GB2392374A

GB2392374A - A beverage sachet with an annular spacer

Info

Publication number: GB2392374A
Application number: GB0220105A
Authority: GB
Inventors: John Nicholas Reid
Original assignee: Vallid Ltd
Current assignee: Vallid Ltd
Priority date: 2002-08-30
Filing date: 2002-08-30
Publication date: 2004-03-03
Also published as: AU2003259365A1; GB0220105D0; WO2004019741A1

Abstract

A sachet is disclosed for producing a beverage, such as brewed tea or percolated coffee. The sachet 10 comprises two sheets 12, 14 made of a flexible water impermeable material that are sealingly joined to one another to define a pocket. A particulate material 18, such as tea leaves or ground coffee powder, is disposed within the pocket. An annular spacer 16 is within the pocket and bonded to both of the flexible sheets 12, 14. The annular spacer 16 is formed with passages 22 that enable liquid injected into the hollow centre 20 of the annular spacer 16 to flow through the annular spacer 16 into contact with the particulate material 18 contained in the pocket.

Description

DISPENSING OF BEVERAGES

Field of the invention

5 The present invention relates to the dispensing of beverages. Background of the invention

lo In order to dispense beverages such as coffee, tea, chocolate or soup, dispensing machines have normally relied on the use of instant products, these being powders that dissolve completely in water to produce the desired beverage. To make the beverage, it was only necessary to 15 dispense the appropriate amount of instant powder into a cup and to fill the cup with water. This considerably simplified the construction of the vending or dispensing machine, but the taste of the resulting beverages left much to be desired. Most consumers prefer tea made by brewing tea go leaves and coffee made by percolating hot water through ground coffee powder.

To produce beverages of improved quality, machines are known that do use tea leaves and ground coffee powder 25 instead of instant tea and coffee, examples of these being available in the UK under the Flavia and Kenco Singles trade marks. In the known machines, individual sealed sachets or boxes containing tea leaves or ground coffee powder are inserted into a dispensing machine. In the so dispensing machine, the sachet or box is pierced by a tube that is used to inject hot water into it. After the water has filtered through the ground coffee powder or remained in contact with tea leaves for a sufficient time for the tea to brew, the resulting beverage leaves the sachet and falls 35 directly into a cup for dispensing.

- 2 The known sachets and boxes are of complex construction and this adds considerably to their cost. In the case of the Flavia sachets, a funnel needs to be incorporated and sealed into a lateral edge of each sachet to receive and 5 guide the tube that is used to inject hot water into the sachet. In the case of the Kenco Singles boxes, the box is itself a costly moulded component which defines a complex array of passageways to ensure that the water fully contacts the contents of the box.

Object of the invention The present invention seeks therefore to provide a simpler and less costly solution to the problems encountered 15 when dispensing beverages by passing a liquid over a particulate material that may not itself be fully soluble.

Summary of the invention

so According to the present invention, there is provided a sachet for producing a beverage, comprising two sheets made of a flexible water impermeable material that are sealingly joined to one another to define a pocket, a particulate material disposed within the pocket, and an annular spacer 25 arranged within the pocket and bonded to both of the flexible sheets, the annular spacer being formed with passages for enabling liquid injected into the hollow centre of the annular spacer to flow through the annular spacer into contact with the particulate material contained in the JO pocket.

The particulate material contained in the pocket of the sachet may be ground coffee powder, tea leaves or other plant leaves for forming an infusion. However, while the s invention is particularly suited for beverages that require brewing or percolation, there is no reason why the particulate material may not be a fully soluble powder such

- 3 - as instant tea, instant coffee or any freeze dried powder from which a beverage can be produced.

The hollow centre of the spacer, when covered on both 5 sides by the sheets of water impermeable material, forms a small plenum chamber. In use, a tube is introduced into the plenum chamber by piercing one of the two sheets. The thickness of the spacer keeps the two sheets apart to ensure that the tube does not pierce both sheets and that it does lo not pass out of the other side of the sachet. A liquid, normally hot water, is then injected into the plenum chamber to build up a pressure in the plenum chamber. The pressure forces the pierced sheet back to effect a seal against a stop surrounding the inserted end of the tube. Liquid then 15 flows through the passages into the pocket of the sachet and these passages act as a manifold to direct the liquid to all parts of the pocket so that it comes into contact with the entire contents of the pocket.

so The radial passages in the spacer need to be sufficiently fine not to be blocked by the particulate material contained in the sachet and to moderate the rate at which liquid enters into the sachet.

25 The spacer may conveniently be formed as an injected moulded plastics component.

The passages may be formed by radial slits or channels in one or both axial end surfaces of the spacer that are 30 bonded to the sheets of impermeable material.

If the passages need to be finer than can be formed in a spacer made as a one-piece moulding, it is alternatively possible to form the spacer of two halves having depressions 35 in their mating surfaces which define the desired passages when the two halves are mated with one another.

- 4 If the spacer is formed of two mating halves, it is desirable for the two moulded halves to be joined to one another by flexible hinge to assist in their alignment during assembly and to enable their assembly to be 5 automated.

It is also preferred for the two halves to have mating projections and depressions to allow the two halves to interlock with one another.

Advantageously, the axial end surfaces of the spacer that are bonded to the sheets defining the pocket are convex outwards so that the water impermeable sheets are stretched across the centre of the annular spacer. Because the sheets 15 are in tension, they may be pierced more easily by the tube used to inject a liquid into the sachet.

The invention will now be described further, by way of example, with reference to the accompanying drawings, in 20 which: Figure 1 is schematic section through a sachet of the invention suitable for making tea and infusions, Figure 2 shows a blank of which the two halves can be assembled to form a spacer, 25 Figure 3 is a section through a spacer assembled from the blank of Figure 2, the section plane passing through two of the radial passages along which liquid may flow, Figure 4 is a section through the two halves of the blank of Figure 2, the section plane passing through lugs so and sockets that maintain the spacer in an assembled condition, Figure 5 is a section through an alternative form of spacer moulded in one piece, Figure 6 is a section, drawn to an enlarged scale, 35 through part of the sachet shown in Figure 2 during the injection of water into the sachet,

Figure 7 is a section similar to that of Figure 1 through a sachet suitable for making coffee, and Figure 8 is a section similar to that of Figure 3 showing an alternative construction of the spacer.

The sachet 10 shown in Figure 1 is formed of two sheets 12, 14 of a water impermeable plastics material. The sheets 12, 14 are welded to one another around the periphery of the sachet to form a closed pocket and the sachet is filled with a predetermined quantity of a granular material 18, such as tea leaves or coffee powder.

Though there is nothing to preclude the use of the invention in the preparation of instant beverages which are 15 made from a fully soluble powder, the invention is particularly well suited to beverages that need to be brewed, for example tea, infusions and coffee. With such beverages, the liquid needs to remain in contact with the granular material for some time and the granular material go does not dissolve fully in the liquid.

The sheets 12,14 may be laminated, that is to say each sheet may comprise several layers having different chemical composition that are bonded to one another. Thus, the inner 25 layer of each sheet may be formed by a material such as polypropylene to enable the sheets to the welded to one another while the outer layer may be formed of a polyester for improved strength and impermeability. A metallic layer, such as aluminium, may also be included in the laminated 30 structure of each sheet.

A spacer 16 is placed within the sachet 10 and is bonded to both of the sheets 12,14. As shown in Figure 6, the spacer 16 defines a central plenum chamber 20 which has 35 radial passages 22 through which a liquid (usually hot water) injected into the plenum chamber 20 can flow into contact with the granular material 18. One function of the

À 6 spacer 18 is to ensure that the tip of a needle 28 used to pierce one of the sheets 12 remains within the enclosed space of the sachet and does not pass all the way through both of the sheets 12 and 14. The spacer 16 also acts as a 5 manifold to ensure that the injected liquid reaches all parts of the interior of the sachet to make full contact with the tea leaves.

Figures 2 to 4 show the construction of one possible lo embodiment of the spacer 16. The spacer is formed from two injection moulded halves 16a and 16b that are assembled to one another. The two halves are moulded together and can be connected to one another by a film hinge 16c, as shown in Figure 2, though this is not essential. Each half 16a, 16b 15 is annular and is formed with radial recesses 22a and 22b, respectively, which radiate from a central hole 20a, 20b.

The recesses 22a and 22b together define the passages 22 when the two halves 16a and 16b are mated to one another as shown in Figure 3.

The two halves may be glued to one another and/or secured to one another by lugs 24 which project from one half and engage in a socket 26 in the other half. The lugs 24 can have an enlarged and barbed head to assist in 25 preventing separation of the two halves after they have been pressed together.

It is of course not essential to form recesses 22a and 22b in both halves of the spacer as forming them in only one 30 of the halves would suffice. It is even possible not to form recesses in either of the two halves if the length of the lugs 24 exceeds the depth of the sockets 26 to leave a slight gap between the two halves when assembled to one another. It is not even essential that the gap be present 35 permanently in that if the engagement of the lugs 24 in the sockets 26 allows some free play, then the two halves will separate under the pressure of the liquid that is injected

- 7 the plenum chamber 20 at the centre of the spacer 16 to create the desired gap.

The spacer 116 shown in Figure 5 is moulded in one 5 piece with deep recesses 122 formed in at least one side of the spacer 116 and radiating from a central hole 120. When the spacer 116 is welded to the sheets from which the sachet is made, the end surfaces of the recesses 122 define enclosed passages through which a liquid injected into the lo hole 120 may pass radially through the spacer 116.

The spacer in Figure 8 is formed of two halves 86a and 86b. In its assembled state, the spacer is shaped as a hollow doughnut having annular cavity 88 separated from the 15 central opening 80 by a tubular wall 82. Holes 88 in the tubular wall 82 allow liquid to flow into the annular cavity 88 without encountering resistance to flow. The two halves 86a and 86b are coupled to one another by mechanical engagement between the two halves of the tubular wall 82.

to Formations on a narrow peripheral portion of each half of the spacer create the passages through which liquid can flow out of the spacer and into the sachet.

Figure 8 also shows that a deflectable lip 92 may be 25 formed at the mouth of the passages to act as a one-way valve. Such a lip will deflect under pressure to allow liquid to leave the spacer but will prevent movement of liquid and particulates into the spacer.

So Referring now to Figure 6, in use the sachet is fed into a filling station where the spacer 16 lines up with a needle 28. The needle 28 is itself guided by a tube 30 having at its free end a resilient sealing washer 32, made for example of silicone. The tube 30 and needle 28 are moved 35 from right to left, as viewed in Figure 6, until the needle punctures the upper sheet 12 and the tube 30 comes to rest against a portion of the sheet 12 supported from within by

the spacer 16. This limits the penetration of the needle 28 into the sachet and prevents it from puncturing the sheet 14 on the opposite side of the sachet. Because the spacer 16 is formed with convex outer surfaces, the sheets 12 and 14 are 5 stretched across the central hole in the spacer and the resulting tautness of the sheets assist in the puncturing of the sachet by the needle 28.

Liquid is now injected under pressure into the plenum lo chamber 20. The pressure of the liquid acts in the manner indicated by the arrows to push the sheet 12 upwards into sealing contact with the washer 32 to prevent the liquid from escaping from the sachet. The liquid then passes through the passages 22 in the spacer 16 and enters the 15 sachet where it comes into contact with the granular material 18 to commence the brewing of the beverage.

After the liquid has slowly passed through the granular material the beverage is dispensed from the sachet into a 20 Cup. The advantage of providing a lip on the spacer, such as the lip 92 shown in Figure 8, is that the tip of the needle 28 will only ever come into contact with the liquid injected 25 into the sachet and never with the resulting beverage. The tip of the needle therefore always remains clean and there is no risk of cross contamination when using different types of beverage sachets in the same dispensing machine.

so The brewed beverage may leave the sachet in a variety of ways. In the case of tea or plant leaves, it suffices to puncture an array of small holes in a region of the sachet to act as a sieve which allows the liquid to leave the sachet while the leaves are retained. The holes may be 35 covered by a label that is cut before the dispensing operation, the label acting to keep the contents of the sachet fresh while the sachet is in storage.

- 9 - In the case of ground coffee, such a sieve formed as part of the sachet would not be suitable to retain the ground coffee powder. It is preferred to bond on the interior of the sachet a sheet of water permeable filter 5 paper 40 as shown in Figure 7 of the drawings. The filter paper 40 aside from retaining the ground coffee powder in the sachet regulates the rate at which the hot water can percolate through the coffee powder.

lo It is an important advantage of the sachet of the invention that several such sachets can be connected to one another to form a continuous web. The web can be fan folded and stored in a dispensing machine in this manner, so that sachets can be advanced one at a time towards a dispensing IS station. In this manner, the invention for the first time permits fully automated dispensing of brewed tea and percolated coffee.

Claims

- 10 CLAIMS

1. A sachet for producing a beverage, comprising two sheets made of a flexible water impermeable material that 5 are sealingly joined to one another to define a pocket, a particulate material disposed within the pocket, and an annular spacer arranged within the pocket and bonded to both of the flexible sheets, the annular spacer being formed with passages for enabling liquid injected into the hollow centre of the annular spacer to flow through the annular spacer into contact with the particulate material contained in the pocket.

2. A sachet as claimed in claim 1, wherein the spacer 15 is formed as an injected moulded plastics component.

3. A sachet as claimed in claim 2, wherein the passages are formed by radial slits in one or both axial end surfaces of the spacer that are bonded to the sheets of 2 0 impermeable material.

4. A sachet as claimed in claim 2, wherein the spacer is formed of two halves having mating surfaces which define between them the desired passages when the two halves are 25 mated with one another.

5. A sachet as claimed in claim 4, wherein the mating surface of at least one of the two halves is formed with recesses.

6. A sachet as claimed in claim 4 or 5, wherein the two moulded halves are joined to one another by flexible hinge. 35

7. A sachet as claimed in any of claims 4 to 6, wherein two halves to have mating formations to allow the two halves to interlock with one another.

l

8. A sachet as claimed in any of claims 4 to 7, wherein a deflectable lip is provided at the mouth of the passages to act as a one-way valve and prevent flow of liquid and particulates into the spacer.

9. A sachet as claimed in any preceding claim, wherein the axial end surfaces of the spacer that are bonded to the sheets defining the pocket are convex outwards so that the water impermeable sheets are stretched across the lo centre of the annular spacer.

10. A sachet as claimed in any preceding claim, further comprising a water permeable filter bonded to the interior of the sachet.

11. A sachet as claimed in any one of claims 1 to 9, wherein at least one of the sheets is formed with an array of holes to act as a sieve through which liquid may pass out of the sachet while retaining the granular material within 20 the sachet.

12. A sachet constructed substantially as herein described with reference to and as illustrated in the accompanying drawings.