of the hole 14. A seal is therefore formed in three ways.

Firstly by compression distorting the expanding seal 4 to a barrel shape forming a closer fit into the hole 14.

Secondly by such forming action having expanded the part of the seal inside the can to be a greater diameter than that of the hole.

Thirdly by leaving that part of the seal 4 which is now of greater diameter than the hole 14 to grip the underside of the hole 14 inside the can at the same time as the surface 4 is compressed against the outside top surface of the can. Thus a firm gas tight seal is formed which can contain the pressures of gasses normally associated with drinks cans.

Another form of seal is shown in Fig 3 which operates exactly the same as the previously described seal in Fig 2. In this Fig 3 example the diameter of the threaded portion of the driven member 8 is narrower than that shown in the Fig 2 example. Also the driving member 7 is differently shaped but such shape is not restricted to that shown in Fig 3. 1,

A similar arrangement to Fig 3 is shown in Fig 4, again illustrating a differently shaped driving member 97 and a differently pitched thread on the driven member 8.

A further arrangement is shown in Fig 5 in which the driving member S is a lever which pivots on a bearing contained in the top of the driven member 6.

Fliping the lever 5 over through 180 caused the surface 5a to bear on the compression washer 3 thus achieving the same compression action as in the

previous examples.

A final example is shown in Fig 6 which still retains the same compression principal but in this case the turning action to achieve the pressure is achieved by rotating the driving member bring the driven member 11 to bear on the compression washer 3 but in this case the driving member 10 itself extends downwards through the expanding seal 4.

A further version of the sealing unit is intended wherein there is incorporated a provision for storage of the can seal after it has been broken from the can.

There could also be many other possible arrangements to achieve the deformation of the expanding seal 4 and the drawings are only shown here by

way of example.

Claims

Claims 1 A sealing unit for drinks cans comprising at least a driving

member, a driven member and a seal arranged so that the driving member co-acts with the driven member to apply pressure to said seal.
2 A sealing unit according to claim 1 whereby pressure applied to said seal causes said seal to expand
3 A sealing unit according to claim 1 or 2 where a compression washer is placed between the driving member and the seal.
4 A sealing unit according to any preceding claim where the driving member comprises a cap or knob incorporating a screw thread.
A sealing unit according to claims 1,2 or 3 where the driving member consists of any nut including a wing-nut with a female thread, which engages a corresponding male thread on a driven member.
6 A sealing unit according to claims 1,2 or 3 where the driven member is a bolt
7 A sealing unit according to any preceding claim where the driven member is constructed with a male thread which can co-act with the driving member.
8 A sealing unit according to claims 1,2 or 3 where the driving member consists of a lever so formed that when it is rotated about a horizontal axis it co-acts with the driven member so that pressure is applied to the seal.