PREPARATION SYSTEM FOR EXTRACTING A PRODUCT CONTAINED IN A CAPSULE

The preparation system has a capsule 11 which is provided with a conical side wall 13, a first end 13a of which has a larger outer diameter than the second end 13b. The capsule 11 is provided at the first end 13a with an outwardly projecting flange 15 to which a foil 19 is attached which foil closes the capsule. The preparation device 1 has a pressure cylinder 3 which is slid over the capsule 11 and presses the flange 15 against a counter plate 5. The pressure cylinder has to be liquid-tight in contact with the capsule. The outer diameter of the first end 13a of the side wall 13 of the capsule being larger than the inner diameter of the pressure cylinder 3. When the pressure cylinder is slid over the capsule, the capsule will compress in the axial direction, such that the deformed part of the side wall 13 forms a liquid-tight seal between the capsule 11 and the pressure cylinder 3.

TECHNICAL FIELD OF THE INVENTION

The invention relates to a preparation system for preparing a beverage by extracting a product contained in a capsule, in particular ground coffee beans, in a suitable preparation device, said preparation system comprising:a capsule with:an at least partly conical side wall with two ends, of which a first end has a larger outer diameter than the second end, the outer diameter of the side wall from the second end until the first end gradually increases in diameter and does not jump in diameter,an outwardly projecting flange present at the first end of the side wall,a bottom closing the capsule at the second end of the side wall,a foil with its edge on the flange and attached to the flange and closing the capsule at the first end,a preparation device into which the capsule can be placed and which is equipped with:a counter plate,a pressure cylinder which is pushed over the side wall of a capsule introduced into the preparation device and presses with one end against the flange of the capsule, thereby pressing this flange against the counter plate in the preparation device, the end of the pressure cylinder being stepped such that in the pressure direction of the pressure cylinder an inner part of the end of the pressure cylinder projects from an outer part of the end of the pressure cylinder.

The pressure cylinder has to be in liquid-tight contact with the capsule so that no liquid can leak between the flange and the pressure cylinder. The pressure cylinder can have a circular cylindrical or conical shape.

BACKGROUND OF THE INVENTION

Such a preparation system is known from WO2013/184652A1. The capsule of this known preparation system is provided with an annular tray which receives the end of the pressure cylinder and then deforms when the pressure cylinder is moved to the working position to obtain a liquid-tight seal. The capsules of this well-known preparation system are an alternative to the capsules that Nestlé offers under the brand name Nespresso®. In the preparation devices that cooperate with these capsules, the pressure cylinder is provided with irregularities that leak with capsules without special provisions, which makes the capsules actually unusable. The Nespresso® preparation system capsule has an elastic layer on the flange that contacts the uneven end of the pressure cylinder during extraction and provides a liquid-tight seal between the pressure cylinder and the capsule flange. The disadvantage of this known capsule is that an extra sealing element has to be applied, which increases the production costs of the capsule.

SUMMARY OF THE INVENTION

An object of the invention is to provide a capsule for use in the Nespresso® preparation system, whereby a better sealing is obtained during use than with the capsule known from WO2013/184652A1. To this end, the preparation system according to the invention is characterized in that:from the second end to a first location at a first distance from the first end the outer diameter of the side wall of the capsule is less than the inner diameter of the pressure cylinder at the end,from the first place to a second place at a second distance from the first end, which second distance is smaller than the first distance, the outer diameter of the side wall of the capsule is less than the outer diameter of the inner part of the end of the pressure cylinder, andfrom the second place to the first end the outer diameter of the side wall of the capsule is greater than the outer diameter of the inner part of the end of the pressure cylinder.

When moving the pressure cylinder over the capsule, the capsule is first centered in the pressure cylinder by the part of the side wall with a diameter greater than the inner diameter of the inner part of the end of the pressure cylinder. When the pressure cylinder is moved further, due to the increasing diameter of the side wall of the capsule, from a certain point this side wall is no longer pressed radially inwards, but is pressed axially together. The compressed part of the side wall forming a seal between the capsule and the pressure cylinder.

An embodiment of the preparation system according to the invention is characterized in that from a third place at a third distance from the first end, which third distance is smaller than the second distance, up to the first end, the side wall of the capsule is cylindrical. The end of this cylindrical part facing away from the flange forms a hinge. During deformation of the side wall of the capsule by the pressure cylinder, the side wall of the capsule rotates inwards and folds around the inner part of the end of the pressure cylinder forming a seal between the capsule and the pressure cylinder. This provides a better seal than without the presence of this cylindrical part of the side wall of the capsule. Hereby, the side wall of the capsule deforms plastically.

Preferably, a part of the side wall of the capsule adjacent to the flange is made thicker or thinner over the entire circumference than the remaining part of the side wall. As a result, more material deforms when the pressure cylinder is slid over the capsule, so that an even better seal between the flange and the pressure cylinder is obtained.

A further embodiment of the preparation system according to the invention is characterized in that the side wall of the capsule is provided with a circumferential slot and/or circumferential rib. As a result, the inner edge or end of the pressure cylinder, when sliding over the capsule, hooks behind a boundary edge of the circumferential slot or behind the circumferential rib, after which the part of the side wall between this circumferential slot or circumferential rib and the flange is pressed together by the pressure cylinder. The pressed-together part forms a seal between the flange and the end of the pressure cylinder.

Yet a further embodiment of the preparation system according to the invention is characterized in that an annular reinforcing element is present in the capsule which is at least partly in contact with the inner side of the side wall of the capsule at the flange and extends over the entire inner circumference. This reinforcing element forms a reinforcement of the side wall of the capsule. If this reinforcement is designed as a ring, this ring can for instance have an L-shaped, rectangular or round shape. This reinforcing element can be of rigid, hard material if the part of the side wall where the reinforcing element is located serves to center the capsule with respect to the pressure cylinder, or of a supple soft compressible material if the part of the side wall where the reinforcing element is located serves to be crushed or otherwise deformed.

Preferably, the annular reinforcing element is provided with an annular first part being in contact with the inside of the side wall and an annular second part extending parallel to the foil.

Further, the reinforcing element preferably comprises a sleeve-shaped part that for at least part of its length is in contact with the inside of the capsule. This sleeve-shaped part forms a reinforcement of the wall of the capsule, so that the capsule wall can be made thin.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1shows a first embodiment of the preparation system according to the invention in cross-section in which only the parts of the preparation apparatus necessary for the explanation are shown. The preparation system consists of a preparation device1and co-acting capsules11which can be introduced into the preparation device. Each capsule is provided with a conical side wall13with two ends, a first end13aof which has a larger outer diameter than the second end13b.At the first end13a,the capsule11is provided with an outwardly projecting flange15on which a sealing foil19is mounted and at the second end13b,the capsule is provided with a bottom17.

The preparation device1has a circular cylindrical pressure cylinder3which, for extracting the ground coffee beans present in the capsule introduced into the preparation device, is slid over the side wall13of the capsule11and with an end presses the flange15of the capsule against a counter plate5present in the preparation device. This end4of the pressure cylinder is provided with unevenness, for example protruding serrations or teeth. The counter plate5is provided with a wafer structure7which is provided with through-flow openings for allowing the prepared liquid to flow out of the device.

The end4of the pressure cylinder3is stepped such that in the pressure direction of the pressure cylinder3(this is towards the counter plate) an inner part4aof the end4of the pressure cylinder protrudes relative to an outer part4bof the end4of the pressure cylinder.

Simultaneously with the displacement of the pressure cylinder, the bottom17of the capsule is pierced by needles9present in the device through which hot water is injected under pressure into the capsule. Due to pressure build-up in the capsule, the foil19is pressed against the wafer structure7and thereby tears open at various places, so that the extract can flow out of the capsule. The pressure cylinder has to connect liquid-tight to the capsule so that no liquid can leak between the flange and the pressure cylinder.

InFIG. 2, the capsule11is shown separately in side view. The outer diameter of the side wall13of the capsule11is from the second end13bto a first location21at a first distance22from the first end13a,smaller than the inner diameter of the pressure cylinder3at the end4. From the first place21to a second place23at a second distance24from the first end13a,which is smaller than the first distance22, the outer diameter of the side wall13of the capsule11is smaller than the outer diameter of the inner part4aof the end4of the pressure cylinder3. During the displacement of the pressure cylinder3over a first distance, a slightly conical part of the side wall13will be pressed radially inwards, so that the capsule11centers in the pressure cylinder3.

From the second place23to the first end13a,the outer diameter of the side wall13of the capsule11is larger than the outer diameter of the inner part4aof the end4of the pressure cylinder3. As a result, when the pressure cylinder3is moved further, the side wall13folds around the inner part4aof the end4of the pressure cylinder3. By designing the side wall13of the capsule11cylindrically from a third place25at a third distance26from the first end13a,which is smaller than the second distance24, up to the first end13a,the side wall13can be formed better around the inner part4aof the pressure cylinder3because the end of the cylindrical part acts as a hinge when deforming the side wall13.

InFIGS. 3 and 4, the capsule preparation system is shown in side view during the centering of the capsule relative to the pressure cylinder, respectively, while forming a seal. In the situation shown inFIG. 3, the inside of the pressure cylinder3just comes into contact with the outside of the side wall13of the capsule11, this is at the first place21on the side wall of the capsule. As the pressure cylinder3is moved further over the capsule11, the side wall13of the capsule will be pressed in radial direction and due to the slightly increasing diameter of the side wall of the capsule, the frictional resistance between the pressure cylinder and the capsule will increase.

Upon reaching a kink in the side wall13of the capsule11, the pressure cylinder3will then compress the side wall13in the axial direction, with the side wall13pivoting inward at the third place25. This is shown inFIG. 4wherein the side wall13folds around the inner part4aof the end4of the pressure cylinder3, so that a circular tray is formed which forms a seal between the pressure cylinder and the capsule11.

In the embodiment shown inFIG. 5, in the capsule61there is a reinforcing element67which contacts the inside63bof the side wall63of the capsule at the location of the flange65. This reinforcing element67is formed by a ring69extending over the entire inner circumference and having a U-shaped cross-section. The outer upright wall69aof the ring69contacts the inner side63bof the side wall63of the capsule61. This reinforcing element67ensures that the side wall63of the capsule61when pressing in, hinges about the edge of the reinforcing element that contacts the inside of the sidewall63of the capsule.

A part64of the side wall63of the capsule61adjacent to the flange65is over the entire circumference thinner than the remaining part of the side wall63. As a result, more material deforms during sliding of the pressure cylinder over the capsule, so that an even better sealing between the flange and the pressure cylinder is obtained.

Furthermore, the side wall63of the capsule61is provided with a peripheral slot68. As a result, the inner edge of the pressure cylinder hooks behind a bounding edge of the peripheral slot68when sliding over the capsule, after which the part of the side wall between this peripheral slot and the flange is pressed together by the pressure cylinder and forms a seal.

Instead of the reinforcing element67, a ring of hard material can also be clamped in the capsule61, which ring is provided with ridges (type of toothing) over the outer circumference and is formed according to the toothing present on the inside of the pressure cylinder. In this case, during use, the side wall63of the capsule is clamped between the pressure cylinder and the ribbed ring and a seal is formed between the pressure cylinder and the capsule.

In the embodiment shown inFIG. 6, the reinforcing element77next to an annular part79with an upright edge79awhich contacts the inside73bof the side wall73of the capsule71at the flange75, further has a sleeve-shaped part81that over a part of the length is in contact with the inner side73bof the capsule71. This sleeve-shaped part forms a reinforcement of the wall of the capsule, so that the capsule wall73can be made thin.

The capsule is preferably made of aluminum or other metal. However, the capsule can also be made of plastic or fibrous material. If the capsule is made of aluminum, it is preferably provided with a plastic layer or coating for protection, for example PP, PET or PE. In addition to a glossy layer, this coating can also contain a matte layer. A non-slip layer on the outside of the side wall is preferred. In a possible embodiment a thin sleeve of aluminum, fiber material or plastic is applied over the capsule, which sleeve deforms in the manner described above to form a seal.

Although the present invention is elucidated above on the basis of the given drawings, it should be noted that this invention is not limited whatsoever to the embodiments shown in the drawings. The invention also extends to all embodiments deviating from the embodiments shown in the drawings within the scope of the invention defined by the appended claims.