Method and device for preparing a beverage, preferably milk froth or hot milk

Abstract

Method and device for producing milk froth, in particular for preparing beverages containing milk froth using coffee machines. The beverage, preferably cold milk, is at least partially introduced into a container before the preparation. The introduced beverage, in the container positioned on a placement surface of a station, is guided through at least one line, which leads away from the station, to a device for preparing milk froth or hot milk. The beverage is subsequently led back into the container, and this circulation is repeated until the beverage has a certain temperature and/or consistency. Using this method, a container can be used by operating personnel in a conventional way for preparation of the beverage, because the beverage can thus be prepared manually and specifically in accordance with the desires of the guest, while the milk froth or the like can be produced and served with constant and high quality.

Description

The invention relates to a method and device for preparing a beverage, preferably milk froth or hot milk, in accordance with the preambles to claim 1 and claim 6 respectively.

For the production of steam, in particular in a coffee machine, the principle is known, as disclosed in the printed publication DE 44 45 436, of controlling the quantity of delivery of steam by way of a simple valve as a manual operating unit. The emission of steam is used essentially for preparing coffee specialities containing milk, such as Cappuccino, Latte Macchiato, or milk coffee, and in this situation for the production of milk froth. The hot steam is conveyed, by way of a lance immersed into the milk, into a cup or container, such that the milk is heated, and the desired milk froth is produced by the upwards and downwards movement of the cup during the ingress of the steam.

A device of this type is also disclosed in EP-A-1 501 398. This consists essentially of a steam generator and a compressed air source, as well as a steam delivery line and, connected to this, a compressed air line, which is extended by the steam lance immersed into the milk. The mixing of the two media, steam and air, therefore already takes place before the steam lance. As a result, it is difficult to adjust the quality of the milk froth, and to change it depending on the type of beverage which is to be prepared. In this situation, devices of this type are nowadays required to satisfy high demands in respect of product quality, although their conditions of use and operation often vary considerably from case to case.

The invention is based on the object of providing a method and device of the type referred to heretofore, with which fresh milk or the like is at least partially filled in a known manner into a container, such as a jug, but, in consequence, milk froth in particular can be produced in best quality for a beverage.

This object is solved according to the invention by the features of claim 1 and claim 6 respectively.

With this method according to the invention, a container can be used by the operator in an inherently conventional manner for the preparation of the beverage, since in this way the beverage can be prepared manually and individually for the guest in accordance with his preferences, while the milk froth or the like can be produced and served constantly with the same and high quality.

The invention makes provision in this situation for the beverage filled in the container, positioned on a standing surface of a station, to be conveyed through at least one line, leading away from the station, to a device for preparing, preferably, milk froth or hot milk, and back into the container, and this circulation is repeated, preferably until the beverage exhibits a specific temperature and/or consistency.

This device is provided with a froth production unit, which comprises at least one line leading away from the station, a pump suctioning the milk or the like out of the container and conveying it, an air inlet, at least one choke, and a heating means which can be switched on and off, for the milk or the like. The circulating line is guided back to the station, and makes it possible for the milk or the like which has been prepared to be led back again into the container.

With one preferred embodiment of this arrangement, the invention makes provision for this device to be a constituent part of a coffee machine, which is placed out of sight beneath the table. As a result, the arrangement is practically invisible to the customer or consumer using it.

As an alternative to this, the coffee machine equipped with the device can be placed so as to be easily accessible on a counter or table. This allows, among other things, for the direct actuation of the coffee machine, as a result of which handling is made easier.

The invention and its further advantages are explained in greater detail hereinafter on the basis of exemplary embodiments and making reference to the Figures. The Figures show:

FIG. 1 is a hydraulic schematic of a device according to the invention, with a station and a container standing on it;

FIG. 2 is a longitudinal section of the station and the container standing on it, with closed passage openings;

FIG. 3 is the longitudinal section according to FIG. 2, with open passage openings;

FIG. 4 is a partial view of a service table with the station and the container standing on it, and with a coffee machine indicated among the table furniture items;

FIG. 5 is a schematically represented coffee machine, with a station placed next to it, and a container standing on it, and

FIG. 6 is a hydraulic schematic of a device according to the invention, with a container for the delivery of the beverage.

The device 1 shown in FIG. 1 for preparing a beverage is constructed as a separate milk preparation module, or integrated in a coffee machine. With this device 1, hot milk, cold or hot milk froth, or a milk mixture for Cappuccino, Latte Macchiato, chocolate, vanilla, or other beverages are made.

With this device 1, provision is preferably made for a standing surface 9′ on a serving table, or, with a coffee machine, for a container 10 which can be put in place by hand. As the container 10, a metal milk jug is being used. Use could also be made of a milk jug or a vessel made of porcelain, or a cup or the like. This container 10 can be raised from the station 9 or set down on it, wherein corresponding centring means, such as centring bolts, make possible the exact positioning of the container on the station.

With the method according to the invention, the filled beverage in the container 10, positioned on the standing surface 9′ of a station 9, is conveyed through a line 5 leading away from the station 9 to the device 1 for preparing preferably cold or hot milk froth or hot milk, and then conveyed back into the container 10. This circulation of the beverage which is to be prepared, from the container through the line, through the device, and back to the container is automatically repeated until the beverage exhibits a specific temperature and/or consistency. This could, however, in principle also be controlled as a dependency of time and/or quantity.

This froth production unit 3 of the device 1 for heating the milk or producing cold or hot milk froth consists essentially of a line 5 leading away from the station 9 on the table, a temperature sensor 21, a choke 14 from a pump 13 conveying the beverage, and, upstream or downstream of this, an air intake 12. Arranged following this is a connection element 16, connected to the steam line 22, leading at a right angle into the line 5, for the delivery of the steam, a temperature measuring device 17, and a mixed froth consistency measuring device 18. The line 5 is then guided back to the station 9.

This milk froth consistency measuring device 18 is advantageously formed by an electrical sensor, with which the electrical conductivity or electrical resistance of the flowing milk froth is measured. It would also be possible to do without this measuring device 18, however, and, in order to attain a desired consistency of the beverage containing froth, its temperature is determined with the temperature measuring device 17, and on the basis of this temperature the revolution speed of the pump 13 is adjusted by regulating or controlling in such a way that a reference temperature can be adjusted, and therefore also this desired consistency. This could also be attained, however, by controlling the quantity of air introduced via the air inlet 12, by means of a proportional valve 12′.

This device 1 comprises a heating assembly with a steam line 22 for heating the beverage, for example by means of steam, which can be delivered in a controlled manner from a boiler, which is not shown in any greater detail. The steam line 22 leads via a closure valve 32, actuated by a corresponding control unit, and a non-return valve 33, into a line 5 of the froth producing unit 3, through which the milk or the like circulates. The hot steam is introduced through this steam line 22 into the beverage flowing in the line 5 in such a way that the beverage is heated rapidly.

The device 1 is further shown with a water feed for cleaning, with a delivery line 19 leading into the line 5, a filter unit 15, and a valve 35. Also provided for this cleaning is a two-way valve 23 for a loop of the line 5 through an additional line 6 with a cleaning medium inlet 19, and also a non-return valve 26.

During the cleaning of the froth production unit 3, the line 5, and the container 10, the valves 35, 23 are switched in such a way that water is suctioned into the line 5 by means of the pump 13, and a circuit is formed through the line 6 with the cleaning medium inlet 19, for example with cleaning tablets 19′, through the line 5, the container 10, and back again through the pump 13 into the line 6, and the water is therefore circulated. At the end of the cleaning process, the two-way valve 24 can be opened, and the cleaning water flows away into a catchment container 37.

Advantageously, cleaning is often carried out only with water without the involvement of the line 6, wherein the water is circulated via the line 5 through the froth production unit 3 and the container 10, and is then guided into the catchment container 37.

According to FIG. 2 and FIG. 3, the container 10 shown in the lower part contains a wall and a base 10′, with two passage openings 11, 11′ running next to one another, and a closure element 20. This closure element 20 is composed of a vertical axis 25, subjected to preliminary tension by means of a pressure spring 34, a closure element 31 secured to the top of this, and, projecting so as to correspond to this, an inlet 36 and outlet 35 for the passage openings 11, 11′. In addition to this, corresponding sealing elements 37, 38 arranged in the base 10′, which ensure that the container is tightly sealed when the beverage is filled into it and it stands on the station.

Provided in the station 9 are line connections 45 for connecting the passage openings 11, 11′ to the lines 5, and a lifting device 46 with a piston 47 is provided, which is vertically adjustable and comes in contact with the lower face side of the vertical axis 25 in the container 10. This piston 47 can be moved by the lifting device 46 in a controlled manner into two positions, and has the effect that the closure element 31 of the closure element 20 in the interior of the housing can be positioned by way of this vertical axis 25 into a closed position or open position, as can be seen in FIG. 2 and FIG. 3 respectively. This pressure spring 34 taking effect on the vertical axis 25 makes it possible for the closure element 31, with the vertical axis 25, to move automatically into the closed position, and therefore the container is always closed when it is not intended that the beverage should circulate.

In this way, preferably a certain selectable quantity of cold milk or a milk mixture can be filled as required into this container 10, represented as a jug. After the jug has been set down on the station 9, the cold milk is suctioned out of it, and, by way of the circulations, provided for example as cold or hot milk froth. In this way, an excellent milk froth can be produced in seconds. The operator can therefore prepare the beverages more rapidly than if the milk or the like must be produced by a conventional steam lance inserted into the jug on the coffee machine, manually, by hand movements. Added to this is the fact that a person who orders the beverage and is standing next to the table does not see, and also does not perceive, that, for example, milk froth is being produced in the jug standing on the station 9.

With the exemplary embodiment according to FIG. 4, the device 1 according to the invention, as a separate milk preparation module, and also a coffee machine 27 and an associated refrigerator 27′, are accommodated in a table furniture unit 28. A station 9 connected to the device 1 is mounted on a table plate 29. The coffee machine 27, explained hereinafter, has an outlet, not visible, above the table plate 29, which can be provided with a column or similar element. In addition to this, advantageously, the hot steam required in the device 1 is produced in the coffee machine 27, which are connected to one another by a steam delivery line, not shown in any greater detail.

FIG. 5 shows a variant with which the coffee machine 27 is free-standing on a surface 39′ of a counter 39, a table, or the like, and this station 9, with the container 10 which can be placed on this, is arranged next to the coffee machine 27, wherein the device 1, not visible, is integrated into the coffee machine 27. Of the coffee machine 27, shown only in principle, there can be seen the housing 41, on the front side the outlet(s) 42 for the coffee, on the upper side the coffee bean container 44, and a drip tray 43 beneath, on which can be stood a cup or the like for filling with coffee and/or milk or milk froth. Next to the coffee machine 27 and the drip tray 43, advantageously, this station 9 is placed laterally, which is provided with the lines of the device 1 passing into the interior of the housing 41 of the coffee machine 27.

This method and device according to the invention for the heating of milk can be used both with a milk module as a separate unit, or, as explained heretofore, can be integrated in a coffee machine, in particular for producing Cappuccino or other hot milk beverages.

With a further variant according to FIG. 6, the beverage is not conveyed from a container 10 which can be set in place, but from a container 61, in a known manner to a device which is configured in a similar manner to that according to FIG. 1, and from this there is a connection to an outlet 71, beneath which, for example, a cup can be placed. In this situation, the milk is suctioned through a suction line 65 by a controllable pump 64, such as a gear pump. In addition to this, an air delivery line 63 with a switchable air control valve 66 is arranged upstream of the pump 64, and hot steam is conveyed as a heating medium through two steam lines 67, each provided with a closure valve 68 and a non-return valve 69, transversely into this passage opening 65, wherein it would also be possible for only one steam line 67 to be provided. In addition, chokes 71 are advantageously provided downstream of the pump 64 in the line 65.

According to the invention, the beverage is conveyed by the line 65, leading away from the container 61, into the froth production unit 60, for the preparation of the beverage, preferably of milk froth or hot milk, from which, via a line 65′, it is conveyed into a chamber 62 and then back into the froth production unit 60, and this circulation is repeated preferably until the beverage exhibits a specific temperature and/or consistency, and, following this, the beverage is conveyed to the outlet 73.

For this purpose, in each case a two-way valve 72 is arranged in the line 65, upstream and downstream of the pump 64, through which the beverage is conveyed either via the line 65′ into the chamber 62 for this circulation or this loop, or is conveyed directly to the outlet 73. From this chamber 62, the cold or hot milk mixture is then again suctioned by the pump 64, via the two-way valve 72, and, depending on the situation, is again conveyed either into the chamber 62 or to the outlet 73. The chamber 62 is preferably dimensioned in such a way that the beverage portion which is to be prepared corresponds at least approximately to that portion which is required for the cup or container which has been provided at the outlet 73. This beverage portion is determined by a controlled opening or closing of a valve 74 in the line 65.

Furthermore, a temperature measuring device 17 or a consistency measuring device 18 respectively is arranged in the froth production unit 60, which, depending on the measurement, by means of a corresponding control unit, can cause the two-way valves 72 to be switched.

This device according to FIG. 6 is integrated in a coffee machine or in a separate milk froth producer, and allows for the production of high quality milk froth in a cold or hot state.

It is of course possible for the invention to be explained by way of other exemplary embodiments. For example, instead of a steam source as the heating medium, another form of heating of the beverage can be provided, for example by means of a known water heater or the like.

The at least one, or both, passage opening(s) provided in the container could also be arranged in its side wall.

In principle, it would also be possible for hoses to be used in the container instead of the passage openings and the closure element, which are immersed into the container. These hoses would then be provided with closure valves having the same effect.

Claims

1. Method for preparing a beverage, preferably of milk froth or hot milk, with which the beverage, preferably cold milk, is filled at least partially into a container (10) before the preparation, or the beverage is conveyed from a container (61), characterized in that the filled beverage is conveyed in a container (10) positioned on a standing surface (9′) of a station (9) by means of at least one line (5, 65), leading away from the station (9) or from the container (61), to a device for the preparation preferably of milk froth or hot milk, and back into the container (10) or into a chamber (62), and this circulation is repeated preferably until the beverage exhibits a specific temperature and/or consistency.

2. Method according to claim 1, characterized in that the beverage is conveyed from at least one passage opening (11), preferably provided in the base of the container (10), into the line (5), and through at least one second passage opening (11′) back again into the container (10).

3. Method according to claim 1, wherein when the container is placed onto the standing surface of the station, the at least one passage opening is automatically connected to the line, wherein a closure element is arranged, which opens or closes the passage of the beverage from or into the container.

4. Method according to claim 1, wherein by means of a device integrated in the service table or the coffee machine, the beverage suctioned out of the container for preparation to provide a beverage containing froth, preferably milk froth, is processed and/or heated, and is then conveyed back into the container, and this circulation is repeated until the beverage exhibits a specific temperature and/or consistency.

5. Method according to claim 1, wherein in order to attain a desired consistency of the beverage containing froth, its temperature is measured, and, on the basis of this temperature measurement, revolution speed of a pump is adjusted by means of a regulating or controlling device in such a way that a reference temperature is adjusted, and therefore also this desired consistency.

6. Device for carrying out the method according to claim 1, comprising a froth production unit which comprises at least one line leading away from the station or from the container,a pump, suctioning and conveying the milk out of the container or the vessel,an air delivery line arranged upstream or downstream of the pump,at least one choke, anda heating means for the milk, wherein the line is guided back to the station or into the at least one chamber, and which makes it possible for the milk which is to be prepared to be conveyed again into the container or into the chamber.

7. Device according to claim 6, characterized in that by the placing of the container (10) onto the standing surface (9′) of the station (9) in a specific position, an automatic tight connection is established with the at least one line (5) of the froth production unit (3), wherein a closure element (20) is arranged in the container, which can be actuated by a lifting device (46) with a piston (47).

8. Device according to claim 6, wherein as the heating medium, a steam line of a heating device is provided, with a connection element running transversely into the line, wherein the heating device comprises a boiler which produces hot water vapor, which is conveyed through this steam line into this line circulating the milk.

9. Device according to claim 6, wherein the froth production unit and/or the heating device of the device is a separate device or integrated in a coffee machine, wherein this separate device or the coffee machine is placed in an unseen position in a service table or on a counter.

10. Device according to claim 6, further comprising a temperature measuring device and/or a consistency measuring device for the milk froth arranged in the froth production unit, by means of which the milk flowing through the line is measured or determined, wherein, with the consistency measuring device, the electrical conductivity or the electrical resistance of the flowing milk froth is evaluated.

11. Container for a device according to claim 6, wherein at least one opening is provided in the container, which serve in each case to connect a line of the device, wherein a closing element is arranged which opens or closes the at least one passage opening, and therefore opens or closes the passage of the beverage which is to be prepared out of the container or into it.

12. Container according to claim 11, characterized in that the closing element (20) is composed of a vertical axis (25), subject to preliminary tension by means of a pressure spring (34), a closure element (31) secured on the top of this, and of the projecting inlet (36) and outlet (35) corresponding to this element in the container (10) for the passage openings (11, 11′).