EP0094368B1 - Filter element and process for making a hot drink infusion with the aid of this filter element - Google Patents

Description

The present invention relates to a device for preparing a hot drink, consisting of a filter and a container, the filter consisting of a casing the upper part of which is open, at least part of the side walls of which is impermeable to water. water and the bottom of which consists of at least one filtering sheet retaining a dose of aromatic plant substances which is left to infuse in a determined quantity of boiling water, possibly poured all at once into the above-mentioned envelope in order to obtain an infusion collected in a container in which the filter is fitted.

This filter element makes it possible to prepare a hot drink such as an infusion of coffee or tea in a flared and elongated container and more particularly in a cup provided by an automatic dispenser.

French patent application No. 2215188 discloses an individual coffee cup-filter combination, using a cartridge of fresh ground coffee, disposable after use, in which the filter is fitted into the cup.

The cup has on the inner wall, locking tabs serving as eclipsable stops intended to carry the filter during the brewing operation.

To prepare a cup of filter coffee, pour into the filter placed above the cup a quantity of boiling water corresponding to the capacity of the cup. The infusion is obtained by the slow passage of boiling water through the coffee bed. The filter drips directly into the cup.

This known filter is not ideally suited to be used in conjunction with an elongated cup because of the lack of stability of the assembly. In particular, this filter model is not suitable for use in automatic dispensers.

Another disadvantage of this known filter consists in the fact that when it drips out, the coffee cools down quite quickly.

Also known from US Patent No. 3539355 is an open and expandable sachet filter containing a determined quantity of fresh ground coffee.

To prepare an infusion, fill the sachet with hot water and close the upper slit of the bag by tightening a cord which also has the function of compressing the bag and forcing the water to pass through the filter.

The use of a bag filter is not very easy and handling of the wet bag is not easy.

The present invention aims to remedy the above drawbacks. It relates to a device for preparing a hot drink, consisting of a filter and a container, the filter consisting of an envelope the upper part of which is open, at least part of the side walls of which is impermeable to water. water and the bottom of which consists of at least one filtering sheet retaining a dose of aromatic vegetable substances which is left to infuse with a determined quantity of hot water which may be poured at once into the above-mentioned envelope in order to obtain an infusion collected in a container in which the filter (1) is fitted (such a device is known from French patent application No. 2215 188). This envelope is essentially characterized in that it can fit into the aforementioned container and in that it comprises at least one part having a specific weight less than that of water allowing the filter element to float when the water it contained has run out.

According to a feature of the invention, the aforementioned vegetable substance is the grinding of roasted coffee beans or tea.

In a particular embodiment, the container is a flared cup. The filter element advantageously has a shape which matches that of the above-mentioned cup and the filter-cup assemblies form mutually interlocking elements.

In another embodiment, the sensor container is a coffee pot.

The present invention also relates to a method for preparing a hot drink and in particular a filter coffee, by infusion using a device for preparing a hot drink, consisting of a filter and a container, the filter being consisting of an envelope, the upper part of which is open, at least part of the side walls of which is impermeable to water and the bottom of which consists of at least one filter sheet retaining a dose of aromatic plant substances which are left infuse with a determined quantity of hot water, possibly poured at once into this envelope, in order to obtain an infusion collected in a container in which the filter (1) is fitted (such a process being known from US Pat. No. 3,539,355 ), characterized in that the filter is fitted in the container to the bottom of the container before hot water is poured, in that the water passes slowly through the filter sheet and spreads in the container while the filter, which comprises at least at its base, a part having a specific gravity lower than that of water, undergoes an upward thrust in the infusion contained in the container and finally floats on the hot drink when the water qu 'it contained has flowed entirely into the container.

The present invention also relates to an automatic distributor of hot drinks delivering containers for drinking, containing a dose of aromatic vegetable substances which must be infused with a determined quantity of hot water delivered by a fountain included in the distributor (such dispenser is known from FR-A 2171 036), characterized in that the containers each comprise a filter according to one of claims 1 to 4.

• - la fig. 1 est une coupe verticale d'un gobelet au fond duquel repose un élément de filtre suivant l'invention;
• - la fig. 2 est une coupe transversale d'un gobelet montré à la fig. 1 suivant la ligne II-II' ;
• - la fig. 3 est une coupe transversale du gobelet montré à la fig. 1 suivant la ligne IIl,III' ;
• - les fig. 4 à 6 illustrent la mise en oeuvre de l'élément de filtre précité;
• - la fig. 7 montre en perspective un distributeur automatique de boissons chaudes sur lequel repose un élément de filtre dans lequel est versée de l'eau bouillante.

Other details and particularities of the invention will emerge from the following detailed description of two embodiments of the invention given by way of non-limiting example. This of description refers to the accompanying drawings, in which:

• - fig. 1 is a vertical section of a cup at the bottom of which rests a filter element according to the invention;
• - fig. 2 is a cross section of a cup shown in FIG. 1 along line II-II ';
• - fig. 3 is a cross section of the cup shown in FIG. 1 along line III, III ';
• - figs. 4 to 6 illustrate the implementation of the aforementioned filter element;
• - fig. 7 shows in perspective a vending machine for hot drinks on which rests a filter element into which is poured boiling water.

In one embodiment of the invention, the filter element designated as a whole by the reference notation 1, consists of a frustoconical envelope 2, relatively thin, made of H.D. polyethylene film or of expanded polystrene.

This envelope 2, produced for example from a thin sheet of aforementioned plastic which can be welded, is cut into a well-defined shape and shaped so as to obtain a container of frustoconical shape. The filter element 1 is provided at its base with a lower ring 3 having a specific weight much lower than that of water. A space 4 is delimited upwards and downwards by a sheet of filter paper 5,6, possibly protected by a grid not shown. This space is lined with aromatic plant substances, for example the grinding of roasted coffee beans 7. The quantity of grind 7 corresponds to the individual dose necessary for the preparation of a cup of good coffee. Space 4 must be dimensioned so that this coffee can swell in order to better develop its aroma. The particle size of the filter paper 5,6 is chosen so as to obtain a sufficient filtration speed.

The filter element 1 is intended to be fitted into a container 8 generally consisting of a cup of frustoconical shape.

As shown in Figure 1, the filter element 1 follows the shape of the cup 8 and rests on the bottom thereof by its base consisting of the lower ring 3 made for example of expanded polystyrene.

The lower ring 3 is high enough and wide enough to allow the filter element 1 to float when the water it contained has completely drained, so that the coffee grounds 7 are no longer in contact with the infusion 9 of coffee obtained.

The lower ring 3 has any profile having indentations 10, in order to better increase the float effect and in order to better support an internal filter plate 11, however, leaving a sufficient passage section to obtain a sufficient filtration speed.

As shown in Figure 3, the side wall 12 of the filter element 1 has all around the filter element, a sufficient gap between this element and the inner wall 13 of the cup 8. This gap allows the brewing of coffee spread evenly around the filter element.

The frustoconical shape of the filter element 1 allows it to fit perfectly into the cup 8 above, but also to accommodate a series of other similar cups 14 each provided with a filter element 1 '.

At its upper part, the cup 8 has two distinct sealing edges, one of which corresponds to the upper edge 15 of the container and the other to an annular projection 16 arranged in the vicinity of the above-mentioned upper edge, below this one. ci, arranged so that it can rest on the upper edge of the previous cup when the cups are stacked.

The first rim 15 is profiled so as to remove the cutting edge and so as to possibly receive an annular projection 17 from the filter element 1 contained in the cup 8.

An airtight packaging is thus obtained which makes it possible to keep the coffee grounds protected from air and moisture and perfectly preserve the aroma of the coffee by preventing it from being fanned in the dispensing apparatus. automatic 18.

A conservation of several weeks is thus guaranteed in the automatic vending machine for hot drinks, despite the severe humidity conditions prevailing there.

To prepare an infusion using the filter element 1 according to the invention, a filter element 1 is placed at the bottom of the container or cup 8 intended to collect the above infusion, after having possibly placed a piece of sugar in the cup 8. If the cup 8 is supplied by an automatic hot drink dispenser 18, a filter element 1 is already placed in the cup 8. The apparatus is actuated using a coin mechanism 19 and of control buttons 20. A certain amount of boiling water is poured into the envelope of the filter element 1, corresponding to the capacity of the cup 8.

Under the action of boiling water, the coffee grounds 7 swells and develops its aroma. Under the influence of gravity, boiling water slowly crosses the filter bed consisting of ground coffee 7 retained by filter sheets 5, 6 of determined particle size allowing a sufficient filtration speed and extracts the coffee. The coffee infusion spreads into the cup 10. The level of liquid collected rises in the cup as the boiling water passes through the filter. Under the upward pressure of the lower ring, having a specific gravity significantly lower than water, the filter element 1 rises slowly at the same time as the level of the infusion in the cup 8 rises. At the end of the operation, the lower filter plate 11 rises above the level of liquid in the cup 8. The excess filtrate drops drop by drop into the cup 8 so that the elé filter 1 drained without causing stains around the cup 8 (fig. 4 to 6).

• 1. Il permet la présentation d'un gobelet pouvant être jeté après l'emploi et d'un élément de filtre 1 sous une forme convenant parfaitement à la mise en vente à l'aide d'un distributeur automatique de boissons chaudes 18.
• 2. Il confère au filtre placé dans le gobelet, une stabilité plus grande que ne le permettrait le procédé classique suivant lequel on place le filtre au-dessus du récipient ou de la tasse. Cette mise en place du filtre dans le gobelet 8 permet d'abaisser nettement le centre de gravité de l'ensemble au temps initial, lorsqu'on vient de verser l'eau bouillante dans l'élément de filtre 1.
• 3. Il garde le café plus chaud. L'élément de filtre 1 est immergé dans l'infusion de café. La surface de contact du café filtré avec l'air ambiant est inférieure à celle du procédé connu. En particulier, on ne retrouve pas, dans le procédé suivant l'invention, la formation de gouttelettes à la sortie de l'élément de filtre 1, si ce n'est en fin d'opération. Ces gouttelettes présentent une grande surface spécifique et entraînent un refroidissement du café.
• 4. Il permet de conserver tous les avantages du procédé connu, à savoir la création d'une atmosphère agréable créée par l'arôme du café, le report du temps d'attente chez le consommateur et la préparation d'un café d'excellente qualité.
• 5. Empilés les uns dans les autres, les gobelets et les éléments de filtre susdits ne nécessitent que peu de place et sontfaciles à transporter.

This process makes it possible to prepare excellent coffee. Compared to the known conventional method, the method according to the invention has the following advantages:

• 1. It allows the presentation of a cup which can be discarded after use and of a filter element 1 in a form which is perfectly suitable for sale with the aid of an automatic distributor of hot drinks 18.
• 2. It gives the filter placed in the cup a greater stability than would allow the conventional method according to which the filter is placed above the container or cup. This positioning of the filter in the cup 8 makes it possible to significantly lower the center of gravity of the assembly at the initial time, when the boiling water has just been poured into the filter element 1.
• 3. It keeps the coffee hotter. The filter element 1 is immersed in the coffee brew. The contact area of the filtered coffee with the ambient air is less than that of the known process. In particular, in the process according to the invention, the formation of droplets at the outlet of the filter element 1 is not found, except at the end of the operation. These droplets have a large specific surface area and cause the coffee to cool.
• 4. It allows all the advantages of the known process to be preserved, namely the creation of a pleasant atmosphere created by the aroma of the coffee, the postponement of the waiting time at the consumer and the preparation of an excellent coffee. quality.
• 5. Stacked one inside the other, the aforesaid cups and filter elements require little space and are easy to transport.

The process according to the invention has the merit of keeping the coffee very hot. This is important because boiling coffee helps digestion by helping dissolve fat impregnated with food. We also have the advantage of being able to prepare your filter coffee yourself, just before consuming it. The ground coffee 7 is kept very fresh thanks to the seal formed by an edge 15 of the cup and the rim 16 of the next cup 14. This edge 15 provides thermal insulation which facilitates the hand grip of the element of filter by the consumer at the end of the operation.

It is obvious that the invention is not limited to the details described above and that numerous modifications can be made to these details without departing from the scope of the invention as defined by the claims below.

Thus, the filter element according to the invention, instead of containing a dose of roasted coffee beans, can also contain tea.

The filter element can also be used with a coffee or tea pot to prepare a pot of coffee or tea.

The filter element can be manufactured in various ways. Thus, the lower ring of expanded polystyrene could be made of hollow synthetic material.

Claims (7)

1. A device for preparing a hot drink composed of a filter (1) and of a container (8), the filter being constituted by a casing of which the upper portion is open, of whose lateral walls at least a portion is impermeable to water and of which the base is constituted by at least one filter sheet (11) retaining a dose of aromatic vegetable substances which is left to infuse with a predetermined quantity of hot water which may be poured in one go into this casing (2) in order to obtain an infusion which is collected in the container (8) in which the filter (1) is fitted, characterised in that the filter (1) fits in the container (8) to the bottom thereof in that at least its base comprises a portion (3) having a specific gravity lower than that of water and such that the filter (1) floats on the infusion (9) when the water which it contained has flown out.

2. A device according to claim 1, characterised in that the above-mentioned vegetable substance is ground grains of roasted coffee or of tea.

3. A device according to any one of claims 1 and 2, characterised in that the container (8) is a flared tumbler.

4. A device according to claim 3, characterised in that the casing (2) has a shape which matches that of the tumbler (8) and in that the filter/tum- bler assemblies form mutually fitting elements.

5. A device according to any one of claims 1 and 2, characterised in that the container (8) is a coffee jug.

6. A process for preparing a hot drink and, in particular, a filter coffee, by infusion by means of a filter (1) constituted by a casing (2) of which an upper portion is open, of which at least a portion of the lateral walls is impermeable to water and of which the base is constituted by at least one filter sheet (11) retaining a dose of aromatic vegetable substances (7) which is left to infuse with a predetermined quantity of hot water which may be poured in one go into this casing (2) in order to obtain an infusion (9) collected in a container (8) in which the filter (1) is fitted, characterised in that the filter (1) is fitted in the container (8) to the base thereof before the hot water is poured, in that the water passes slowly through the filter sheet (11) and spreads out in the container (8) while the filter (1) which comprises, at least at its base, a portion (3) having a specific gravity lower than that of water, is thrust upwards in the infusion contained in the container (8) and finally floats on the hot drink when the water which it contained has flown out entirely into the container.

7. An automatic dispenser (18) of hot drinks delivering drinking containers containing a dose of aromatic vegetable substances (7) which must be allowed to infuse with a predetermined quantity of hot water delivered by a fountain included in the dispenser (18), characterised in that the containers each comprise a filter (1) according to one of claims 1 to 4.

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