RU2805221C1 - Mixing device, for example, for preparing foamed milk - Google Patents

Abstract

FIELD: mixing.

SUBSTANCE: mixing device comprises inner and outer tanks, which form passages between them for the mixing fluid. The inner container can be received in the outer container in at least two different orientations. Each orientation defines a different set of passages, each including a mixing chamber and a lift passage that leads from the first vessel to the mixing chamber.

EFFECT: different orientations create different port designs for different mixing purposes.

15 cl, 11 dwg

Description

TECHNICAL FIELD

The present invention relates to a mixing device for mixing two fluids. Particularly, but not exclusively, the invention relates to the field of beverage preparation, and more particularly to the field of automatic preparation of foamed milk drinks.

BACKGROUND OF THE ART

Generally, fully automatic espresso makers provide an automatic milk brewing function that brews coffee and prepares frothed milk. In most cases, steam is used to heat and froth the milk, much like a barista would. To improve the usability of the device and ensure consistent performance for all users, regardless of their qualifications, several milk frothing modules have been developed. As a rule, these modules are designed to be removable from the base unit, since all parts in contact with the milk must be cleaned.

The milk frothing function typically works by heating water in a thermoblock inside the machine to generate steam, which is then passed into the milk frothing unit. Foamed milk is commonly used in dairy recipes, and cappuccino is one example.

One structure of the milk frothing unit includes an inner milk container and an outer part. When they are connected to each other, a set of passages is formed, including a lifting passage through which milk from the interior of the milk container is drawn into the mixing chamber. In the mixing chamber, milk is mixed with steam, which is supplied to the milk frothing unit from the external inlet. Steam is used for heating and can also be mixed with air for foaming.

This type of milk frothing unit is, for example, described in each of WO2019/129599 and WO 2019/129515.

The design of the milk, steam and air passages and the flow restrictions in these passages determine the functionality of milk frothing.

However, different users may have different preferences, or different types of milk foam may be desired for different types of beverage. More generally, different applications require different mixing characteristics.

It would be desirable to allow the user to control the foaming characteristics, or more generally the mixing characteristics, without the need to have multiple components.

DISCLOSURE OF THE INVENTION

The invention is defined by the claims.

According to the examples, in accordance with one aspect of the invention there is provided a mixing device comprising:

a first, inner, container for containing a first fluid containing liquid;

a second, outer container for receiving the first container;

an external inlet for the second fluid in a stationary position relative to the second container and

passages formed between the first and second containers,

wherein the first container is configured to receive the second container with a selected one of at least two different orientations,

and the passages contain:

when in a first orientation, a first set of passages comprising: a first mixing chamber for mixing at least a first fluid and a second fluid, a first inlet passage that leads from the outer inlet to the first mixing chamber, and a first lift passage that leads from the first container to the first mixing chamber; And

when in a second orientation, a second set of passages comprising: a second mixing chamber for mixing at least the first fluid and the second fluid; a second inlet passage that leads from the outer inlet to the second mixing chamber; and a second lift passage that leads from the first container to the second mixing chamber.

In this mixing device, two possible sets of passages are formed depending on the orientation in which the first container is installed in the second container. Each set of passages provides mixing of the liquid in the first inner container with a fluid (ie, liquid or gas) supplied to the outer inlet of the second container. The liquid rises up the lift passage into the mixing chamber.

By providing different possible sets of passes, different mixing properties can be achieved, for example, for mixing different pairs of fluids, or for mixing the same pair of fluids but in a different ratio, or mixing with various other properties, such as the degree of mixing with air to create foam.

Sets of passages can be used to mix milk and steam. Alternatively, the externally introduced fluid may be water, and the mixing device mixes the first liquid in the container with water, for example, to dilute and heat the first liquid.

Different sets of passages, for example, have different passage sizes and/or different flow restrictions. Flow restrictions, for example, are used to regulate the flow rate through different passages, and they can be adjusted differently in different sets of passages.

The mixing chamber is basically the volume in which fluid and liquid meet before being received as a product from the device.

There may be exactly two sets of passes, but there may be more. For example, the square (top) first, inner container may provide the possibility of forming four different passage designs.

The first container may contain a set of external walls, and:

in a first orientation, a first set of passages is formed between an inner wall of the second container and a first outer wall of the first container; And

in a second orientation, a second set of passages is formed between the same inner wall of the second container and a second outer wall of the first container.

Thus, one wall of the second, outer, container is provided to form both sets of passages, while different walls of the first, inner, container are used to form different sets of passages.

The first container may include a first opening between the interior volume of the first container and the first lift passage and a second opening between the interior volume of the first container and the second lift passage.

Each opening allows fluid to pass into a corresponding lifting passage. By using only one opening, liquid can only reach the lifting passage in use.

A closing member may be provided to cover one of the first and second openings depending on the orientation.

Thus, the lifting passage, which is not in use, is isolated from the contents of the first, inner, container.

The locking device is, for example, provided for fixing the first container to the second container. The locking position provides the necessary interaction between the two containers to form the first or second set of passages in a sealed manner.

In one type of design, the locking device may include a closure element for closing one of the first and second openings depending on the orientation. Thus, closing the opening is an automatic part of the connection between the first and second containers.

In one embodiment, the locking device includes a rotary shaft for moving the first container laterally into the second container and a head for actuating the shaft, the head also being configured to close one of the first and second openings that is located on the open side. The swivel connection allows the side connection of two containers, as well as closing an unused opening.

In an alternative type of construction, the first container includes a first valve for the first opening and a second valve for the second opening, and the second container includes a valve actuator for opening one of the valves such that the other valve functions as a closing member. Thus, in this case, one hole is opened by pressing the valve open, while the other remains closed.

In all examples, the first container may have a first, vertical, axis, and the first and second orientations are at 90 degrees with respect to each other about the first axis. This allows two adjacent sides of the first, inner, container, which may have channels, to be covered by the second container. This further allows the first, inner container to be inserted by means of a lateral sliding fit into the second, outer container.

Alternatively, the first container may have a first, vertical, axis, and the first and second orientations are at an angle of 180 degrees with respect to each other about the first axis. This ensures that sealing of the unused opening leading to the unused lift passage is only necessary in one place.

The second container may have at least one open side such that the first container is received by the second container through a lateral sliding fit through the open side. This is one way to connect two containers together. Alternatively, one of them can be pushed into the other from above.

As mentioned above, the device can be used to mix various fluids, typically for the preparation of beverages. In one example, the first container is configured to contain milk, the outer inlet is configured to contain steam, and at least one of the first and second mixing chambers is configured to mix milk, steam, and air.

The device is, for example, a milk frothing unit for a coffee machine, such as an espresso machine.

The device may further comprise a first air passage leading to the first mixing chamber in a first orientation and a second air passage leading to a second mixing chamber in a second orientation. The air passage is used for foaming in addition to the heating provided by the steam.

The device, for example, is configured to provide different milk frothing characteristics in the first and second orientations. Thus, the user can select the characteristics of the milk foam by selecting the orientation of the first, inner, container relative to the second, outer, container. Different foaming characteristics may, for example, be different temperatures or different percentages of foam.

The device may be configured to provide different milk flow rates through the first and second lift passages. This can be achieved with other passage sizes and/or other flow restriction sizes.

In addition, according to the invention there is provided a coffee machine comprising:

device for producing liquid coffee extract;

device as defined above and

dispensing device configured to dispense:

liquid coffee from a device for obtaining liquid coffee extract and

frothed milk from the mixing device.

BRIEF DESCRIPTION OF THE DRAWINGS

Examples of the present invention will be described in detail below with reference to the accompanying drawings, in which:

in Fig. 1A and 1B show two views of the beverage preparation apparatus;

in Fig. 2A is an exploded view of an exemplary mixing device;

in Fig. 2B shows the mixing device of FIG. 2A assembled;

in Fig. 3A is a detailed view of the channel structure of the mixing device of FIG. 2A;

in Fig. 3B shows the fluid flow passing through the channel structure of FIG. 3A;

in Fig. Figure 4 shows an example of a seal design;

in Fig. 5 schematically shows a known arrangement;

in Fig. 6 is a top view showing a first embodiment according to the present invention;

in Fig. 7 shows the device according to FIG. 6 in the second orientation;

in Fig. 8 is a top view showing a second embodiment in accordance with the present invention;

in Fig. 9 shows a first example of the implementation of closing an unused hole;

in Fig. 10 shows a second example of the implementation of closing an unused hole, as viewed from the first side; And

in Fig. 11 shows the example of FIG. 10, viewed from the other side.

IMPLEMENTATION OF THE INVENTION

According to the invention, there is provided a mixing device comprising inner and outer containers which define passages between each other for mixing fluid. The inner container may be received within the outer container in at least two different orientations. Each orientation creates a different set of passages, each of which includes a mixing chamber and a lift passage that leads from the inner container to the mixing chamber. Different orientations create different passage designs to accommodate different mixing functionalities.

The mixing device can be used to mix any two fluid streams (one of which is liquid from the internal container). Mixing may be for the purpose of heating and/or for the purpose of dilution and/or for the purpose of foaming (or foam formation). It is of primary interest for preparing beverages or liquid foods such as heated milk, tea, soup, hot chocolate, etc.

In one example of particular interest, the mixing device is a milk frothing unit for receiving steam supplied to it by an espresso coffee machine.

In FIG. 1A and 1B show an example of a 10 espresso coffee machine. In FIG. 1A is a perspective view, and FIG. 1B is a front view. This example is a coffee machine with a bean grinding function, although other options are possible.

It contains a main body 12 in which a water tank, a water heater and a tank for receiving coffee beans are located. There is an internal grinding mechanism to produce ground coffee, a brewing chamber or brewing group to receive ground coffee, and a pumping system to pump heated water through the ground coffee.

The coffee machine includes a coffee outlet 14 from which an espresso drink (without milk) comes out. The coffee outlet 14 faces downwards and is located above the drip tray 16. Moreover, in FIG. 1A and 1B show a user interface 18 for receiving user selection signals, such as selection of water and other beverages. At least some of the selected beverages are beverage recipes that include steamed milk and therefore require steam generation. There may also be a steam option that is not part of the beverage selection, for example to provide the user with the ability to prepare heated and/or frothed milk independent of any beverage being prepared by the coffee machine.

The operation of the coffee machine when preparing the espresso coffee drink is completely conventional, and the general operation of the coffee machine is not described further. In addition, the fully functional espresso coffee machine depicted is only one example of the type of coffee machine to which the invention can be applied.

An outlet nozzle 20 is provided for supplying steam to froth milk or hot water depending on the user's selection in the user interface 18. The steam output can be used to heat and/or froth milk, while the hot water only output option gives the user additional options such as making soup, tea, hot chocolate, etc. It should be noted that instead of one nozzle, there may be separate nozzles for steam and hot water (not shown).

An outlet nozzle 20 is located in a docking area 21 for receiving a beverage container or a milk frothing unit.

The invention relates to a mixing device, for example, for preparing foamed milk. This could be, for example, a modification of the mixing device disclosed in WO 2019/129599 and WO 2019/129515, although the invention has a more general applicability.

In FIG. 2A shows the mixing device 100 disclosed in WO 2019/129599 and WO 2019/129515. The mixing device contains: a first, inner, container 110, a second, outer, container 120 configured to receive the first, inner, container, and a seal 130 located between the first and second containers.

The seal is, for example, a seal press-fitted into the side wall of one of two containers such that when the two containers are assembled, the seal is located between them. The interface between the seal and one of the containers forms a closed channel structure that forms fluid paths for milk and steam. By separating the two containers, all parts can be easily cleaned. The seal may be a single seal or may be made of different parts. The seal may be molded into the second container through a two-step molding process, or it may be a separate seal that is removable from a recess in the second container.

The mixing device includes a channel structure 140, which is formed by a seal 130 and a first container 110 when the mixing device is assembled. In the example shown in FIG. 2A, the first container 110 includes a protruding channel portion 145 that further defines a channel structure. The channel structure connects the first opening 150 at the bottom of the first container and the mixing chamber 160 near the top of the first container. In addition, the second container includes an external inlet 175 (see FIG. 2B) connected to a first seal opening 170 formed in the seal 130. A channel structure 140 further connects the first seal opening 170 to the first opening 150 and the mixing chamber 160.

In FIG. 2B shows the mixing device 100 of FIG. 2A in assembled condition.

This drawing clearly shows that the second container 120 further includes an external inlet 175 for receiving steam, for example, from an espresso coffee machine. This steam is then supplied to the first hole 170 of the seal. The second container further includes a third opening 180 which, when assembled, is connected to the mixing chamber 160 of the first container, thereby allowing the contents of the mixing chamber to be conveniently received from the mixing device.

The operation of the mixing device is described with reference to FIG. 3A. In FIG. 3A shows a detailed view 200 of the channel structure 140 of the mixing device of FIG. 2A.

The channel structure 140 may be divided into several sections according to the work performed by each section. During operation, milk may be supplied to the first container 110 and steam may be supplied to the first seal opening 170 (via the outer inlet 175). As steam enters the channel structure 140, milk 215 is drawn from the first container into the milk passage 210 (hereinafter also referred to as the first channel portion or lift passage 210) through the first opening 150. Steam 225 enters the second channel portion 220 through the first seal opening 170 and then passes through the third channel portion 230 and into the mixing chamber 160. The steam flow creates a negative pressure in the first channel portion 210 (i.e., the lift passage), thereby drawing milk through the first channel portion 210.

Milk 215 is drawn along the first channel section 210 until it meets the intersection of the three channel sections, where the steam flow draws the milk and steam into a third channel section 230 ending at an end 235 that opens into a mixing chamber 160. Third channel section 230 may be configured to cause a Venturi effect to be applied to the milk and steam as they pass through the third channel portion.

Steam is used to heat the milk, and it operates the venturi (i.e., reduced pressure) to suck the milk into the first channel portion 210.

Air is introduced at end point 235 by suction due to flow rate. The introduced air creates bubbles for the desired foaming.

The Venturi effect can be achieved by simply limiting the cross-sectional area of the third channel section 230 relative to the first channel section 210 and the second channel section 220. The increase in the speed of milk and steam as they enter the third channel section, in combination with air suction, determines the foaming characteristics of the mixing device, and the pressure difference prevents milk and steam from leaking through the wrong channels.

The first channel portion 210 is generally vertical in use and extends upward from the first (milk inlet) opening 150. In the upper part, on one side it is connected to the second channel section 220, at the distal end of which a steam inlet is located, and on the other hand it is connected to the third channel section 230, at the distal end of which a mixing chamber 160 is located. Thus, in the picture In an embodiment, the channel structure 140 is T-shaped, and the seal 130 is correspondingly T-shaped.

In FIG. 3B shows a simplified view of the intersection of three channel sections.

As described above, milk 215 flows along the first channel section 210 due to the negative pressure created by the steam 225 passing from the second channel section 220 to the third channel section 230. As can be seen from the drawing, the width of the channels decreases as milk and steam enter the third channel section, As a result, the flow of milk and steam is affected by the Venturi effect, which is used to draw milk through the channel.

At the end 235 of the third channel section 230, air suction is provided so that a mixture of milk, steam and air enters the mixing chamber. The purpose of the mixing chamber is to release large bubbles and retain only small air bubbles in the mixture. The mixture of air, milk and steam forms a fluid that enters the mixing chamber.

In FIG. 4 shows the seal 130 of FIG. in more detail. 3A.

The different channel sections are exposed to a variety of different conditions during operation of the mixing device 100. Thus, the design of the channel sections and the seal affects the milk frothing function. This design includes the width, cross-sectional area and length of the channel sections, as well as any flow restrictions along the channel sections. In particular, the speed of liquid (milk, steam and air) entering the mixing chamber affects the characteristics of the foam.

A device for frothing milk to the degree described above is known. The invention provides a design that allows the user to select milk frothing characteristics or, more generally, different mixing characteristics or functions (since the invention is not limited to a milk frothing device).

In FIG. 5 is a schematic top view of the above-described apparatus showing a first inner container 110 and a second outer container 120, as well as first, second and third openings 150, 175, 180, and a mixing chamber 160. The first container is configured to receive the first a fluid, in particular a liquid, which in this example is milk.

The first opening 150 will be referred to as the "opening" which leads to the first channel portion 210. This first channel portion will be referred to as the "lift passage." The second channel portion 220 will be referred to as the "inlet channel." The outer inlet 175 is configured to receive the second fluid in a fixed position relative to the second container 120.

In accordance with the invention, the first, inner, container 110 can be placed in the second, outer, container 120 in at least two different orientations. Each orientation creates a different set of passages, each including its own mixing chamber and lift passage.

In FIG. 6 shows a first example of a device in accordance with the present invention.

The first internal container 110 is schematically shown to be square (as viewed from above) so that it can be rotated about a vertical axis into different orientations. For an example with two possible orientations, the two containers are preferably designed such that they only fit together in those two orientations.

The second, outer, container 120 has only one set of channel sections, while the first, inner, container has channel sections on two of its surfaces.

Thus, a first set of passages may be formed comprising a first opening 150, a first lift passage (not shown in the plan view), a first inlet passage, and a first mixing chamber 160 when in a first orientation. There is also a second set of passages that may be formed in a second orientation comprising a second opening 150a, a second lift passage (not shown in the plan view), a second inlet passage, and a second mixing chamber 160a when in the second orientation.

In FIG. 6 shows the device in a first orientation, and FIG. 7 shows the device in a second orientation in which the first, internal, container 110 is rotated 90 degrees.

The opening (150 or 150a) that is not in use must be covered to prevent the contents of the first container from leaking. In FIG. 6 shows schematically the first and second closure elements 600, 602. One of them is used to close one of the first and second openings that is not in use. Thus, the unused lift passage is isolated from the contents of the first, inner, container 110. There are various methods for implementing closure of the unused opening, as discussed in more detail below.

In this mixing device, two possible sets of passages are formed, depending on the orientation in which the first container 110 is installed in the second container 120. Each set of passages provides mixing of the liquid in the first, internal, fluid reservoir supplied to the outer inlet 175. Various sets of passages may be designed to mix different pairs of fluids. For example, one set of passages may be configured to mix milk from the first container with steam supplied to an external inlet of the second container for heating. The use of steam limits the dilution of the milk. Another set of passages may be designed to supply hot water to the external inlet for heating and dilution, thereby creating another pair of fluids. Alternatively, cold water may be introduced into the external inlet 175 simply for dilution.

Different sets of passages, for example, have different passage sizes and/or different flow restrictions.

In FIG. 6 and 7 show an example in which the first container 110 has a first vertical axis and the first and second orientations are at 90 degrees relative to each other about the first axis. This allows two adjacent sides of the first inner container that have channels to be covered by a second container by creating a second container substantially enclosing three sides of the first inner container (not shown). This hides the visible channel portions of the first container 110.

In FIG. 8 shows an example in which the first container also has a first, vertical, axis, and the first and second orientations are at an angle of 180 degrees with respect to each other about the first axis. This ensures that sealing of the unused opening leading to the unused lift passage is only necessary in one place. Thus, one closure element 800 is shown in FIG. 8.

The first container and the second container are fixed together to ensure proper formation of passages. The locking position provides the necessary interaction between the two containers to form the first or second set of passages in a sealed manner.

In FIG. Figure 9 shows the first example of the implementation of closing an unused hole.

The first, inner container 110 contains a first valve 900 for a first opening and a second valve 902 for a second opening. They are normally closed. The second container 120 includes a valve actuator 904 for opening one of the valves when the two containers are connected to each other while the other valve remains closed. This example is shown based on a 180 degree rotation, but the same design can be used with any rotation angle.

Thus, fixing the two containers together provides the function of opening the valve.

In FIG. 10 shows a second example of the implementation of closing an unused hole. In this case, fixing the two containers together provides the function of closing an unused hole.

The locking device in this example includes a rotary shaft 1000 for moving the first container laterally into the second container. The shaft is part of the second container and has a thread 1002 that engages a static thread 1004 of the first container. Thus, the rotation of the shaft brings the two containers closer together in the lateral direction. The shaft 1000 has a head 1006 for driving the shaft, and the head carries a seal 1008 for closing one of the first and second holes, which is located on the open side. The swivel connection allows the side connection of two containers, as well as closing an unused opening.

In FIG. 11 shows the example of FIG. 10, when viewed from the side of the first container, on which unused channels are located. Thus, a second set of passages can be seen comprising a second mixing chamber 160a, a second inlet passage 220a, and a second lift passage 210a. However, these passages are not closed, since they are not associated with the surface of the second container.

In the above examples, the second container 120 has at least one open side such that the first container is received by the second container through a lateral sliding fit through the open side. However, this is only one way to connect two containers together. Alternatively, one of them can be pushed into the other from above.

As will be clear from the above discussion, the milk frothing device also includes an air passage. If foaming is implemented in both orientations, there is a first air passage leading to the first mixing chamber in the first orientation, and a second air passage leading to the second mixing chamber in the second orientation.

However, other mixing functions may not require an air passage. For example, the first orientation may be for mixing the first and second fluids and air, while the second orientation may be only for mixing the first and second fluids.

When two (or more) different frothing functions are provided, differences can be achieved with different passage sizes and/or different flow restriction sizes in any one or more of the milk, steam and air passages.

Other variations of the described embodiments can be understood and implemented by one skilled in the art in putting the claimed invention into practice after reading the drawings, description and appended claims. In the claims, the word “comprising” does not exclude other elements or steps, and the grammatical means of expressing the singular do not exclude the presence of the plural. The mere fact that certain measures are set out in different dependent claims does not mean that a combination of these measures cannot be used to advantage. No item numbers in the claims should be construed as limiting the scope of the invention.

Claims (32)

1. Mixing device containing: a first, inner, container (110) for containing a first fluid containing liquid; a second, outer container (120) for receiving the first container; an external inlet (175) for the second fluid in a stationary position relative to the second container and passages formed between the first and second containers, wherein the first container is configured to receive the second container with a selected one of at least two different orientations, and the passages contain: when in a first orientation, a first set of passages comprising: a first mixing chamber (160) for mixing at least a first fluid and a second fluid, a first inlet passage (220) that leads from an outer inlet (175) to the first mixing chamber chamber, and a first lift passage (210) that leads from the first container to the first mixing chamber; And when in a second orientation, a second set of passages comprising: a second mixing chamber (160a) for mixing at least the first fluid and the second fluid; a second inlet (220a) that leads from the outer inlet (175) to the second mixing chamber; and a second lift passage (210a) that leads from the first container to the second mixing chamber. 2. The device according to claim 1, in which the first container contains a set of external walls, and: in a first orientation, a first set of passages is formed between an inner wall of the second container and a first outer wall of the first container; And in a second orientation, a second set of passages is formed between the same inner wall of the second container and a second outer wall of the first container. 3. The device according to claim 1 or 2, in which the first container (110) contains a first opening (150) between the internal volume of the first container and the first lifting passage (210) and a second opening (150a) between the internal volume of the first container and the second lifting passage (210a). 4. The device according to claim 3, containing a closing element (600, 602, 800) for closing one of the first and second holes (150, 150a) depending on the orientation. 5. Device according to any one of paragraphs. 1-4, comprising a locking device for fixing the first container to the second container. 6. The device of claim 5, wherein the locking device comprises a closure element for closing one of the first and second openings depending on the orientation. 7. Device according to any one of paragraphs. 4-6, wherein the first container includes a first valve (900) for the first opening and a second valve (902) for the second opening, and the second container includes a valve actuator (904) for opening one of the first and second valves such that the other valve functions as a closing element. 8. Device according to any one of paragraphs. 1-7, in which the first container has a first, vertical, axis, and the first and second orientations are at an angle of 90 degrees with respect to each other about the first axis. 9. Device according to any one of paragraphs. 1-8, in which the first container has a first, vertical, axis, and the first and second orientations are at an angle of 180 degrees with respect to each other about the first axis. 10. Device according to any one of paragraphs. 1-9, wherein the second container has at least one open side such that the first container is received by the second container through a lateral sliding fit through the open side. 11. Device according to any one of paragraphs. 1-10, in which: the first container (110) is designed to contain milk, and the outer inlet (175) is intended to contain steam; And at least one of the first and second mixing chambers (160) is designed for mixing milk, steam and air. 12. Device according to any one of paragraphs. 1-11, comprising a first air passage leading to a first mixing chamber in a first orientation, and a second air passage leading to a second mixing chamber in a second orientation. 13. Device according to any one of paragraphs. 1-12, the device being configured to provide different milk frothing characteristics in the first and second orientations. 14. Device according to any one of paragraphs. 1-13, the device being configured to provide different flow rates of milk through the first and second lifting passages (160, 160a). 15. A coffee machine comprising: device for producing liquid coffee extract; device according to any one of paragraphs. 1-14 and dispensing device configured to dispense: liquid coffee from a device for obtaining liquid coffee extract and frothed milk from the mixing device.