Beverage capsule

Abstract

A capsule for use in a coffee machine having a brew chamber, which capsule is formed from a ductile metal such as aluminium. The capsule has a generally hemispherical form with an upper surface and a lower surface, an annular flange being provided at the lower surface. The capsule is provided with a beverage precursor and is closed by a foil, wherein the foil has a diameter which is greater than the outer diameter of the capsule.

Description

[0001] Beverage Capsule

[0002] The invention relates to a beverage capsule for an espresso machine, in particular for making espresso under high pressure.

[0003] Powered espresso machines are well known. The conventional espresso machine comprises a water chamber, a heating element adapted to heat the water to around 95-98 C, which is then pumped under high pressure of 15 to 19 bar to a filter holder or portafilter. Lower pressure systems also exist. The filter holder typically comprises a handle portion and a holder portion provided with two or three lugs that are adapted to engage in the installed position with the machine brewhead to where the water is pumped. The holder portion is adapted to receive a filter, which is usually a metal bowl with a number of perforations through its bottom. In use, the filter is filled with finely ground coffee and the water is forced through the coffee at the high pressure generated by the pump to produce the espresso coffee which is collected in a cup placed under the filter holder.

[0004] The classic coffee machine suffers from two potential drawbacks. The first drawback is that ground coffee starts to lose its freshness and flavour after a few days and so for the optimum espresso, the user will also need to have a coffee grinder. The other drawback is that the used espresso coffee has to be removed from the filter, which can lead to mess as the grinds are fine.

[0005] This led to the development of ESE coffee pods, which can be used in many espresso machines. Coffee pods are generally individually wrapped to maintain freshness and consist of a small pod made of a perforated filter paper which contains the coffee. The pod is placed in the filter holder and then disposed of after use. Coffee pods are convenient but have to fit the filter holder and be placed correctly otherwise water can leak around the edge.

[0006] This in turn lead to the development of capsule machines. The coffee capsules for these machines are completely sealed. The capsule machines do not use the conventional filter holder. A capsule machine typically has a two part mechanism. The first part receives the capsule and is provided with an extraction surface upon which the capsule rests. The second part is provided with a locking lever which is used to make the first and second parts integral. In use, the second part cuts the upper surface of the capsule to allow water to enter the capsule and percolate down through the capsule, where it exits through the lower surface of the capsule at multiple locations determined by the geometry of the extraction surface. An example of such a machine is disclosed in EP 0870457 or W02005 / 004683. Capsules in the known capsule coffee machines are, in use, inserted into a capsule cage of the machine which holds the capsule in position so that it may be cut by a cutting member.

[0007] Capsule machines have proved to be commercially very successful as they are very convenient to use and produce a consistent product. However, each manufacturer’s coffee machines and capsules are designed to work with the manufacturers own brand. The most popular brand of capsule is Nespresso ®, which uses a sealed capsule made of aluminium. In use, the capsule is clamped into position in the machine with a capsule cage part holding the capsule so that it can be cut by typically three prongs to enable water under pressure to enter the coffee capsule.

[0008] A further refinement in the coffee capsule field has been the introduction of coded capsules that in principle allow the capsule machine to adjust operating parameters such as the length of the brew time or the brew temperature. The code on the capsule provides instructions to the machine with respect to at least some of the operating parameters, which enables the brew cycle to change depending on, for example, the contents of the coded capsule. An example of such a capsule is disclosed in EP2569229.

[0009] A further problem arises with the centrifugal extraction process disclosed in EP2569229 as the solution of this document requires the transfer of a high amount of torque to the capsule via the capsule lid to enable the extraction of the coffee. The capsule lid requires the use of an expensive closure foil so that the lid does not tear under the high torque.

[0010] The present invention therefore seeks to provide an improved coffee capsule.

[0011] According to the invention there is provided a capsule for use in a coded capsule beverage system, which beverage system comprises a centrifugal unit adapted to rotate the coded capsule in use, the coded capsule comprising a body having an inner profile comprising an opening, the body having a flange, wherein the capsule comprises a body with an opening, the body comprising a capsule wall having an outer profile, which capsule wall has an outer diameter at the opening the diameter of the capsule body being less than the diameter of the coded capsule body, wherein the capsule is provided with a beverage precursor and is closed by a foil, wherein the foil has a diameter which is greater than the outer diameter of the capsule

[0012] Preferred aspects of the invention are disclosed in the sub-claims.

[0013] The invention advantageously provides a solution to enable small production runs in a centrifugal capsule beverage system such as a coded capsule system. The solution also advantageously allows for coded capsules systems to become home compostable as it enables the use of paper capsules.

[0014] Exemplary embodiments of the invention will now be described with reference to the drawings, in which:

[0015] Fig. 1 shows a known coded capsule;

[0016] Fig. 2 shows a first embodiment of a capsule;

[0017] Fig. 3 shows a second embodiment of a capsule;

[0018] Fig. 4 shows a third embodiment of a capsule;

[0019] Fig. 5 shows a partial cut view of a capsule in the capsule;

[0020] Fig. 6 shows a capsule with a large diameter lid;

[0021] Fig. 7 shows schematically the large diameter lid 25 in the capsule machine

[0022] Fig. 8 shows a rim without a fold

[0023] Fig. 9 shows a stack of capsules

[0024] Fig. 10 shows an alternative approach to that of Fig 9

[0025] Fig. 11 shows a cross sectional detail of the capsule with lidding

[0026] Fig. 12 shows the capsule of Figure 4 in the centrifugal cell

[0027] Fig. 13 shows a further detail of the capsule.

[0028] Figure 1 shows a known coded capsule for use in a coffee machine using a centrifugal extraction system such as that disclosed in WO2010 / 026053. The coffee machine is provided with a centrifugal unit 4 comprising a centrifugal cell 5, which has a capsule holder and, in use, a capsule. The centrifugal unit is connected to a water reservoir and driven by a rotary motor. The centrifugal unit further comprises a collecting part and an outlet for the extracted beverage.

[0029] The machine further comprises a pump and a thermoblock together with a flowmeter so that the flow of heated water to the capsule can be controlled. Flow of the coffee from the capsule is then restricted which helps in the formation of the crema in the centrifuged beverage,

[0030] The capsule shown in Figure 1 comprises a hemispherical body 1 with a flange-like rim 2 and is closed with a foil 3 attached to the underside of the rim. The capsule is filled with beverage ingredient such as ground coffee and will be made from an anodised aluminium material, which provides an oxygen barrier to ensure that the coffee stays fresh. A code 6 is provided on the flange. The hemispherical body is provided with a plurality of indentations 7 to strengthen the capsule wall.

[0031] The capsule is designed for rotating around an axis A. This axis A crosses perpendicularly the centre of the membrane which has the form of a disk. This axis A exits at the centre of the bottom of the body. This axis A defines the circumference which is a circular path located on the capsule and having the axis A as reference axis. A code is spread along the circumference of the flange, which can be read by a code reader in the machine. The code typically comprises successive segments which are individually rectilinear but extend along the circumference. As it is technically difficult to move the code reader, the code reader remains fixed in position and reads the code as the capsule is rotated.

[0032] It is possible to purchase closure foils so that a capsule can be reused by cutting off the original foil, washing and drying the capsule and then refilling it with the chosen coffee which enables use of specialist coffee or because of environmental concerns. However, apart from the mess created each time, the grind produced in domestic coffee grinders is not always suitable for extraction in a capsule and so the resulting coffee is often unsatisfactory. Delamination of the foil in use and other leaks also occur.

[0033] To address these problems, the invention proposes the use of a capsule within a capsule shown in Figures 2 to 4. The capsule 8 of the invention is used inside a donor capsule 1 . The donor capsule 1 can be an original manufacturer capsule with the associated code on the rim, from which the closing foil has been cut off. Figure 2 shows a perspective view of a first embodiment of the capsule, comprising a generally hemispherical body 10 having a flange 11. A plurality, preferably ten, of generally rectangular recessed portions 12 are provided in the body wall extend from adjacent to the flange 11 to an upper portion of the capsule. The upper portion of the capsule 8 comprises a plurality of annular portions 13. The top most part of the capsule comprises a slightly recessed circular portion 14. The free edge of the flange 11 is rolled over, with the orientation of the roll over being towards the capsule wall.

[0034] Figure 3 shows a further embodiment of the capsule 8 in which like parts are labelled with like numbers. The principal difference between this embodiment and that of Figure 2 is that the flange 11 has been cut off. Figures 2 and 3 are particularly suitable for use with a ductile metal such as aluminium. Figure 4 shows a further design of capsule suitable for use with plastic materials including biodegradable bioplastics such as polylactic acid comprising a generally hemispherical body 20. A plurality, preferably ten, of generally rectangular recessed portions 21 are provided in the body wall extend from adjacent to the bottom edge 24 to an upper portion of the capsule. The upper portion of the capsule comprises a plurality of annular portions

[0035] 22. The top most part of the capsule comprises a slightly recessed circular portion

[0036] 23. In each case the capsule has an opening on its lower side, will be filled with ground coffee and closed with a foil 15. The dimensions of the outer diameter, inner diameter, thick ness and angle edge are important to ensure that the capsule fits into the coffee machine, does not get stuck on the blades and does not interfere with the Main Machine Seal, (i.e does not affect its compression required to get a good seal. This design is should preferably be used for capsules materials that require a minimum thickness to be greater than 0.4mm. (eg injection moulded and perhaps paper based capsules).

[0037] Figure 5 shows a partial cut view of the capsule 8 in the donor capsule 1. The capsule 1 has had its original foil closure removed along with the coffee. The capsule 8 is closed by the foil 15. The coffee is not shown for ease of understanding. The edge of the flange 2 of the capsule 1 extends in both directions perpendicular to the plane of the flange 2 thereby creating a small recess on the underside of the flange to which the original foil was adhered. The rolled over edge of the flange 11 is flattened. The wall of inner capsule 8 is shown as being spatially separated from the interior wall of the capsule 1. The rim flattening could take place as a second operation after deep drawing to form the general capsule shape or it could also be flattened on the filling line machine or as a post process after filling. In this embodiment, the outer diameter of the flange 11 is greater than the diameter of the lid 15. The outer edge of the lid 15 is located substantially at the mid point of the flange 11 and can be joined to the flange by an adhesive to close the capsule once it has been filled. Preferably the maximum stack height range is in the range of 0.01 to 0.4mm for a seal.

[0038] In the known coded capsule systems, Vertuo ®, the finished outer diameter of the capsule 8 cannot be greater than 54.6 mm, so that it can easily fit into a Vertuo donor capsule 1 taking into account manufacturing tolerances. As an outer diameter smaller than 53.7mm leaks, the flattened rim should be as close to 54.6 mm as possible. As a standard capsule grows by 1.6mm in outer diameter, when flattened down to 0.4mm. (58.0mm up to 59.6mm). Therefore the outer rolled edge of capsule before flattening is preferably 54.8 - 1.6 = 53.0mm. The capsule rim should be less than 0.4mm thick (including with lid fitted), be flat, circular, and as smooth as possible to avoid an obstruction being erroneously detected.

[0039] The capsule 8 aims to follow as closely as possible to the inner profile of the capsule 1 . A typical separation between the capsule wall and the interior wall of the capsule 1 is 0.1 mm. Due to the hydraulic and centrifugal forces on the capsule involved with the extraction process, the inner capsule 8 expands out. This would cause distortions to the capsule and thus the rim, which can interfere with the main machine seal but the approach here mitigates against this. Interference with the main machine seal could cause the capsule to leak which would result in a short shot of coffee and reduced customer satisfaction

[0040] Co-axial misalignment of the capsule and the brew chamber can occur. This is caused by being slightly undersized, compared to the lower chamber, the hinge mechanism that brings the upper and lower brew chamber together, and piercing the capsule.

[0041] Misalignment between the capsule 1 and the capsule 8 can cause the main machine seal to lap over the inner capsule 8 and cause a leak. Preferably, the inner capsule 8 is as tightly controlled coaxially to the outer capsule as possible and the outer diameter of the lidding is large enough to compensate for this coaxial misalignment, and always ensure the lidding is positioned under the seal. In this embodiment the lid and capsule body help create the seal.

[0042] Figure 6 shows a further embodiment of the capsule 8 with a large diameter lid 25. The large diameter lid 25 has a diameter which is greater than the diameter to the free edge of the capsule 8 or capsule flange 11. The large diameter lid accommodates misalignment in the lidding relative to the main machine seal. Figure 7 shows schematically how the large diameter lid 25 looks in the capsule machine. The extra lidding material wraps around the outer rim of the donor capsule (eg the capsule of Figure 1 ). The additional lidding 25 ensures any misalignment with the capsule, relative to the machine main seal is accommodated and the seal integrity during extraction is maintained. In this embodiment the lidding provides the additional seal.

[0043] The large diameter lid which is trapped in the centrifugal cage 5 further helps to avoid movement of the capsule 8 in the capsule 1 when the closure foil is being pierced by the coffee machine. It further assists with the transfer of drive torque to the capsule 8. The embodiment of Figure 4 is particularly suitable for use with a paper capsule.

[0044] The drive motor that rotates the capsule is positioned in the bottom of the machine, and thus transfers the rotational motion on to the capsule from below. The upper portion of the brew chamber or centrifugal cell is driven by the capsule lidding though the blades that have pierced it. Therefore rotational torque is transferred between the lidding and the capsule via the heat seal between the two parts. This transfer of torque induces a rotational torque load on the lid seal. If the lid seal joint is not sufficiently strong enough the lidding could separate away from the capsule or delaminate. Any break down / delamination of the heat seal between the lid and the capsule will automatically put too much pressure on the main machine seal and cause a leak This embodiment alleviates this issue by increasing the outer diameter of the lidding to be greater than the diameter of the capsule 1. This provides sufficient friction to transfer the rotational torque between the lower and upper machine, allowing for a smaller heat seal surface, preferably less than less than 1 ,85mm in width or use of materials that might otherwise be too weak such as home compostable lidding (eg polylactic acid or paper) or normal pure aluminium lidding that is not reinforced with plastic or which is made of a home compostable material such as paper.

[0045] Figure 8 shows a further embodiment of the rim 31 that does not have a fold. This type of rim is more vulnerable to damage in the unfilled state during transport and separating (destacking) the capsules from their transport stacks. In a preferred embodiment, as the number of rolls that form the rim can vary from capsule to capsule, and the OD can change or become uneccentric as it is flattened, the flange 11 is cut off from the embodiment described above during or after the filling process at the last possible moment before it goes in the carton to leave the rim shown in Figure 7. It would also be possible to cut off the flange prior to filling.

[0046] To facilitate destacking of the unfilled capsule it is preferable to enable the capsule to nest in a way that provides a minimum pitch / gap of 0.5mm between each capsule rim. A step / ledge 32 on the capsule wall is added as shown in Figure 9 which provides this pitch.

[0047] Figure 8 shows an alternative approach to that of Figure 5 in which the flange is cut off during the filling process, preferably before the capsule is filled and the lid applied so that the lid foil diameter can be greater than the outer diameter of the cut capsule. The rim may be cut and removed in one piece or it may be cut into various segments by a knife edge press tool, with the waste being vacuumed or blow away. A second vacuum station may be provided to further remove and aluminium residue.

[0048] The capsule has 40 ribs 34, which are arranged to nest between internal ribs 7 of the capsule 1. These ribs further help prevent the capsule from expanding during extraction. Expansion of the capsule wall could cause a crease to form in the rim which would lead to a coffee leak during extraction. The interlock ribs help transfer the rotational motion from the donor capsule 1 to the capsule 8, which puts less pressure on to the lid foil.

[0049] Figure 11 shows a cross sectional detail of the capsule with lidding 25 positioned inside the donor capsule 1 and Figure 12 shows the capsule in the extraction position within a centrifugal coffee machine showing element of the centrifugal cell 5.with the capsule 8 in the extraction position. The capsule 8 sits inside the capsule 1 with the edge of the rim 24 adjacent to the machine seal 6. The capsule 10 is closed by a foil 15 which extends underneath the machine 6 to adjacent to the rolled edge of the flange of the capsule 8.

[0050] Figure 13 shows a further detail of the capsule, in which the material thickness of the capsules is greater than 0.4mm. In this embodiment, the flange sits on top the clone capsule flange

[0051] Material thickness of 0.4mm and under the inner capsules can have a flange that sits at a height slightly higher than the flange of the donor capsule. In this embodiment, as the pressure builds in the capsule, due to water pressure / centrifugal force, the sides push outwards, forcing the side of the capsule, / lid against the side and bottom of the machine main flexible seal.

[0052] It would further be possible to add a tab to the foil to facilitate the removal of the capsule 8 from the capsule 1 .

Claims

Claims1. A capsule for use in a coded capsule beverage system, which beverage system comprises a centrifugal unit adapted to rotate the coded capsule in use, the coded capsule comprising a body having an inner profile comprising an opening, the body having a flange, wherein the capsule comprises a body with an opening, the body comprising a capsule wall having an outer profile, which capsule wall has an outer diameter at the opening the diameter of the capsule body being less than the diameter of the coded capsule body, wherein the capsule is provided with a beverage precursor and is closed by a foil, wherein the foil has a diameter which is greater than the outer diameter of the capsule.

2. A capsule according to Claim 1 , wherein the foil material wraps around the outer rim of the coded capsule.

3. A capsule according to Claim 1 or Claim 2, wherein the outer diameter of the lidding is positioned under sealing or clamping elements of the centrifugal unit4. A capsule according to any one of Claims 1 to 3, wherein the centrifugal unit traps the foil between the unit and the rim of the coded capsule.

5. A capsule according to any one of Claims 1 to 4, wherein the capsule is generally hemispherical.

6. A capsule according to any one of Claims 1 to 5, wherein the foil is generally circular.

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