GB2503774A

GB2503774A - A coffee capsule having a frustoconical shape with a weakened surface area to be broken by water or cutting implement.

Info

Publication number: GB2503774A
Application number: GB1307699.7A
Authority: GB
Inventors: Alex Gort-Barten
Original assignee: Individual
Current assignee: Individual
Priority date: 2012-07-04
Filing date: 2013-04-29
Publication date: 2014-01-08
Anticipated expiration: 2033-04-29
Also published as: GB2503774B; GB2503697A; GB2503697B; GB201211878D0; GB201307699D0

Abstract

A coffee machine capsule 1, designed to be sealed in use, with a frusto-conical form, with an upper surface 2 and a lower surface 3. The surface having a weakened area 8 intended to break when water at a given pressure is applied, however this area can also be pieced or cut by an implement. The weakened zone can be a circle or annulus, and a groove or undercut, also the interior of the upper surface, is of a stepped profile. The upper surface 2 is described as the surface with the smaller diameter in comparison to the other surface; it is also described as the water inlet surface.

Description

Coffee Cansule The invention relates to a capsule for making espresso coffee using an espresso machine.

Powered espresso machines are weDi known. The conventiona 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 bolder typically comprises a handle portion and a holder portion provided with two or three tugs that are a$apted to engage in the installed position with the machine brewhead to where the steam is pumped. The holder portion is adapted to receive a filter, which is usually a metal howl with a number of perforations through its bottom. In use, the filter is filled with finely ground coffee and the steam is forced through the coffee at the high pressure generated by the pump to produce the espresso coffee which i.s collected in a cup placed under the filter holder, 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 clays 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 he removed from the filter, which can lead to mess as the grinds are fine.

This lead to the development of 13SF coffee pods, which can he used in many espresso machines. Coffee pods are generally individually wrapped to maintain freshness and consist of a small pod made of a perfbrated lifter paper which contains th.e 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.

This in turn lead to the development of capsule machines. The coffee capsules for these machines are completely sealed. The capsule machines do not usc 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 surthee 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 tipper 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 arc, 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, Capsule machines have proved to be commercially very successful as they are very convenient to use and produce a consistent product. However, each manufacturers coffee machines and capsules are desilped to work with the manufacturers own brand. The most popular brand of capsule is Nespresso®, which uses a sealed capsule. In use, the capsule is clamped into position in the machine with a tubular part holding the capsule so that i.t can he cut by three prongs to enable water under pressure to enter the coffee capsule. The main alternative to this type of capsule is perforated with 6 to 9 holes to enable the water to enter the capsule. The perforations have one significant design drawback in that air can enter the capsule. Consequently, the capsules are packaged in small quantities in nitrogen filled bags to enable the shelf life of the coffee to match that of a sealed capsule. This results in significantly increased transport and. packaging costs, The present invention seeks to provide a coffce capsule which can be used in both a conventional powered espresso machines as well as in a sealed capsule machine.

According t.o the invention there is provided a capsule for use in a coffee machine having a generally frustocon.ical form with an upper surface and a lower surface, wherein the upper surface is provided with a weakened area adapted to break when water is applied to th.e weakened area under a pressure of 8 bar or greater.

Preferably, the weakened area comprises an annulus or circle, Preferably the weakened area comprises a groove or undercut in the upper surface. Preferably, weakened area adapted to break when water is applied to the weakened area under a pressure between 1 5 bar and 1 9 bar. Preferably, the groove or underctt is arranged so as to receive a cutting implement in a coffee machine. Preferably, the capsule is made from polypropylene.

The capsule of the invention advantageously provides a sealed capsule that has a commercially acceptable shelf life and which can be used in both manual espresso machines and capsule machines.

ATI exemplary embodiment of the invention will now be described with reference to the drawings, in which: Figi shows a perspective view of the capsule Fig. 2 shows a cross sectional view of the capsule Fig. 3 shows a detailed cross section of an upper surface Figure 1 shows a perspective side section of capsule 1 having a generally frustoconical form. The upper end of the cone frustrum has a. smaller diameter than the lower end, The surface 2. of the upper end of the cone is provided with a zone of weakness S in the form of an annular groove on the outer surface of the capsule. In use, cutting members of the capsule machine will usually sit just above the surface of the groove but do not pierce the capsule so that in use the water pressure bursts the weakened section and creates the path for the water to ingress the top of the capsule and into the coffee. In a manual machine that does not have cutting members, the water will simply tear or break the capsule at the zone of weakness 8.

Depending on the tolerances on the machine and capsule, it is possible that the cutting members vili penetrate the annular groove. As this area is thinner than the remaining walls, it is easer to pierce the capsule than on the thicker walls. This also facilitates the withdrawal of the cutting members.

If the capsule is made of a food grade plastic such as polypropyTene, in particular with a harrier material such as EVOH (ethylene vinyl alcohol), this anangement substantially reduces air movement between the inside and the outside of the capsule thereby greatly extending the time that the coffee in the capsule retains its aromas, EVOI-Lis used as a blended copolyiner or aso in a layered construction, In use, the capsule should be flushed with nitrogen prior to being filled to prevent oxygen degrading the quality of the coffee, This in turn. enables the producer to achieve an acceptable shelf life for the coffee without the use of a nitrogen filled pillow bag. In a particularly preferred embodiment the capsule wall is generally about 0.8mm thick but the wall around the zone of weakness is only about 0.5mm thick. Figure 3 shows in more detail the interior surface of the upper end 2. has a small stepped profile 7 in the region of the zone of weakness, so that the vail is thicker near the edge of the groove. This encourages the wail to tear near the centre of the groove 8 or undercut rather than at the edge.

The lower end of the capsule is provided with a foil seal 3, which foil seal, in use, is pressed against a filter element typically comprising a plurality of the upstanding truncaled pyramids arid adapted to assist in the tearing of the foil in use so that the coffee extracted from the coffee granules can percolate out of the capsule through holes in the filter.

The interior of the capsule is provided with several strengthening ribs to reduce the likelihood of the capsule collapsing under the pressures to which it is subjected in use.

The pressure on the inside of the capsule is typically in the range of 3 to 8 bar depending on the coffee machine and the packing density of the coffee in the capsule.

This pressure is sufficient to cause the foil to tear against a filter plate in the coffee machine. Also having a. thicker upper surface area with the internal supporting ribs will stop the rear of the capsule collapsing under pressure.

The capsule is provided with a flange 4 at its lower end, which flange 4 is adapted to cooperated with a retaining mechanism of a coffee machine in use so that the capsule can he hdd in th.e correct position when in use in the coffee machine. The flange is provided with a small groove 5, which aids die centring of the retaining mechanism..

The capsule does not have a regular conical outer di.anieter over its entire length. Th.e outer diameter of the upper part of the capsule is initially vertical and increases at a first rate until it reaches shoulder 6 when the outer diameter increases by a small amount to provide a shoulder to the rim of the capsule.

Alternatively, it would be possible to have the outer diameter of the capsule increase at a second rate greater than the first rate until the rim of the capsule.

The provision of the shoulder 6 has been found to solve the problem of the capsules becoming stuck in the tubular retaining member of capsule machines such as that disclosed in W02005008543. In use the capsule can be inserted in a conventional machine and the arrangement of the annular zone of weakness enables the upper surface of the capsule to b torn by water pressure from the espresso machine without the need for a cuffing device. The capsule is therefore suitable for use in conventional espresso machines as well as capsule machires as the pressure of the water will force the foil against the filter plate of the espresso machine to enable the extracted coffee to percolate out of the capsule.

Although the zone of weakness has been described as an annulus, it could also be circular