Vending machine for preparing an infusion drink

Abstract

A beverage dispenser (1) for producing an infusion beverage has a pressure line (2) which is connected to a suction line (3) via a vacuum generation device (4), such that a vacuum is generated in the suction line (3) by means of a fluid (5) flowing in the pressure line (2) and a liquid (6) is drawn in via the suction line (3) and discharged together with the fluid (5) via the pressure line (2), characterized in that a slotted diaphragm (7) is inserted into the suction line (3), which opens when there is a deviation from normal atmospheric pressure and closes automatically after the pressure deviation ceases, in order to prevent a backflow of the liquid (6) drawn in the suction line (3).

Description

[0001] The invention relates to a beverage vending machine for the production of an infusion beverage according to the preamble of claim 1.

[0002] Vending machines, such as those used to produce various infused beverages, have a complex flow system with a variety of different units, flow lines or fluid lines.

[0003] A beverage dispenser for preparing a brewed beverage, in the embodiment concerned, has, for example, a pressure line connected to a suction line via a vacuum generation device. The fluid supplied via the pressure line creates a vacuum in the suction line within the vacuum generation device. This vacuum causes a liquid to be drawn in through the suction line and also introduced into the vacuum generation device, so that the drawn-in liquid mixes with the fluid. The mixture produced in this way is then dispensed via the pressure line or via a dispensing device connected to the pressure line. Such solutions are already known in numerous variations. The fluid can be a gas or a liquid.

[0004] German patent DE 10 2010 028 729 B4 discloses a milk frother for use in a beverage vending machine designed as a coffee machine. This frother features a frothing chamber in which steam generated within a pressure line mixes with drawn-in milk to create a milk-air mixture. The vacuum steam system employed operates on the Venturi principle. To prevent backflow of milk from the suction line into the milk container, this design utilizes a stationary, labyrinthine flow resistance within an air supply device. Particular emphasis is placed on the absence of moving parts, such as valves, within the milk frother. However, this solution results in a complex mixing chamber design, primarily due to the labyrinthine structure.Furthermore, the use of a labyrinth may present significant cleaning difficulties, as milk-carrying fluid lines are generally relatively difficult to clean due to the protein deposits that form.

[0005] A different approach is taken in DE 10 2009 034 234 B4. This document discloses a beverage dispenser that includes a device for producing milk foam and / or heated milk, wherein a pressure line is equipped with a lip valve whose operation corresponds to a one-way valve. This effectively prevents backflow of the rinsing medium used for cleaning the beverage dispenser. The lip valve surrounds the pressure line and is designed such that, in the closed state, it allows rinsing of the downstream areas that come into contact with milk, while, according to the disclosure in this document, in the open state, it additionally allows rinsing of the fluid line system located upstream of the lip valve. Further prior art is disclosed in DE 10 2012 214 104 A1, DE 10 2009 055 384 A1, and GB 1 354 691 A.

[0006] The fluid lines used in vending machines are often flexible hoses. These are typically made of silicone and are sometimes transparent or translucent, making the liquids inside visible. This is particularly problematic when the liquid is milk. When the liquid is drawn from a tank or container, usually located outside the vending machine, via such a suction line, at least part of the line is exposed. After the suction process is complete, the milk remaining in the line flows back into the tank or container due to the loss of vacuum.This is perceived as unhygienic by the user of such a beverage dispenser and also leads to the fact that during a subsequent suction process, the air present in the suction line must first be drawn in, which in turn leads to performance losses.

[0007] The invention therefore addresses the problem of providing a beverage dispenser in which an unwanted backflow of the liquid drawn in via the suction line can be effectively and easily avoided.

[0008] According to the invention, this problem is solved by a beverage vending machine with the features of claim 1.

[0009] Advantageous embodiments and further developments of the invention are set out in the following dependent claims.

[0010] A beverage dispenser for producing an infusion beverage with a pressure line connected to a suction line via a vacuum generation device, such that a vacuum is generated in the suction line by means of a fluid flowing in the pressure line, and a liquid is drawn in via the suction line and discharged together with the fluid via the pressure line, has been further developed according to the invention in such a way that a slotted membrane is inserted into the suction line, which opens when there is a deviation from normal atmospheric pressure and closes automatically again after the pressure deviation ceases, in order to prevent a backflow of the liquid drawn in the suction line.

[0011] The advantages achievable with the invention lie particularly in its very cost-effective, easy-to-implement solution, which can even be retrofitted to existing vending machines and effectively prevents the unwanted backflow of liquid drawn in through the suction line. There is no loss of user-friendliness when using a vending machine equipped with the invention. Furthermore, it can be noted that an air cushion that previously formed within the suction line can be avoided by the backflow of the liquid already present in the suction line into the container, so that during the next suction process, liquid is immediately present in the suction line and an air cushion does not first need to be extracted. This results in a significant overall improvement in the functionality of the vending machine. For the purposes of the invention, a vacuum is understood to be a pressure whose absolute value is below normal atmospheric pressure.

[0012] A first embodiment of the invention consists in the diaphragm being designed to open alternately depending on the applied pressure. This represents a clear distinction from the prior art solution with a lip valve, which merely functions as a one-way valve. The diaphragm's ability to open alternately allows both the suction of liquid via the suction line and a flushing process of the suction line, which is essential for necessary cleaning and takes place in the opposite direction to the suction direction. With this further development of the invention, the diaphragm allows both processes to be carried out without any impairment. Nevertheless, the backflow of liquid present in the suction line when the vacuum is released is effectively prevented.

[0013] Furthermore, if the membrane is manufactured in one piece from an elastically deformable plastic or rubber material, it can be produced extremely cost-effectively and in any desired geometry. Plastic or the aforementioned rubber material also offer a definable elasticity, so that the properties regarding the pressure present in the suction line and the opening and closing times of the membrane can be determined very precisely in advance.

[0014] For inserting the diaphragm into the suction line, it is advantageous if the diaphragm has a reinforced edge and a central section comprising at least two diaphragm lips formed by a slit. The central section is preferably located within the reinforced edge, so that the reinforced edge completely surrounds this central section. Due to the elastic design of the diaphragm, the reinforced edge, in particular, ensures that it presses optimally against the inner wall of the suction line, thereby creating a seal between the diaphragm and the suction line. Furthermore, the inherent elasticity of the diaphragm lips formed by the slit allows them to open as long as a vacuum is present in the suction line and to close automatically when this vacuum is removed.

[0015] In the previously described variant, the diaphragm is inserted directly into the suction line, so that the reinforced edge area presses directly against the inner wall of the suction line, forming a seal. Alternatively, the diaphragm can also be inserted into a receiving sleeve, which has pins at opposite ends for attaching the suction line. In this version, the suction line is cut once and then attached to the pins of the receiving sleeve on both sides. This re-establishes the flow-conducting connection with the diaphragm in between. The receiving sleeve can have a centrally reinforced area for inserting the diaphragm, which can be opened and closed, for example, by a screw connection, thus facilitating the insertion and, if necessary, replacement of the diaphragm.

[0016] A further specific embodiment of the invention consists in the membrane having a cross-slot. Here, a "cross-slot" is preferably defined as a slit in the membrane in which two slits are arranged at right angles to each other. However, the term "cross-slot" should not be interpreted restrictively. Rather, it also includes embodiments in which the slits run, for example, at an acute or obtuse angle to each other.

[0017] According to an alternative embodiment, the membrane can also be multiply slotted, which means, for example, that several slots extend radially from a central point in the middle of the membrane, forming a multitude of individual membrane lips whose intersection point preferably coincides in the center of the membrane's central section. This results in a lemon-slice-like pattern in the central section of the membrane according to the invention within the suction line of the beverage dispenser.

[0018] A further preferred embodiment of the invention consists in the vacuum generation device being designed according to the principle of a Venturi nozzle. In this embodiment, a fluid flows through the pressure line, from which, according to the Venturi principle, the suction line branches off in a constricted section. This creates a vacuum in the suction line and a suction effect, which draws in the liquid present in the suction line and mixes it with the fluid in the pressure line, so that a liquid mixture or a foam can be formed as required. For better understanding, it should be noted here that, in the context of the invention, "fluid" is understood to mean both a gas and a liquid. The liquid drawn in via the suction line is provided in a suitable container or tank and is drawn directly from it via the suction line.The liquid mixture formed in the pressure line, or the foam generated therein, is subsequently discharged via at least one dispensing device which, viewed in the direction of flow, is arranged downstream of the pressure line.

[0019] A beverage vending machine according to the invention, in a specific embodiment, is a coffee machine with a mixing or frothing section for heating and / or frothing the liquid, which in this case is milk. The vacuum generation device, as previously described, serves to draw milk from a container via the suction line. In the area of ​​the vacuum generation device, this milk is combined with water. It should be noted that the water is first heated in a heating device in order to heat the resulting liquid mixture after it is combined with the milk. If the water supplied in the pressure line is heated to the point of producing steam, the milk drawn in via the suction line can then be additionally frothed.It is particularly important that the membrane is integrated into the suction line and consequently forms part of it. The milk is combined with the water or steam in the mixing or frothing section of the beverage dispenser, downstream of which, viewed in the direction of flow, at least one dispensing device for the heated and / or frothed milk is located. This dispensing device can be a nozzle or a liquid outlet, as is known per se.

[0020] The invention is explained in more detail below with reference to the accompanying drawings. The exemplary embodiments shown do not represent a limitation to the variants depicted, but merely serve to illustrate a principle of the invention. Identical or similar components are always designated with the same reference numerals. In order to illustrate the functionality according to the invention, only highly simplified schematic representations are shown in the figures, in which components not essential to the invention have been omitted. However, this does not mean that such components are not present in a solution according to the invention.

[0021] It shows: Fig. 1: a beverage vending machine, using a coffee machine as an example, in a perspective view, Fig. 2: a highly simplified schematic representation of the principle of a beverage vending machine with a vacuum generation device, Fig. 3: Partial cross-sectional view of a suction line of the beverage vending machine and Fig. 4: partial cross-sectional view of a receiving sleeve with a membrane and an attached suction line.

[0022] In the Fig. The beverage vending machine 1 shown in Figure 1 is a vending machine for preparing various coffee drinks, in other words, a coffee machine. Designed as a mobile, stand-alone unit, the beverage vending machine 1 consists of a housing 15 in which all functional elements for preparing the drinks are concealed from view. At the front of the beverage vending machine 1, it has an upper projection 16 and, at a height difference, a lower projection 17, between which a dispensing area 18 is formed. The lower section of this recessed dispensing area 18 is bounded by a shelf 21 on which a [missing information - likely a specific item or component] is placed. Fig. A container (not shown) can be placed on the tray, into which a beverage produced in the beverage dispenser 1 is poured. The tray 21 is also equipped with several, in this case two, drain openings 22, which serve to drain residual liquid into a collection tray located below the tray 21. This residual liquid could be, for example, residue from the detergent or cleaning fluid regularly used to clean the flow pipe system of such a beverage dispenser 1. A central outlet 19, located below the upper extension 16 in the dispensing area 18, serves to fill the aforementioned container and is shown in the illustration. Fig. 1 only a small part is visible. Below the central outlet 19, two dispensing devices 20 in the form of nozzles are also indicated, through which, for example, various coffee drinks or steam or the frothed milk produced in the beverage dispenser 1 can be dispensed. Spaced laterally from the central outlet 19, in the Fig. Figure 1 further shows a suction line 3 which is inserted into a tank or container containing milk or another liquid to be processed in the beverage dispenser 1. This can also be the cleaning fluid mentioned previously. The container or tank can also be arranged on the support surface 21 so that the suction line 3 can be inserted into the container or tank.

[0023] From the Fig. Figure 2 shows, in a highly simplified, schematic representation, the principle of a beverage vending machine 1 according to the invention, which has a vacuum generation device 4 that functions according to the Venturi principle. As can be seen from the Fig. As can be seen in Figure 2, a fluid 5, in this case water, is stored in a water tank 23. The water tank 23 is connected to a pressure line 2, through which the fluid 5 is discharged at a defined pressure. On its way to the vacuum generation device 4, the fluid 5 passes through a section of the pressure line 2 containing a heating device 24. This heating device 24 heats the fluid 5 in the pressure line 2, and this heating can be carried out until the fluid 5 changes its state of matter to a gaseous state. Continuing with the example where the fluid 5 is water, the heating device 24 generates steam 25 within the pressure line 2, which then passes through the vacuum generation device 4. This device, operating on the Venturi principle, is a section of the pressure line 2 with a reduced cross-section.Following the vacuum generation device 4, the pressure line 2 widens again, forming a mixing or foaming zone 27 where the liquid 6 and the fluid 5 are mixed together. This is achieved by the... Fig. The arrow P indicates that a dispensing device 20 is connected to the mixing or foaming area 27, through which the mixture thus produced can be discharged. In the constricted area of ​​the vacuum generation device 4, a branch of the suction line 3 is also provided, and a diaphragm 7 is integrated into the suction line 3. This diaphragm allows the intake of the liquid 6, which is milk, from the container 26 only when a vacuum is present. If the vacuum is released, the diaphragm 7 closes automatically due to its inherent elasticity, thereby preventing, according to the invention, a backflow of the liquid within the suction line 3 into the container 26.

[0024] The Fig. Figure 3 shows a partial and cross-sectional view of a suction line 3. The diaphragm 7 is inserted within the suction line 3. It consists of a reinforced outer section 8 and a central section 11, which is reduced in cross-section and, in this case, has a slot 9 in the form of a cross-slot. In this example, the cross-slot 9 forms a total of four approximately equal-sized diaphragm lips 10. The elasticity of these lips allows them to draw in a liquid 6 from a tank or container when a vacuum is applied and to close automatically when the vacuum decreases. The diaphragm 7 is located in the... Fig. However, the embodiment of a membrane 7 shown in Figure 3 also allows for a counterflow principle, such that the membrane lips 10 can also open in the opposite direction. This is necessary, for example, when the fluid lines of the flow line system of the beverage dispenser 1 need to be cleaned with a cleaning fluid. This naturally also applies to the suction line 3, whose cleaning is made possible by the membrane 7 in the manner described above.

[0025] In the Fig.Figure 4 shows another way in which the membrane 7 can be integrated into the suction line 3. Here, the suction line 3 is cut once. The resulting ends of the suction line 3 are placed onto a pin 13 or 14 of a receiving sleeve 12, respectively, and thus seal against the environment. The receiving sleeve 12 has a reinforced central section in which the membrane 7 is held, and its reinforced edge 8 creates a seal within the receiving sleeve 12. REFERENCE MARK LIST: 1 vending machine 2 Pressure line 3 Suction line 4 Vacuum generating device 5 Fluid 6 Liquid 7 Membran 8 Edge area 9 slots 10 membrane lips 11 Central Section 12 Mounting sleeve 13 cones 14 cones 15 cases 16 Upper porch 17 Lower porch 18 Output area 19 Central outlet 20 dispensing facilities 21 parking spaces 22 drain openings 23 Water tank 24 Heating system 25 Water vapor 26 containers 27 Mixing or foaming area

Claims

[1] Vending machine (1) for producing an infusion beverage with a pressure line (2) which is connected to a suction line (3) via a vacuum generation device (4), such that a vacuum is generated in the suction line (3) by means of a fluid (5) flowing in the pressure line (2) and a liquid (6) is drawn in via the suction line (3) and discharged together with the fluid (5) via the pressure line (2), characterized by , that a slotted membrane (7) is inserted into the suction line (3), which opens when there is a deviation from normal atmospheric pressure and closes automatically again after the pressure deviation ceases, in order to prevent a backflow of the liquid (6) drawn into the suction line (3). [2] Vending machine according to claim 1, characterized by , that the membrane (7) is designed to open alternately depending on the applied pressure. [3] Vending machine according to one of the above claims, characterized by, that the one-piece membrane (7) is made of an elastically deformable plastic or rubber material. [4] Vending machine according to one of the preceding claims, characterized by that the membrane (7) has a reinforced edge region (8) and a central section (11) having at least two membrane lips (10) formed by a slit (9). [5] Vending machine according to one of the above claims, characterized by , that the membrane (7) is inserted into a receiving sleeve (12) which has pins (13, 14) at its opposite ends for attaching the suction line (3). [6] Vending machine according to one of the above claims, characterized by , that the membrane (7) has a cross-shaped slit. [7] Vending machine according to one of the above claims, characterized by , that the membrane (7) is slotted multiple times. [8] Vending machine according to one of the above claims, characterized by , that the vacuum generating device (4) is designed according to the principle of a Venturi nozzle. [9] Vending machine according to one of the above claims, characterized by , that the beverage dispenser (1) is a coffee dispenser with a mixing or frothing area (27) for heating and / or frothing the liquid (6) milk, which can be drawn in by means of the vacuum generation device (4) via the suction line (3) integrating the membrane (7) and can be heated by means of the fluid (5) water supplied via the pressure line (2) and heated by a heating device (21), wherein at least one dispensing device (20) for dispensing the heated and / or frothed milk (6) is arranged downstream of the mixing or frothing area (27) in the direction of flow.

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