HK1179135B - Coffee machine having a brewing device and having a coffee post-heater arranged downstream of the brewing device - Google Patents

Description

Coffee machine with brewing device and with coffee post-heater arranged downstream of brewing device

Technical Field

The present invention relates to a coffee machine with a brewing device having a brewing device for preparing and dispensing a brewed coffee beverage, and to a method of brewing and dispensing a brewed coffee beverage by means of such a coffee machine.

The invention relates in particular to a brewing device for brewing a coffee beverage with a brewing unit, wherein the brewing unit is connected to a brewing water supply line on an inlet side and to a coffee dispensing line on an outlet side.

Background

Coffee brewing devices are known per se, which are supplied with hot brewing water on the inlet side and which dispense the brewed coffee at their outlet accordingly during or after completion of the brewing process. For the most part, such brewing devices are correspondingly supplied with hot water or brewing water from a water tank, which is first conducted through a flow-through water heater by means of a pump or the like and heated there. In addition, brewing devices are also known in which the brewing water is first completely heated in a larger brewing water tank and then fed to the brewing unit. After the heating process, the brewing water then also travels through a more or less long tube path until reaching the inlet of the brewing device.

In particular, this leads to the problem that the pipeline paths between the brewing water heating means and the inlet of the brewing unit can comprise different temperatures depending on the type, time and frequency of the previous brewing process. It is therefore not possible to predict which brewing water temperature is actually available at the inlet of the brewing unit. This is disadvantageous in that, for example, too high brewing temperatures extract more bitter substances from the coffee to be brewed, so that the dispensed coffee tastes more bitter.

On the other hand, too low a brewing temperature is likewise undesirable, since in this case the desired aroma is not dissolved from the coffee powder and the dispensed coffee thus tastes rather dull. Brewing temperatures in the range from 90 ℃ to 95 ℃ are generally considered desirable.

In connection with this known problem, various solutions are known from the prior art for further increasing the brewing water temperature on the inlet side at the brewing unit, taking into account additional pipeline paths between the brewing water heating means and the actual brewing unit, if necessary.

Such an auxiliary brewing water heating device is known, for example, from U.S. patent specification 6,701,068B2, which is arranged directly upstream of the region from which the heated brewing water is dispensed. The actual brewing water primary heating means, which takes fresh cold water on the inlet side, heats and then feeds the water to a line or pipe section on its outlet, which connects the water to the brewing water secondary heating means, is located upstream in the flow direction of said brewing water secondary heating means. Before the brewing process, a possible undesired cooling of the brewed water takes place in particular in said line or pipe section, respectively, and is compensated again by the brewing water auxiliary heating means, so that sufficiently hot brewing water for brewing is available.

A similar solution is known from us patent application 2005/0066820a1, in which, on the way to the inlet of the brewing unit, the brewing water preheated in the boiler is likewise led through a further heating element implemented as a through-flow heater, wherein, in this case, the control of the further heating element is carried out as required with the aid of a control unit. The heated brewing water is introduced through a brewing water supply line into a brewing chamber of the brewing unit that can be automatically filled with ground coffee, so that brewed coffee, in particular in the form of espresso coffee, can be made in the brewing chamber. In the present case, the brewed coffee is fed to the nozzle for dispensing coffee through a coffee dispensing line and is dispensed from the coffee machine at this position through the outlet opening of the nozzle, wherein the coffee dispensing line is connected with one of its two ends to the outlet of the brewing chamber and with its other end opens into the nozzle, so that the coffee dispensing line forms a continuous fluid connection connecting the brewing chamber to the outlet opening of the nozzle.

Such a solution is known from us patent application 2008/0008461a1, in the case of which the brewing water temperature is kept constant by means of adjustment with the aid of a single brewing water heating device, by interconnecting a temperature sensor into the brewing water path between the brewing water heater and the brewing unit. In the case of this solution known from the prior art, an attempt is thus made, by means of regulation, to keep the brewing water temperature at a constant value at the inlet of the brewing unit.

Finally, a device is known from DE 69911675T2, in the case of which a brewing unit, in this case of a coffee machine for preparing espresso coffee, can be pivoted from an operating position into a rest position. After pivoting to the rest position, the heat transfer area of the brewing unit rests against the heating element. During the subsequent brewing process, the brewing unit heated in this way (in the rest position) is pivoted back again into its operating position and can thus compensate for a possibly too low temperature of the supplied brewing water. In the present case, heated brewing water is introduced under pressure into the brewing chamber of the brewing unit, so as to be able to produce coffee in the form of espresso coffee brewed in the brewing chamber, wherein the brewed coffee flows out of the brewing chamber through a duct and can be dispensed from the coffee machine.

Due to the reproducibility of the taste of the brewed coffee beverage, a particular challenge is faced by coffee machines having brewing devices in which the coffee beverage brewed in the respective brewing device has to be supplied to the coffee outlet of the coffee machine through a relatively long coffee dispensing line. This applies, for example, to automatic coffee machines, in which coffee brewed in brewing water is automatically supplied to the brewing chamber of the brewing unit and subsequently brewed with pressurized brewing water in order to prepare, for example, espresso coffee. In such coffee machines, the heated brewing water or the respective brewed coffee beverage, respectively, has to be guided in a line over a relatively long distance for the most part before the coffee machine can dispense the respective brewed coffee beverage. Thus, relatively large heat losses distributed throughout the entire length of the pipeline can occur, which heat losses can moreover fluctuate very much in magnitude. Thus, the multiple coffee beverages that are prepared consecutively can vary widely, taking into account the temperature of the coffee beverage and taking into account the taste of the coffee beverage.

Disclosure of Invention

The present invention is based on the object of avoiding the above-mentioned drawbacks and specifying a coffee machine with brewing device, particularly suitable for preparing espresso coffee, by means of which it is possible to ensure, in an easy to implement and effective manner, always the optimum quality of the coffee beverage dispensed.

Another object to be understood is to specify a corresponding method of brewing and dispensing a coffee beverage with a quality that is always optimal.

Thanks to this coffee machine, the object on which the invention is based is solved by means of the subject matter of claim 1.

Coffee machine for preparing an brewed coffee beverage and for dispensing the brewed coffee beverage through at least one coffee outlet, comprising: brewing device for preparing a brewed coffee beverage by brewing a predetermined quantity of coffee in pressurized brewing water, wherein the brewing device comprises: a brewing unit having a brewing chamber for containing a predetermined amount of coffee; a brewing water supply line connected to the brewing unit and which opens into the brewing chamber for feeding brewing water into the brewing chamber; and means for introducing brewing water into the brewing chamber. The device for introducing brewing water is therefore designed to introduce brewing water under pressure into the brewing chamber through the brewing water supply line. The brewing chamber further comprises an outlet for the brewed coffee beverage and the brewing device comprises a coffee dispensing line forming a continuous fluid connection of the brewed coffee beverage between the outlet of the brewing chamber and the coffee outlet. Thus, the coffee dispensing line comprises a first end connected to the outlet of the brewing chamber and the first end comprises an inlet for receiving the brewed coffee beverage, the inlet being in fluid connection with the outlet of the brewing chamber. The coffee dispensing line further comprises a second end comprising an outlet for dispensing the brewed coffee beverage in fluid connection with the coffee outlet.

According to the invention, the brewing device comprises a coffee post-heater for post-heating the respective brewed coffee beverage in the coffee dispensing line, wherein the coffee post-heater is arranged between the outlet of the brewing chamber and the coffee outlet and is designed as a through-flow heater for heating the brewed coffee beverage while the brewed coffee beverage flows through the coffee dispensing line.

The essential point of the invention is that the coffee post-heater is arranged between the outlet of the brewing chamber and the coffee outlet of the coffee machine, for example on or in the coffee dispensing line, and that the brewed coffee beverage can be heated by the coffee post-heater, correspondingly, when it is located in the coffee dispensing line or when it flows through the coffee dispensing line in a direction towards the end region of the coffee dispensing line on the dispensing side. In this way, the actual brewing process can be carried out at the optimal brewing temperature in the brewing unit without the risk that the brewed beverage can cool down to such an extent that the taste quality of the brewed beverage is affected when on the way into the coffee dispensing apparatus after leaving the brewing unit, e.g. due to a long run interruption.

Although the problem has been recognized in the prior art that a brewing temperature that is too low or highly fluctuating, can accordingly have a negative effect on the quality of the brewed beverage, typically coffee, leaving the brewing unit, it has not been recognized that after brewing has taken place and after leaving the brewing unit, the brewed beverage must typically be supplied to the coffee dispensing unit through a further line, which in turn has a negative effect on the quality of the brewed beverage, because there is a risk of the beverage cooling down again before being dispensed from the coffee dispensing unit.

Therefore, it has to be considered that the temperature of the coffee beverage dispensed at the end of the coffee dispensing unit is eventually again dependent on the temperature level of these lines or the coffee dispensing means located downstream of the brewing unit. In particular, when its temperature is too low, the taste quality of the brewed coffee is negatively affected. In the case of coffee, the temperature target of the dispensed coffee is, for example, 80 ℃ to 85 ℃. In particular when the portions are located downstream of the outlet of the infusion unit, and therefore when the coffee dispensing line and the corresponding coffee dispensing device have cooled to room temperature, for example after a long interruption of the operation of the coffee machine, this (ideal) temperature generally drops.

In an advantageous embodiment of the coffee maker, provision is made, for example, for the coffee afterheater to be activated when the coffee brewed after an infusion process has taken place enters the coffee dispensing line from the brewing unit. In this way it is ensured that the post-heater is in operation only when the brewed beverage is actually to be dispensed, which is advantageous in particular for energy saving reasons. For this purpose, it is advantageous if possible to design the post-heater such that: on the one hand, the post-heater transfers the heat, which is usually generated by the heating element, to the coffee dispensing line, and on the other hand, the post-heater in turn has a small mass, so that the post-heater can act as dynamically as possible on a restart, respectively, after a possible brewing pause or after a short downtime according to a control curve which is as steep as possible.

However, according to another embodiment of the invention, it can likewise be advantageous to activate the coffee afterheater when the supply of brewed coffee from the brewing device to the coffee dispensing line has terminated. This possibility can be taken into account, in particular, immediately after the brewing process has ended, when remnants of the brewed beverage are still located in the coffee dispensing line. In this case, by virtue of the activation of the post-heater, a steam bubble is generated in the coffee dispensing line which has the effect of creating an overpressure in this region of the coffee dispensing line, which lasts for a sufficiently long period of time. In this way, the liquid still present in the coffee dispensing line is drained in the direction of the coffee dispensing device, so that on the one hand an almost complete dispensing of the brewed beverage into the cup can be obtained and on the other hand an earlier brewed beverage is avoided from being left in the coffee dispensing line for a longer time. In this way it is then also ensured that almost no residues from the previous brewing process enter the dispensing device and thus almost no residues from the previous brewing process enter the cup in the next brewing process. This is satisfactory on the one hand, since these brewing residues can of course also cool down in succession and can negatively influence the temperature of the dispensed brewed beverage, and on the other hand, these brewing residues in the coffee dispensing line can be effectively prevented from oxidizing or deteriorating, for example in response to longer interruptions in operation. For this purpose, it can be advantageous, if possible, to arrange the post-heater in close proximity to the end of the brewing unit on the dispensing side, so that the path of the coffee dispensing line affected by the operation of the coffee post-heater, and thus the path that can be effectively evacuated by the formed steam bubbles, occupies a large part of the total path of the coffee dispensing line between the brewing unit and the dispensing device, if possible.

In a particular embodiment of the brewing device, provision is made that the post-heater comprises a tube, wherein the heating element extends adjacent to the tube. The heating element in turn comprises a power connection, wherein, upon application of a voltage, the energy used is converted into heat and the heating element is heated. A conduit is inserted into the liquid path of the coffee dispensing line and comprises a coffee supply connection and a coffee dispensing connection for this purpose leading to respective opposite ends of the conduit. However, it goes without saying that the after-heater can also be designed in the form of an externally applied heating element, which can be applied to an existing, continuous coffee dispensing line, for example by means of gluing or welding, by making a sufficient thermal contact.

However, it is also possible to fixedly connect at least partially the heated conduit inserted in the liquid path of the coffee dispensing line to the heating element extending adjacent thereto. In particular, therefore, the heating element can then be fused or adhered locally in order to ensure good thermal contact.

In another particularly preferred embodiment of the post-heater of the brewing device, in addition to the tube and the heating element extending adjacent thereto, a housing is provided which consists of a material which is as heat-conducting as possible. For this purpose, aluminum can be considered in particular, but also other materials with good heat conductivity can be considered. In particular, the housing can thus be a cast housing, which is implemented by at least partially recasting the pipe and the heating element. By providing a housing for the post-heater, not only is the mechanical stability improved, but due to the heat storage and heat conduction properties of the materials used, it is ensured in particular that as little heat loss as possible occurs during the heat transfer of the heating element to the pipe.

In a particular embodiment of the invention, the tube of the heating element is made of chrome steel or aluminum, thus ensuring a defined heat transfer from the heating element extending adjacent to the tube.

In a further exemplary embodiment of the invention, provision is made for the heating element, which is designed as a resistance heater, to be embodied as a ceramic thick-film heater. For this purpose, the heating element is applied to a ceramic substrate comprising a certain thickness and thus a limited heat storage capacity. Since the delay in the regulating action of the heating element is relatively small, a uniform heat transfer can take place through the heating element to the pipe running adjacent to the heating element, said heat being generated by the heating element. However, it goes without saying that the heating element can also be implemented as a normal PTC heating resistor (heating resistor with a positive temperature coefficient). When using a common PTC heating resistor, with dimensions previously defined, it can be achieved in an advantageous manner that a natural regulation of the heating temperature takes place without additional regulating elements.

Drawings

Further details of the invention will be explained by means of an exemplary embodiment of a coffee maker through the figures.

Fig. 1 shows a schematic design of a coffee machine according to the invention with a brewing device comprising a brewing unit;

figure 2 shows a longitudinal section of the infusion unit according to figure 1; and

fig. 3 shows a three-dimensional view of a coffee post-heater for use in the coffee maker according to fig. 1.

Detailed Description

Fig. 1 shows a schematic view of a coffee machine 100 according to the invention, the coffee machine 100 having a brewing device 10, wherein the brewing device 10 in the exemplary embodiment shown consists of a brewing unit 30, a coffee post-heater 50 and a coffee dispensing line 40.

The coffee dispensing line 40 connects the brewing unit 30 to the coffee dispensing device 45 and comprises an end region 41 and an end region 42, the end region 41 being on the brewing unit side connected to the brewing unit 30 and the end region 42 being on the dispensing side connected to the coffee dispensing device 45. An end region 41 on the end side of the brewing unit abuts a first end 40-1 of the coffee dispensing device 45 for receiving the coffee beverage brewed in the brewing unit. In this example, the coffee dispensing line 40 branches off in an end region 42 on the dispensing side and comprises two ends 40-2, the two ends 40-2 being located opposite the first end 40-1 and opening into two coffee outlet openings 47, the two coffee outlet openings 47 being arranged adjacently, and the coffee beverage brewed in the brewing unit 30 can flow out of the coffee dispensing line 40 through the coffee outlet openings 47, for example into a beverage vessel 49 arranged below the coffee outlet openings 47. In the exemplary embodiment shown, the coffee post-heater 50 is arranged in the end region 41 on the brewing unit side. On the inlet side, the brewing device 10 is connected to a brewing water supply line 31, through which brewing water supply line 31 heated brewing water is supplied to the brewing unit 30 in order to brew a coffee beverage in the brewing unit 30.

The brewing water in the brewing water supply line therefore contains a temperature suitable for brewing the respective coffee beverage, preferably in the range between 90 ℃ and 95 ℃. Thus, the required brewing water temperature in the brewing water supply line 31 is ensured by the heating in the brewing water heater 24. For this purpose, fresh water is supplied from the water tank 20 to the brewing water heater 24, wherein in the exemplary embodiment shown the required water pressure is established by a pump 23 arranged between the water tank 20 and the brewing water heater 24.

Furthermore, a flow meter 22 is provided which can be arranged in the fresh water path between the water tank 20 and the brewing water heater 24 in order to provide information on the amount of heated fresh water and thus on the amount of brewing water supplied to the brewing device. When a positive flow is recognized by the flow meter 22, it can be concluded that a brewing process is now taking place, and when no flow is recognized, it can be concluded that a brewing process has not taken place accordingly by this information. Needless to say, a similar flow meter can also be arranged between the brewing water heater 24 and the brewing unit 30. Furthermore, a similar flow meter can be arranged in the coffee dispensing line 40 additionally or exclusively. In these cases, it may be necessary to design these similar flow meters for higher liquid temperatures and/or to design them to be more durable accordingly, in view of susceptibility to contamination by the precipitates.

It is also possible to perform the information that the brewing process is taking place and the information that the brewing process is not taking place or has ended, respectively, by means of other measuring means, such as a pressure sensor. Furthermore, it is possible to provide this information, in particular in response to the integration of the brewing device according to the invention into an automatically operated coffee machine, by program sequence control of the automatic coffee machine or coffee pot.

According to the described embodiment, the control unit 29 of the coffee maker 100 is connected to said means for identifying the water supply to the brewing unit 30, i.e. to the flow meter 22. The control unit 29 further comprises a connection 50.1 to the coffee afterheater 50, and the control unit 29 is designed to activate or deactivate the coffee afterheater 50 via the connection 50.1, respectively. This activation of the coffee post-heater 50 takes place according to a corresponding assessment of the information received from the flow meter 22, that is to say according to an assessment of whether a brewing process (identifying the water flowing through) is taking place. In order to obtain information about whether the brewing process is currently completed and the possible continuation time for adjusting the coffee post-heater 50, the control unit 29 can also comprise a timer.

The drain valve 27 can be installed in the brewing water supply line 31, i.e. in the line path between the brewing water heater 24 and the brewing unit 30, the drain valve 27 releasing the flow path of the brewing water in the direction of the brewing unit 30 after a corresponding brewing water pressure is generated by the pump 23. After the brewing process has been completed and the pump 23 has thus been switched off, the corresponding non-return function of the drain valve 27 then ensures that no or preferably a small amount of brewing water flows back again through the brewing water supply line 31 in the direction of the brewing water heater 24.

It is also possible to provide a drain valve unit 28 in the brewing water supply line between the drain valve 27 and the brewing unit 30, wherein a connection can be established between the brewing water supply line 31 and the drain line 28.1, for example after switching the drain valve 28 (from the position shown in fig. 1 to another position), so that, for example, after brewing a coffee beverage, excess brewing water from the brewing unit 30 can be supplied to the drain line 28.1 in each case and can be drained through the drain line 28.1 (to a receptacle not shown in fig. 1).

It is also possible to provide a switching valve 25, connecting the switching valve 25 to the outlet of the brewing water heater 24, and the switching valve 25 being connected to a frothing device 26 for preparing milk froth.

Details of the brewing unit 30 can be seen from fig. 2. The brewing unit 30 is designed for the fully automated preparation of brewed coffee beverages, in particular espresso coffee, and in view of the brewing unit 30 construction, the brewing unit 30 is based on principles known, for example, from EP 0559620 or EP 2196116. The brewing unit 30 comprises a number of components which are fastened to the support structure 32 and which can be mounted to the coffee machine 100 as a whole together with the support structure 32. The brewing unit 30 comprises in particular a brewing cylinder 33, the brewing cylinder 33 being supported on the support structure 32 such that it can pivot about a rotation axis R (oriented perpendicular to the plane of the drawing in fig. 6). The brewing cylinder 33 can thus be pivoted (by means of a drive not shown in fig. 2) in two different positions. Fig. 2 shows the brewing cylinder 33 in a position in which the brewing unit 30 is ready for preparing a brewed coffee beverage. In this position, the brewing cylinder 33 is positioned such that one end of the brewing piston 34, which is linearly movable by the driver 34-2 in the longitudinal direction of the guide 34-1 fastened to the support structure and along the guide 34-1, is moved into the brewing cylinder 33 along the longitudinal axis A of the brewing cylinder 33 through the opening 33-1 comprised on one end of the brewing cylinder 33, thereby tightly closing this opening 33-1 by the brewing piston 34. At one end located opposite the opening 33-1, the brewing cylinder comprises a second opening 33-2, which is tightly closed by a piston 35 movable along the longitudinal axis a of the brewing cylinder 33. During brewing of coffee, the brewing piston 34 and the piston 35 are positioned relative to the brewing cylinder 33 such that the brewing chamber 36 is contained in the brewing cylinder 33 between the brewing piston 34 and the piston 35.

In order to be able to prepare a coffee beverage by means of the brewing unit 30, it must first be ensured that the brewing chamber 36 is filled with coffee powder. As can be seen from fig. 2, one end of the brewing water supply line 31 leads to a brewing water tube 35-1, the brewing water tube 35-1 being contained in the piston 35 and being connected to the brewing chamber 36 via a plurality of openings (not shown in fig. 2). The hot brewing water can be guided under pressure to the brewing chamber 36 through the brewing water supply line 31 (as indicated in fig. 2 by the arrow 31'). As further illustrated in fig. 2, the outlet 37 of the brewing chamber 36 is integrated into the brewing piston 34. The coffee beverage brewed in the brewing chamber 36 can leave the brewing chamber 36 through the outlet 37. As can be seen in fig. 2, an end 40-1 of the coffee dispensing line 40 is connected to the outlet 37, so that the brewed coffee beverage can flow at this end 40-1 into the coffee dispensing line 40 and can flow to the coffee outlet opening 47 of the coffee maker 100 (as indicated by arrow 40' in fig. 2). As further illustrated in fig. 2, a valve 38 is located in the outlet 37 of the brewing chamber 36. The valve 38 is designed such that the outlet 37 of the brewing chamber 36 is kept closed as soon as the brewing water pressure in the brewing chamber 36 falls below a predetermined minimum value, and the outlet 37 for dispensing the brewed coffee beverage (e.g. espresso) is released when the brewing water pressure in the brewing chamber 36 exceeds the predetermined minimum value.

In order to fill the brewing chamber 36 with coffee powder before the preparation of the coffee beverage or in order to remove coffee powder for the brewing of the coffee beverage again from the brewing cylinder 33 after the preparation of the coffee beverage, the brewing cylinder 33 can be pivoted relative to the side edge 32-1 of the support structure 32. For this purpose, the brewing piston 34 must first be moved along the guide 34-1 by the driver 34-2, so that the brewing piston 34 no longer protrudes into the brewing cylinder 33 and does not close the opening 33-1. With the brewing cylinder 33 pivoted towards the side edge 32-1 of the support structure 32, the opening 33-1 of the brewing cylinder 33 is freely accessible, so that optionally brewed coffee powder can be removed (e.g. automatically) through the opening 33-1 (with the aid of the piston 35), or certain coffee powder can be filled (e.g. automatically) into the brewing cylinder 33 through the opening 33-1 for brewing.

The valve 38 can be designed such that the coffee powder can be brewed with brewing water in the brewing chamber 36 at a pressure of 5Bar or more. A pump 23 can be included accordingly, so that brewing water can be introduced into the brewing chamber with a pressure of 5Bar or more. Under these conditions, the brewing unit 30 particularly provides for the preparation of an espresso beverage in the form of espresso coffee.

The course of the brewing process of the coffee beverage according to the invention will be defined in more detail below by way of example by the embodiment shown in fig. 1.

After the pump 23 is activated, fresh water from the water tank 20 is delivered in the direction of the brewing water heater 24, wherein the amount of water passing through is determined by the flow meter 22 and this information is provided to the control unit 29. The brewing water heater 24 heats fresh water passing therethrough to a temperature required to brew a coffee beverage, which is typically between 90 ℃ and 95 ℃. The switching valve 25 is connected so as not to supply heated brewing water or steam to the frothing device 26, respectively. The liquid path of the heated brewing water accordingly extends downstream from the brewing water heater 24 in the direction towards the outlet valve 27, which outlet valve 27 releases the liquid path in the brewing water supply pipe 31 in the direction of the water discharge valve unit 28 through the pressure gradient established. The drain valve is switched accordingly so as to feed the passing brewing water to the inlet of the brewing unit 30 being part of the brewing device 10.

At the beginning of the brewing process, the brewing unit 30 is in a state ready for brewing by a corresponding preparation, for example by filling the brewing chamber 36 with coffee powder. The brewing water, the temperature of which is accordingly maintained, is now used, stationary with respect to the inlet of the brewing unit 30, within the brewing unit 30 to prepare and dispense the coffee beverage to the outlet 37 of the brewing chamber 36. The delivery of the brewed coffee beverage can be a simple delivery of the brewing water through the coffee powder, with a corresponding filtration then. Needless to say, the preparation of the coffee beverage can also take place in a different way in the brewing unit.

The brewed coffee beverage then flows into the coffee dispensing line 40 on which the coffee post-heater 50 is arranged. Due to the duration of the brewing process and due to possible heat losses within the brewing unit 30, the prepared brewed coffee beverage that is supplied to the coffee post-heater 50 may contain a temperature that is lower than the optimal serving temperature of the coffee beverage. For example, a temperature range from 80 ℃ to 85 ℃ can be considered as an optimum drinking temperature.

Once the coffee has been dispensed, the coffee post-heater 50, the design of which will be defined in more detail below, will be activated. The coffee post-heater 50 then heats the coffee beverage in the coffee dispensing line 40 to a temperature that is sufficiently high to ensure that, after being dispensed into the beverage vessel, the coffee beverage assumes a temperature that is within the optimal serving temperature range. The coffee beverage heated to the optimum drinking temperature then flows out of the coffee dispensing line 40 into the coffee dispensing device 45, the coffee dispensing device 45 serving to dispense coffee as uniformly and generally without splashing as possible through the coffee outlet opening 47 into a coffee vessel 49 located below the coffee dispensing device 45.

When the brewing session has terminated, that is to say when it has been determined by the flow meter 22 that a sufficient amount of brewing water has been supplied to the brewing unit 30, the brewing water heater 24 and the pump 23 are switched off and the throughflow through the brewing device 10 is interrupted. By a corresponding evaluation of the timer of the control unit 29, it is now possible to allow the coffee afterheater 50 to continue to run for a limited time, even after the brewing process has terminated, or to restart the coffee afterheater 50 accordingly. Due to the fact that no more liquid is supplied to the coffee dispensing line 40, the remaining liquid located in the coffee dispensing line 40 is thus further heated. Due to this expansion of the steam bubble, it is also possible that the course of this action leads to a pressure build-up within the coffee dispensing line 40 because the steam bubble is formed in the direct vicinity of the end region 41 of the coffee dispensing line 40 on the side of the brewing unit, as a result of which the residual liquid, in this case thus the residue of the now freshly brewed coffee beverage, is drained in the direction of the coffee dispensing device 45 and thus enters the coffee vessel. In this way it is ensured to a large extent that a residual amount of brewed coffee is prevented from remaining in the coffee dispensing line 40. On the one hand, this is satisfactory in order not to supply any or only a small amount of residual beverage remaining in the coffee dispensing line and possibly cooled to the coffee dispensing device 45 in response to a possible next brewing session, which would otherwise further reduce the beverage temperature. On the other hand, this is also of interest for hygienic reasons, since the risk of beverage residues located in the coffee dispensing line 40 deteriorating in response to longer stagnation times can thus be avoided.

Fig. 3 shows a perspective view of the coffee afterheater 50, since the coffee afterheater 50 can be used, for example, in connection with the coffee maker 100 explained in connection with fig. 1.

As can be seen in fig. 3, the coffee afterheater 50 comprises a housing 55, preferably the housing 55 is composed of a material that is as heat conductive as possible, such as aluminium. In the case of the production of this housing 55 by casting, it is possible in particular to embody the housing 55 as a massive body, wherein the material, which is thus aluminum, surrounds the embedded elongated heating element 54 and the tube 61 extending adjacent to the heating element 54.

The conduit 61 penetrating the housing 55 represents the flow path of the beverage to be post-heated, wherein the flow direction is indicated by the arrow provided with reference sign 60. The course of the tubes 61 in the interior of the housing block 55 is schematically shown in fig. 3 by means of dashed lines, the course of the tubes 61 extending parallel to one another.

The conduit comprises a supply connection 51 and a dispensing connection 52 for the purpose of mounting the coffee post-heater 50 in the coffee dispensing line 40. The coffee dispensing line 40 can for example comprise two tubes, wherein the dimensions of the two tubes are such that one end of one tube can be inserted into the supply connection 51, while the other end of the one tube forms the end region 41 of the coffee dispensing line 40 on the brewing unit side, and one end of the other tube can be inserted into the dispensing connection 52, while the other end of the other tube forms the end region 42 of the coffee dispensing line 40 on the dispensing side. In the alternative, it is also possible to connect the supply connection 51 of the coffee post-heater 50 directly to the outlet 37 of the brewing unit 30 or the brewing chamber 36, respectively, so that the supply connection 51 forms the end region 41 of the coffee dispensing line 40 on the side of the brewing unit.

The resistance heating element 54 extends adjacent to the tube 61, the course of the resistance heating element 5 in the interior of the housing 55 in turn also being indicated by dashed lines. For the purpose of supplying power, the heating element 54, which is, for example, a PTC heating resistor, includes a power supply connection 53. It is not necessary to explain further that the heating element 54 can be provided with an electrical insulator in order to prevent unintentional short-circuiting of the current path through the metal housing.

After a corresponding voltage is applied to the power supply connection 53, the heating element 54 heats up and dissipates the majority of the heat generated in this way to the well-conducting housing 55, so that in turn a heat transfer to the pipe 61 takes place. Thereby also heating the liquid passing through the tube 61 and thus also the coffee according to the invention which has to be post-heated.

However, it is also possible not to arrange the tube 61 and the heating element 54 in the heat-conducting housing 55, but to guide it in a path directly adjacent to one another and to connect the two by forming a heat-conducting transition, for example by fusing or adhering. Likewise, the shape of the conduit 61 and the shape of the heating element 54 and possibly the shape of the housing 55 are not limited to a sufficiently straight course either. Conversely, it is also possible, for example, to design the coffee afterheater 50 in a curved shape so as to be curved in a U-shaped manner.

In the exemplary embodiment shown, the material of the housing 55, which is almost completely thermally conductive in the flow direction 60, is subsequently composed of chrome steel or aluminum by recasting the surrounding pipe 61. In the case shown, the heating element 54 is designed as a heating resistor, preferably a PTC heating resistor, but it can also be designed, for example, as a ceramic thick-film heater. It is ensured that in all cases, when using the coffee machine according to the invention, the beverage to be dispensed can be brought to a beverage temperature during the brewing process which lies within the range of the optimal drinking temperature.

The brewing device 10 can be designed such that, when the respective brewed coffee beverage is post-heated, the heating element 54 is heated to a predetermined temperature in each case, wherein the respective current flowing through the heating element 54 is controlled accordingly by the control unit 29. As the coffee beverage passes through the coffee dispensing line 40, the temperature of the respective brewed coffee beverage can vary en route between the coffee post-heater 50 and the respective outlet opening 47, wherein the respective variation of the coffee beverage temperature is a function of the current temperature of the coffee dispensing line 40 in the region between the coffee post-heater 50 and the respective coffee outlet opening 47. In order to ensure that the temperature of the coffee beverage dispensed by the coffee dispensing apparatus 45 is within a predetermined range, the respective current flowing through the heating element 54 can be controlled, for example, depending on the present temperature of the coffee dispensing line 40.

In the present example, a temperature sensor 48 for providing a measurement of the temperature of the coffee line 46 is arranged on the end region 42 of the coffee dispensing line 40 on the dispensing side, for example in the vicinity of the coffee outlet opening 47, wherein the coffee post-heater 50 can be controlled by the control unit 29 in dependence on the respective provided measurement for the respective temperature of the dispensing line 40. For this purpose, the temperature sensor 48 is connected to the control unit 29 by means of a connection 48.1 shown in fig. 1, so that the control unit 29 can obtain information about the respective temperature of the coffee line 46 measured by the temperature sensor 48 and the control unit 29 can control the current flowing through the heating element 54 in dependence on the temperature measurement of the temperature sensor 48.

It is also possible to position the temperature sensor 48 at another location on the coffee line 46, for example at a region of the coffee dispensing line 40 between the coffee post-heater 50 and the end region 42 of the coffee dispensing line 40 on the outlet side, or on the coffee post-heater 50.

In the alternative, it is also possible to arrange a plurality of temperature sensors on the coffee line 46 (distributed along the coffee line 46), and/or to arrange one or more temperature sensors on the coffee dispensing line 40 (for measuring the temperature of the coffee dispensing line 40 at different locations), wherein each temperature sensor can be connected to the control unit 29, so that the control unit 29 can obtain information about the temperature of the coffee dispensing line 40 measured by each temperature sensor, and the control unit 29 can control the current flowing through the heating element 54 in dependence on the respective temperature measurement of the respective temperature sensor.

The coffee machine 100 can be designed such that the temperature of the coffee beverage dispensed by the coffee dispensing apparatus 45 can be influenced by a user, wherein the user can select, by means of a pre-selection device, a set-point value for the temperature contained in the coffee beverage dispensed from the coffee dispensing line 40 before the corresponding coffee beverage is prepared. For this purpose, the coffee post-heater 50 can be controlled by the control unit 29 according to a corresponding preselected setpoint value. In particular, the control unit 29 is able to control the current flowing through the heating element 54 according to a corresponding preselected setpoint value. Furthermore, the respective preselected setpoint value can also be varied within a predetermined temperature range by the preselection device.

The selection of the corresponding set point value can be performed by conventional means. For example, the coffee maker 100 shown in fig. 1 comprises a preselection device 70, the preselection device 70 being used for preselecting a set-point value for the temperature of the coffee beverage dispensed from the coffee dispensing line 40, and the preselection device 70 being realized as a keypad having a plurality of buttons 70.2. In each case, the button 70.2 designates the temperature of the coffee beverage dispensed from the coffee dispensing line 40 as a different set point value, for example as a different value in a temperature range between 80 ℃ and 95 ℃. By pressing the corresponding button 70.2, the respective set point values can be gradually changed accordingly. As indicated in fig. 1, the preselection device 70 is connected to the control unit 29 by a connection 70.1, so that a set point value selected by means of the button 70.2 can be transmitted to the control unit 29 and can be taken into account by the control unit 29 when controlling the coffee afterheater 50 or when controlling the current through the heating element 54.

Needless to say, the preselection device 70 can be replaced by a preselection device of a different design, such as a knob for entering the respective set point value, a slider bar, a touch-sensitive screen, a numeric keypad or other device providing a continuous or gradual change of the set point value.

In the context of the present invention, the coffee afterheater 50 can also be replaced by a flow-through heater of another design, for example a tubular heating glass element (for example made of glass with an integrated heating resistor made of wire in the form of a tube) or an inductively heatable tube.

Claims (16)

1. A coffee machine (100), the coffee machine (100) for preparing an infused coffee beverage and for dispensing the infused coffee beverage via at least one coffee outlet (47), the coffee machine (100) comprising:

brewing device (10), the brewing device (10) being intended for preparing the brewed coffee beverage by brewing a predetermined amount of coffee in pressurized brewing water, the brewing device (10) comprising: a brewing unit (30), the brewing unit (30) having a brewing chamber (36) for containing the predetermined quantity of coffee; a brewing water supply line (31), the brewing water supply line (31) being connected to the brewing unit (30) and the brewing water supply line (31) opening into the brewing chamber for feeding the brewing water into the brewing chamber; and means (20, 23, 28) for introducing the brewing water into the brewing chamber (36),

the means (20, 23, 28) for introducing the brewing water are designed to introduce the brewing water under pressure into the brewing chamber (36) through the brewing water supply line (31),

wherein the brewing chamber (36) comprises an outlet (37) for the brewed coffee beverage, and the brewing device (10) comprises a coffee dispensing line (40), the coffee dispensing line (40) forming a continuous fluid connection of the brewed coffee beverage between the outlet (37) and the coffee outlet (47) of the brewing chamber (36),

wherein the coffee dispensing line (40) comprises a first end (40-1), the first end (40-1) being connected to the outlet (37) of the brewing chamber, and the first end (40-1) comprising an inlet for receiving the brewed coffee beverage, the inlet being in fluid connection with the outlet of the brewing chamber; and the coffee dispensing line (40) comprises a second end (40-2), the second end (40-2) comprising an outlet being in fluid connection with the coffee outlet (47) for dispensing the brewed coffee beverage,

the method is characterized in that:

the brewing device (10) comprises a coffee post-heater (50), the coffee post-heater (50) being configured for post-heating the respective brewed coffee beverage in the coffee dispensing line (40), wherein the coffee post-heater (50) is arranged between the outlet of the brewing chamber and the coffee outlet, and the coffee post-heater (50) is designed as a through-flow heater for heating the brewed coffee beverage while the brewed coffee beverage flows through the coffee dispensing line (40).

2. The coffee machine (100) of claim 1,

wherein the brewing device (10) further comprises: at least one device (22) for identifying the water supply to the brewing unit (30); and/or at least one means for identifying the coffee beverage supply into the coffee dispensing line (40).

3. The coffee machine (100) of claim 2,

wherein the brewing device (10) further comprises a control unit (29), the control unit (29) being connected to the at least one means for identifying a water supply to the brewing unit (30) and/or to the at least one means for identifying a coffee beverage supply into the coffee dispensing line (40),

wherein the control unit (29) is designed to activate the coffee afterheater (50) when it is recognized that water is supplied to the brewing unit (30), or

Wherein the control unit (29) is designed to activate the coffee post-heater (50) when it is recognized that coffee beverage is supplied to the coffee dispensing line (40).

4. The coffee machine (100) of claim 2,

wherein the brewing device (10) further comprises a control unit (29), the control unit (29) being connected to the at least one means for identifying the supply of water to the brewing unit (30) and/or to the at least one means for identifying the supply of coffee beverage into the coffee dispensing line (40), wherein the control unit (29) is designed to activate the coffee post-heater (50) when it is identified that the supply of water to the brewing unit (30) or the supply of coffee beverage into the coffee dispensing line (40) has ended.

5. The coffee machine (100) according to claim 3 or 4, wherein the coffee machine (100) comprises a preselection device (70), the preselection device (70) being adapted to preselect a set-point value for the temperature of the coffee beverage dispensed from the coffee dispensing line (40), wherein the respective preselected set-point value can be varied within a predetermined temperature range by the preselection device (70), and the coffee post-heater (50) can be controlled by the control unit (29) in accordance with the respective preselected set-point value.

6. The coffee machine (100) according to claim 3 or 4, wherein the coffee machine (100) has one or more temperature sensors (48), the temperature sensors (48) being adapted to provide a measurement value for the temperature of the coffee dispensing line (40), wherein the coffee post-heater (50) is controllable by the control unit (29) in dependence of the measurement value provided accordingly for the respective temperature of the dispensing line (40).

7. The coffee machine (100) according to claim 6, wherein at least one respective temperature sensor (70) is arranged on an end region (42) of the coffee dispensing line (40) on the dispensing side, or on a region of the coffee dispensing line (40) between the coffee post-heater (50) and the end region (42) of the coffee dispensing line (40) on the dispensing side, or on the coffee post-heater (50).

8. The coffee machine (100) of any of claims 1-4,

wherein the coffee post-heater (50) comprises a coffee supply connection (51) and a coffee dispensing connection (52) and a heating element (50) having at least one power supply connection (53), and wherein the coffee supply connection (51) and the coffee dispensing connection (52) in each case open into opposite ends of a duct (61), the duct (61) extending adjacent to the heating element (54).

9. The coffee machine (100) of claim 8,

wherein the conduit (61) is at least locally fixedly connected and/or welded and/or adhered to the heating element (54), the heating element (54) extending adjacent to the conduit (61).

10. The coffee machine (100) according to claim 8, wherein the coffee post-heater (50) further comprises a housing (55) made of a heat conductive material, wherein the housing (55) is designed such that the heat conductive material of the housing (55) at least partially surrounds the duct (61) and the heating element (54).

11. The coffee machine (100) of claim 8, wherein the duct (61) is composed of chrome steel or aluminum.

12. The coffee machine (100) of claim 8, wherein the heating element (54) is a ceramic thick film heater or a PTC heating resistor.

13. The coffee machine (100) according to any one of claims 1-4, wherein the coffee machine (100) comprises a water tank (20), a brewing water heater (24), a pump (23), a drain valve (27) and a coffee dispensing device (45), wherein the brewing water supply line (31) of the brewing device (10) is connected to the pump (23) and an end region (42) of the coffee dispensing line (40) on the dispensing side is connected to the coffee dispensing device (45).

14. Method for brewing and dispensing a coffee beverage by means of a coffee machine (100) according to any one of claims 1 to 13, the method comprising the following method steps:

a) bringing the brewing unit (30) into a brewing ready state;

b) supplying brewing water heated to a brewing temperature to a brewing water inlet of the brewing unit (30) through a brewing water supply line (31);

c) brewing a coffee beverage in the brewing unit (30);

d) dispensing the brewed coffee beverage into a coffee dispensing line (40) such that the coffee beverage flows through the coffee dispensing line; and

e) activating a coffee afterheater (50), and the coffee afterheater (50) heats the coffee beverage flowing through the coffee dispensing line (40).

15. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

wherein the brewing device (10) further comprises: at least one device (22) for identifying the water supply to the brewing unit (30); and/or at least one device for identifying the coffee beverage supply into the coffee dispensing line (40),

wherein method step e) is performed when it is recognized that water is supplied to the brewing unit (30), or

Wherein method step e) is performed when it is recognized that a coffee beverage is supplied to the coffee dispensing line (40).

16. The method of claim 14, wherein the first and second light sources are selected from the group consisting of,

wherein the brewing device (10) further comprises: at least one device (22) for identifying the water supply to the brewing unit (30); and/or at least one device for identifying the coffee beverage supply into the coffee dispensing line (40),

wherein method step e) is performed when it is recognized that the supply of water to the brewing unit (30) or the supply of coffee beverage into the coffee dispensing line (40) has ended.