HK1208605B - Coffee machine and method for cleaning water tank of coffee machine - Google Patents

Description

Coffee machine and method for cleaning a water tank of a coffee machine

Technical Field

The present invention relates to a device for supplying liquid to a beverage machine, in particular to a coffee machine or a coffee vending machine, and to the use of the device in a coffee machine or a coffee vending machine.

Background

The device for providing a liquid, such as a brewing liquid, is used in beverage machines in the semi-cooking and cooking field, in particular in coffee machines or coffee vending machines, and comprises a water tank which serves as a buffer reservoir and which is directly or intermittently connected to a water connector, in particular to a drinking water supply system, by means of a water inlet. By providing such an intermittently controllable "stationary mains water supply", fresh water can always be kept in a usable state in the water tank, for example for preparing a coffee beverage, which reduces possible damage in taste due to standing water.

Devices known from the background art for supplying a beverage machine with a tank that can be directly connected to a drinking water supply system are generally provided with an operating float switch or other sensor device, which, when the tank is filled or refilled, respectively, through a fixed mains supply system, is interconnected with a suitable control device when the target water level is reached, by means of a reed switch, closes an inlet valve installed in the path between the water connector and the water inlet.

Document US 6401729B 1 discloses a device for flushing or for cleaning a reservoir storing a beverage, such as coffee, tea or a concentrated beverage, wherein the device is adapted to be able to flush two such reservoirs for beverages simultaneously. The device known from US 6401729B 1 comprises a water tank (96) with at least one water inlet (104) for filling the water tank (96), which is connected to a water connector (100) by a valve (102). The water inlet (104) can be controlled by means of a valve (102) with the aid of a control device (94). The control device fills the water tank (96) with pressurized water until a fill level sensor (106) outputs a signal from which it is known that the water tank (96) has reached or exceeded a first (i.e., full) liquid fill level of the water tank. For this purpose, the filling level sensor (106) is electrically connected to the control device (94). The control device is also designed to control the water inlet as a function of the signal of at least one fill level sensor (106). According to US 6401729B 1, once the metering valve (100) is opened by means of the control device (94), the flushing water located in the water tank (96) is conducted to the spray head (114) through the output line (108). The water sprayed is then introduced into the holder (20) by means of the spray head (114), thereby initiating the brewing process, which will not be described in detail herein. Although US 6401729B 1 describes a cleaning process, said cleaning process is not used for cleaning the water tank (96), but for cleaning the beverage reservoir 24 or 26, respectively, i.e. the possibility for emptying or cleaning the water tank (96), respectively, is not described.

For example, from us patent specification 5,063,836 a coffee maker is known having a water tank which represents a buffer reservoir and comprises two water level sensors connected to a control unit. As long as the lower level sensor does not report that the filling level has been reached or exceeded (i.e. the lower level sensor is attached inside the water tank at this filling level), the inlet valve between the fixed mains supply system and the inlet of the water tank is thereby opened, so that the water inlet is also opened. In order to prevent the situation that the inlet valve remains open for a long time, which could lead to overflow of the water tank due to defects in the water level sensor or, if applicable, also due to contamination or calcification, a second water level sensor is arranged above the first water level sensor, which second water level sensor is used to ensure that the inlet valve is closed by transmitting a corresponding signal to the control device once the water filling level is reached, at which the second upper sensor is attached.

Such devices known from the prior art have the disadvantage that cleaning, for example in the form of descaling, is difficult. In the case of the devices known from the prior art, it is therefore not possible to fill the tank with descaling liquid of a predetermined concentration up to a level at which substantially complete cleaning or descaling, respectively, of all the components arranged inside the tank is ensured. Furthermore, in the case of the devices known from the prior art, the cleaning or descaling liquid, respectively, cannot be completely removed from the water tank once the concentrated cleaning or descaling liquid is added.

Disclosure of Invention

The invention is based on the following tasks: a versatile device for supplying a beverage machine, in particular a coffee machine or a coffee vending machine, with liquid in such a way that cleaning and descaling, respectively, can be carried out more easily and more thoroughly has further been developed.

According to the invention, this task is achieved by means of the device according to the invention.

In particular, this task is accomplished in that: device destined to provide a beverage machine, in particular a coffee machine or a coffee vending machine, with liquid, the device having: a water tank having at least one water inlet configured to be controllably connected to a water connector, in particular to a superpressure water connector and preferably to a drinking water supply system, in order to fill the water tank; a control device for controlling the water inlet, the control device being configured to be connected in a controllable manner; and at least one fill level sensor for generating a signal which is at least indicative of whether a first fill level of the liquid inside the water tank has been reached or exceeded, wherein the at least one fill level sensor is configured to be connected or connected to the control device for transmitting the signal, and wherein the control device is designed to control the water inlet in dependence on the signal of the at least one fill level sensor and in dependence on at least one operating mode, wherein the operating mode is a fill mode or a clear mode.

According to the invention, the device further comprises a controllable discharge device for discharging liquid from the water tank, wherein the control device is further designed to: in the filling mode, the water inlet is connected to the water connection when the first filling level is not reached or exceeded, and in the emptying mode, the control device interrupts the connection of the water inlet to the water connection independently of the first filling level, so that a complete emptying of the water tank is provided by controlling the discharge device.

This has the particular advantage that, in the respective operating mode, the water tank can be completely emptied before a new filling, for example in order to terminate a cleaning or descaling process, thereby minimizing possible resulting damage to the taste of the subsequently purchased beverage.

Thus, for example, at least one selectable operating mode is provided from at least two or more operating modes of the device. For example, the device behaves in such a way that it can be operated at least in a filling mode or in an emptying mode. In this case, a selectable "at least one operating mode" is provided, for example from two operating modes "filling mode" and "emptying mode", thus making this "at least one operating mode" a filling mode or an emptying mode of the device. Such an operating mode can be preselected manually by the operator, for example by means of communication between the beverage maker and the control device, or also automatically. In this way, the filling can be adapted to the respective requirements. The filling mode, and thus for example coffee, may be selected in particular if a regular beverage selection is desired, when the water tank is emptied as thoroughly as possible after termination of cleaning or descaling or when the device is switched off, and thus a compromise to the taste of a subsequent coffee selection is avoided.

A control device is also provided which is designed to connect the water inlet to the water connector in the filling mode when the first filling level is not reached or exceeded. If the filling mode is pre-selected manually or automatically as operating mode, it is ensured in this way that a sufficient amount of fresh water is always available for the next beverage selection without the filling height of the water tank having to be controlled manually.

Since the device according to the invention also comprises a controllable discharge device for discharging liquid from the water tank, a simplified emptying of the water tank can also be achieved, which emptying can be used for discharging cleaning or descaling liquid, respectively, by virtue of the controllability of the discharge device, or also for rinsing the beverage maker, such as a coffee maker, for example.

For example, the discharge device may comprise a pump which behaves in such a way that it can pump liquid from the water tank and is adapted to empty the water tank. Such a pump (hereinafter also referred to as "emptying pump") may for example represent a continuous or intermittent pumping of liquid from a water tank into a residual water tank adapted to contain the pumped liquid and to store at least the pumped liquid for a period of time.

The discharge device may also (as an alternative or in addition to the pump or the emptying pump, respectively) comprise a controllable valve which can be opened for discharging liquid from the water tank, for example into the remaining water tank. For example, such a valve may be arranged in an inlet of the water tank for discharging liquid, for example in a liquid discharge line.

In the filling mode, the connection of the water inlet to the water connection can advantageously be interrupted when the first filling level is reached or exceeded. In this case it is ensured that a sufficient amount of fresh water is always available for the next beverage selection without having to prevent overflow of the water tank, which represents a buffer tank (if it can even be applied manually).

In this context, the control device can also be designed to interrupt the connection of the water inlet to the water connection in the emptying mode independently of the first filling level. If the emptying mode is pre-selected automatically or manually, the water reservoir (i.e. the water tank) can then be emptied substantially completely in this way, without new fresh water always having to be filled into the water tank when the water filling level falls below the minimum water filling level.

Furthermore, the device may be enabled to operate in at least three different operating modes, for example in a "flush mode" in addition to the already mentioned operating modes "fill mode" and "empty mode". In this case, the "at least one operating mode" can be selected from operating modes such as "filling mode", "emptying mode" and "flushing mode", so that this "at least one operating mode" is thus a filling mode, emptying mode or "flushing mode" of the device.

By providing such a flushing mode, the water tank can be systematically filled to any level, without the need to separate the water connector from the water inlet when the first filling level is reached. In particular in response to cleaning or descaling, in this way it is possible to systematically provide a large amount of rinsing water for rinsing the fluid system of a beverage machine, in particular a beverage machine, without the need for repeated filling. At the same time, substantially the entire inner volume of the water tank can be cleaned.

In this context, furthermore, a signal of at least one fill level sensor can also be provided to additionally indicate whether the liquid in the water tank reaches or exceeds the second fill level. Accordingly, the second fill height defines a greater volume of liquid within the tank than the first fill height. For this purpose, in particular, at least one further fill-level sensor can also be provided, which is arranged above the first fill-level sensor.

The cleaning or descaling process can be changed to a greater extent due to the possibility of additional evaluation of a higher second fill height, which improves the cleaning or descaling performance, respectively.

In the flushing mode, in this context, the control device can be designed to connect the water inlet to the water connection when the second filling level is not reached or exceeded and to interrupt the connection of the water inlet to the water connection when the second filling level is reached or exceeded.

In the flushing mode, a larger water capacity can be provided in an automated manner for flushing the fluid system of the beverage maker, in particular of the coffee maker, which further reduces the possible risk of taste for subsequent beverage purchasations due to the more thorough cleaning.

Alternatively or in addition, the control device can be designed to evaluate the second filling level in the filling mode to interrupt the connection of the water inlet to the water connector in the filling mode and, if possible, to issue a warning signal when the second filling level is reached or exceeded.

In the event of a malfunction due to, for example, an independently provided fill level sensor for the first fill level, in normal operation (i.e. in the fill mode), when the first fill level is exceeded and the second fill level is reached, a safe way of closing the water inlet is provided, i.e. the water connector is forcibly disconnected from the water inlet. At the same time, a warning signal in the form of, for example, an optical signal or an acoustic signal can be emitted, whereby the operator of the beverage machine can perceive the fault and, if possible, can find a remedy.

In this context, the control device can also be designed to control the discharge device continuously or at intervals as a function of the signal of the at least one fill-level sensor and the at least one operating mode.

In the emptying mode, in particular, emptying of the descaling liquid into the fluid systems of the beverage maker, and thus for example into the pipe systems of the coffee maker, can thereby be performed intermittently, whereby these fluid systems can be exposed to the cleaning liquid or descaling liquid for a long time, and this leads to a further improvement of the cleaning performance. Subsequent flushing of the fluid system in the flushing mode (i.e. after substantially complete emptying of the water tank) and subsequent filling of the water tank with fresh water may be performed in continuous operation of the discharge device, so that subsequent beverage purchasers may be made available again with the beverage maker more quickly.

Furthermore, some standard devices in water tanks comprise a water filter arranged upstream of the outlet of the water tank. In principle, such a water filter arranged in the water tank is a water softener for at least partially softening or deionizing water, respectively. Due to the commonly used ion exchange technology, the performance of the filter depends on the basic lime content (carbonate hardness) of the fresh water which can be filled into the tank via the water inlet, and on the amount of liquid which flows through the filter, so that it is difficult to judge the economically reasonable point in time for replacing the filter (or corresponding filter insert) in the case of conventional devices.

In this context, it is also possible for the at least one fill level sensor to be designed not only to output a signal to the control device as to the fill level being reached, but also to determine the water tank water hardness, preferably by means of a conductivity measurement (i.e. by measuring the conductivity of the water), and to transmit the water tank water hardness to the control device by means of the at least one signal in response to wetting by the water. The control device is thus also designed to determine a replacement interval of a water filter provided in the water tank, depending on the water tank water hardness, and preferably to output a filter replacement signal when the determined replacement interval is exceeded. The replacement signal represents the point in time at which the water filter or the filter insert of the water filter (if applicable) should preferably be replaced.

By measuring the water hardness in the water tank, the replacement interval at which the filter or the filter insert should be replaced can be determined to maintain the filtering effect. For this purpose, the values of the flow meter or the time lapse values can also be calculated in the control device.

In addition to the advantages already mentioned, this can in a simple manner prompt the user of the beverage maker to an economically reasonable point of time for changing the water filter (or changing the filter insert).

In this context, it is also possible for the device to further comprise a water hardness sensor at the outlet of the water tank, which water hardness sensor is designed to determine an "outlet water hardness" (i.e. the hardness of the water leaving the water tank through the outlet after flowing through the filter) by means of an electrical conductivity measurement (i.e. by measuring the electrical conductivity of the water), preferably in response to wetting by the water, and to transmit the outlet water hardness to a control device of the device and/or to a different control device, for example to the control electronics of the beverage machine, by means of at least one signal. In this case, the control means of the device or the control electronics of the beverage maker are also designed to compare the respective measured water hardness of the water tank with the respective measured outlet water hardness; for example, for this purpose, a difference between the measured outlet water hardness and the measured water tank water hardness or a ratio between the measured outlet water hardness and the measured water tank water hardness may be determined.

Such a comparison between the water tank water hardness and the outlet water hardness may determine a "comparison replacement interval" of the water filter provided in the water tank, for example, according to a ratio between the outlet water hardness and the water tank water hardness (hereinafter, referred to as "water hardness ratio") or according to a difference between the outlet water hardness and the water tank water hardness (hereinafter, referred to as "water hardness difference"), and may preferably output a filter replacement signal when the determined "comparison replacement interval" is terminated. In this context, the "comparative replacement interval" is to determine a time interval which is determined on the basis of a comparison between the water tank water hardness and the outlet water hardness, and the end of the "comparative replacement interval" is represented as a point in time at which the filter or the insert of the filter, respectively, should preferably be replaced.

This comparison between water tank water hardness and outlet water hardness (e.g. by determining the above-mentioned "water hardness ratio" or the above-mentioned "water hardness difference") allows to draw conclusions on the degree of wear of the filter. If this water hardness difference falls to an advanced or predefinable value, while the wear of the filter or filter effect increases, or if the water hardness difference becomes smaller than or equal to a predetermined value, the control means of the device or the control electronics of the beverage maker output to the user information about the determined comparative replacement interval or a filter replacement signal, by means of which the economically sensible point in time for replacing the water filter (or the replacement insert) can be determined more accurately. When the determined water hardness ratio increases to or above a predetermined value, the control means of the device or the control electronics of the beverage maker may thus output information or a filter change signal to the user relating to the determined comparative change interval.

With the device according to the invention it is also possible to provide a method for automatic cleaning or descaling, respectively, which method is performed by the control device and which method comprises the following steps:

-initiating a filling mode and filling the water tank until a first filling level is reached;

-adding a cleaning agent, preferably a descaling agent, to the water tank;

-initiating a emptying mode and emptying the water tank;

-initiating a flushing mode and filling the water tank until a second filling level is reached;

-initiating a emptying mode and emptying the water tank;

-initiating a filling mode and filling the water tank until a first filling level is reached;

-initiating a emptying mode and emptying the water tank, preferably intermittently.

Drawings

Exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings.

Fig. 1 shows, in a schematic sectional view, a device according to the invention for providing a liquid according to an exemplary embodiment.

FIG. 2 shows the portion of FIG. 1 designated A;

fig. 3 shows, in a schematic sectional view, a device according to the invention for providing a liquid according to another exemplary embodiment.

Detailed Description

Fig. 1 shows, in a schematic cross-sectional view, a device 100 according to an embodiment of the present invention for supplying a beverage maker 110, in particular for a coffee maker or a coffee vending machine, with liquid.

The device 100 comprises a water tank 10 to which a so-called mains water clamp 13, as shown on the left hand side in fig. 1, is clamped, which will be described in detail below with reference to fig. 2.

The water inlet 11 is led through the interior of the housing of the mains water holder 13 and the inlet opening 11a of the water inlet protrudes into the interior of the water tank 10. On the outside, the pipe of the water inlet 11 is provided with a valve connector 12, which in turn is connected to one side of a hydraulic servo valve 20.

The hydraulic servo valve 20 behaves in a controllable manner and is designed in such a way that it can respectively establish and separate or interrupt a (fluid) connection, for example a water connection 21 directly connected to a potable water supply system, if a suitable signal is present on the control line 32 of the hydraulic servo valve. It goes without saying that the hydraulic servo valve 20 can also be replaced by a valve of another design.

Control lines 32, which may represent a central interface in the form of a mini-hub, are connected to the control device 30.

The control means 30 further comprise a status line 34 connected to the beverage maker 110, which makes it very simple to provide a manual selection option at the user interface of the beverage maker 110 (which typically occurs in any case when the beverage maker 110 is operated by a user). A corresponding signal representing the operating mode can then be transmitted from the beverage maker 110 to the control device 30 via the status line 34.

The control device 30 is also connected to a signal line 33 which leads at least partially through the housing of the mains water holder 13 to a first fill-level sensor 41 and a second fill-level sensor 42, which are arranged at the sensor probe 40 and which establish an electrical signal connection to the fill-level sensors 41, 42. The sensor probe 40, the first fill level sensor 41 and the second fill level sensor 42 can be seen in an enlarged view of the mains water clamp 13 in fig. 2.

Furthermore, additional information representing whether the mains water holder 13 is properly attached to the water tank 10 is transmitted to the control device 30 via the signal line 33. For this purpose, the mains water clamp 13 comprises a detection switch 121 which transmits a corresponding signal to the control device 30. In case the mains water clamp 13 is not properly mounted to the water tank 10, the control means 30 is arranged to prevent filling of the water tank 10, i.e. opening of the hydraulic servo valve 20. The control device 30 actuates the LED120 via signal line 33, while an optical signal is output to the operator.

The first fill level sensor 41 is arranged at the first water fill level and outputs a corresponding signal to the control device 30 via the signal line 33 when it is wetted by the liquid, i.e. when the fill level assigned to it in the water tank 10 is reached or exceeded. When the second filling level (i.e. a higher filling level inside the water tank 10) is reached or exceeded, the second filling level sensor 42, which is positioned above the first filling level sensor, also transmits a signal to the control device 30 via the signal line 33 in a corresponding manner.

The sensor probe 40 is arranged in a height-adjustable manner by means of suitable adjusting means and therefore allows the filling level of the first filling level sensor 41 and the filling level of the second filling level sensor 42 to be adjusted within certain limits.

For example, when taking product and during continuous operation of the beverage maker, i.e. in a filling mode of the beverage maker (e.g. a coffee maker), the control device 30 controls the hydraulic servo valve 20 in such a way that the refilling is always carried out intermittently up to a water level (so-called operating position) specified by the first filling level sensor 41. When the water level in the water tank 10 falls below this first filling level, the first filling level sensor 41 transmits this drop in water level via the signal line 33 to the control device 30, in response to which the control device 30 opens the hydraulic servo valve 20 and thus establishes a connection between the water inlet 11 and the water connector 21 until the sensor again provides a corresponding signal in response to reaching the first filling level, in response to which the hydraulic servo valve 20 is closed again.

Both fill level sensors 41, 42 are therefore not limited to a particular measurement method; however, the electrical resistance is preferably measured between two electrically conductive measuring surfaces which are arranged on the circular measuring rod of the sensor probe 40 in order to be flushed together with the circular measuring rod, wherein the signal jumps of the electrical conductivity of the water and air are calculated by the electronics of the control device 30 or by electronics which are integrated in the fill level sensors 41, 42, respectively. It is very advantageous here that possible lime scale on such a sensor alternative can be easily cleaned by means of a common cleaning agent.

Depending on the operating mode, the control by the control device 30 takes place in such a way that the water tank 10 is filled up to a first filling level at the first filling level sensor 41 or up to a second filling level at the second filling level sensor 42, or no refilling takes place.

As shown in fig. 1, the water tank 10 has an outlet 15 through which (clean) water or a different liquid can be discharged from the water tank 10. The arrow 15' in fig. 1 thus indicates the outflow direction of the liquid flowing out through the outlet 15.

In order to empty the water tank 10 in a controlled manner, a device 100 according to an embodiment of the invention, as shown in fig. 1 and 2, may be equipped with a discharge device, not shown in fig. 1 and 2, for discharging liquid from the water tank, wherein the discharge device may be controlled so as to continuously or intermittently discharge the respective liquid from the water tank 10 at least for a period of time.

Such discharge means may comprise an emptying pump, which may be controlled, for example, in such a way that it may continuously or intermittently pump liquid from the water tank into, for example, a residual water tank (not shown in fig. 1 and 2), wherein such pumping may take place, for example, via the outlet 15 (or in a different way in alternative embodiments). For this purpose, for example, the emptying pump may be part of the device 100, or may be arranged, for example, at the device 100 and may be controlled by the control device 30. In an alternative embodiment, a pump (not shown in fig. 1 and 2, but shown in fig. 3 and described in the context of fig. 3) integrated in the beverage maker 110 and designed for delivering water or a different liquid in a fluid system of the beverage maker (110) for supplying the beverage maker 110 with water, may also be used as a purge pump. Such a pump of the beverage maker 110 is correspondingly controlled by the control electronics 30a (shown in fig. 3) of the beverage maker 110 and is connectable to the water tank 10 in such a way that water or a different liquid can be pumped by means of the pump from the water tank 10, for example, into a water outlet (not shown in fig. 1-2), for example, into a remaining water tank of the beverage maker 110. Thus, furthermore, it is also possible to have the emptying pump connected to a flow meter 50 (fig. 3) in the beverage maker 110, so that it is also possible to monitor to determine the point in time at which the water tank 10 is substantially completely emptied.

Due to the design according to the shown embodiment, a substantially automated descaling of the water tank 10 is possible, for example. This design only requires filling a certain amount of detergent concentrate into the water present in the water tank 10 and changing the operation mode of the device 100 and initiating an automatic descaling process, e.g. after operating a button on the beverage maker 110.

The addition of fresh water is prevented in a targeted manner during this descaling process, because the control device 30 always controls the hydraulic servo valve 20 in such a way that there is no connection between the water inlet 11 and the water connection 21. After the emptying pump has emptied the water tank 10 substantially completely, the added fresh water is released to a level corresponding to the arrangement of the second fill level sensor 42. This water quantity is first of all directed into a corresponding discharge system (for example a residual water tank) by means of an emptying pump, whereby the water tank is flushed. The added fresh water is then released to a level corresponding to the arrangement of the first fill level sensor 41. The entire fluid system of the beverage maker (and thus, for example, the coffee maker) is then rinsed with this fresh water.

It goes without saying that the entire device 100 for providing liquid, for example, or also only parts of the device (for example the water tank 10) can be integrated in the beverage maker 110 and that a beverage maker 110, in particular a coffee maker, with a device 100 according to the invention can be provided, in which case only the water connector 21 of the device 100 and, if applicable, the separate power supply 31 are led to the outside.

Fig. 3 shows a device for providing a liquid according to another exemplary embodiment of the present invention in a schematic sectional view. Wherein the exemplary embodiment according to fig. 3 comprises a device 100 according to fig. 1 and 2 with a water tank 10 and which is shown in connection with a beverage maker 110 according to fig. 1, which in the following cases is represented as a coffee maker or a coffee vending machine, respectively.

It is important to note that although the water inlet for supplying water into the water tank 10 shown in fig. 1 and 2, which water inlet supplies water into the water tank via the water connection 21 and the hydraulic servo valve 20 and which water inlet appears to be controllable, is not explicitly shown in fig. 3, in the example according to the exemplary embodiment of fig. 3 there is a corresponding water inlet for supplying water into the water tank 10 and which water inlet appears to be substantially similar to the water inlet in fig. 1 (in terms of its function and design). According to fig. 3, a mains water holder 13 corresponding to the mains water holder 13 according to fig. 2 is correspondingly clamped into the water tank 10 of the device 100.

As shown in fig. 3, the water tank 10 comprises a water outlet 15 through which (clean) water or a different liquid can flow out of the water tank 10, wherein a filter 80 is positioned in the water tank 10 at the outlet 15, through which filter the water or the respective liquid, respectively, located in the water tank 10 must flow in each case in order to reach the outlet 15. In the exemplary embodiment shown, the filter 80 comprises a filter insert in the form of an ion exchanger which behaves as a deionizer and in this way descale the water or liquid, respectively, which is flowing through the filter 80.

As indicated in fig. 3, the beverage maker 110 comprises a water line 45 which is connected at one end to the outlet 15, such that water or a different liquid can flow from the water tank 10 into the water line 45 and can be dispensed in the beverage maker 110 through the water line 45. A pump 51 for conveying the water in the water line 45 in the flow direction 45 'and a continuous-flow heater 52, which are arranged in series one after the other in the flow direction 45' of the water and the respective liquid, respectively, are integrated in the water line 45. The continuous flow heater 52 is designed to heat the water which is fed to the continuous flow heater 52 by means of the pump 51, wherein the continuous flow heater 52 can heat the water to different temperatures, so that the continuous flow heater 52 produces water or steam in the water line 45. As also indicated in fig. 3, the water line 45 branches off from downstream of the continuous flow heater 52 with respect to the flow direction 45' of the water into a first branch 45.1 of the water line 45 and a second branch 45.2 of the water line 45, wherein the first branch 45.1 of the water line 45 is used for supplying hot water produced in the continuous flow heater 52 via the non-return valve 54 to the brewing unit 60 for the purpose of brewing coffee, and the second branch 45.2 of the water line 45 serves the purpose of supplying steam generated in the continuous flow heater 52 via the control valve 53 and via the steam line 69 to the steam nozzle 70, or for the purpose of supplying liquid from the water tank 10 via the control valve 53 to the liquid outlet line 82, this liquid outlet line can allow liquid (for example water or cleaning or descaling agent) which is in each case supplied to the liquid outlet line 82 to enter, for example, into the residual water tank 81 via an outlet 82.1 of the liquid outlet line 82.

As indicated in fig. 3, the control valve 53 comprises three different positions and is connected to the second branch 45.2 of the water line 45, the steam line 69 and the liquid outlet line 82 in such a way that, i.e. in the first position of the control valve 53, the second branch 45.2 of the water line 45 is in fluid connection with the steam line 69 and the steam nozzle 70, and in a second position of the control valve 53, as shown in fig. 3, the second branch 45.2 of the water line 45 is in fluid connection with the liquid outlet line 82 or the remaining water tank 81 respectively, in the third position of the control valve 53, the second branch 45.2 of the water line 45 is connected, i.e. there is neither a fluid connection between the second branch 45.2 of the water line 45 and the steam line 69, nor a fluid connection between the second branch 45.2 of the water line 45 and the liquid outlet line 82 or the residual water tank 81. In the following example, the control valve 53 behaves in such a way that it can be controlled by means of control electronics in such a way that it can assume each of the three positions mentioned above.

As can also be seen from fig. 3, the beverage maker 110 comprises control electronics 30a for controlling the operation of the beverage maker 110. By controlling the pump 51, the continuous flow heater 52, the control valve 53 and the brewing unit 60 accordingly, the control electronics 30a thus behave, for example, so as to cause a supply of hot water to the brewing unit 60, so that the brewing unit 60 can brew the coffee beverage and can supply the coffee beverage via the coffee dispensing line 61 to the coffee outlet 62 for dispensing the coffee beverage.

By controlling the pump 51, the continuous flow heater 52 and the control valve 53 accordingly, the control electronics 30a also appear to cause a portion of the steam to be supplied to the steam nozzle 70, wherein the steam nozzle 70 may appear to, for example, allow steam to escape from the outlet opening, or the steam nozzle can be used for the purpose of heating milk or making milk foam.

Furthermore, by controlling the pump 51, the continuous flow heater 52 and the control valve 53 accordingly, the control electronics 30a also appear to cause that liquid can be pumped from the water tank 10 and can be discharged into the residual water tank 81 via the liquid outlet line 82, for example via the outlet 82.1. For this purpose, the control valve 53 can be adjusted to the position shown in fig. 3, so that a fluid connection exists between the second branch 45.2 of the water line 45 and the liquid outlet line 82. Liquid can then be pumped from the water tank 10 via the outlet 15, the water line 45, the control valve 53 and the liquid outlet line 82 by means of the pump 51, so that the liquid thus pumped can be collected in the remaining water tank 81.

In this example, the control electronics 30a of the beverage maker 110 can control the apparatus 100 in such a way that the apparatus 100 operates in an emptying mode in which the water tank 10 can be completely emptied or can be partially emptied. In the emptying mode, the control device 30 can control the water inlet 11 in such a way that the connection between the water inlet 11 and the water connection 21 (fig. 1) is interrupted, i.e. independently of the signals of the fill level sensors 40, 41. This has the result that fresh water cannot flow into the water tank 10 via the water inlet 11. If, as described above, liquid is subsequently pumped from the water tank 10 via the outlet 15, the water line 45, the control valve 53 and the liquid outlet line 82 by means of the pump 51, the water tank 10 can be completely emptied or partially emptied in case no fresh water can flow into the water tank 10 via the water inlet 11. By pumping the liquid, the liquid is drained out of the water tank 10 and the filling height of the water tank 10 can in this way be lowered to any height. The water tank 10 can be emptied completely, if desired.

Subsequently, the water tank 10 may be filled with a cleaning agent to clean the water tank 10 (as already explained herein with reference to fig. 1 and 2).

Those parts of the device shown in fig. 3 which are arranged for draining liquid from the water tank 10 form a "discharge device" according to the invention, which parts are designated by reference numeral 44 in fig. 3. The discharge device 44 according to fig. 3 comprises at least a pump 51. The water line 45 and the liquid outlet line 82 may also be part of the drain 44.

According to this exemplary embodiment, the first fill level sensor 41 of the mains water holder 13 is also designed to determine information relating to the water hardness of the water located in the water tank 10 (hereinafter "water tank water hardness") in response to wetting and to transmit this information to the control device 30 (for example via the signal line 33 shown in fig. 3). It goes without saying that, in addition or alternatively, the second fill-level sensor 42 can also be designed accordingly, so that it can also determine information about the water hardness of the water located in the water tank 10 (water tank water hardness) and can transmit this information to the control device 30 (for example via the signal line 33 shown in fig. 3).

As can be seen in fig. 3, the control device 30 of the device 100 is connected via a signal line 30.1 to the control electronics 30a of the beverage machine 110, so that signals or data, respectively, can be transmitted between the control device 30 and the control electronics 30a via the signal line 30.1. The control electronics 30a are embodied, for example, in such a way that the measured value of the water hardness of the water tank determined by the first fill level sensor 41 and/or the measured value of the water hardness of the water tank determined by the second fill level sensor 42 is transmitted to the control device 30 of the beverage maker 110.

As indicated in fig. 3, a water hardness sensor 43 is also positioned in the water line 45 of the beverage maker 110 and in the vicinity of the outlet 15 of the water tank 10, which outputs information relating to the water hardness of the water dispensed at the outlet 15 (hereinafter referred to as "outlet water hardness") to the control electronics 30a via a signal line 43.1. In the case of a high water tank water hardness, the dispensed water should have a lower water hardness than the water in the water tank 10 due to the flow through the filter 80.

Furthermore, the control electronics 30a of the beverage maker 110 are now designed to compare the information from the sensors 41, 42, 43 relating to the water hardness, and, if the difference between the outlet water hardness and the water hardness of the water tank falls below a certain (predetermined) value, to output a signal to the user, for example by means of an LED (not shown) or by means of a screen or a different display, in order to show the user that the filter 80 is not sufficiently deionizing and descaling the water flowing through the filter 80 and that an acceptable filtering effect (in terms of descaling) cannot be achieved, so that this filter 80 should be replaced by another filter, which ensures that the water has an optimum lime content which falls below the predetermined (maximum) value before entering the water line 45 of the beverage maker 110.

Fig. 3 shows the device 100 and the beverage maker 110 as separate units. It is important to note that the device 100 may also be an integral component of the beverage maker 110. The control means 30 of the device 100, which is shown in fig. 3 as a separate unit, is spatially separated from the control electronics 30a of the beverage maker 110. It is important to note that the control unit 30 may also be implemented as an integral component of the control electronics 30 a. In this case, the first fill level sensor 41 and the second fill level sensor 42 would be directly connected to the control electronics 30a of the beverage maker 110 via the signal line 33. The entire function for controlling the device 100 can thus be carried out in the control electronics 30a of the beverage maker 110 or can be realized by means of the control electronics 30a of the beverage maker 110, the entire function for controlling the device being given to the control device 30 in the above description or the entire function for controlling the device being realized by means of the control device 30, respectively.

Claims (19)

1. A coffee maker (110) comprising an apparatus (100) for providing liquid to the coffee maker (110), wherein the apparatus (100) comprises:

-a water tank (10) having at least one water inlet (11) for filling the water tank (10), the water inlet (11) being configured to be controllably connected to a water connector (21), and the water tank having an outlet (15) for liquid to flow out of the water tank (10);

-a control device (30) for controlling the water inlet (11) configured to be connected in a controllable manner; and

-at least one fill level sensor (41, 42) for generating a first signal indicating whether a first fill level of liquid within the water tank (10) has been reached or exceeded, and the coffee maker (110) further comprises:

-a water line (45) connected to the outlet (15) of the water tank (10) such that liquid flowing out of the water tank (10) through the outlet (15) can be discharged through the water line (45),

-a continuous flow heater (52) and

a brewing unit (60) for brewing coffee, which brewing unit is connected to the water tank (10) via the water line (45) and the continuous flow heater (52) such that water can be supplied from the water tank (10) to the brewing unit (60) via the water line (45) and the continuous flow heater (52) so that coffee can be brewed,

wherein the at least one fill-level sensor (41, 42) is configured to be connected or connected to the control device (30) for transmitting the first signal, and wherein the control device (30) is designed to control the water inlet (11) as a function of the first signal of the at least one fill-level sensor (41, 42) and as a function of at least one operating mode,

wherein the operating mode is a fill mode or a purge mode,

wherein the device further comprises a controllable discharge device (44) for discharging liquid from the water tank (10) through the outlet (15),

wherein, in the filling mode, the control device (30) is further designed to connect the water inlet (11) to the water connection (21) when the first filling level is not reached and not exceeded, and to interrupt the connection between the water inlet (11) and the water connection (21) independently of the first filling level in the emptying mode,

and wherein the control device (30) is designed to cause the discharge device (44) to discharge liquid from the water tank (10) by controlling the discharge device (44),

it is characterized in that

In the emptying mode, the control device (30) is designed to interrupt the connection between the water inlet (11) and the water connector (21) and to cause the discharge device (44) to completely discharge the liquid contained in the water tank (10) through the outlet (15) and to allow the liquid to be discharged through the water line (45) and the continuous-flow heater (52) to achieve a complete emptying of the water tank (10).

2. The coffee maker (110) of claim 1, wherein

The discharge device (44) comprises a pump (51) embodied in such a way that it can continuously or intermittently pump liquid from the water tank (10).

3. The coffee machine (110) according to claim 1, wherein, in a filling mode, the control device (30) is further designed to interrupt the connection between the water inlet (11) and the water connector (21) when the first filling level has been reached or exceeded.

4. The coffee machine (110) of claim 1, wherein the at least one operating mode is a fill mode, an empty mode, or a flush mode.

5. The coffee machine (110) according to claim 4, wherein the first signal of the at least one fill level sensor (41, 42) further determines whether a second fill level of liquid within the water tank (10) has been reached or exceeded, wherein the second fill level determines a volume that is greater than the first fill level.

6. Coffee machine (110) according to claim 5, wherein, in the flushing mode, the control device (30) is designed to connect the water inlet (11) to the water connector (21) when the second filling level is not reached and not exceeded, and wherein, in the flushing mode, the control device (30) is further designed to interrupt the connection between the water inlet (11) and the water connector (21) when the second filling level is reached or exceeded.

7. The coffee machine (110) according to claim 5, wherein, in the filling mode, the control device (30) is designed to interrupt the connection between the water inlet (11) and the water connector (21) and to output a warning signal when the second filling level is reached or exceeded.

8. The coffee machine (110) according to claim 6, wherein, in the filling mode, the control device (30) is designed to interrupt the connection between the water inlet (11) and the water connector (21) and to output a warning signal when the second filling level is reached or exceeded.

9. Coffee machine (110) according to any one of claims 5 to 8, wherein said control means (30) are also designed to control said discharge means continuously or discontinuously as a function of said first signal of said at least one fill level sensor (41, 42) and as a function of said at least one operating mode.

10. Coffee machine (110) according to any one of claims 5 to 8, comprising a valve (20) configured to be controlled by the control means (30) and designed to establish a fluid connection between the water inlet (11) and the water connector (21) or to separate a fluid connection between the water inlet (11) and the water connector (21).

11. Coffee machine (110) according to any one of claims 5 to 8, wherein said at least one fill level sensor (41, 42) is further designed to determine a water tank water hardness in the water tank in response to wetting by the liquid and to transmit information relating to the water tank water hardness to the control device (30) by means of a second signal,

the coffee maker comprises an outlet (15) for letting out liquid from the water tank (10), and a filter (80) for deionizing or descaling liquid flowing from the water tank (10) through the outlet (15).

12. The coffee machine (110) according to claim 11, comprising an additional water hardness sensor (43) arranged at said outlet (15) and designed to determine an outlet water hardness in response to a wetting by the liquid flowing out from said outlet (15).

13. The coffee machine (110) of claim 12, comprising control electronics (30a),

wherein the additional water hardness sensor (43) is embodied to transmit information relating to the outlet water hardness to the control electronics (30a) by means of a third signal,

wherein the control electronics (30a) are operative to compare the information relating to the outlet water hardness with the information relating to the water tank water hardness and to provide a signal to replace the filter if the difference between the water tank water hardness and the outlet water hardness is less than or equal to a predetermined value.

14. A coffee-making machine (110) according to claim 13,

wherein the control electronics (30a) are embodied to control the operation of the coffee maker (110), and the control device (30) is an integral part of the control electronics (30 a).

15. The coffee machine (110) according to claim 1, wherein the water inlet (11) is configured to be controllably connected to an over-pressure water connector.

16. The coffee machine (110) according to claim 1, wherein the water inlet (11) is configured to be controllably connected to a potable water supply system.

17. Method for cleaning a water tank (10) of a coffee machine (110) according to any one of claims 5 to 14, wherein the method comprises the following method steps:

-initiating a filling mode and filling the water tank (10) until a first filling level is reached;

-adding a cleaning agent to the water tank (10);

-initiating a emptying mode and emptying the water tank (10);

-initiating a flushing mode and filling the water tank (10) until a second filling level is reached;

-initiating a emptying mode and emptying the water tank (10);

-initiating a filling mode and filling the water tank (10) until the first filling level is reached;

-initiating a emptying mode and emptying the water tank (10),

wherein the second fill height is higher than the first fill height.

18. Method for cleaning a water tank of a coffee maker according to claim 17, wherein in the step of adding a cleaning agent to the water tank (10), a descaling agent is added to the water tank (10).

19. Method for cleaning a water tank of a coffee maker according to claim 17, wherein in the step of initiating the emptying mode and emptying the water tank, the water tank is intermittently emptied.