Patent Description:
As is known, the art offers an extreme variety of automatic machines provided with a preparation and dispensing unit suitable for producing an infusion by passing hot water under pressure through a capsule, containing the food preparation to be infused, placed inside a dedicated infusion chamber. Conventional espresso coffee machines generally have an infusion chamber comprising an inlet side of the pressurized water and a side from which the infused/extracted beverage escapes during the passage of water through the capsule. Perforation means are present on the water inlet side suitable for perforating the bottom of the capsule thus allowing pressurized water to enter the capsule in order to extract the beverage. Such beverage then escapes from the upper part of the capsule at the cover which, subjected to the internal pressure of the water, opens and thus allows the extracted beverage to pass through, which is collected in a dedicated external container. The edge of said upper part of the capsule rests on the side opposite the water inlet side and, by virtue of its profile, seals against the side of the infusion chamber from which the beverage escapes. For the correct operation of the extraction machine it is essential that the infusion chamber closes correctly and seals even under pressure so that there are no significant leaks of hot water outside the infusion chamber itself. The aluminum capsules of the known type therefore comprise a cup provided with a circular perimetral edge suitable for making a seal engagement with a relative abutment edge of the infusion chamber, in such a way as to guarantee the sealing of the water under pressure and make the infusion operation more efficient by forcing the water to pass inside the capsule so as to maximize the effectiveness of the extraction of the beverage. Although aluminum has the considerable advantage of being impermeable to oxygen and water, which means that the coffee in the capsules has a long shelf life, it easily deforms during the filling and packaging step, and is therefore difficult and expensive to implement a reliable seal on the edge of the cup. Considering that conventional espresso coffee machines comprise a heating element suitable for heating the water up to about <NUM>-<NUM>, which is then pumped at high pressure (generally with appropriate pumps) into the infusion chamber, obtaining a reliable seal, which avoids significant leaks and forces pressurized water to pass inside the capsule, is one of the most felt problems in the specific sector.

There is also the problem of making a capsule that may be used in different types of extraction machines, guaranteeing compatibility and reliability on multiple machine models. In fact, it often happens that a capsule works well on some machines and less well on others, even if the machines are based on the same extraction methodology. This is because the closing of the abutment edge of the infusion chamber on the perimetral edge of the capsule does not always occur reliably due to (even slightly) different operating modes, construction and more or less wide tolerances.

And again, it is extremely important to be able to create a capsule provided with a perimetral edge capable of guaranteeing an effective seal while maintaining a simple geometry from the constructive point of view, in particular in the case of capsules in which the cup is made of aluminum which, as is known, does not allow for the complex geometries achievable, for example, with the injection molding technology.

In the prior art, capsules are disclosed in <CIT> and <CIT>.

The object of the present invention is to provide a capsule which overcomes the aforementioned drawbacks and therefore guarantees reliable operation.

Such object is achieved by a capsule according to claim <NUM>. The dependent claims describe embodiment variations.

The features and the advantages of the capsule according to the present invention will become apparent from the following description, made by way of a nonlimiting example with reference to the accompanying figures, in which:.

With reference to the accompanying figures, <FIG> shows an aluminum capsule <NUM> according to the invention inserted in an infusion chamber <NUM> (shown only partially) of an extraction device for preparing beverages.

<FIG> instead shows only the aluminum capsule <NUM>, of the single-dose type for preparing a beverage, for example coffee, infusion, soluble, decoction or the like.

The capsule <NUM> comprises a hollow body called cup <NUM> defining therein a compartment for containing at least one substance to be infused or dissolved or extracted by means of a liquid under pressure, such as for example coffee or tea, typically in granular or powder form.

The cup <NUM> comprises an annular side wall <NUM> extending in height along a central axis X, between a bottom wall <NUM> and an opposite front end <NUM> defining an opening <NUM>. Such opening <NUM> is covered by a cover <NUM>, perforable or yielding, which closes the capsule <NUM>.

Preferably, the side wall <NUM> has an overall substantially truncated cone shape on the outside, for example realized by the succession of truncated cone surfaces having different angular openings.

The bottom wall <NUM> is intended to be crossed by the liquid injected by the extraction device for preparing the beverage, typically hot water or other food liquid, such as milk.

For this purpose, according to an embodiment variant shown in <FIG>, the bottom <NUM> provides a perforable central portion <NUM> by specific perforation means of the extraction machine when the capsule is in use, so as to realize passages for the liquid towards the inside of the cup <NUM>. Preferably, the perforable central portion <NUM> is provided with a reinforcement edge <NUM> suitable for providing stiffness to the bottom <NUM> of the cup <NUM>, avoiding the deformation thereof during the perforation step for the injection of the liquid under pressure. Preferably, the reinforcement edge <NUM> is an inward fold made in the wall of the cup <NUM>. Preferably, the reinforcement edge <NUM> defines a wavy shape, visible in <FIG>.

At the front end <NUM>, the cup <NUM> comprises a collar <NUM>, typically arranged at the free end of the side wall <NUM>, projecting radially externally. The collar <NUM> has a front face 7b facing towards the opening <NUM> of the cup <NUM>, and an opposite rear face 7a. The front face 7b of the collar <NUM> is intended for union with the peripheral annular region of the cover <NUM> which closes the cup <NUM> at the front end <NUM>. The rear face 7a of the collar <NUM>, on the other hand, is intended to engage with an abutment edge <NUM> of the infusion chamber <NUM> of the extraction device.

In this regard, with reference to <FIG>, the extraction device comprises an infusion chamber <NUM> suitable for housing at least part of the cup <NUM> of the capsule <NUM> therein.

The infusion chamber <NUM> is movable with respect to a receiving plate <NUM> between an open position, which allows the capsule <NUM> to be inserted and removed, and a closed position. When the infusion chamber <NUM> is in the closed position, as shown in <FIG>, it forms a closed chamber around the capsule <NUM> when the heated and pressurized water is fed into the cup <NUM> (through the bottom <NUM>) to carry out the beverage infusion and extraction step.

The receiving plate <NUM> is provided with at least one opening (not shown), to allow the beverage to flow into the final container, for example a cup.

The infusion chamber <NUM> is provided with a compression edge <NUM> having an external portion 31a facing the rear face 7a of the collar <NUM> of the capsule <NUM>.

In the embodiment described and shown in <FIG>, the compression edge <NUM> is of the double crown type and comprises two circular crowns (which define an internal edge <NUM> and an external edge <NUM>) connected by an annular recess <NUM>. It should be noted that only the inner edge <NUM> is used to perform, abutting against the rear face 7a of the collar <NUM> of the capsule <NUM>, the sealing of the infusion chamber. The external edge <NUM> is shorter than the internal edge <NUM> and does not compress the collar <NUM> of the capsule or part of it.

The rear face 7a of the collar <NUM> is therefore intended to engage with the internal edge <NUM> of the infusion chamber <NUM> of the extraction device to seal the infusion chamber. In this regard, the collar <NUM> is provided with a particular geometry in such a way as to act itself as a sealing ring of the capsule <NUM>. The collar <NUM> is in fact intended to sealingly engage, at least partially, with the internal edge <NUM> of the infusion chamber <NUM> of the extraction device and provides, with the internal edge <NUM>, a head seal.

The collar <NUM> of the cup <NUM>, due to features of the material and structural and dimensional features, is at least partially deformable under the action of compression of the internal edge <NUM> of the machine, so as to provide the seal; the deformation is of a plastic type.

The collar <NUM> comprises an end <NUM>, for example a hollow edge obtained by folding back on itself of the terminal portion of the cup <NUM>. In the example of <FIG>, the terminal portion of the cup <NUM> forms a curl end <NUM>. Such end <NUM> allows the capsule to be kept in position by virtue of the side arms of the infusion chamber (as seen in <FIG>) until the end of the extraction.

The collar <NUM> comprises a flat horizontal portion <NUM>, on whose front face 7b is attached the cover <NUM> which closes the cup <NUM> at the front end <NUM>. Preferably, the flat portion <NUM> extends for about <NUM>. Advantageously, the flat portion <NUM> is wide to facilitate the welding step of the cover <NUM>.

The collar <NUM> comprises a seal step <NUM> intended to sealingly engage with the internal edge <NUM> of the infusion chamber <NUM> of the extraction device. The seal step <NUM>, clearly visible in <FIG>, is defined by a tilted raised portion <NUM> (i.e. defined by a truncated cone annular wall) preferably at an angle between <NUM>° and <NUM>°, preferably of <NUM>°, with respect to the central axis X. Preferably, the raised portion <NUM> extends for about <NUM>. The seal step <NUM> is also defined by an abutment portion <NUM> tilted at an angle between <NUM>° and <NUM>°, preferably of <NUM>°, with respect to the horizontal plane. Preferably, the abutment portion <NUM> extends for about <NUM>.

As may be seen in <FIG>, the seal step <NUM>, and in particular the abutment portion <NUM>, is engaged by the internal edge <NUM> during the closing step of the infusion chamber <NUM>. Continuing in its closing path, the internal edge <NUM> compresses the seal step <NUM> as shown by way of example in <FIG> until it deforms, creating a crease <NUM> which is inserted at least partially into the annular recess <NUM> (i.e. between the internal edge <NUM> and the external edge <NUM>) realizing a seal engagement with the compression edge <NUM> of the extraction device during the closing step of the infusion chamber. Advantageously, the geometry of the seal step <NUM> allows the aluminum to deform as a whole when clamped between the compression edge <NUM> and the receiving plate <NUM>, as in <FIG>. Advantageously, the geometry of the seal step <NUM> allows a high adaptability of the capsule <NUM> to the different shapes of the compression edge <NUM> of the infusion chamber to be obtained. Advantageously, the presence of a raised portion <NUM> and an abutment portion <NUM>, both tilted, facilitates the deformation of the seal step <NUM>.

The side wall <NUM> of the cup <NUM> comprises a centering step <NUM> which is arranged above the collar <NUM>. Such centering step <NUM> is intended to abut against the internal wall of the infusion chamber of the extraction device in order to improve the centering of the capsule <NUM> inside the infusion chamber to ensure the correct positioning of the seal step <NUM> in axis with respect to the internal edge <NUM>. The centering step <NUM>, clearly visible in <FIG>, is defined by a tilted raised portion <NUM> (i.e. defined by a truncated cone annular wall) preferably at an angle between <NUM>° and <NUM>°, preferably of <NUM>°, with respect to the central axis X. Preferably, the raised portion <NUM> extends for about <NUM>. The centering step <NUM> is also defined by an abutment portion <NUM> preferably tilted at an angle between <NUM>° and <NUM>°, preferably of <NUM>°, with respect to the horizontal plane. Preferably, the abutment portion <NUM> extends for about <NUM>.

As may be seen in <FIG>, during the closing step of the infusion chamber <NUM>, the internal wall of the compression edge <NUM> engages the centering step <NUM>, and in particular the raised portion <NUM> which is configured as an abutment portion for guiding the centering of the capsule <NUM> in the infusion chamber itself. Advantageously, the centering step <NUM> provided with a raised portion <NUM> and an abutment portion <NUM>, both tilted, facilitates centering of the capsule.

In normal use, the capsule <NUM> according to the present invention is inserted into the infusion chamber <NUM> of the extraction machine (<FIG>) and, once the movement of the components of the machine itself is activated, the rear face 7a of the collar <NUM> of the capsule <NUM> engages with the compression edge <NUM> of the infusion chamber <NUM> to form a closed chamber around the capsule <NUM> and carry out the step of infusing and extracting the beverage.

During the handling step of the machine components (<FIG>), it is possible that there is a misalignment of the capsule <NUM> inside the infusion chamber, and therefore that the seal step <NUM> of the collar <NUM> of the capsule <NUM> is not perfectly coaxial with the compression edge <NUM> of the machine. However, the internal wall of the compression edge <NUM> of the machine, in its advancement path, may touch the centering step <NUM>, pushing the capsule <NUM> to align itself axially in the center of the infusion chamber.

The compression edge <NUM> of the machine then ends up in abutment against the seal step <NUM> (<FIG>) and deforms it (<FIG>) to realize a sealed closing. In the capsule <NUM> according to the present invention, the seal is achieved by deforming the seal step <NUM>. As shown in <FIG>, when the infusion chamber is closed, the seal step <NUM> is plastically deformed to provide the necessary seal to prevent any leakage of liquid from the infusion chamber.

Advantageously, the compression edge <NUM> deforms the seal step <NUM> into a wavy crease <NUM> which allows a plurality of sealing points to be obtained with said compression edge <NUM> against potential water leaks from the infusion chamber.

Advantageously, the centering step <NUM>, in addition to acting as a centering of the capsule in its housing in the infusion chamber, is slightly deformed towards the outside, thus contributing to the seal against potential leaks of water from the infusion chamber.

Advantageously, the deformation of the seal step <NUM> does not touch the flat portion <NUM> of the collar <NUM> thus avoiding risks of compromising the welding of the cover <NUM>.

Advantageously, also the curl end <NUM> of the collar <NUM> is not deformed during the closing step, thus continuing to hold the capsule in position by virtue of the side arms of the extraction chamber (as seen in <FIG>) until the end of the extraction.

Innovatively, the capsule according to the present invention overcomes the drawbacks mentioned with reference to the prior art, since it allows a reliable seal to be provided while maintaining a geometry that is constructively easy to manufacture.

Claim 1:
A single-dose capsule (<NUM>) for preparing infusion or soluble beverages in an extraction device provided with an infusion chamber, said capsule comprising:
- a cup (<NUM>) made of aluminum comprising a bottom wall (<NUM>), a collar (<NUM>) at an opposite end defining an opening (<NUM>), an annular side wall (<NUM>) extending in height along a central axis (X) between said bottom wall (<NUM>) and said collar (<NUM>), the cup defining, therein, a compartment containing at least one food substance;
- a cover (<NUM>) sealingly closing said opening (<NUM>);
wherein:
- the collar (<NUM>) comprises a flat horizontal portion (<NUM>), having a front face (7b) to which the cover (<NUM>) is fastened;
- the collar (<NUM>) comprises, internally with respect to the flat portion (<NUM>), a plastically deformable seal step (<NUM>) for making a seal with the infusion chamber of the extraction device, said seal step (<NUM>) comprising a raised portion (<NUM>), which is tilted with respect to the central axis (X);
- the side wall (<NUM>) comprises a centering step (<NUM>) for centering the cup (<NUM>) inside the infusion chamber of the extraction device; said centering step (<NUM>) comprising a raised portion (<NUM>), which is tilted with respect to the central axis (X);
wherein said seal step (<NUM>) also comprises an abutment portion (<NUM>);
characterised in that
the abutment portion (<NUM>) of the seal step (<NUM>) is tilted by an angle between <NUM>° and <NUM>° with respect to a horizontal plane defined by the flat portion (<NUM>) of the collar (<NUM>).