Cooling device for operation with a hot beverage preparation device

Abstract

In a cooling device for operation with a hot beverage preparation device, a filling level sensor is used to detect the filling level of a cooled storage container. The storage container has a lid which is transparent to a measurement signal from the filling level sensor. The filling level sensor is mounted above the lid and measures the signal component which penetrates through the lid and which is reflected by a liquid located in the storage container.

Description

[0001] Cooling device for operation with a hot beverage preparation device

[0002] Description

[0003] The present invention relates to a cooling device for operation with a hot beverage preparation device, comprising a cooled receiving chamber for storing liquid beverage additives and at least one storage container for a liquid beverage additive that can be inserted into the receiving chamber.

[0004] Hot beverage preparation appliances are known for preparing various drinks, such as different coffee drinks with or without added milk. Milk refrigerators, designed as standalone appliances, are known for keeping milk chilled.

[0005] The fill level of beverage ingredients stored in storage containers should be monitored frequently.

[0006] EP2228633B1 describes an optical monitoring system for a coffee machine's reservoir, detecting whether its fill level falls below a predetermined level and thus requires refilling. For this purpose, a light beam, preferably in the infrared range, is directed laterally into the reservoir and then reflected back to the sensor board via a mirror. Depending on whether the liquid level is above or below the monitoring level, the refractive index changes, altering the path of the light beam and thus whether it returns to the sensor or not. Continuous fill level monitoring is not possible with this system.

[0007] US9945711B2 describes a beverage maker that prepares hot or cold beverages from water and liquid beverage additives stored in reservoirs. The reservoirs are equipped with a level sensor that uses infrared radiation to detect whether the liquid level in a reservoir has fallen below a certain level. This is achieved by detecting whether an infrared signal is reflected by the beverage additive in the reservoir. This device cannot measure the actual liquid level in the reservoir, but only determines whether a predetermined level has been reached.

[0008] The present invention aims to provide a level monitoring system for a storage container located in a cooling device.

[0009] The problem is solved by the features of claim 1. Advantageous embodiments are described in the dependent claims. In addition, an arrangement with such a cooling device and a hot beverage preparation device connected to the cooling device is described.

[0010] The cooling device of the type mentioned above comprises at least one electromagnetic level sensor for detecting the fill level in the storage container by means of an electromagnetic measuring signal. The level sensor is arranged in the receiving chamber such that, when the storage container is in place, it is located above the storage container and emits the measuring signal from above towards an opening of the storage container.

[0011] Preferably, the storage container has a lid that is at least partially transparent to the electromagnetic measurement signal and seals the opening of the storage container. The level sensor is arranged in the receiving chamber such that, when the storage container is in place, it is located above the lid and emits the measurement signal from above towards the lid. This allows the level sensor to detect that portion of the electromagnetic measurement signal that penetrates the lid, is reflected by the liquid surface of the beverage additive in the storage container, and then returns to the level sensor.

[0012] The level sensor therefore measures its distance to the liquid surface through the lid. The lid prevents beverage additive from sloshing into the reservoir, for example, due to tilting movements when adjusting the reservoir, and from contaminating the sensor with spilled or splashed liquid. Since the upper part of the cooled reservoir, particularly its upper boundary wall, is generally warmer than the lower part and side walls, ice formation, which could impair the level sensor, is less likely there. Therefore, the level sensor's measurement signal is less susceptible to interference. Furthermore, if the reservoir's geometry is known, the volume of the beverage additive can be determined from the measured level.

[0013] The fill level in the storage container is preferably detected using an infrared signal. Therefore, an infrared sensor is used as the fill level sensor. Infrared sensors are reliable and inexpensive.

[0014] Alternatively, the fill level in the storage container is detected using a radar signal. In this embodiment, a radar sensor is used as an electromagnetic sensor. Radar sensors enable precise measurement of the fill level through multiple layers of plastic. This allows the fill level sensor to be installed, for example, in or behind the upper boundary wall of the cooled receiving chamber of the cooling device and still reliably detect the fill level.

[0015] In an advantageous embodiment, the level sensor is arranged within a vertical projection of the lid. This results in a direct path to and from the level sensor for both the measurement signal emitted by the level sensor and the signal reflected from the surface of the beverage additive in the reservoir. Consequently, a larger proportion of the measurement signal returns to the level sensor, enabling more precise level measurement.

[0016] The electromagnetic level sensor comprises a transmitter and a receiver. In an advantageous embodiment, the transmitter and receiver of the sensor are arranged such that the reflection angle for the measurement signal is 20° or less. The reflection angle is the angle enclosed by two straight lines that represent the shortest path of the measurement signal from the transmitter to the liquid surface and back to the receiver. Since this angle depends on the fill level, the specified value is defined for a completely full container. For other fill levels, i.e., when the reservoir is not completely full, the reflection angle will be smaller. A shallow reflection angle allows the transmitter and receiver of the level sensor to be located close together, thus reducing the sensor's footprint and enabling it to be designed, for example, as a single component.

[0017] In a further advantageous development, a processing unit is provided that processes an output signal from the level sensor. The output signal can, for example, be an electrical voltage corresponding to a fill level. Given the known geometry of the storage container, the volume of the beverage additive in the container can be calculated based on the fill level. Of course, the output signal can also be a data set with multiple measurements, for example, in the case of a multi-zone sensor.

[0018] According to the invention, the processing unit can be arranged either in the cooling device or in the hot beverage preparation device connected to it. It is therefore within the scope of the invention that an output signal from the level sensor or a derived evaluation result can be transmitted directly via an interface between the cooling device according to the invention and a hot beverage preparation device connected to the cooling device. The selection and arrangement of the sensor according to the invention achieves a measurement accuracy of 100 ml, preferably even 50 ml, for the determined fill volume of the beverage additive.

[0019] In principle, the storage container can have any geometry. Given the known fill level and geometry, the fill volume of the storage container can be calculated. Preferably, the storage container has a geometry in which the fill volume depends essentially linearly on the fill level. This greatly simplifies the calculation of the fill volume using the fill level and increases accuracy.

[0020] It is in accordance with the invention that a storage container whose filling volume depends essentially linearly on the fill level may have areas in which the filling volume depends non-linearly on the fill level. For example, a cuboid storage container may have rounded lower edges, whereby at the level of the lower edges the filling volume depends non-linearly on the fill level, but the filling volume of the cuboid storage container then nevertheless depends linearly on the fill level.

[0021] Furthermore, the present invention relates to an arrangement comprising a cooling device of the type described above and a hot beverage preparation device connected to the cooling device. The cooling device is connected to the hot beverage preparation device via a liquid line. By means of a pump, preferably arranged in the cooling device and connected to the storage container via a liquid line, beverage additive is conveyed from the storage container to the hot beverage preparation device via the liquid line and dispensed at a beverage outlet of the hot beverage preparation device during a preparation process.

[0022] Furthermore, the cooling device can be connected to the hot beverage preparation device via a signal line. An output signal from the fill level sensor is transmitted to the hot beverage preparation device via this signal line. If the fill level falls below a critical minimum, the hot beverage preparation device can then issue a corresponding warning message, prompting the user to refill the beverage additive and / or preventing or restricting the dispensing of products containing the relevant beverage additive.

[0023] In an alternative embodiment of the arrangement, the cooling device has a processing unit. The processing unit receives an output signal from the level sensor and calculates, for example, the fill level or volume of the storage container. This calculation result is transmitted to the hot beverage preparation device via a signal line. The hot beverage preparation device can receive the calculation result and, for example, inform the user about the remaining volume in the storage container by means of a display. In this embodiment of the arrangement, the hot beverage preparation device does not require any means of converting the output signal of the level sensor into a fill level or a related quantity.

[0024] The fill level can advantageously also be transmitted via a WAN interface (IoT interface), which can be located, for example, in the hot beverage preparation device, to a remote server or a mobile device of an operator. This allows the operator to be informed early on, and preferably also depending on their current geographical location or their distance from the hot beverage preparation device, when a liquid beverage additive such as milk stored in the connected cooling unit of the corresponding machine needs to be refilled.

[0025] Further advantages and features of the invention will become apparent from the following description of exemplary embodiments with reference to the figures. These show:

[0026] Figure 1 shows a schematic view of a cooling device with an installed reservoir and a level sensor arranged according to the invention in a first embodiment.

[0027] Figure 2 shows a schematic representation of a cooling device in a second embodiment with an additional computing unit and liquid conveying system.

[0028] Figure 3 shows a schematic representation of a cooling device in a third embodiment with two storage containers and

[0029] Figure 4 shows a schematic representation of a transmitter / receiver arrangement serving as a level sensor.

[0030] In the embodiment shown in Figure 1, a hot beverage preparation device 1 designed as a coffee machine is equipped with a cooling device 2 designed as an accessory. The cooling device 2 serves here as a milk refrigerator for the chilled provision of milk or milk foam as beverage additives for milk-based hot beverages.

[0031] The cooling device 2 has a cooled receiving chamber 3 into which a storage container 5 with liquid beverage additive 4, in this case milk, is placed. The storage container 5 is closed at the top by a lid 6. A level sensor 7 is mounted in the cooling device 2 above the lid 6. The level sensor 7 is an infrared sensor. The lid 6 is made of a plastic that is transparent, at least in the infrared range, so that an infrared measurement signal 8 emitted by the level sensor 7 can penetrate the lid 6.

[0032] The level sensor 7, as schematically shown in Figure 4, comprises a transmitter 7a and a receiver 7b, which are spaced a known distance apart. When the level sensor 7 emits a measurement signal 8, this signal is reflected by the surface of the liquid (milk) contained in the reservoir 5. The level sensor 7 can be configured to measure the angle at which the measurement signal is reflected. This can be achieved by using a spatially resolved receiver 7b. From the measured angle and the known distance between transmitter 7a and receiver 7b, the distance of the level sensor 7 to the milk surface is determined. The distance from the bottom of the reservoir 5 to the level sensor 7 is known, and the level 9 can be determined from the difference between this distance and the distance between the level sensor and the milk surface.

[0033] Instead of using a spatially resolved measurement to determine the reflection angle, the distance between the level sensor 7 and the liquid surface can also be determined by a time-of-flight measurement, and the level sensor 7 can be designed accordingly. Alternatively, a radar sensor can be used as the level sensor 7, which measures the distance of the level sensor 7 to the milk surface using the frequency-modulated continuous wave method.

[0034] In the event that there is no milk in the storage container, a signal component of the measurement signal 8 reflected from the bottom of the storage container 5 reaches the level sensor 7, from which it can be concluded that the storage container 5 is empty.

[0035] Figure 2 shows a further development of the first embodiment shown in Figure 1. A signal line 13 and a liquid line 15 lead from the cooling device 2 to the hot beverage preparation device 1. In this embodiment, the level sensor 7 is an analog sensor that generates an analog output signal 12. This output signal 12 is an electrical voltage whose magnitude corresponds to a measured distance value. The output signal 12 is fed to a processing unit 11, which is connected to the signal line 13 leading to the coffee machine. The cooling device 2 also has a pump 14, which is connected to the liquid line 15 and the reservoir 5. The processing unit 11 receives the analog output signal 12 as its input. The processing unit 11 evaluates a mathematical formula to obtain a distance value from the electrical voltage.The fill level 9 is obtained by subtracting the distance value from the distance between the bottom of the reservoir 5 and the fill level sensor 7. The dimensions of the reservoir 5 are known to the processing unit 11. It can then evaluate a geometric formula to determine the fill volume of the reservoir 5. The calculated fill volume is transmitted to the coffee machine via signal line 13. The coffee machine displays the current fill volume on a screen. Alternatively, or additionally, the coffee machine can also use the fill volume to determine how many and which beverages can still be dispensed and block the dispensing of beverages for which there is insufficient beverage additive.

[0036] By means of pump 14, milk is supplied from the storage container 5 via the liquid line 15 to the coffee machine in order to produce a milk-coffee mixed drink such as milk coffee.

[0037] Figure 3 shows another embodiment of the cooling device 2. Compared to the first embodiment 1 shown in Figure 3, two storage containers 5, 5' are adjustable or installed in the receiving chamber 3. For example, storage container 5 contains milk as a beverage additive 4, while the second storage container 5' can contain another beverage additive, such as a cold-extracted coffee drink. It would also be possible to store two different types of milk, such as lactose-free milk and regular UHT milk.

[0038] The storage containers 5, 5' each have a lid 6. Above the two lids 6, each storage container 5, 5' has its own level sensor 7, 7', which sends an electromagnetic measurement signal 8 towards the lid 6 below. As in the first embodiment, the lids 6 are at least partially transparent to the measurement signals 8. The fill levels 9, 9' can be different. The measurement can be location-based or time-of-flight, as in the first embodiment. An infrared sensor or a radar sensor can also be used as the level sensor 7. This allows the fill levels 9, 9' of several beverage additives 4 cooled in the same cooling device to be detected.

[0039] Figure 4 schematically shows an arrangement of the level sensor 7, comprising a transmitter 7a and a receiver 7b, and a storage container 5. The storage container 5 is completely filled with beverage additive 4, for example, milk. Transmitter 7a and receiver 7b of the level sensor are located within a vertical projection 10 of the lid 6. Transmitter 7a emits an electromagnetic measurement signal 8, for example, an infrared signal. The measurement signal 8 penetrates the lid 6, which is partially transparent to the measurement signal, and is reflected from the surface of the beverage additive 4. Since the storage container 5 is completely full, the measurement signal 8 is reflected immediately below the lid 6. The reflected portion of the measurement signal penetrates the lid 6 again and is detected by receiver 7b.The shortest possible path for the measurement signal 8 is shown, which it can take to travel from transmitter 7a, reflected off the surface of the beverage additive 4, to receiver 7b. The two partial beams, transmitter 7a - surface and surface - receiver 7b, enclose the reflection angle α. The reflection angle α is greatest when the reservoir 5 is completely full and decreases for lower fill levels 9 of the reservoir 5.

[0040] One use case for the fill level monitoring system according to the invention could be the transmission of the fill level or an early warning via an IoT interface to an operator. The current fill level is measured in the cooling device and transmitted to the connected hot beverage preparation machine. This machine has a processing unit that, based on the measured fill level and the previous consumption, determines that the current fill level should still be sufficient for a certain period, e.g., 30 minutes. This information is transmitted via an IoT interface of the hot beverage preparation machine to a mobile device of the operator.Its mobile device uses the current geographical position and the known location of the hot beverage preparation machine to determine how long the operator will be traveling to reach the machine's location and provides information on when the operator should leave, given the current traffic situation, to refill the liquid beverage additive in time.

Claims

Claims 1. Cooling device (2) for operation with a hot beverage preparation device (1), with - a refrigerated receiving room (3) for storing liquid beverage additives (4), - at least one storage container (5) for a liquid beverage additive (4) that can be placed in the receiving space (3) and - at least one electromagnetic level sensor (7) for detecting a level (9) in the storage container (5) by means of an electromagnetic measuring signal (8), wherein - the level sensor (7) is arranged in the receiving chamber (3) such that, when the reservoir (5) is in place, it is located above the reservoir (5) and sends the measurement signal (8) from above towards an opening of the reservoir (5).

2. Cooling device (2) according to claim 1, wherein - the storage container (5) has a lid (6) which closes the opening of the storage container (5), - the lid (6) for the measurement signal (8) emitted by the level sensor (7) is at least partially transparent or provided with an opening. - the level sensor (7) is arranged in the receiving chamber (3) such that, with the reservoir (5) in place, it is located above the lid (6) and sends the measurement signal (8) from above towards the lid (6).

3. Cooling device (2) according to claim 1 or 2, wherein the level sensor (7) is designed as an infrared sensor.

4. Cooling device (2) according to claim 1 or 2, wherein the level sensor (7) is designed as a radar sensor.

5. Cooling device (2) according to one of the preceding claims, wherein the level sensor (7) is arranged within a vertical projection (10) of the lid (6) when the storage container (5) is in place.

6. Cooling device (2) according to one of the preceding claims, wherein the level sensor (7) comprises a transmitter (7a) and a receiver (7b) and wherein the transmitter (7a) and the receiver (7b) are arranged such that when the storage container (5) is completely full they enclose a reflection angle α of less than 20°.

7. Cooling device (2) according to one of the preceding claims, wherein the cooling device (2) comprises a computing unit (11) which processes an output signal (12) of the level sensor (7) and which is configured to determine a level (9) of the storage container (5) with an accuracy of 100 ml or better, in particular 50 ml or better, by means of the output signal (12) of the level sensor (7).

8. Cooling device (2) according to one of the preceding claims, wherein the storage container (5) has a geometry such that its filling volume depends substantially linearly on its fill level (9).

9. Cooling device (2) according to one of the preceding claims, comprising a pump (14) and a liquid line (15) to be connected to a hot beverage preparation device (1) for the automated provision of the beverage additive (4) from the storage container (5) of the cooling device (2) for the preparation of hot beverages.

10. Cooling device (2) according to one of the preceding claims, with a signal connection for connection to a hot beverage preparation device (1) via which an output signal (12) of the level sensor (7) is reported to the hot beverage preparation device (1).

11. Arrangement comprising a cooling device (2) according to one of the preceding claims and a hot beverage preparation device (1) connected to the cooling device (2), wherein the hot beverage preparation device (1) is supplied with beverage additive (4) from the storage container (5) of the cooling device (2) for the preparation of hot beverages via a pump (14) and a liquid line (15), and wherein an output signal (12) of the level sensor (7) or an evaluation result derived therefrom is transmitted to the hot beverage preparation device (1) via a signal line (13), wherein the hot beverage preparation device (1) is configured to process or display the output signal (12) of the level sensor (7).

12. Arrangement according to claim 10, wherein the cooling device (2) is configured according to claim 7 and wherein a calculation result of the computing unit (11) is transmitted to the hot beverage preparation device (1) via the signal line (13), wherein the hot beverage preparation device (1) is configured to process or display the calculation result of the computing unit (11).

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