Apparatus for preparing a consumable beverage with a fine-bubbled foam layer

The invention relates to an apparatus for preparing a consumable beverage with a fine-bubbled foam layer. The invention comprises a beverage unit for dispensing the beverage under pressure and at least one nozzle which is in fluid communication with the beverage unit for supplying the beverage to the nozzle for generating a jet of the beverage by means of the nozzle. The apparatus further comprises a collecting unit into which the jet spouts to obtain the beverage with the fine-bubbled foam layer. The collecting unit comprises a chamber with at least one outflow opening for dispensing the beverage with the fine-bubbled foam layer and a jet impact element included in the chamber with a top which is clear of an inner wall of the chamber. The nozzle and the jet impact element are oriented relative to each other such that the jet spouts against a part of the top of the jet impact element so that the jet, after impact on the jet impact element, forms a mist of the beverage which flows against and/or along the inner wall of the chamber and then leaves the chamber via the at least one outflow opening as the beverage with the fine-bubbled foam layer.

The invention relates to an apparatus for preparing a consumable beverage with a fine-bubbled foam layer, such as coffee or milk with a fine-bubbled foam layer, comprising a beverage unit for dispensing the beverage under pressure and at least one nozzle which is in fluid communication with the beverage unit for supplying the beverage to the nozzle for generating a jet of the beverage by means of the nozzle and a collecting unit into which the jet spouts to obtain the beverage with the fine-bubbled foam layer.

The invention also relates to a method for preparing a consumable beverage with a fine-bubbled foam layer, such as coffee or milk, whereby a liquid jet which comprises the beverage is generated and whereby the liquid jet is supplied to a collecting unit so that the jet spouts into the collecting unit to obtain the beverage with the fine-bubbled foam layer.

The invention further relates to a unit comprising such a collecting unit and a container for receiving a pad which comprises an envelope of filtering paper and which is filled with a product to be extracted, such as ground coffee.

The invention also relates to such a unit and such a pad which is received in the container of the unit.

Such an apparatus and method are known from a possible embodiment of an apparatus of European patent application EP 0 878 158.

In the known apparatus the collecting means comprises a buffer reservoir which, in the example, comprises a bottom with upright side walls. In use, the jet spouts into the buffer reservoir which is thus filled with the beverage to be processed. Thus is formed a liquid surface in the buffer reservoir. The liquid jet hereby spouts into the liquid surface whereby air is beaten into the beverage so that a fine-bubbled foam layer is formed. The buffer reservoir further comprises a run-out path for discharging from the buffer reservoir the beverage with the fine-bubbled foam layer.

After some time the spouting of the beverage into the buffer reservoir stops. The buffer reservoir will, in this example, then empty. The buffer reservoir may, to this end, be provided with an specifically arranged outflow opening in the bottom of the buffer reservoir.

Although in the known system a desired quality of beverage with a fine-bubbled foam layer is formed, it is a drawback that it takes some time before the buffer reservoir has completely emptied. Particularly the associated dripping after may take a relatively long time. When, for instance with the known apparatus and according to the known method, one cup of coffee is prepared, the emptying of the buffer reservoir and the dripping after may take half a minute. The dripping after itself may take 20 seconds. Moreover, the known system has considerable dimensions.

The invention contemplates providing an apparatus and a method with which the signaled problem can be met, if so desired.

The apparatus according to the invention is accordingly characterized in that the collecting unit comprises a chamber with at least one outflow opening for dispensing the beverage with the fine-bubbled foam layer and a jet impact element included in the chamber with a top which is clear of an inner wall of the chamber whereby the nozzle and the jet impact element are oriented relative to each other such that the jet spouts against at least a part of the top of the jet impact element, whereby the beverage, after impact on the jet impact element, leaves the chamber via the at least one outflow opening as the beverage with the fine-bubbled foam layer. Surprisingly, it is found that in the chamber air is beaten into the beverage.

Because in the apparatus according to the invention no liquid level needs to be built up in the chamber, this chamber can, after the spouting of the jet into the chamber has stopped, empty relatively rapidly, if so desired, whereby the dripping after will be relatively short. For the relatively short dripping after it is only necessary that the at least one outflow opening of the chamber is sufficiently large. As this outflow opening has no functional meaning, this opening may be sufficiently large, if so desired, to shorten the dripping after. Also, such an apparatus may be made relatively small.

In particular it holds that the chamber is further provided with at least one air supply opening so as to be able to efficiently supply air to the chamber. Preferably, it holds that the top of the jet impact element is positioned between the air supply opening and the at least one outflow opening. It further particularly holds that the top is directed at least practically toward the nozzle. The impact of the jet against the top may thus be relatively strong so that the beverage, after the impact, is very finely atomized. In particular, it holds that the chamber is further provided with a product supply opening for supplying the jet to the chamber. In this connection, it preferably holds that the top of the jet impact element is positioned between the product supply opening and the outflow opening. Preferably, it further holds that the top is directed at least practically toward the product supply opening. In particular, it further holds that the air supply opening and the product supply opening coincide. The air supply thus prevents the mist particles from being able to move so close to the nozzle that these particles disturb the jet.

In particular, it holds that a surface of the top is made convex or flat. It is found that if the surface of the top is convex a mist of droplets is obtained which, as regards their diameter, is very homogeneous. It is found that this is conducive to obtaining a homogeneous fine-bubbled foam layer.

Preferably, it holds that a normal from the surface of the top and the position where the jet impacts on the top is directed at least practically parallel to the jet. The jet will thus impact on the surface perpendicularly so that the interaction between jet and surface is greatest. In other words, the velocity component of the jet in the direction of the normal is equal to the velocity of the jet itself and hence maximal.

The method according to the invention is characterized in that the collecting unit comprises a chamber with at least one outflow opening for dispensing the beverage with the fine-bubbled foam layer and a jet impact element included in the chamber with a top which is clear of an inner wall of the chamber whereby the jet is directed such that the jet spouts against a part of the top of the jet impact element whereby the beverage, after impact on the jet impact element, then leaves the chamber via the at least one outflow opening as the beverage with the fine-bubbled foam layer.

The unit according to the invention comprises such a collecting unit, a nozzle and a container for receiving a pad which comprises an envelope of filtering paper and which is filled with a product to be extracted, such as ground coffee, whereby the container and the collecting unit are mechanically connected with each other and whereby the container comprises at least one outlet which is in fluid communication with an inlet of the nozzle.

The assembly according to the invention comprises such a unit and a pad which comprises an envelope of filtering paper and which is filled with a product to be extracted, such as ground coffee, whereby the pad is received in the container and extends over a bottom of the container to upright side walls of the container.

InFIG. 1reference numeral1denotes an apparatus for preparing a consumable beverage with a fine-bubbled foam layer, such as coffee or milk with a fine-bubbled foam layer. The apparatus1comprises a beverage unit2for dispensing a consumable beverage under pressure, in this example coffee. The apparatus1is further provided with a nozzle4. An outlet6of the beverage unit2is connected by means of a hose8with an inlet10of the nozzle4. The nozzle4is thus in fluid communication with the beverage unit2for supplying the beverage to the nozzle4. Thus is generated by means of the nozzle4a jet12of the beverage. The apparatus1further comprises a collecting unit14into which the jet12spouts to obtain the beverage with a fine-bubbled foam layer. The collecting unit14comprises a chamber16which is provided with at least one outflow opening18for dispensing the beverage with the fine-bubbled foam layer. The collecting unit14further comprises a jet impact element20included in the chamber16. The jet impact element20is provided with a top22which is clear of an inner wall24of the chamber. The nozzle4and the jet impact element20are oriented relative to each other such that the jet12spouts against at least a part of the top22of the jet impact element20whereby the beverage, after impact on the jet impact element, leaves the chamber via the at least one outflow opening as the beverage with the fine-bubbled foam layer. Surprisingly, in the chamber16air has been beaten into the beverage and this in such a manner that a beverage with a fine-bubbled foam layer is obtained.

In this example, on impact against the top22of the jet impact element20the jet12will form a mist and/or turbulence of beverage which flows against and/or along the inner wall24of the chamber16and then leaves the chamber via the outflow opening18as the beverage with the fine-bubbled foam layer. That on impact against the top22the jet forms a mist and/or turbulence of beverage which flows against and/or along the inner wall24of the chamber16has been obtained by adjusting the strength of the jet and the size of the chamber to each other. The jet should be sufficiently strong and/or the chamber should be sufficiently small.

As soon as the beverage unit2stops dispensing the beverage to the nozzle4under pressure, the forming of a mist of the beverage in the chamber16is stopped. The chamber16will then be able to empty rapidly via the outflow opening18. In this example the outflow opening18has a diameter of 5 mm, as a result of which the chamber16is empty within a few seconds. Prolonged emptying (for tenths of seconds) of the chamber16including dripping after is out of the question here.

In this example, the collecting unit14comprises a channel28with an inlet opening30and an outflow opening32. The outlet opening32forms, in this example, a product supply opening of the chamber16for supplying the jet12to the chamber16. The nozzle is positioned, in this example, at some distance from the inlet opening30of the channel28. As a result, air34is, in use, also drawn by the jet12into the chamber16via the inlet opening30of the channel28. The product supply opening32of the chamber16hereby also functions as an air supply opening32′.

Because a combination of the jet of beverage and air is supplied to the chamber16, air, in combination with the generated stream of mist particles, can be beaten into the beverage whereby, surprisingly, a beverage with a fine-bubbled foam layer is obtained. Through the air stream from the inlet opening30into the chamber16it is ensured that the mist particles cannot leave the chamber16via the inlet opening30. The air stream provides, as it were, a sealing of the inlet opening30from mist particles in the chamber16. The mist particles are therefore prevented from moving to the nozzle4and disturbing the jet. In use, the mist particles are formed through impact of the jet12against a part of the top22. First, these mist particles will move up and sideward directly after impact against the top22. Thus is formed a laminar and/or turbulent stream of mist particles in the chamber, which mist particles can further flow against and/or along the inner wall24. As a result of gravity the mist particles will then flow down again. Subsequently, the mist particles form a liquid beverage again whereby air is beaten into the beverage such that a fine-bubbled foam layer is formed, which beverage can then leave the chamber16via the outflow opening18. The beverage is then ready for consumption.

In this example it holds that the top22of the jet impact element20is positioned between the air supply opening32′ and the outflow opening18. It further holds that the top22is directed toward the nozzle4. In this example it also holds that the top22is positioned between the product supply opening32and the outflow opening18. In particular, it hereby holds that the top22is directed toward the product supply opening32. In this example it holds that a surface of the top22is made convex. It is found that in that case, in the first instance, the mist particles formed after impact move up while spread over a space angle Ω.

In this example it holds that a normal38from the surface36of the top22at a position where the jet12impacts on the top22is directed at least practically parallel to the jet12. It further holds that a normal38at the middle of the surface36of the top22is directed at least practically to the nozzle4. Moreover, it holds that a normal38from the surface36of the top22at the position where the jet12impacts is directed to the product supply opening32. It further holds that the top22is positioned in a middle of the chamber16. In this example, the inner wall24of the chamber16is made at least practically rotation symmetrical about a rotation symmetrical axis40. The mentioned middle is, in this example, a point of this rotation symmetrical axis40. In this example, the jet impact element20is positioned in a lower part of the chamber16. The jet impact element20is, in this example, made pole-shaped. An axial direction of the pole-shaped element extends in a longitudinal direction of the chamber16. The above-mentioned rotation symmetrical axis40extends through the top22. In this example, about the rotation symmetrical axis40there is thus obtained a rotation symmetrical collecting unit14.

In this example, the distance H1from the product supply opening32to the top22is greater than the distance H2from the top22to the outflow opening18of the chamber16. In this example, it also holds that H2is greater than zero. Because the mist stream is particularly formed in the chamber16between the top22and the product supply opening32, a large part of the chamber16can thus be utilized for the mentioned lamination and/or turbulent streams of the mist.

InFIG. 1it holds that a cross-section of the chamber16is made substantially heart-shaped, but this is not essential. This is, for instance, visible inFIG. 2.

InFIG. 2parts corresponding toFIG. 1are provided with the same reference numerals. InFIG. 2it now holds that an inner wall24of the chamber16is made at least substantially cylindrical. It further holds that, in this example, the surface36of the top22is flat.

InFIG. 3is shown an alternative embodiment of an apparatus according to the invention. The apparatus comprises a unit42which is provided with a collecting unit14. Parts of the collecting unit14corresponding toFIGS. 1 and 2are provided with the same reference numerals as inFIGS. 1 and 2. The unit42further comprises the nozzle4. Besides, the unit42comprises a container44for receiving a pad46which is filled with a product to be extracted, such as ground coffee. The container44and the pad46may be of a type as described in European patent 0 904 717. The container44is provided with a cup-shaped bottom48which is bounded by an upright side wall50. The upright side wall extends around the bottom. The bottom and the upright side wall thus bound a cup-shaped inner space of the container in which, in use, the pad is received. The pad46extends over the bottom48to the upright side wall50. In the bottom48is provided an outflow opening which, in this example, is formed by the nozzle4. This outflow opening forms an outlet of the container. In this example, the inlet10of the nozzle is also in fluid communication with the outlet of the container, because the inlet10and an outlet11of the nozzle form the outlet of the container. Also, grooves are provided in the bottom of the container. The apparatus1further comprises a cover52with which the container can be closed. The apparatus1further comprises a hot water unit54for supplying hot water under pressure to an inner space of the cover52. The cover52is provided at its bottom side with a number of outflow openings56. In use, hot water is thus supplied via the outflow openings56to a top side of the container44. The container44and the hot water unit54form, in combination, the beverage unit2ofFIGS. 1 and 2. In this example, it further holds that the collecting unit14and the container44are mechanically connected with each other. In this example, it further holds that the nozzle4is mechanically connected with the container44. The nozzle4, the container44and the collecting unit14thus form a mechanical unit. In this example, it holds that in the channel28an air inflow opening58is provided. The air inflow opening58is positioned between the nozzle4and the top22of the jet impact element20. The air flows again via the product supply opening32into the chamber16. The product supply opening therefore also functions as an air supply opening32′ of the chamber16. The jet impact element20is, in this example, connected with the chamber16by means of three cross arms60.

The pad46extends over the bottom48of the container44to the upright side walls50of the container. The assembly of pad46and unit42also forms a part of the invention.

The apparatus ofFIG. 3operates as follows. By means of the hot water unit54hot water is supplied under pressure to the inner space of the cover52. This hot water leaves the cover52under pressure via the outflow openings56of the cover52. Hot water is thus supplied to the top side of the container44. This water is pressed through the pad46which, in this example, is filled with ground coffee. There is thus formed a coffee extract which leaves the container44via the nozzle4. Because the coffee extract is supplied to the nozzle4under pressure, a jet of the beverage is thus formed. This jet12impacts on top of the top22of the jet impact element20, as discussed in relation toFIGS. 1 and 2. The beverage with the fine-bubbled foam layer, in this example the coffee extract with the fine-bubbled foam layer, leaves the chamber16via the outflow opening18. In this example, the outflow opening18is formed by the openings which are formed between the cross arms60.

Finally,FIG. 4shows an assembly according to the invention which comprises a unit42according to the invention and a pad46. The unit42according to the invention is again provided with a container44, as discussed in relation toFIG. 3. A difference withFIG. 3is that the apparatus1is now provided with two air supply openings58.1and58.2which also discharge into the channel28.

The invention is by no means limited to the above-described exemplary embodiments, Thus, the air inflow openings may discharge not only into the channel, but also into the chamber16itself. This may, for instance, occur near a top side of the chamber16. However, other places within the chamber16are also conceivable.

It is also conceivable that instead of a jet a multiplicity of jets impact on the jet impact element20. In this connection, a multiplicity of nozzles4may be used which each direct a jet to the jet impact element20. Besides, it is possible that the nozzle4is provided with a multiplicity of outlets for generating a multiplicity of jets. The multiplicity of jets may also impact on a multiplicity of jet elements which are included in the chamber16. It is also conceivable that the chamber is provided with a multiplicity of jet impact elements20which are each impacted by at least one jet originating from, for instance, a multiplicity of nozzles. In the apparatus ofFIGS. 3 and 4it is also possible that between the outlet of the container and the inlet of the nozzle a fluid connection is present in the form of, for instance, a hose. The jet impact element may, as stated, have the form of a flat plate. Also, the top22may be made convex, as shown inFIG. 1, whereby near an edge23holes extending from above to below the top22are provided. The top22may also be made concave (seeFIG. 5). Besides, the top22may be made concave over the outer circumference with a point in the middle (seeFIG. 6). The collecting unit14may also be made as shown inFIG. 7. Moreover, for instance in the apparatus ofFIGS. 1-4,7, the jet impact element may be replaced by a cylinder or tube which, in the drawing, extends in the horizontal direction between the walls24of the chamber. The part of an outer side of the cylinder or tube on which the jet may impact then forms the top of the jet impact element which is clear of the walls24. The diameter of the cylinder or tube may, for instance, be equal to the diameter of the top inFIGS. 1-7.

The nozzle may, for instance, also be formed by a nozzle as described in EP 1 092 377. Besides, the nozzle may be formed by a plate100with an opening102as shown inFIGS. 8aand8b. The thickness b of the plate is, for instance, 0.1-0.5 mm, preferably 0.2-0.4 mm.

Moreover, for each embodiment it holds that d3<d2(see, for instance,FIGS. 2 and 7). In general, the following further holds.

The diameter of the jet when leaving the nozzle may, for instance, vary from 0.2-1.6 mm, more in particular from 0.4-1.4 mm, preferably from 0.6-1 mm and more preferably 0.7-0.9 mm. In this example, this diameter is approximately 0.8 mm.

The diameter of the top (for instance d3inFIG. 7) may, for instance, vary from 1.4-10 mm, more in particular from 1.5-8 mm, preferably from 1.75-5 mm and more preferably from 1.75-3.0 mm. In this example, this diameter is 2 mm.

The diameter of the chamber at the top (see, for instance, d2inFIGS. 2 and 7) divided by the diameter of the top (see, for instance, d3inFIGS. 2 and 7) is, for instance, greater than 1.1, preferably greater than 1.2 and more preferably greater than 2.0. The mentioned ratio is preferably approximately equal to 2.5.

It further holds, for instance for this ratio, that this is, for instance, smaller than 5. It also holds, for instance for this ratio, that this may vary from 1.1-5, preferably from 1.5-4 and more preferably from 1.75-3. The top of the impact element may, for instance, be manufactured from POM, PP, ABS or metal.

The diameter d4of the opening (inlet)10of the nozzle may, for instance, vary from 0.3-1.5 mm, more preferably 0.6-1.0 mm and even more preferably 0.7-0.9 mm.

A greatest diameter d5of the chamber may, for instance, be 1 to 4 times and preferably 1 to 3 times greater than the diameter d2of the chamber at the top (see, for instance,FIG. 1). A diameter of the outflow opening18of the chamber may, for instance, vary from 3 to 15 mm, more preferably from 0.5 to 8 mm and even more preferably from 4 to 6 mm.

The orientation of the apparatus ofFIGS. 1-8is not relevant. Thus, the apparatus ofFIG. 3may also be tilted and even be placed upside down. Beverage supplied to the nozzle may also be understood to mean a concentrate which, after being dispensed by the apparatus, is still be diluted with water. The consumable beverage is then a concentrate still to be diluted.

Such variants are each considered to fall within the scope of the invention.