HOT BEVERAGE PREPARATION APPARATUS WITH STEAM LANCE

Abstract

In a hot beverage preparation machine having a beverage discharge head for discharging a prepared hot beverage and a steam lance separate from the beverage discharge head for frothing milk contained in a milk container, the milk container can be positioned in a frothing position in front of the hot beverage preparation machine so that the steam lance is immersed in the milk container, and further has at least one milk outlet arranged to cooperate with the steam lance and is capable of discharging milk into the milk container positioned in the frothing position via the milk outlet, the milk outlet is spatially spaced rearward of the steam lance and terminates above the free end of the steam lance so that when the steam lance is immersed the milk container is positioned in the frothing position below the milk outlet.

Description

[Technical field]

[0001] The present invention relates to a hot beverage preparation machine having at least one beverage discharge head for discharging a prepared hot beverage and a steam lance separate from the beverage discharge head for frothing milk contained in a milk container, the milk container being capable of being positioned in a frothing position in front of the hot beverage preparation machine such that the steam lance is immersed in the milk container, and further having at least one milk outlet arranged to cooperate with the steam lance and capable of discharging milk via the milk outlet into the milk container positioned in the frothing position. [Background technology]

[0002] Hot beverage preparation devices, in particular coffee makers, are often provided with a device for generating milk foam to enable the preparation of coffee beverages such as cappuccino or latte macchiato. In addition to fully automatic coffee makers having an internal milk system for releasing the frothed milk foam, a so-called steam lance is often provided, via which it is possible to release the steam used to froth the milk in the milk container. The steam can also be mixed with air, which is necessary for frothing the milk. A frothing device with a steam lance is disclosed, for example, in WO 2019 / 141409.

[0003] EP 2 878 241 B1 discloses a coffee maker with a steam lance in which a milk supply pipe is also connected to the steam discharge pipe so that milk can first be discharged via the steam lance into a milk container positioned below the steam lance and then frothed with steam.

[0004] EP 3756516 A1 discloses a milk frothing device with a steam lance, which in addition to the steam discharge pipe has a second, separate pipe connected to the milk supply pipe, so that in the milk frothing device too it is possible to first discharge milk via the steam lance and then froth it.

[0005] However, a disadvantage of discharging milk via a steam lance is that the high temperatures reached when discharging the steam can cause milk residues to denature and stick inside the steam lance, especially in the area leading to the milk supply line, which over time leads to hygiene problems as the inside of the steam lance is difficult to clean. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Application No. 2019 / 141409 [Patent Document 2] European Patent No. 2878241 [Patent Document 3] European Patent Application Publication No. 3756516 [Patent Document 4] International Publication No. 2021 / 074038 [Non-patent literature]

[0007] [Non-Patent Document 1] German Utility Model No. 202021101017 Summary of the Invention [Problem to be solved by the invention]

[0008] SUMMARY OF THE PRESENT EMBODIMENT An object of the present invention is to provide a hot beverage preparation machine with a steam lance which does not cause such hygiene problems. [Means for solving the problem]

[0009] This problem is solved by the features of claim 1. Advantageous embodiments result from the dependent claims.

[0010] In a hot beverage preparation device of the type mentioned at the beginning, the invention provides that the milk outlet is arranged spatially separated behind the steam lance and terminates above the free end of the steam lance in such a way that the milk container with the immersed steam lance is positioned in the foaming position below the milk outlet. This makes it possible to position the milk container in the foaming position and firstly release the dispensed amount of milk into the milk container via the milk outlet, and then froth the milk by releasing steam via the steam lance immersed in the milk container or in the milk contained therein. Since the milk outlet is arranged separately from the steam lance, it is not heated by hot steam and therefore milk residues remaining at the milk outlet cannot be denatured and stick to it. The milk outlet can be configured, for example, as a downwardly curved discharge pipe protruding from the front of the hot beverage preparation device. The discharge pipe can also be advantageously inclined forwards at the discharge angle relative to the direction of the steam lance, so that the released milk flows along the steam lance into the milk container.

[0011] The hot beverage preparation machine is preferably provided with a control device that is configured to release the dispensed amount of milk via the milk outlet into a milk container positioned at the frothing position when the frothing process is activated. In conventional coffee makers with steam lances, an operator usually has to manually fill the milk container. This is usually done more or less by eyeballing, which often leads to too much milk being frothed and then having to be discarded. Automated dispensing ensures that the amount of milk according to the selected beverage is always dispensed and then frothed, which would leave a surplus or ultimately result in an insufficient amount of milk being frothed for the desired beverage. Dispensing can be performed by flow measurement or by specifying the operating time of a milk pump that supplies milk to the milk outlet.

[0012] The control device can furthermore be configured to release the release of steam via the steam lance after the milk has been released, thereby enabling a fully automated frothing, whereby the operator only has to position the milk container in the frothing position and then activate the frothing process via a corresponding user interface, for example a touch screen. The steps of milk release and subsequent steam release for frothing are carried out in an automated manner by the control device.

[0013] Furthermore, a temperature sensor can be provided, preferably arranged to cooperate with the steam lance, which detects the temperature of the milk contained in the milk container during the frothing process and informs the control device. Furthermore, the control device can be configured to terminate the release of steam when a set temperature is reached. Since the milk is fed into the milk container at a predefined initial temperature, for example from a milk refrigerator, the final temperature depends on the amount of steam or on the activation time of the steam release. Thus, via the temperature sensor it is possible to conclude not only whether the milk foam has reached the desired temperature, but also whether the desired foam consistency has been obtained, which likewise depends on the activation time of the steam release. The temperature sensor can in particular be arranged at the free end of the steam lance.

[0014] In a preferred development of the invention, the hot beverage preparation machine is provided with a number of milk outlets for different milk types, which are arranged adjacent to one another behind the steam lance. The type of milk to be used for the frothing process can be selected via a user interface. Thus, not only can different milk types be provided, such as normal whole milk, lactose-free milk, low-fat milk or vegan milk substitutes (e.g. soy milk, oat milk, coconut milk, almond milk, pea milk, etc.), but also, by providing them via separate milk outlets, it is possible to ensure that mixing of different milk types is avoided due to milk residues remaining in the milk line from previous milk discharges. This is of great advantage for customers / consumers who are particularly strict vegan or who have food allergies or intolerances to certain milk types or milk components.

[0015] It is also possible within the scope of the invention to provide an air supply line connected to the steam lance, via which air for frothing the milk is supplied to the steam. The controlled supply of air ensures an improved and reproducible frothing of the milk, so that the same consistency of milk foam is always obtained in each frothing process. In particular, air can be added to the steam in a first stage of frothing, and in a second stage the air supply can be closed, allowing only the steam to be released, so that the milk foam is further refined and the consistency improved.

[0016] The supply of air can be carried out in a known manner by means of the Venturi effect via an air valve. However, it is preferable to arrange an air pump (compressor) in the air supply pipe, which supplies air under overpressure for frothing the milk. The use of an air pump allows a good metering of the amount of air and the supply of air under pressure improves the frothing process.

[0017] In a preferred development of the invention, the steam lance can be arranged in the beverage preparation device so that it can be pivoted vertically via a joint, which facilitates the positioning of the milk container, since the steam lance can be pivoted from above into the milk container or placed thereon and pivoted downwards, so that the steam lance can penetrate sufficiently deep into the milk container such that the free end of the steam lance is fully immersed in the milk contained therein, particularly when a milk container with a corresponding height is used in order to prevent milk from splashing.

[0018] In a preferred embodiment, the milk line leading to the milk outlet is switchably connectable via a valve mechanism to a beverage outlet head of the hot beverage preparation device for selectively dispensing milk into a beverage container positioned below the outlet head or into a milk container positioned at the foaming position, thus allowing not only the discharge of a beverage containing milk via the outlet head but also the manual addition of milk foam to the hot beverage discharged via the outlet head after the milk has been separately frothed.

[0019] Furthermore, it is possible for the milk line inlet to be selectively connectable via a switching valve to the flow heater or via a bypass line bypassing the flow heater with the milk pump. This makes it possible to selectively discharge warm milk via the flow heater or cold milk via the bypass line. Discharging warm milk is advantageous if milk is supplied directly via the beverage outlet head to a hot beverage. Conversely, discharging cold milk via the bypass line is advantageous if the milk is discharged via the milk outlet into a milk container for frothing, since cold milk provides a better frothing result.

[0020] Furthermore, an air valve is preferably connected to the fluid line connected to the suction side of the milk pump and a throttling element can be arranged in the fluid line connected to the pressure side of the pump. Due to the controlled supply of air to the suction side of the milk pump and the pressure increase in the pump by the throttling element, milk foam is generated already in the milk pump. The milk foam can then be discharged via the beverage delivery head, either directly or via a flow heater. On the other hand, if milk is discharged via the milk outlet into a milk container for separate frothing of the milk, the air valve is closed so that no frothing of the milk occurs in the milk pump and thus unfrothed milk comes out of the milk outlet. It is thus possible to selectively discharge the milk foam to the delivery head (one-step mixed drink) or to froth the milk separately via a steam lance and then add it to the hot beverage discharged via the delivery head (two-step mixed drink). [Brief description of the drawings]

[0021] Further advantages and embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the drawings. [Figure 1] FIG. 1 is a front view of a coffee maker configured as a countertop device, having two coffee brewing units and a central frothing unit. [Diagram 2] A detailed view of the whisk unit in Figure 1. [Diagram 3] The so-called water flow structure of the milk passage of the frothing unit in Figure 2. [Figure 4] FIG. 1 shows an embodiment of a frothing unit with a milk outlet inclined towards the steam lance. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The coffee maker 1 shown in Figure 1 is a countertop device having two coffee brewing units 2a and 2b arranged respectively to the left and right of the coffee maker 1. A milk frothing unit 10 is provided in the middle of both coffee brewing units 2a, 2b.

[0023] The coffee brewing units 2a, 2b are constructed as a type of fully automatic coffee maker with known construction, water heater, brewing unit and grinder. The exact construction does not need to be described here. In FIG. 1, in the center of each coffee brewing unit 2a, 2b, a discharge head 3a, 3b can be seen, via which the freshly brewed coffee beverage is discharged. Operating levers 4a, 4b arranged on the sides of the discharge heads 3a, 3b are used to influence the brewing parameters, such as the pressure or the flow rate during the brewing process. In the upper area of ​​both coffee brewing units 2a, 2b, a graphic user interface is arranged in the form of a touch screen 5a, 5b each. Via the user interface, it is possible to select the beverage and to start the brewing process or the beverage preparation process. The preparation of the beverage may also include the discharge of milk or milk foam via the discharge heads 3a, 3b in a manner that is also known. For this purpose, the coffee maker 1 is connected to a milk refrigerator, not shown in FIG. 1, which comprises several milk containers from which milk can be supplied by means of a milk pump. A milk refrigerator that can be used in conjunction with a coffee maker is disclosed in WO 2021 / 074038, the full text of which is hereby incorporated by reference in order to avoid unnecessary repetition.

[0024] Of particular interest within the scope of the present invention is the frothing unit 10, which is the central module of the coffee maker 1, the front of which is illustrated in detail in FIG. 2. The frothing unit is used to manually or separately froth milk in a frothing vessel 15, such as a milk pot or a tall cup vessel. For this purpose, the frothing unit 10 has two steam lances 11a, 11b (the steam lances are also often called steam tubes), through which it is possible to emit steam or steam mixed with air by actuating the associated operating levers 12a, 12b in order to froth the milk contained in the frothing vessel 15. At the free ends of the steam lances 11a, 11b, respectively frothing nozzles 13a, 13b are provided. The steam lances 11a, 11b are hinged to the front panel of the frothing unit 10 via swivel joints 14a, 14b, respectively, so that it is possible to swivel the steam lances from above into the frothing vessel 15 in the frothing position. Behind each of the steam lances 11a, 11b there are four milk outlets 16 through which different types of milk can be discharged into the frothing container 15. Between the steam lances 11a, 11b there is a hot water outlet pipe 17 with an associated operating lever 18 through which hot water can be discharged for pre-heating cups or for preparing tea or other beverages.

[0025] The release of milk via the milk outlet 16 and the subsequent frothing process can be controlled via the graphic user interfaces 5a, 5b of the coffee maker 1, with the left touch screen 5a being preferably assigned in terms of control technology to the left steam lance 11a and the right touch screen 5b to the right steam lance 11b.

[0026] The paths of the milk lines to and within the frothing unit 10 are shown in the water flow configuration illustrated in Fig. 3. Four milk suction lines M1, M2, M3, M4 are illustrated in the water flow configuration, which are connected to four milk containers in a milk refrigerator (not shown). The milk paths from the suction lines to the associated milk outlets 16 have essentially the same structure, so that only the structure of the upper milk path will be described here as an example.

[0027] To each of the suction lines M1 to M4 there is connected an air supply line 20 with an air valve V. The air valve V can be opened or closed to cut off or release the air supply. To supply a defined amount of air, the air valve V can be operated periodically, i.e. intermittently, and the amount of air can be metered via the cycle frequency and / or the duty cycle. The milk induction lines M1 to M4 are each connected to the suction side of a milk pump M. On the outlet side, the milk pump M is connected to a throttle element WM in the form of a fixed orifice or, in this case, a spiral mixer, which acts as a pressure boost element. A directional control valve 21 in the form of a 3 / 2-way valve is provided downstream of each of the throttle elements WM. The directional control valve 21 is used to direct the milk flow in the direction of the associated milk outlet 16 via a flow heater in the form of a thermoblock H4 or a bypass line 22 bypassing the thermoblock H4. A total of two thermoblocks H4.1, H4.2 are provided for the four parallel milk lines, each with two separate flow paths. Such a flow heater is disclosed in German utility model no. 202021101017, the full text of which is hereby incorporated by reference in order to avoid unnecessary repetition.

[0028] After the flow heater H4, the bypass pipe 22 and the flow path 23 through the flow heater merge again and lead to another diverter valve in the form of a 3 / 2-way valve 24. Via the diverter valve 24 it is possible to switch the milk flow between the milk outlet 16 and a direct discharge via the outlet head 3a or 3b of the coffee machine. It is thus possible to feed the milk via a pipe 25 to the associated milk outlet 16 or, by switching the valve 24, to direct the milk flow via an outlet pipe 26 which leads to the outlet head 3a or 3b. Furthermore, a drain valve 27 is additionally arranged in the outlet pipe 26, via which it is possible to connect the milk line directly to the drain and to carry out the emptying and rinsing process.

[0029] 3 also shows a steam tube 30 leading to the steam lance 11. The steam tube 30 is connected to a steam generator, not shown, in the form of a pressure boiler or a flow heater for steam. The steam tube 30 is connected to an air supply tube 31, which is connected to an air pump 32. On the inlet side, the air pump 32 is connected to an air suction port via an orifice 33. By activating the air pump 32, it is thus possible to precisely supply air to the steam in the steam tube 30. Furthermore, a temperature sensor 34 is connected to the steam lance 11, which together with the steam lance 11 is immersed in the frothing vessel 15 positioned below it in order to measure the temperature of the milk contained in the vessel during the frothing process.

[0030] The circuit shown in Fig. 3 is provided twice in the coffee machine 1, once for each steam lance 11a, 11b and the associated rear milk outlet 16. The components shown in Fig. 3 are controlled via the control unit of the coffee machine 1 and the associated user interface 5a or 5b. For example, when discharging a coffee drink with milk foam via the discharging head 3a, the milk pump associated with the type of milk (M1 to M4) selected via the touch screen 5a is activated to produce milk foam, and air is supplied to the suction side of the pump M via the air valve V. The valve 21 is switched to the lower switching position so that the milk flow is directed through the thermoblock H4. The valve 24 is likewise switched to the lower switching position so that the milk foam is discharged via the tube 26 to the discharging head 3a. At this point the drain valve 27 is in the upper switching position.

[0031] For the separate production of milk foam in the frothing vessel 15, milk is likewise supplied via the associated milk pump M. The valve 21 is switched to the upper switching position, so that the milk flow is led via the bypass line 22. The valve 24 is switched to the upper switching position, so that the milk flow is led via the milk line 25 to the associated milk outlet 16 and discharged into the frothing vessel 15 arranged below the milk outlet. The milk is then frothed in the frothing vessel 15 arranged below the milk outlet by releasing steam via the steam pipe 30 and the steam lance 11a connected to the steam pipe and by supplying air to the steam via the air pump 32. When the milk temperature measured by the temperature sensor 34 at the end of the steam lance 11a reaches a set value, e.g. 50°C, the temperature sensor signals that the frothing of the milk is completed and the supply of steam is terminated.

[0032] In FIG. 4 an alternative embodiment is shown in which the milk outlet 16 is configured as a downwardly curved outlet pipe protruding from the front part 10' of the frothing unit 10, which is inclined forward with respect to the direction of the steam lance 11 at an outlet angle 19, so that the released milk flows along the steam lance 11 into a milk container positioned below the steam lance. The peripheral area of ​​the steam lance 11 facing towards the front can be configured flat or slightly concave in order to be able to better direct the milk flow along the outside. The outlet angle can be, for example, 10 to 20 degrees with respect to the vertical. The steam lance 11 is conventionally pivotable in the vertical direction via a joint 14 and has a frothing nozzle 13 at its free end. By actuating the operating lever 12 it is possible to release steam or steam mixed with air into the milk placed in the frothing container 15 for frothing.

Claims

1. A hot beverage preparation device (1) having steam lances (11; 11a, 11b) for frothing milk or a milk substitute in a milk container (15), wherein the milk container (15) can be positioned in front of the hot beverage preparation device (1) at a frothing position such that the steam lances (11; 11a, 11b) are immersed in the milk container (15), and further has at least one milk outlet (16) arranged to cooperate with the steam lances (11; 11a, 11b), and is capable of discharging the milk or milk substitute into the milk container (15) positioned at the frothing position via the milk outlet, In a hot beverage preparation device (1), the milk outlet (16) is spatially spaced apart and positioned behind the steam lances (11; 11a, 11b), and terminates above the free end of the steam lances (11; 11a, 11b) so that the milk container (15) is positioned at the frothing position below the milk outlet (16) when the steam lances (11; 11a, 11b) are immersed in it. The hot beverage preparation device (1) is provided with beverage dispensing heads (3a, 3b) for dispensing the prepared hot beverage, and milk dispensing ports (16) adjacent to each other and positioned behind the steam lances (11; 11a, 11b) when the hot beverage preparation device (1) is viewed from the front, wherein the steam lances (11; 11a, 11b) are separate from the beverage dispensing heads (3a, 3b), and the type of milk used in the frothing process can be selected via a user interface (5a, 5b).

2. The hot beverage preparation apparatus (1) according to claim 1, characterized in that it has a control device configured to release the amount of milk or milk substitute distributed through the milk outlet (16) into the milk container (15) positioned at the frothing position when the frothing process is activated.

3. The hot beverage preparation apparatus (1) according to claim 2, characterized in that the control device is further configured to release steam through the steam lances (11; 11a, 11b) after the milk has been released.

4. The hot beverage preparation apparatus (1) according to claim 2 or 3, further comprising a temperature sensor (34) arranged to cooperate with the steam lance (11; 11a, 11b), wherein the temperature sensor detects the temperature of the milk or milk substitute placed in the milk container (15) during the frothing process and notifies the control device, and the control device is configured to terminate the release of steam when a set value is reached.

5. A hot beverage preparation apparatus (1) according to any one of claims 1 to 3, characterized in that an air supply pipe (31) is connected to the steam lance (11; 11a, 11b), and air for frothing the milk or milk substitute is supplied to the steam via the air supply pipe.

6. The hot beverage preparation apparatus (1) according to claim 5, wherein an air pump (32) is located inside the air supply pipe (31), and the air pump supplies air for frothing the milk or milk substitute under excessive pressure.

7. The hot beverage preparation device (1) according to any one of claims 1 to 3, characterized in that the steam lances (11; 11a, 11b) are arranged in the hot beverage preparation device (1) so as to be able to rotate vertically via a joint (14).

8. The hot beverage preparation apparatus (1) according to any one of claims 1 to 3, characterized in that the milk tubes (22, 23) leading to the milk outlet (16) are switchably connected to the beverage dispensing heads (3a, 3b) via a valve mechanism (24) to selectively dispense milk or a milk substitute into a beverage container located below the beverage dispensing heads (3a, 3b).

9. The hot beverage preparation apparatus (1) according to claim 8, characterized in that the inlets of the milk pipes (22, 23) can be selectively connected to a flow heater (H4.1, H4.2) or to a milk pump (M) via a bypass pipe (22) that bypasses the flow heater (H4.1, H4.2) via a switching valve (21).

10. The hot beverage preparation apparatus (1) according to claim 9, characterized in that an air valve (V) is connected to a fluid pipe (M1 to M4) connected to the suction side of the milk pump (M), and a throttling element (WM) is arranged in a fluid pipe connected to the pressure side of the milk pump (M).

11. The hot beverage preparation apparatus (1) according to claim 10, characterized in that the air valve (V) is controlled to be switched to a closed state by the steam lance (11; 11a, 11b) for the frothing process and to be switched to an open state at least temporarily when frothing milk or milk substitute is released through the beverage dispensing heads (3a, 3b).

12. The hot beverage preparation device (1) according to any one of claims 1 to 3, characterized in that the milk outlet (16) is configured as a downwardly curved discharge pipe protruding from the front part (10') of the hot beverage preparation device (1).

13. The hot beverage preparation apparatus (1) according to claim 12, characterized in that the discharge pipe is inclined forward with respect to the direction of the steam lance (11) at the discharge angle (19), so that the discharged milk flows along the steam lance into a milk container (15) positioned below the steam lance.

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