EP2385921B1 - Capsule with a rupturable membrane used in preparing a drink - Google Patents

Description

Field of the invention

The present invention is in the field of the preparation of beverages, eg coffee-based, by extraction of a concentrated dose, eg ground coffee, contained in a capsule. It relates more particularly to the doses used for this purpose as well as to devices using such doses and to the methods used when using such doses.

State of the art

Capsules and machines operating according to the aforementioned principle have existed for many decades.

Licences US 2,899,886 , US 2,968,560 , US 3,403,617 and US 3,607,297 describe devices where the capsule is initially perforated in several places, then traversed by water under pressure.

Other capsules with a membrane are described in the following patent documents: EP 0 468 079 A , EP 0 806 373 A , EP 0 554 469 A .

Other capsules of the prior art are described in the documents DE 2063398 A1 , US 2002/078831 A1 and EP 1595817 A1 .

General presentation of the invention

One of the objectives of the present invention lies in the creation of a capsule preferably formed of biodegradable material, comprising a fuse membrane which bursts when exceeding its mechanical strength. The bursting zone of the membrane is confined in one or more holes arranged in a cover which covers the outer face of the membrane.

This objective is achieved with the capsule as defined in the claims.

According to the invention, the membrane that burst is advantageously for example NATUREFLEX NE30 or NM30 or any other material.

The various embodiments of the invention are described with reference to the figures (where a hole in the membrane (4) is considered to be non-circular in shape).

1. 1: Corps de la capsule (en bio ou autre).
2. 2: Café (ou autre produit similaire)
3. 3: Tricot (ou tissus ou autre matière filtrante telle que papier etc.) sous forme de membrane déformable.
4. 4: Membrane (Natureflex avec résine de soudage marter bi ou autre dessus ou dessous).
5. 5: Couvercle (en bio ou autre).
6. 6: Feuille de papier (ou carton ou autre).

In these, there is illustrated the capsule according to the invention (where the hole of the membrane (4) is considered non-circular shape) which comprises the following elements:

1. 1: Body of the capsule (bio or other).
2. 2: Coffee (or other similar product)
3. 3: Tricot (or fabrics or other filtering material such as paper etc.) in the form of a deformable membrane.
4. 4: Membrane (Natureflex with marter bi welding resin or other top or bottom).
5. 5: Lid (organic or other).
6. 6: Sheet of paper (or cardboard or other).

Preferably, the extraction element of the capsule is formed as follows: The knit 3 and placed on the membrane 4 which is welded to a solid element (5).

• L'eau rentre dans la capsule par n'importe quel procédé (aiguilles, lames, éléments auto perçants comme ceux illustrés sur la face supérieure du corps de la capsule);
• la pression monte dans la capsule;
• le café extrait se filtre à travers le tricot 3;
• la pression va déformer la membrane 4 au niveau du ou des trou(s) du couvercle 5;
• le couvercle étant d'une épaisseur suffisante pour que la membrane se repose sur la base en fig. 3-5-7-9. Celle va dépasser sa résistance mécanique et éclater.
• le café sous pression va donc sortir au travers du tricot 3 et passer dans les trous de la base illustrée en fig. 3-5-7-9 en dessous de la capsule.

The operating principle is as follows:

• The water enters the capsule by any method (needles, blades, self piercing elements as those illustrated on the upper face of the body of the capsule);
• the pressure rises in the capsule;
• the extracted coffee is filtered through the knit 3;
• the pressure will deform the membrane 4 at the hole (s) of the lid 5;
• the cover being of sufficient thickness for the membrane to rest on the base in Fig. 3-5-7-9 . That will exceed its mechanical strength and burst.
• the pressurized coffee will therefore go out through the knit 3 and pass through the holes in the base illustrated in FIG. Fig. 3-5-7-9 below the capsule.

The thickness of the lid (5) may vary depending on the diameter of the hole thereof as well as the thickness and material of the bursting membrane.

The diameter of the hole (s) of the cover 5 may vary according to many parameters (for example, without limitation): thickness and materials forming the knit 3 and / or the membrane 4 intended to burst, product 2 content in the capsule. There may also be several holes in the lid. The holes may be aligned with the entries in the capsules, or offset therefrom.

It is also possible to provide local weakenings of the membrane to facilitate its bursting.

The shape of the hole or holes may also vary. The figures 10 and 11 illustrate different possibilities (where the hole of the membrane (4) is considered non-circular).

It should be noted that a non-circular shape has the advantage of asymmetries in the way of breaking the membrane. Such asymmetries therefore make it possible to better control the burst, both from the point of view of the bursting zone and from the moment when the membrane bursts. The presence of asymmetries in the shape of the hole most often results in bursting the membrane faster than in the case where the section is circular in shape. In the latter case, the distribution of the tensions in the membrane is indeed perfectly homogeneous.

The whole is advantageously designed using materials for example biodegradable or partially biodegradable. Of course the embodiments given above are as non-limiting examples and modifications are possible within the scope of the present invention. Also, the different variants can be combined together.

Claims (10)

1. Capsule for the preparation of a drink, for example coffee, comprising a hollow element (1) designed to contain a dose (2), for example of ground coffee, said hollow element comprising a side wall, a top face, a bottom face with at least one membrane (4), said membrane being designed to burst under the pressure of a liquid inserted into the capsule in order to allow the liquid to flow through the dose, said capsule also comprising a lid (5) with at least one hole, said lid covering the outer face of the membrane and said hole allowing the membrane (4) to burst being of non-circular form.
2. Capsule according to one of Claim 1, wherein a filtering element such as a knitted fabric (3) or a woven fabric or a paper or other element is placed between the inside of the capsule and the membrane (4).
3. Capsule according to one of the preceding claims, wherein the filtering element (3) is not attached to the capsule, but simply placed between the dose and the membrane (4).
4. Capsule according to one of Claim 1, wherein the membrane (4) is placed between the inside of the capsule and a filtering element such as a knitted fabric (3) or a woven fabric or a paper or other element.
5. Capsule according to one of Claims 2, 3 and 4, wherein the filtering element is formed of threads of biodegradable material, preferably of cotton or silk or other material.
6. Capsule according to one of the preceding Claims, wherein the hole has a cross section in the form of an ellipse.
7. Capsule according to one of the preceding Claims, wherein the hole has a cross section in the form of a polygon.
8. Capsule according to Claim 7, wherein the polygon is convex.
9. Capsule according to Claim 7, wherein the polygon is concave.
10. Capsule according to one of the preceding claims, wherein the lid (5) comprises several holes.

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