Plug-in element and milk frothing device

Abstract

Plug element (1) of a line coupling for guiding a gaseous and / or liquid medium (2), with a guide element (27) comprising a guide channel (3) which guides the medium (2) from a channel inlet (4) to a channel outlet (5), with a sealing element (6) arranged circumferentially on an outer circumference of the guide element (27), with a deflection plate (7) which is arranged on the guide element (27) at a distance from the channel outlet (5) substantially perpendicular to the flow direction of the medium (2), with radial recesses (8-1 to 8-n) on the circumference of the deflection plate (7), and with webs (28-1 to 28-n) which project radially from the cover plate (7) between the individual recesses (8-1 to 8-n).

Description

[0001] The invention relates to a plug-in element of a line coupling for guiding a gaseous and / or liquid medium and a milk frothing device incorporating such a plug-in element. The plug-in element and / or the milk frothing device can be used, in particular, with a hot beverage preparation device with which hot beverages or hot liquid foods, such as coffee, tea, hot milk, cocoa drinks, or even soups, can be prepared. Hereinafter, the terms "hot beverage preparation device," "fully automatic coffee machine," and "preparation device" are used synonymously, so that one of these terms always includes the other and they are therefore interchangeable.

[0002] From EP 2 164 371 A1, a plug-in element with a cover for a hose coupling is known, in which an opening is provided in the wall of a steam channel of the plug-in element and a drain element blocks the steam channel in the area of ​​the opening. The steam thus flows outside the steam channel between the drain element and the cover, whereby limescale particles are retained by the drain element. In addition, from DE 10 2011 081 018 B3, a filter plug for hose lines is known, comprising a filtering hollow body with perforations and wedges for precise insertion into a hose line.

[0003] The object of the present invention is to provide an alternative plug-in element which effectively prevents the escape of lime granules.

[0004] This problem is solved according to the invention by a plug-in element, in particular a male plug-in element, a line coupling with the features of independent claim 1, and a milk frothing device with the features of independent claim 11. The plug-in element serves to guide a gaseous and / or liquid medium and has a guide element with a guide channel that directs the medium from a channel inlet to a channel outlet. The medium can, in particular, be water, steam, or a mixture of water, steam, and air. For the sake of simplicity, only steam or water vapor will be referred to in the following. A sealing element is arranged circumferentially on an outer circumference of the guide channel to seal the plug-in element against a cover slid over the guide element. An O-ring or a shaft seal can, for example, serve as the sealing element.Finally, a deflection plate is provided on the guide element, which is arranged at the channel outlet at a distance from it essentially perpendicular to the flow direction of the medium and which has radial recesses on its circumference.

[0005] The plug-in element can be used together with a corresponding cover in a milk frothing device according to the invention. The cover is detachably coupled to the plug-in element and has a nozzle through which the medium ejected from the channel outlet is directed. The guide element is typically arranged in a housing wall of the coffee machine, so that the guide channel usually protrudes horizontally from the housing. A steam source in the coffee machine generates the steam and directs it to the plug-in element.

[0006] Since the cover is detachably connected to the plug-in element, meaning it can be removed for cleaning, for example, uncontrolled escape of steam from the duct outlet must be prevented to protect the area around the coffee machine. According to the invention, such uncontrolled escape of steam is prevented by the deflector plate, which is attached to the duct outlet essentially perpendicular to the direction of steam flow. "Essentially perpendicular" here means any angle that sufficiently deflects the steam so that, for example, a person standing in front of the coffee machine is not directly exposed to the steam. The deflector plate thus protects people standing directly in front of the coffee machine from the escaping hot steam.

[0007] When the cover is attached to the plug-in element, the milk frothing device can produce milk foam using steam in a known manner. The steam is guided through the channel into the cover, where it exits through the nozzle. The steam can carry limescale deposits, such as limescale grains, which can clog the nozzle if they enter the cover. Therefore, the entry of limescale grains into the nozzle must be prevented. According to the invention, recesses are provided on the circumference of the deflector plate for this purpose. These recesses are spaced apart by ribs and allow the steam to pass through. The ribs, which project radially from the cover plate between the individual recesses, act similarly to a sieve or the tines of a comb and retain larger limescale grains. This is because the recesses are smaller than the nozzle outlet opening and also smaller than the diameter of the channel.Limescale particles that pass through the recesses are smaller than the nozzle's outlet opening. Larger particles, however, are retained by the comb-like ridges. This prevents limescale particles that reach the nozzle through the recesses from clogging it, instead ejecting them through the nozzle. This effectively prevents the nozzle from becoming clogged.

[0008] The limescale particles that collect behind the cover plate or in the recesses can then be removed when cleaning the coffee machine. For example, the cover can be removed and the plug-in element cleaned of the limescale particles.

[0009] With the arrangement described above, the steam can pass through the recesses between the ribs. The recesses thus increase the surface area through which the steam can flow, reducing the risk of all recesses becoming clogged and consequently the risk of the plug-in element becoming blocked by retained limescale. Even a larger quantity of limescale particles can be effectively retained in this way without causing the milk frother to fail.

[0010] Further, particularly advantageous embodiments and developments of the invention result from the dependent claims and the following description, whereby the features of different embodiments can be combined to form new embodiments.

[0011] In an advantageous embodiment, radially open recesses can be arranged at regular intervals around the entire circumference of the deflector plate. If they are provided around the entire circumference of the deflector plate, and not just, for example, in the lower region, the area over which the steam can pass through the deflector plate is increased. This allows for an even larger retention space for limescale particles, so that the hot beverage preparation device, and in particular its milk frother, can be operated reliably and without failure over extended periods.

[0012] In a further advantageous embodiment, the diameter of the deflection plate, where the recesses project furthest radially into the deflection plate, can be at least equal to the diameter of the channel outlet. The water vapor is thus completely deflected by the deflection plate and reliably redirected as it exits the channel outlet. This ensures that no water vapor can escape directly linearly from the channel outlet, i.e., in the axial direction of the guide channel.

[0013] The radially projecting ribs define the outer circumference of the deflection plate. In principle, the ribs can rest against the inside of the attached cover and support it. In a further advantageous embodiment, the outer circumference of the deflection plate, or the radial extension of some or all of the ribs, can correspond at least to the outer circumference of the guide element in the area of ​​the channel outlet. The cover, which can be fitted onto the guide element and the deflection plate as a female plug-in element, typically has an inner diameter that corresponds to the outer diameter of the guide element plus the dimensions of the compressed sealing device when the cover is in place. If the circumference of the deflection plate is adapted to the circumference of the guide element, a gap is created between a cylindrical cover and the outer circumference of the deflection plate at each rib, which also has the dimensions of the compressed seal.The gap is typically smaller than the nozzle. This provides additional cross-sectional areas for steam to pass through at some or all of the ribs.

[0014] At least three ribs are required if they also serve to reliably support the cover radially on the guide element. Alternatively, a suitably dimensioned annular gap can extend between them. According to a further advantageous embodiment of the invention, the deflector plate, or at least the ribs, can be made of a harder or softer material than the cover and be manufactured with a certain oversize. At least when the cover is first placed on the guide element, the softer material, for example, of the cover, rubs against the harder material, for example, of the deflector plate, thereby centering the cover relative to the deflector plate. This centering is maintained even during subsequent actuations because the cover is always placed on the plug-in element in the same manner and position.This further simplifies the dimensioning of the cross-sectional area for the steam.

[0015] According to a further advantageous embodiment, the material of the deflection plate, or at least its webs that support the cover, or the cover itself, can be made of an elastic material, and the supporting webs can, in turn, be manufactured with a certain excess. Due to the elastic compliance of the cover, for example, it can be fitted tightly and centrally onto the webs without the need to manufacture the webs with a tight tolerance to a specific remaining dimension for an annular gap between the deflection plate and the cover. This also simplifies the manufacture of the plug-in element.

[0016] In a further advantageous embodiment, the plug-in element can have a number of connecting webs that connect the guide element to the deflection plate. In particular, the connecting webs can be designed as axially parallel extensions of the guide element in the direction of the deflection plate. With the cover in place, the water vapor flowing axially from the channel outlet thus has radial passages between the connecting webs, allowing it to flow through the recesses in an axially parallel direction.

[0017] In a further advantageous embodiment, the plug-in element can have a single cylindrical connecting web with a smaller outer radius than the outer radius of the guide channel and with at least one radial opening. When the cover is in place, the smaller outer radius creates an annular space between the outer surface of the cylindrical connecting web and the inner surface of the cover. The size of the radial opening corresponds at least to the cross-sectional area of ​​the guide channel to avoid creating a fluidic constriction. The radial opening of the connecting web allows water vapor to escape from the space between the guide element and the deflection plate. The arrangement of the radial opening thus determines the direction of deflection for the water vapor when the cover is removed. In an axial section, the connecting web can, for example, be U-shaped.The radial opening is formed between the free ends of its parallel U-shaped legs. Consequently, water vapor from the guide channel is not vented in all radial directions under the cover plate—as would be the case with a multitude of individual connecting bridges—but rather deflected in only one direction through the radial opening. When the cover is attached to the guide element, limescale grains and other particles initially collect there. If they block the nearest recesses, the water vapor can flow through the annular space and along the outside of the cylindrical connecting bridge to the remaining exposed recesses in the deflection plate and be directed to the nozzle. If the radial opening is directed downwards, the limescale grains or other particles fall out of the space between the guide element and the deflection plate by gravity as soon as the cover is removed.Therefore, extensive cleaning of the guide element is unnecessary. Furthermore, the plug-in element with the cylindrical connecting bridge according to the invention is easier to manufacture than with a plurality of individual connecting bridges.

[0018] The principle of the invention is explained in more detail below with reference to the accompanying figures. The different figures show identical components with identical reference numerals. They show: Fig. 1: a sectional view of an embodiment of the plug-in element according to the invention, Fig. 2: a schematic representation of the plug-in element of the Fig. 1, and Fig. 3: a sectional view of an embodiment of the milk frothing device according to the invention.

[0019] The plug-in element 1 according to the invention Fig. The guide element 1 is shown in a sectional view along its longitudinal axis 13. It essentially consists of a guide element 27, which contains a centrally extending guide channel 3 and represents a largely rotationally symmetric body. The guide element 27 extends from a channel inlet 4 to a channel outlet 5. While the guide channel 3 runs straight inside the guide element 27 with a constant diameter, the outer contour of the guide element 27 has regions 16 to 22 with different radii. Regions 16 and 17 have different and increasing radii and are recessed into a coffee machine housing when the plug-in element 1 is mounted from the outside. A contact surface 15, which acts as a stop for the plug-in element 1 against the housing, forms the transition between the second region 17 and the third region 18, which has the largest radius of all regions 16 to 22.From the third area 18 onwards, the radii of the areas decrease until they reach an area 21, which adjoins a larger diameter area 22. Area 21 thus forms a recess in the outer wall of the guide element 27, in which an O-ring 6 (see figure) is placed. Fig. 3) can be arranged as a sealing element. The radius of the area 21 plus the diameter of the O-ring 6 is dimensioned such that the O-ring 6 is compressed with sufficient force when a cover 11 (see figure) is placed. Fig. 3) is pushed onto the plug-in element 1.

[0020] A connecting web 9 adjoins the end face of the guide element 27 on its side facing the channel outlet 5, connecting the guide element 27 to the cover plate 7. In an axially parallel sectional view, the inner contour of the connecting web 9 has a downward-facing U-shape. The opening 25 of the U-shape also points downwards in the installed position of the plug-in element 1. The connecting web 9 therefore consists of two parallel, straight U-shaped legs or sections 23, which are connected to each other by a semicircular arc segment 24. The opening 25 of the connecting web 9, or the distance between the two sections 23, is larger than the opening of the guide channel 3 through which the steam 2 is guided. Simultaneously, the outer contour of the connecting web 9 is recessed from the outer contour of the area 22.The distance of both the outer contour of the semicircular arc segment 24 and the distance of the downward-pointing ends of the sections 23 from the central axis 13 is therefore less than the radius of the area 22.

[0021] Held by the connecting web 9, a crown-cap-shaped deflecting plate 7 is attached to it. In axial view, it is disc-shaped and has approximately the radius of the area 22. Radial arc-segment-shaped recesses 8-1 to 8-n are cut into its circumference at regular intervals. Recesses in a lower region of the circumference are marked 8-m. The size or diameter of the recesses 8-1 to 8-n is significantly smaller than the diameter of the guide channel 3. In particular, the diameter of the recesses 8-1 to 8-n is smaller than an outlet opening of a nozzle 12, which is mounted in the cover 11 (see Fig. 3).

[0022] In Fig. 2 is the solid body of the plug-in element 1 of the Fig. Figure 1 is shown in an isometric view. For clarity, only areas 18 and 22 are labeled. The recesses 8-1 to 8-n are distributed regularly around the circumference of the deflection plate 7 and are separated by webs 28-1 to 28-n. The width of the webs 28-1 to 28-n is less than the diameter of the recesses 8-1 to 8-n. Three webs 28-a, 28-b, 28-c are slightly longer in the radial direction than the adjacent webs 28-1 to 28-n and maintain the cover 11 at a uniform distance from them. The outer contour of the connecting web 9, in contrast to its inner contour, is round or circular segment-shaped and, as already explained, is recessed from the outer contour of area 22 or the deflection plate 7.

[0023] When the plug-in element 1 is inserted into a coffee machine, hot steam 2 flows through the guide channel 3 during operation (see. Fig. 3) If the cover 11 is not placed on the plug-in element 1, the deflector plate 7 ensures that the water vapor 2 does not exit the coffee machine or the guide channel 3 linearly, i.e., forwards. Since the connecting bridge 9 only has an opening 25 on its underside, it forms a guide element for the water vapor 2 together with the deflector plate 7, directing it downwards.

[0024] In Fig. Figure 3 is a milk frothing device 10, shown in a highly schematic representation and also in a sectional view perpendicular to the longitudinal axis 13 of the guide channel 3. It consists of the male connector 1 and the female cover 11. The cover 11 is placed on the guide element 27 and has a nozzle 12 at its lower end, which points away from the guide element 27. When the cover 11 is in place, at least the webs 28 and the O-ring 6 are in contact with its inner surface. Between these, i.e., between the area 22 and the cover plate 7, an annular space 29 is formed in the area of ​​the connecting web 9. This space is in fluidic communication with the cover 11 via the recesses 8-1 to 8-n and with the guide channel 3 via the opening 25. As explained above, the nozzle 12 can produce milk foam using the steam 2 in a manner known per se.The steam 2 is guided through the guide channel 3 into the cover 11, where it exits through the nozzle 12. In addition to water and steam, the steam 2 may also contain lime particles 26. If lime particles 26 larger than the nozzle 12 enter the cover 11, it can become clogged.

[0025] As in Fig.As can be seen in Figure 3, the deflector plate 7 retains the limestone granules 26, while the water vapor 2 can pass through the recesses 8-1 to 8-n between the deflector plate 7 and through the cover 11 to the nozzle 12. If the limestone granules 26 block the lower recesses 8-m, the annular space 29 remains available for the water vapor 2 to reach higher recesses 8-n. It then flows upwards along an outer side of the connecting web 9 and still within the plug-in element 1 until it can flow out through free recesses 8-n in an axially parallel direction into the cover 11. The annular space 29 thus not only provides a kind of bypass for the water vapor 2, but also gives the plug-in element 1 a large retention space for limestone granules 26.

[0026] Since the opening 25 of the connecting bridge 9 faces downwards, the limescale grains 26 collect in the annular space 29 in the area of ​​the opening 25. The cover 11 can therefore be removed to remove the limescale grains 26. The limescale grains 26 fall out of the opening 25 primarily due to gravity. Limescale grains 26 that remain stuck to the guide channel 3, the connecting bridge 9, or the cover plate 7 can be easily removed with a brush or similar tool, or during the descaling process.

[0027] Since the plug-in element and the milk frothing device described in detail above are exemplary embodiments, they can be modified to a wide extent by a person skilled in the art in the art without leaving the scope of the invention. Reference symbol list 1 plug-in element 2 Medium 3 guide channel 4 channel input 5 channel output 6 Sealing element 7 Deflection plate 8-1 to 8-n recesses 9 Connecting bridge 10 Milk frothing device 11 Cover 12 nozzle 13 Central axis 14 Exclusion 15 contact surface 16 to 22 areas of the guide element 27 23 linear section 24 semicircular arc segment-shaped section 25 Opening 26 grains of lime 27 Guide element 28 Bridge 29 Ring space

Claims

[1] Plug element (1) of a line coupling for guiding a gaseous and / or liquid medium (2), with a guide element (27) comprising a guide channel (3) which guides the medium (2) from a channel inlet (4) to a channel outlet (5), with a sealing element (6) arranged circumferentially on an outer circumference of the guide element (27), with a deflection plate (7) which is arranged on the guide element (27) at a distance from the channel outlet (5) substantially perpendicular to the flow direction of the medium (2), with radial recesses (8-1 to 8-n) on the circumference of the deflection plate (7), and with webs (28-1 to 28-n) which project radially from the cover plate (7) between the individual recesses (8-1 to 8-n). [2] Plug element (1) according to claim 1, with radially open recesses (8-1 to 8-n) arranged at regular intervals around the entire circumference of the deflection plate (7). [3] Plug element (1) according to one of the preceding claims, wherein the diameter of the deflection plate (7) where the recesses (8-1 to 8-n) extend furthest into the deflection plate (7) corresponds at least to the diameter of the channel outlet (5). [4] Plug-in element (1) according to one of the preceding claims, wherein the outer circumference of the deflection plate (7) corresponds at least to the outer circumference of the guide element (27). [5] Plug-in element (1) according to one of the preceding claims, comprising a number of connecting webs which connect the guide element (27) to the deflection plate (7). [6] Plug-in element (1) according to claim 5, wherein the connecting webs are formed as axially parallel extensions of the wall of the guide element (27) in the direction of the deflection plate (7). [7] Plug element (1) according to one of claims 5 or 6, comprising a single cylindrical connecting web with a smaller outer radius than the outer radius of the guide element (3) and comprising at least one radial opening, the size of which corresponds at least to the radius of the guide channel (3). [8] Milk frothing device (10) with a plug-in element (1) according to one of the preceding claims, and with a cover (11) which can be detachably coupled to the guide element (27) and has a nozzle (12) through which the medium (2) ejected from the channel outlet (5) is directed. [9] Milk frothing device (10) according to claim 8 with ribs (28-1 to 28-n) arranged between the recesses (8-1 to 8-n), characterized by , that the webs (28-1 to 28-n) and the cover (11) are made of a material of different hardness. [10] Milk frothing device (10) according to claim 8 with ribs (28-1 to 28-n) arranged between the recesses (8-1 to 8-n), characterized by that the webs (28-1 to 28-n) or the cover (11) are made of an elastic material.

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