Milk frother having an aerator

Abstract

The invention relates to a milk frother (2) comprising: - a milk channel (4) for guiding milk (10) in a milk flow direction (13) from a milk container (6) towards a milk outlet (8), and - a frothing portion (16) for converting the milk (10) in the milk channel (4) into a milk froth (12) containing air (20), characterised by - an aerator (54) which is inserted into the milk outlet (8) and has, when viewed in the milk flow direction (13), a milk inlet side (96) and a milk outlet side (98) which is opposite the milk inlet side (96), wherein the aerator (54) comprises a diffuser (58) having a plurality of through-openings (82) which are designed to dispense the milk froth entering at the milk inlet side (96) at the milk outlet side (98) into a plurality of partial milk froth flows in a separated manner.

Description

[0001] Milk frother with flow regulator

[0002] Description

[0003] The present invention relates to a milk frother according to the preamble of claim 1.

[0004] Such a milk frother is known from DE 10 2010 023 781 B2. Furthermore, a beverage dispensing device is known from EP 3 050 470 Al in which a throttling element in the form of a multi-hole orifice is provided in the outlet area, which serves to slow down the flow of the beverage liquid in order to prevent splashing when dispensing the beverage.

[0005] The purpose of the invention is to improve the known milk frother.

[0006] The problem is solved by the features of the independent claims. Preferred further developments are the subject of the dependent claims.

[0007] Starting from a known milk frother with a milk channel for guiding milk in a milk flow direction from a milk container towards a milk outlet and a frothing section for converting the milk in the milk channel into an air-containing milk foam, the specified milk frother according to the invention comprises a jet regulator inserted into the milk outlet with a milk inlet side viewed in the milk flow direction and a milk outlet side opposite the milk inlet side, wherein the jet regulator has a diffuser with several through-openings which are arranged to discharge the milk foam entering at the milk inlet side separately into several partial flows of milk foam at the milk outlet side.

[0008] The milk frother described here is based on the principle that the milk foam should have the most homogeneous bubble pattern possible. This is traditionally achieved using a filter disc, which creates the homogeneous bubble pattern with its eroded and irregularly distributed pore structure. However, the filter disc becomes clogged relatively quickly, especially when using milk substitutes containing some very coarse ingredients. Because of these ingredients, the filter disc must be replaced frequently.

[0009] The present invention addresses this issue by using aerators with diffusers instead of filter discs in milk frothers. A diffuser is understood to be a flow element with reactive behavior, designed to guide, not disrupt, the flow. This is achieved through design features that convert, rather than dissipate, energy. In contrast, restrictors act dissipatively because they interrupt or constrict the flow. Their design generates friction, turbulence, and shock losses, resulting in irreversible energy loss. A diffuser is therefore a component for dispersing or distributing a liquid or gas flow, not for slowing it down. This is achieved by the openings, which homogenize the bubble pattern by equalizing the pressure, velocity, flow rate, and air mixing, thus achieving the same effect as filter discs.Unlike filter discs, aerators can also transport larger ingredients, so that the bubble-homogenizing effect can be achieved even without a timely blockage of the components involved in the milk frother.

[0010] In a further development of the specified milk frother, the through-holes are arranged concentrically around the center of the diffuser. This allows for pressure equalization within the milk channel, thus preventing uneven pressure distribution.

[0011] In a further development of the specified milk frother, the center of the diffuser is designed as a baffle plate. This allows for controlled pressure build-up via the diffuser, which has a positive effect on a homogeneous bubble pattern.

[0012] In another further development of the specified milk frother, the aerator includes a sieve adjoining the diffuser in the direction of milk flow, with which the bubble pattern can be further homogenized.

[0013] In a further development of the specified milk frother, the aerator includes a sieve adjoining the diffuser in the direction of milk flow, with which the bubble pattern can be further homogenized.

[0014] In a preferred further development of the specified milk frother, the aerator includes a further sieve adjoining the sieve in the direction of milk flow, which further increases the homogenization of the bubble pattern.

[0015] In a particular refinement of the specified milk frother, one sieve has a different mesh size, preferably larger than the mesh size of the other sieve. In this way, the bubbles in the milk foam are continuously reduced in size, much like with a funnel, resulting in particularly effective homogenization of the bubble pattern.

[0016] In a further development of the milk frother described above, the aerator has an inlet housing with an inlet side facing in the direction of milk flow and an outlet side opposite the inlet side, in which the diffuser is held. This allows the components of the aerator to be easily disassembled and thus serviced.

[0017] In a further development of the specified milk frother, the inlet housing has flow openings on its outlet side, onto which components, such as the aforementioned sieves, can be easily placed and held without blocking the milk flow.

[0018] In a further development of the specified milk frother, the aerator, viewed in the direction of milk flow, has a pre-filter sieve in front of the diffuser, with which very coarse impurities such as hairs or the like can be filtered out.

[0019] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawings. The drawings show:

[0020] Fig. 1 a perspective view of a milk frother with a milk outlet head,

[0021] Fig. 2 is a perspective view of a lower housing shell of the milk outlet head of Fig. 1, Fig. 3 is a perspective view of an upper housing shell of the milk outlet head of Fig. 1,

[0022] Fig. 4 shows an exploded view of a flow regulator that can be inserted into the milk outlet head of Figs. 2 and 3, and

[0023] Fig. 5 shows a sectional view of a diffuser of the aerator of Fig. 4.

[0024] The figures use identical technical elements with the same reference symbols and describe them only once. The figures are purely schematic and, above all, do not represent the actual geometric relationships.

[0025] Reference is made to Fig. 1, which shows a milk frother 2 in a perspective view. The individual elements inside the milk frother 2 are only structurally indicated.

[0026] The milk frother 2 comprises a milk channel 4 extending through a housing 3, from a milk intake hose 6 to an outlet opening 7 of a milk outlet head 8. During operation of the milk frother 2, when a control button 9 on the housing 3 of the milk frother 2 is pressed, milk 10 is drawn from a milk container (not shown) into the milk channel 4 via the milk intake hose 6, processed into milk foam 12, and transported in a milk flow direction 13 to the outlet opening 7 of the milk outlet head 8 for dispensing.

[0027] To produce the milk foam 12, a pump 14 draws in the milk 10 in a frothing section 16. The milk 10 is enriched with air 20 via a Venturi nozzle 18 located upstream of the pump 14, so that milk 22 permeated with air 20 enters the pump 14 and is mixed there. This is how the milk foam 12 is essentially created. In a subsequent tempering element 24, the milk foam 12 is then further processed and, for example, heated, which causes the air bubbles in the milk foam 12 to expand and stabilize the milk foam 12.

[0028] Further details about the milk frother 2 can be found in the

[0029] DE 10 2010 023 781 B2 can be taken from this document.

[0030] The milk outlet head 8 has a lower housing shell 26 and an upper housing shell 28. A milk channel 30 for the milk foam 12 leads into the upper housing shell 28. Furthermore, the upper housing shell 28 is fixed to the housing 3 by a retaining strut 32. The milk foam 12 can be dispensed into a cup or the like via the outlet opening 7, which is not visible in Fig. 1 but is indicated by a reference numeral.

[0031] The interior space 36 of the milk outlet head 8, enclosed by the two housing shells 26, 28, is explained in more detail below with reference to Figs. 2 to 4.

[0032] The milk foam 12 is fed into the interior 36 via the milk channel 30 and filtered by means of a flow regulator 38 located therein, which is described in more detail in Fig. 4. The interior 36 is formed by a first half-space 40 in the lower housing shell 26 and a second half-space 42 in the upper housing shell 28. An internal thread 44 is formed on a lateral wall of the first half-space 40, into which an external thread 46 can be screwed. This external thread is formed on a lateral surface of a hollow cylinder on the upper housing shell 28. Furthermore, a receiving opening 47 for the retaining strut 32 is formed on the upper housing shell 28.

[0033] The hollow cylinder has a shoulder 48, at the radial end of which a cylinder wall 50 extends axially. A sealing ring 52 can be placed on this shoulder 48. Radially within the shoulder 48, the milk channel 30 enters the second half-space 40 of the interior 36. If the filter element 38 is placed on the shoulder 48, as shown in Fig. 4, the interior 36 is divided between the first half-space 40 and the second half-space 42. The milk foam 12 entering the second half-space 42 passes through the aerator 38, which homogenizes the bubble pattern of the milk foam and, if necessary, filters out dirt particles such as small hairs.

[0034] In Fig. 4, the aerator 38 is shown in an exploded view, which, seen in the milk flow direction 13, consists of a pre-filter 54, a flow regulator 56, a diffuser 58, a first sieve 60, a second sieve 62 and an inlet housing 64.

[0035] The pre-filter 54 is designed as a circular injection-molded part with a limiting ring 66 on its outer circumferential side. The limiting ring 66 holds struts 68 on its inner side, which are meshed together to form a net and are shaped into a cone opposite to the direction of milk flow 13. For the sake of clarity, not all of the struts 68 are labeled with their own reference numerals in Fig. 4. The net thus formed filters coarse particles, such as small hairs or glass shards, from the milk foam flowing in the direction of milk flow 13.

[0036] The flow regulator 56, which is inserted into the diffuser 58, is connected to the pre-filter 54 in the milk flow direction 13. The flow regulator 56 has a circular plate 70 as its base body, into which a circular flow regulator groove 72 is formed in the milk flow direction 13. Openings lead from this flow regulator groove 72, though not visible, through which the milk foam can pass through the flow regulator 56 in the milk flow direction 13. During operation, a rubber ring, also not visible, is inserted into the flow regulator groove 72. This ring influences and thus adjusts the flow rate of the milk foam through the flow regulator 56 depending on the pressure of the milk foam in the milk flow direction 13. The diffuser 58, into which the flow regulator 56 is inserted in the milk flow direction 13, is illustrated in a sectional view in Fig. 5 for a clearer illustration.

[0037] It is circular in shape and has a baffle plate 74 at its center. On the radial outer side of this baffle plate, opposite to the direction of milk flow 13, wall sections 78 extend. These sections are arranged circumferentially to form small slits through which the milk foam can pass radially. For clarity, not all of these wall sections 78 are labelled in Fig. 5. Adjoining the baffle plate 74 is a diffuser groove 80, which extends circumferentially around the baffle plate 74 and in the direction of milk flow 13. Through-openings 82 are formed on the radial outer side of this diffuser groove. Again, for clarity, not all of these through-openings 82 are labelled in Fig. 5. These through-openings 82 will be discussed in more detail later. A radial shoulder 84 adjoins the diffuser groove 80, into which the through-openings 82 extend radially.On the radial shoulder 84, a circumferential outer wall 86 is supported by a bearing shoulder 88, into which the quantity regulator 56 can be inserted in the milk flow direction 13.

[0038] Viewed in the direction of milk flow 13, the diffuser 58 is followed by the first sieve 60 with a first mesh size 90 and the second sieve 62 with a second mesh size 92, the first mesh size 90 being larger than the second mesh size 92.

[0039] All the aforementioned components are placed in the inlet housing 64, which has flow openings 94 at its base to allow the components to be supported while simultaneously permitting the milk foam to pass through. For clarity, not all of these flow openings 94 are labeled with a separate reference symbol. During operation, the milk foam enters from a milk inlet side 96, passes through the pre-filter 54 and the flow regulator 56, enters the diffuser 58, and then passes through the through-openings 82. These separate the incoming milk foam into several partial flows.

[0040] The milk foam is then dispensed via a milk outlet side 98 through flow openings 94 and, for example, released into a cup.

Claims

Patent claims 1. Milk frother (2) comprising a milk channel (4) for guiding milk (10) in a milk flow direction (13) from a milk container (6) towards a milk outlet (8), and a foaming section (16) for converting the milk (10) in the milk channel (4) into an air (20) containing milk foam (12), characterized by a flow regulator (54) inserted into the milk outlet (8) with a milk inlet side (96) seen in the direction of milk flow (13) and a milk outlet side (98) opposite the milk inlet side (96), wherein the flow regulator (54) has a diffuser (58) with several through-openings (82) which are arranged to discharge the milk foam entering at the milk inlet side (96) separately into several partial flows of milk foam at the milk outlet side (98).

2. Milk frother (2) according to claim 1, wherein the through-openings (82) are arranged concentrically around a center of the diffuser (58).

3. Milk frother (2) according to claim 2, wherein the center of the diffuser is designed as a baffle plate (74).

4. Milk frother (2) according to one of claims 1 to 3, wherein the aerator (54) comprises a sieve (60) adjoining the diffuser (58) as seen in the direction of milk flow (13).

5. Milk frother (2) according to claim 4, wherein the aerator (54) comprises a further sieve (62) adjoining the sieve (60) as seen in the direction of milk flow (13).

6. Milk frother (2) according to claim 5, wherein a mesh size (90) of the sieve (60) is different, in particular larger than a mesh size (92) of the further sieve (62).

7. Milk frother (2) according to one of the preceding claims, wherein the aerator (54) has an inlet housing (64) with an inlet side viewed in the direction of milk flow (13) at the inlet and an outlet side opposite the inlet side at the outlet, in which the diffuser (58) is held.

8. Milk frother (2) according to claim 7, wherein the inlet housing (64) has flow openings (94) on its outlet side.

9. Milk frother (2) according to one of the preceding claims, wherein the aerator (54) has a pre-filter sieve (96) in front of the diffuser (58) as seen in the direction of milk flow (13).

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