Milk frothing device with optimized holding system

Description

Domaine technique

[0001] The present invention relates to the field of automatic coffee machines, and more particularly to the field of milk frothing devices intended to cooperate with automatic coffee machines. Etat de la technique

[0002] Document WO2005 / 063093 discloses a milk frothing device comprising: a mixing part comprising a mixing chamber provided with an outlet, a steam inlet, a main flow duct connecting the steam inlet to the mixing chamber, a milk supply duct connected to the main flow duct and an air supply duct connected to the main flow duct, a closing part movable relative to the mixing part between a closed position in which the closing part closes the mixing chamber and the main flow duct and an open position in which the mixing chamber and the main flow duct are open and accessible for cleaning, a seal arranged at a junction area between the mixing part and the closing part and extending around the mixing chamber and the main flow duct, and a holding system configured to hold the closing part in the closed position.

[0003] The main flow duct is more particularly configured such that a flow of steam in the main flow duct from the steam inlet and into the mixing chamber generates a vacuum in the milk supply duct and a vacuum in the air supply duct and causes a suction of milk and air into the main flow duct.

[0004] The particular configuration of the milk frothing device described in document WO2005 / 063093, and more particularly of the mixing part and the closing part, allows easy cleaning of the milk frothing device.

[0005] However, the assembly of the mixing part and the closing part of the milk frothing device described in WO2005 / 063093 requires the insertion of a projecting fixing member, provided on a rear portion of the closing part, into a fixing groove provided on the mixing part, a pivoting of a front portion of the closing part towards the mixing part and finally the movement of a locking member, provided on the front portion of the closing part, into a locking position.However, such assembly kinetics of the mixing and closing parts induce heterogeneous deformations of the seal which are on the one hand likely to harm the integrity of the seal and therefore to induce, over time, fluid leaks at the junction zone, and on the other hand to alter the geometry of the mixing chamber and the main flow duct and therefore to prevent the production of milk foam having the desired consistency.

[0006] A milk frothing device intended to cooperate with an automatic coffee machine is described in document EP3720323. Résumé de l'invention

[0007] The present invention aims to remedy all or part of these drawbacks.

[0008] The technical problem underlying the invention consists in particular in providing a milk frothing device which can be easily disassembled and cleaned and which has a reliable and sealed structure, while ensuring that milk froth of an appropriate consistency is obtained.

[0009] To this end, the present invention relates to a milk frothing device intended to cooperate with an automatic coffee machine, the milk frothing device comprising: a mixing part comprising a mixing chamber provided with an outlet, a hot water / steam inlet and a main flow conduit connecting the hot water / steam inlet to the mixing chamber, a closing part movable relative to the mixing part between a closing position in which the closing part closes the mixing chamber and the main flow conduit and an opening position in which the mixing chamber and the main flow conduit are open and accessible for cleaning, a milk supply conduit connected to the main flow conduit, a seal arranged at a junction area between the mixing part and the closing part and extending around the mixing chamber and the main flow conduit, and a holding system configured to hold the closing part in the closing position.

[0010] The closure portion is configured to occupy an intermediate position located between the closure position and the opening position and in which the closure portion is located opposite the mixing chamber and the main flow duct and is spaced from the mixing portion, and the holding system is configured to give the closure portion only one degree of freedom in translation in a translation direction when the closure portion is moved between the intermediate position and the closure position, the holding system being further configured to ensure compression of the seal when the closure portion is in the closure position.

[0011] Such a configuration of the holding system makes it possible in particular to avoid rotation or pivoting of the closing part relative to the mixing part when moving the closing part from the intermediate position to the closing position, and therefore to ensure axial and uniform compression of the seal when the closing part occupies the closing position. Thus, the holding system according to the present invention makes it possible to preserve the integrity of the seal, and to limit the risks of fluid leakage at the junction zone.

[0012] Furthermore, such a configuration of the holding system makes it possible to avoid a possible inclination of the closing part relative to the mixing part when the closing part is in the closed position, and therefore to guarantee the geometry of the mixing chamber and the main flow duct. As a result, the holding system according to the present invention also makes it possible to guarantee the admission of a predetermined quantity of milk into the mixing chamber, and therefore the obtaining of milk foam having an appropriate consistency.

[0013] The milk frothing device may further have one or more of the following features, taken alone or in combination.

[0014] According to one embodiment of the invention, the holding system is configured to press the closure portion against the mixing portion when the closure portion is in the closed position, so as to compress the seal, and more particularly a sealing lip of the seal.

[0015] According to one embodiment of the invention, the holding system comprises a first guide member and a second guide member secured respectively to the mixing part and to the closing part and configured to be mounted sliding one inside the other, the first and second guide members being configured to guide the closing part in translation relative to the mixing part and in the translation direction when the closing part is moved between the intermediate position and the closing position. Such a configuration of the holding system makes it possible to ensure translational guidance of the closing part while maintaining a holding system of simple structure.

[0016] According to one embodiment of the invention, one of the first and second guide members is a hollow guide member, and the other of the first and second guide members is a projecting guide member.

[0017] According to one embodiment of the invention, the projecting guide member projects downwards from a lower face of the closing part.

[0018] According to one embodiment of the invention, the holding system comprises a locking portion, such as a locking ring, mounted to move between a release position in which the locking portion allows movement of the closing portion towards the open position and a locking position in which the locking portion prevents movement of the closing portion towards the open position. Such a configuration of the holding system allows a user to easily immobilize the closing portion in the closed position.

[0019] According to one embodiment of the invention, the holding system is configured to move the closing portion from the intermediate position to the closing position and towards the mixing portion in the translation direction, and thus to bring the mixing portion and the closing portion closer to each other, when the locking portion is moved from the release position to the locking position.

[0020] According to one embodiment of the invention, the locking portion is annular and is rotatable relative to the closing portion about an axis of rotation and between the release position and the locking position, the axis of rotation being configured to be substantially parallel to the translation direction when the closing portion occupies the intermediate position. Such a configuration of the holding system allows a user to easily immobilize the closing portion in the closed position by simply rotating the locking portion.

[0021] According to one embodiment of the invention, the locking part comprises at least one fixing member, such as a fixing ramp, configured to cooperate with at least one fixing element, such as a fixing lug, configured to be integral in rotation with the mixing part, the at least one fixing member being configured to cooperate with the at least one fixing element during a rotation of the locking part from the release position to the locking position so as to move the locking part in the translation direction and in the direction of the mixing part, the locking part being configured to move the closing part towards the mixing part and in the translation direction during a rotation of the locking part from the release position to the locking position.

[0022] According to one embodiment of the invention, the locking portion comprises a bearing face which extends transversely to the translation direction, said bearing face being configured to move the closing portion towards the mixing portion and in the translation direction during a rotation of the locking portion from the release position to the locking position. Such a configuration of the locking portion makes it possible to ensure uniform compression of the seal.

[0023] According to one embodiment of the invention, the bearing face is configured to slide on the closing portion during a rotation of the locking portion from the release position to the locking position.

[0024] According to one embodiment of the invention, the locking part and the closing part form a subassembly. These arrangements ensure easy handling of the closing part and easy assembly of the closing part on the mixing part.

[0025] According to one embodiment of the invention, the locking part is mounted in a captive manner on the closing part.

[0026] According to one embodiment of the invention, the junction zone is planar, and the translation direction is substantially perpendicular to the junction zone.

[0027] Such a configuration of the milk frothing device according to the present invention allows easy assembly of the milk frothing device, while ensuring optimal compression of the seal.

[0028] According to one embodiment of the invention, the milk frothing device comprises an angular travel limiting device configured to limit an angular travel of the locking portion relative to the closing portion. These arrangements allow a user to easily move the locking portion between the release position and the locking position.

[0029] According to one embodiment of the invention, the angular travel limiting device comprises a first end-of-travel stop configured to prevent rotation of the locking part, in a first direction of rotation, beyond the release position, and a second end-of-travel stop configured to prevent rotation of the locking part, in a second direction of rotation, beyond the locking position.

[0030] According to one embodiment of the invention, the milk frothing device comprises an air supply duct connected to the main flow duct.

[0031] According to one embodiment of the invention, the main flow duct comprises a section restriction forming a milk and air suction system based on the venturi effect. Such a configuration of the milk frothing device makes it possible to control the quantity of air and the quantity of milk admitted into the mixing chamber, without requiring the presence of complex and expensive admission means.

[0032] According to one embodiment of the invention, the main flow duct is configured such that a flow of hot water / steam in the main flow duct from the hot water / steam inlet and into the mixing chamber generates a vacuum in the milk supply duct and a vacuum in the air supply duct and causes milk and air to be drawn into the main flow duct.

[0033] According to one embodiment of the invention, the mixing chamber is of the cyclonic type and extends vertically, the main flow duct opening into an upper part of the mixing chamber and the outlet orifice being located in a lower part of the mixing chamber. Such a configuration of the mixing chamber promotes the mixing of air, milk and hot water or water vapor introduced into the mixing chamber.

[0034] According to one embodiment of the invention, the main flow duct opens into a high point of the mixing chamber and the outlet orifice is located at a low point of the mixing chamber.

[0035] According to one embodiment of the invention, the main flow duct opens tangentially into the mixing chamber. Such a configuration of the main flow duct promotes the mixing of air, milk and hot water or water vapor introduced into the mixing chamber.

[0036] According to one embodiment of the invention, the main flow duct is entirely delimited by the mixing portion and the closing portion. Thus, the milk proteins contained in the milk flowing in the main flow duct are not likely to deform the latter, and therefore to have an impact on the quantity of air introduced into the mixing chamber.

[0037] According to one embodiment of the invention, the mixing part comprises an upper face in which the main flow conduit is arranged and into which the mixing chamber opens.

[0038] According to one embodiment of the invention, the mixing part comprises a receiving groove which is provided in the upper face of the mixing part and in which the sealing gasket is housed.

[0039] According to one embodiment of the invention, the mixing portion comprises a support wall which extends around the mixing chamber and the main flow duct and which partly delimits the receiving groove, the support wall projecting from the upper face of the support portion and the closing portion being configured to bear against the support wall. The presence of such a support wall limits the risks of milk leaking towards the seal, and therefore the risks of degradation of the latter by the milk proteins contained in the milk flowing in the main flow duct.

[0040] According to one embodiment of the invention, the mixing portion and the closing portion are generally circular and extend substantially coaxially when the closing portion occupies the closed position.

[0041] According to one embodiment of the invention, the mixing portion comprises an air intake channel configured to be closed by the closing portion, the air intake channel connecting the air supply duct to the main flow duct and the seal extending around the air intake channel.

[0042] According to one embodiment of the invention, the air intake channel is provided in the upper face of the mixing part.

[0043] According to one embodiment of the invention, the closing part comprises the air supply duct. Such an arrangement of the air supply duct makes it possible to substantially limit the risks of alteration of the air supply duct by the milk proteins contained in the milk flowing in the main flow duct, and therefore to guarantee the admission of a controlled quantity of air into the mixing chamber.

[0044] According to one embodiment of the invention, the mixing part comprises the milk supply conduit. Such an arrangement of the milk supply conduit makes it possible to substantially limit the risks of alteration of the milk supply conduit by the milk proteins contained in the milk flowing in the milk supply conduit, and therefore to guarantee the admission of a controlled quantity of milk into the mixing chamber.

[0045] According to one embodiment of the invention, the mixing part is in one piece.

[0046] According to one embodiment of the invention, the milk supply conduit comprises a calibrated flow passage configured to define a predetermined milk flow rate in the milk supply conduit. These arrangements make it possible to ensure the admission of a predetermined quantity of milk into the mixing chamber, and therefore the obtaining of milk foam having an appropriate consistency.

[0047] According to one embodiment of the invention, the milk supply conduit opens into the main flow conduit near the section restriction.

[0048] According to one embodiment of the invention, the air intake channel opens into the main flow duct near the section restriction.

[0049] According to one embodiment of the invention, the main flow duct comprises: a first portion of conduit which is located upstream of the section restriction and which extends to the section restriction, the first portion of conduit having a passage section which decreases in the direction of the section restriction, and a second portion of conduit which is located downstream of the section restriction and which extends from the section restriction, the second portion of conduit having a passage section which increases in the direction of the mixing chamber.

[0050] According to one embodiment of the invention, the main flow duct is configured to allow a first mixing of the steam, milk and air coming respectively from the hot water / steam inlet, the milk supply duct and the air inlet channel, before their arrival in the mixing chamber.

[0051] According to one embodiment of the invention, the seal is continuous.

[0052] According to one embodiment of the invention, the seal has a constant section. The seal could however have a non-constant section to improve the seal between the mixing part and the closing part in the event of significant deformation of the latter.

[0053] According to one embodiment of the invention, the mixing portion comprises a milk discharge conduit fluidly connected to the outlet of the mixing chamber and configured to be located vertically above a container, such as a cup.

[0054] According to one embodiment of the invention, the milk frothing device comprises a milk reservoir comprising an upper opening, the mixing part being arranged at the upper opening, and is for example housed at least partly in the milk reservoir.

[0055] According to one embodiment of the invention, the holding system is configured to removably, i.e. temporarily and reversibly, fix the mixing part and the closing part to the milk tank.

[0056] According to another embodiment of the invention, the milk frothing device comprises a connecting device which is separate from the holding system and which is configured to removably, i.e. temporarily and reversibly, fix the mixing part and the closing part to the milk container.

[0057] According to one embodiment of the invention, the milk frothing device comprises an immobilization device configured to immobilize in rotation the mixing part relative to the milk reservoir when the mixing part is received in the milk reservoir.

[0058] According to one embodiment of the invention, the at least one fixing element is provided on the mixing part and / or on the milk container.

[0059] According to one embodiment of the invention, the mixing portion comprises a mixing body configured to partially close the milk reservoir and to be removable from the milk reservoir.

[0060] According to one embodiment of the invention, the mixing body is provided with a tubular mounting portion configured to be mounted in the milk tank, and more particularly to be inserted into the milk tank via the upper opening of the milk tank.

[0061] According to one embodiment of the invention, the mixing portion and the closing portion are configured to close the milk container and to be removable from the milk container. In other words, the mixing portion and the closing portion form a cover configured to close the milk container.

[0062] According to one embodiment of the invention, the closure portion is configured to cover the mixing portion.

[0063] According to one embodiment of the invention, the milk supply conduit comprises a milk suction tube extending vertically and opening into a lower part of the milk tank.

[0064] According to one embodiment of the invention, the closing part comprises a filling opening and a flap movable between an open position in which the flap at least partially releases the filling opening and allows milk to be introduced into the milk tank and a closed position in which the flap at least partially closes the filling opening.

[0065] According to one embodiment of the invention, the mixing portion comprises a passage opening configured to be located opposite the filling opening.

[0066] According to one embodiment of the invention, the hollow guide member delimits the passage opening provided on the mixing part, and the projecting guide member is configured to be introduced into said passage opening.

[0067] According to one embodiment of the invention, the milk frothing device further comprises an air flow adjustment device configured to adjust an air flow flowing in the air supply duct. Such a configuration of the milk frothing device according to the present invention, and more particularly the presence of the air flow adjustment device, allows a user to adapt the consistency of the milk foam obtained according to his wishes. The user can for example adjust the air flow introduced into the mixing chamber in order to obtain a more or less firm milk foam.

[0068] The present invention further relates to an automatic coffee machine comprising a hot water / steam outlet nozzle, a boiler producing hot water and / or steam to supply said hot water / steam outlet nozzle, and a milk frothing device according to the present invention, the hot water / steam inlet of the milk frothing device being connected to the hot water / steam outlet nozzle.

[0069] By automatic coffee machine, we understand that the coffee machine includes in particular an infusion chamber which can be supplied with ground coffee by a bean grinder incorporated in the machine, or an infusion chamber which can receive a capsule or a coffee pod or an infusion chamber formed by a spoon intended to be filled with ground coffee and emptied manually. Brève description des figures

[0070] The invention will be better understood with the aid of the description which follows with reference to the appended schematic drawings representing, by way of non-limiting example, an embodiment of this milk frothing device. [ Fig 1 ] is a top perspective view of a milk frothing device according to the present invention. [ Fig 2 ] is a top view of the milk frothing device of the figure 1 . [ Fig 3 ] is a perspective view, truncated longitudinally, of the milk frothing device of the figure 1 . [ Fig 4 ] is a perspective view of a gasket of the milk frothing device of the figure 1 . [ Fig 5 ] is a partial perspective view from above of the milk frothing device of the figure 1 . [ Fig 6 ] is a top perspective view of a mixing portion of the milk frothing device of the figure 1 . [ Fig 7 ] is a partial top view of the mixing portion of the figure 6 equipped with the sealing gasket of the figure 4 . [ Fig 8 ] is a partial perspective view from above of the mixing part equipped with the sealing gasket of the figure 4 . [ Fig 9 ] is a partial perspective view, truncated longitudinally, of the milk frothing device of the figure 1 . [ Fig 10 ] is a partial perspective view, truncated longitudinally, of the mixing portion of the figure 6 . [ Fig 11 ] is a top perspective view of a subassembly of the milk frothing device of the figure 1 . [ Fig 12 ] is a perspective view from below of the subassembly of the figure 11 . [ Fig 13 ] is a bottom view of the subassembly of the figure 11 . [ Fig 14 ] is a partial perspective view from above of an air flow adjustment device of the milk frothing device of the figure 1 . [ Fig 15 ] is a perspective view from above of a support portion and a passage restriction member of the air flow adjustment device of the figure 14 . [ Fig 16 ] is a partial perspective view from above of the air flow adjustment device of the figure 14 . [ Fig 17 ] is a top sectional view of the air flow adjustment device of the figure 14 . [ Fig 18 ] is a perspective view of an automatic coffee machine equipped with the milk frothing device of the figure 1 . Description détaillée

[0071] THE figures 1 à 18 represent a milk frothing device 2 intended to cooperate with an automatic coffee machine 3.

[0072] The milk frothing device 2 comprises a milk reservoir 4 delimiting an internal volume intended to contain milk and comprising an upper opening 5. The milk reservoir 4 may for example have a generally cylindrical shape, and have a circular cross-section. However, the milk reservoir 4 could also have a completely different shape, and for example have an oblong or rectangular cross-section.

[0073] The milk frothing device 2 further comprises a mixing portion 6 arranged at the upper opening 5. The mixing portion 6 more particularly comprises a mixing body 7 provided with an upper face 8 which is generally planar. The mixing body 7 is configured to partially close the milk reservoir 4 and to be removable from the milk reservoir 4. The mixing body 7 may for example comprise a tubular mounting portion 9 configured to be mounted in the milk reservoir 4, and more particularly to be inserted into the milk reservoir 4 via the upper opening 5 of the milk reservoir 4.

[0074] Advantageously, the milk frothing device 2 comprises an immobilization device configured to immobilize in rotation the mixing body 7 relative to the milk reservoir 4 when the tubular mounting portion 9 is received in the milk reservoir 4. The immobilization device may for example comprise immobilization ribs 11 provided on an upper peripheral edge of the milk reservoir 4 and distributed around a central axis of the milk reservoir 4, and immobilization grooves 12 provided on the mixing body 7 and configured to cooperate respectively with the immobilization ribs 11.

[0075] The mixing body 7 further comprises a mixing chamber 13 which opens into the upper face 8 of the mixing body 7 and which is provided with an outlet orifice 14, and furthermore a main flow duct 15 formed in the upper face 8 of the mixing body 7 and opening into the mixing chamber 13. According to the embodiment shown in the figures, the mixing chamber 13 is of the cyclonic type and extends vertically, and the main flow duct 15 opens tangentially into the mixing chamber 13. Advantageously, the main flow duct 15 opens into an upper part of the mixing chamber 13, and for example into a high point of the mixing chamber 13, and the outlet orifice 14 is located in a lower part of the mixing chamber 13, and is for example located at a low point of the mixing chamber 13.

[0076] As shown more particularly on the figure 7 , the main flow duct 15 comprises a section restriction 16 located for example in a central portion of the main flow duct 15, a first duct portion 15.1 which is located upstream of the section restriction 16 and which extends to the section restriction 16, and a second duct portion 15.2 which is located downstream of the section restriction 16 and which extends from the section restriction 16 and to the mixing chamber 13. Advantageously, the first duct portion 15.1 has a passage section which decreases in the direction of the section restriction 16, and the second duct portion 15.2 has a passage section which increases in the direction of the mixing chamber 13.

[0077] The mixing body 7 also comprises a connection end piece 17 configured to be connected to a hot water / steam outlet end piece of the automatic coffee machine 3, and more particularly to be fluidically connected to a boiler which equips the automatic coffee machine 3 and which is configured to produce hot water and / or steam. Advantageously, the connection end piece 17 extends radially relative to a central axis of the mixing body 7, and is configured to extend radially relative to the central axis of the milk tank 4.

[0078] The mixing body 7 further comprises a hot water / steam inlet orifice 21 which is fluidically connected to the connecting end piece 17 and which opens into the first portion of conduit 15.1 and more particularly opposite the mixing chamber 13. The main flow conduit 15 is thus configured to fluidically connect the hot water / steam inlet orifice 21 to the mixing chamber 13, and to allow a flow of hot water / steam into the main flow conduit 15 and into the mixing chamber 13.

[0079] The milk frothing device 2 also comprises a milk supply duct 22 fluidly connected to the main flow duct 15, and therefore configured to be fluidly connected to the mixing chamber 13 via the main flow duct 15. According to the embodiment shown in the figures, the mixing part 6 comprises the milk supply duct 22, and more particularly the mixing body 7 and the milk supply duct 22 are made in one piece.

[0080] As shown more particularly on the figure 3 , the milk supply conduit 22 comprises a milk suction tube 22.1 extending vertically and opening into a lower part of the milk tank 4, and a calibrated flow passage 22.2 located downstream of the milk suction tube 22.1 and opening into the main flow conduit 15 at the section restriction 16. The calibrated flow passage 22.2 is more particularly configured to define a predetermined milk flow rate in the milk supply conduit 22.

[0081] According to the embodiment shown in the figures, the mixing body 7 further comprises an air intake channel 23 which is arranged in the upper face 8 of the mixing body 7 and which opens into the main flow duct 15 at the section restriction 16. The air intake channel 23 is thus configured to be fluidically connected to the mixing chamber 13 via the main flow duct 15.

[0082] The section restriction 16, described previously, induces an increase in the speed of the steam flowing in the main flow duct 15, which generates a depression in the milk supply duct 22 and in the air intake channel 23. The section restriction 16 is therefore more particularly configured to form a milk and air suction system based on the venturi effect. The main flow duct 15 is thus configured such that a flow of hot water / steam in the main flow duct 15 from the hot water / steam inlet 21 and into the mixing chamber 13 generates a vacuum in the milk supply duct 22 and a vacuum in the air intake channel 23 and consequently causes a suction of milk and air into the main flow duct 15 and a flow of the sucked milk and air into the mixing chamber 13. In addition, the second duct portion 15.2, which has a passage section which increases towards the mixing chamber 13, promotes a first mixing of the steam, the milk and the air coming respectively from the hot water / steam inlet orifice 21, the milk supply duct 22 and the air intake channel 23, before their arrival in the mixing chamber 13.

[0083] The mixing body 7 further comprises a milk discharge conduit 24 fluidly connected to the outlet orifice 14 of the mixing chamber 13, and configured to allow discharge of hot milk and milk foam into a container, such as a cup, arranged vertically below the milk discharge conduit 24. Advantageously, the milk discharge conduit 24 is configured to extend radially relative to the central axis of the milk reservoir 4.

[0084] As shown more particularly on the figure 4 And 7, the milk frothing device 2 comprises a seal 25 extending around the mixing chamber 13, the main flow duct 15 and the air intake channel 23. For this purpose, the mixing body 7 comprises a receiving groove 26 formed in the upper face 8 of the mixing body 7 and in which the seal 25 is housed.

[0085] According to the embodiment shown in the figures, the seal 25 comprises a seal body 25.1 housed entirely in the receiving groove 26, and a sealing lip 25.2 extending along the seal body 25.1 and projecting out of the receiving groove 26. Advantageously, the seal 25 is continuous and may for example have a constant section.

[0086] The milk frothing device 2 further comprises a closure portion 27 configured to cover the mixing body 7 and to bear against the mixing body 7. The mixing body 7 may optionally comprise a support wall 7.1 which extends around the mixing chamber 13 and the main flow duct 15 and which internally delimits the receiving groove 26, the support wall 7.1 projecting from the upper face 8 of the mixing body 7 and the closure portion 27 then being configured to bear against an upper edge of the support wall 7.1.

[0087] As shown on the figure 3 , the closure portion 27 is generally planar, and the seal 25 is thus arranged at a junction zone between the mixing portion 6 and the closure portion 27 which is generally planar. According to the embodiment shown in the figures, the mixing portion 6 and the closure portion 27 are generally circular and extend substantially coaxially with the central axis of the milk tank 4.

[0088] The mixing portion 6 and the closing portion 27 are configured to close the milk tank 4 and to be removable from the milk tank 4. The mixing portion 6 and the closing portion 27 thus form a cover configured to close the milk tank 4.

[0089] According to the embodiment shown in the figures, the closing part 27 comprises a filling opening 28 configured to be located opposite a passage opening 29 provided on the mixing body 7 and opening into the milk reservoir 4, and a flap 31 which is movable, and for example pivotally mounted, between an open position in which the flap 31 at least partially releases the filling opening 28 and allows milk to be introduced into the milk reservoir 4 and a closed position in which the flap 31 at least partially closes the filling opening 28.

[0090] The closing part 27 is more particularly mounted to be movable relative to the mixing part 6 between a closing position in which the closing part 27 closes the mixing chamber 13, the main flow duct 15 and the air intake channel 23, and an opening position in which the mixing chamber 13, the main flow duct 15 and the air intake channel 23 are open and accessible for cleaning.

[0091] Advantageously, the milk frothing device 2 also comprises a holding system 32 configured to hold the closure portion 27 in the closed position and to ensure compression of the seal 25 when the closure portion 27 is in the closed position. The holding system 32 is more particularly configured to press the closure portion 27 against the upper face 8 of the mixing body 7 when the closure portion 27 is in the closed position, so as to compress the seal 25, and more particularly the sealing lip 25.2 of the seal 25. According to the embodiment shown in the figures, the holding system 32 is also configured to removably fix, that is to say temporarily and reversibly, the mixing portion 6 and the closure portion 27 to the milk tank 4.However, such attachment of the mixing part 6 and the closing part 27 to the milk tank 4 could be achieved by a connecting device separate from the holding system 32.

[0092] As shown on the figure 3 , the holding system 32 comprises a locking part 33, such as a locking ring, mounted to rotate relative to the closing part 27 about an axis of rotation A and between a release position in which the locking part 33 allows movement of the closing part 27 towards the open position and a locking position in which the locking part 33 prevents movement of the closing part 27 towards the open position. The axis of rotation A is advantageously substantially parallel to, and for example collinear with, the central axis of the milk tank 4 when the mixing part 6 is received in the milk tank 4 and the closing part 27 occupies the closed position.

[0093] According to the embodiment shown in the figures, the closing portion 27 is configured to occupy an intermediate position located between the closing position and the opening position and in which the closing portion 27 rests on the sealing lip 25.2 of the seal 25 and is therefore located opposite the mixing chamber 13 and the main flow duct 15 and is spaced from the mixing portion 6, and the holding system 32 is configured to move the closing portion 27 from the intermediate position to the closing position and towards the mixing portion 6, and therefore to bring the closing portion 27 closer to the mixing portion 6, when the locking portion 33 is moved from the release position to the locking position.

[0094] As shown on the figures 5 And 12, the holding system 32 further comprises a plurality of fixing members 34, such as fixing ramps or fixing grooves, provided on the locking part 33 and distributed around the axis of rotation A, and a plurality of fixing elements 35, such as fixing lugs or fixing notches, provided on the milk tank 4 and distributed around the central axis of the milk tank 4. The fixing elements 35 are configured to cooperate respectively with the fixing members 34 provided on the locking part 33 during a rotation of the locking part 33 from the release position to the locking position, so as to move the locking part 33 towards the mixing part 6. The fixing members 34 and the fixing elements 35 can for example form a bayonet or screw-nut type fixing system.According to the embodiment shown in the figures, the fixing members 34 are provided on an inner surface of the locking part 33, and the fixing elements 35 are provided on an outer surface of the milk tank 4.

[0095] Advantageously, the locking part 33 comprises a bearing face 36 (see in particular the figure 9 ) which extends transversely to the axis of rotation A and which is configured to move the closing part 27 towards the mixing part 6 and parallel to the axis of rotation A during a rotation of the locking part 33 from the release position to the locking position. The bearing face 36 is more particularly configured to slide on the closing part 27 during a rotation of the locking part 33 between the release position and the locking position. The bearing face 36 is annular and is configured to bear against a peripheral edge of the closing part 27.

[0096] According to the embodiment shown in the figures, the locking part 33 is mounted in a captive manner on the closing part 27, such that the locking part 33 and the closing part 27 form a non-removable subassembly.

[0097] As shown more particularly on the figure 13 , the milk frothing device 2 comprises an angular travel limiting device configured to limit an angular travel of the locking portion 33 relative to the closing portion 27. The angular travel limiting device may for example comprise one or more first end-of-travel stops 37 provided on the locking portion 33 and configured to prevent rotation of the locking portion 33, in a first direction of rotation, beyond the release position, and one or more second end-of-travel stops 38 provided on the locking portion 33 and configured to prevent rotation of the locking portion 33, in a second direction of rotation, beyond the locking position.

[0098] Advantageously, the holding system 32 is also configured to give the closing part 27 only one degree of freedom in translation in a translation direction D1, which is for example perpendicular to the junction zone and therefore parallel to the axis of rotation A, when the closing part 27 is moved between the intermediate position and the closing position. For this purpose, the holding system 32 comprises a first guide member 39, such as a hollow guide member, and a second guide member 41, such as a projecting guide member, secured respectively to the mixing part 6 and to the closing part 27 and configured to be mounted sliding one inside the other in the translation direction D1.

[0099] The first and second guide members 39, 41 have complementary and non-circular cross-sections, and are configured to guide the closure part 27 in translation relative to the mixing part 6 and in the translation direction D1 when the closure part 27 is moved between the intermediate position and the closed position. According to the embodiment shown in the figures, the first guide member 39 delimits the passage opening 29 provided on the mixing body 7, and the second guide member 41 projects downwards from a lower face of the closure part 27 and is configured to be introduced into the passage opening 29. However, according to an alternative embodiment of the invention, the first and second guide members 39, 41 could be offset laterally relative to the filling opening 28 and the passage opening 29.

[0100] As shown more particularly on the figure 17 , the closing part 27 further comprises an air supply duct 42 connected to the main flow duct 15 via the air intake channel 23, and an air flow adjustment device 43 configured to adjust an air flow rate flowing in the air supply duct 42. However, according to an alternative embodiment of the invention, the mixing part 6 could be devoid of the air intake channel 23, and the air supply duct 42 could be connected directly to the main flow duct 15.

[0101] According to the embodiment shown in the figures, the air flow adjustment device 43 comprises a support part 44 fixed to the closure part 27 and projecting from an upper face of the closure part 27, and a flow adjustment member 45, such as a flow adjustment knob, supported by the support part 44 and mounted movably, and for example mounted movably in a helical movement, relative to the support part 44 in a direction of movement D2 which may for example be substantially vertical when the milk frothing device 2 rests on a horizontal surface.

[0102] The flow control member 45 and the support part 44 may, for example, extend coaxially with respect to each other, and the support part 44 may, for example, comprise two guide fingers 46 (see in particular figure 14 ) diametrically opposed and slidably mounted respectively in two helical guide grooves 47 provided on the flow adjustment member 45.

[0103] According to the embodiment shown in the figures, the flow rate adjustment member 45 comprises an adjustment part 45.1 which is configured to cover the support part 44 and which comprises an upper wall covering the support part 44 and a peripheral wall having a generally tubular shape and extending around the support part 44. As shown more particularly in the figure 1 , the flow rate adjustment member 45 further comprises a manipulation part 45.2 secured to the adjustment part 45.1 and configured to be manipulated by a user so as to move the flow rate adjustment member 45 in the direction of movement D2.

[0104] The flow rate adjustment member 45 is configured to occupy a plurality of adjustment positions offset from each other in the direction of movement D2. Advantageously, the direction of movement D2 is substantially parallel to the central axis of the milk tank 4 when the mixing portion 6 is received in the milk tank 4 and the closing portion 27 is in the closed position.

[0105] The air flow adjustment device 43 further comprises a sealing element 48 which is annular and which is fixed to the flow adjustment member 45. According to the embodiment shown in the figures, the support part 44 comprises a bearing surface 49, provided on an upper end face of the support part 44, which is annular and against which the sealing element 48 is capable of being compressed depending on the position occupied by the flow adjustment member 45.

[0106] The sealing element 48 and the support portion 44 are configured to define an air flow passage 51 (see figure 16 ) having a passage section which varies depending on the position occupied by the flow rate adjustment member 45. The air flow passage 51 is more particularly configured to fluidically connect an air intake opening 52, defined by the air flow rate adjustment device 43, to the air supply duct 42. According to the embodiment shown in the figures, the air intake opening 52 is defined by a functional clearance between the flow rate adjustment member 45 and the support part 44.

[0107] The flow rate adjustment member 45 is more particularly movable between a maximum adjustment position in which the passage section of the air flow passage 51 is maximum, and a minimum adjustment position in which the passage section of the air flow passage 51 is minimum, and for example zero or substantially zero.

[0108] As shown on the figure 15 , the support part 44 comprises a recess 53 which is formed in the bearing surface 49 and which partly delimits the air flow passage 51. The recess 53 may for example extend radially relative to the direction of movement D2, and have a generally V-shaped cross section.

[0109] As shown more particularly on the figure 17, the air supply duct 42 comprises a calibrated air passage 54 which is located downstream of the flow adjustment member 45 and which is configured to define a maximum air flow in the air supply duct 42.

[0110] According to the embodiment shown in the figures, the support portion 44 comprises an insertion hole 55, which may for example have a diameter greater than one millimeter and preferably greater than 1.5 millimeters, oriented substantially parallel to the direction of movement D2, and the air flow adjustment device 43 comprises a passage restriction member 56, such as a pin or a needle of generally cylindrical shape, having a lower end portion which is housed in the insertion hole 55. The passage restriction member 56 is integral in movement with the flow adjustment member 45, and is therefore mounted movably in the insertion hole 55 in the direction of movement D2. The passage restriction member 56 is elongated and extends in an extension direction which is parallel to the direction of movement D2.The insertion hole 55 and the passage restriction member 56 more particularly delimit the calibrated air passage 54, such that the calibrated air passage 54 is annular.

[0111] According to the embodiment shown in the figures, the support part 44 comprises a cavity 57 which opens into the upper end face of the support part 44 and into which the insertion hole 55 opens. The cavity 57 and the flow adjustment member 45 delimit an internal chamber 58 configured to fluidically connect the air flow passage 51 to the insertion hole 55.

[0112] Of course, the present invention is in no way limited to the embodiment described and illustrated, which has been given only as an example. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention as defined by the claims.

Claims

1. A milk frothing device (2) intended to cooperate with an automatic coffee machine (3), the milk frothing device (2) including: - a mixing part (6) comprising a mixing chamber (13) provided with an outlet orifice (14), a hot water / vapor inlet orifice (21) and a main flow conduit (15) connecting the hot water / vapor inlet orifice (21) to the mixing chamber (13), - a closure part (27) movable relative to the mixing part (6) between a closed position in which the closure part (27) closes the mixing chamber (13) and the main flow conduit (15) and an open position in which the mixing chamber (13) and the main flow conduit (15) are open and accessible for cleaning, - a milk supply conduit (22) connected to the main flow conduit (15), - a seal (25) arranged at a junction area between the mixing part (6) and the closure part (27) and extending around the mixing chamber (13) and the main flow conduit (15), and - a holding system (32) configured to hold the closure part (27) in the closed position, the closure part (27) is configured to occupy an intermediate position located between the closed position and the open position and in which the closure part (27) is located opposite the mixing chamber (13) and the main flow conduit (15) and is spaced apart from the mixing part (6), characterized in that the holding system (32) is configured to confer on the closure part (27) only one translational degree of freedom in a direction of translation (D1) when the closure part (27) is displaced between the intermediate position and the closed position, the holding system (32) being further configured to ensure a compression of the seal (25) when the closure part (27) is in the closed position.

2. The milk frothing device (2) according to claim 1, wherein the holding system (32) includes a first guide member (39) and a second guide member (41) secured respectively to the mixing part (6) and the closure part (27) and configured to be slidably mounted one inside the other, the first and second guide members (39, 41) being configured to guide the closure part (27) in translation relative to the mixing part (6) and in the direction of translation (D1) when the closure part (27) is displaced between the intermediate position and the closed position.

3. The milk frothing device (2) according to claim 1 or 2, wherein the holding system (32) includes a locking part (33) movably mounted between a release position in which the locking part (33) enables a displacement of the closure part (27) towards the open position and a locking position in which the locking part (33) prevents a displacement of the closure part (27) towards the open position.

4. The milk frothing device (2) according to claim 3, wherein the holding system (32) is configured to displace the closure part (27) from the intermediate position to the closed position and in the direction of the mixing part (6) in the direction of translation (D1) when the locking part (33) is displaced from the release position to the locking position.

5. The milk frothing device (2) according to claim 3 or 4, wherein the locking part (33) is annular and is movable in rotation relative to the closure part (27) about an axis of rotation (A) and between the release position and the locking position, the axis of rotation (A) being configured to be substantially parallel to the direction of translation (D1) when the closure part (27) occupies the intermediate position.

6. The milk frothing device (2) according to claim 5, wherein the locking part (33) includes at least one fastening member (34) configured to cooperate with at least one fastening element (35) configured to be secured in rotation to the mixing part (6), the at least one fastening member (34) being configured to cooperate with the at least one fastening element (35) during a rotation of the locking part (33) from the release position to the locking position so as to displace the locking part (33) in the direction of translation (D1) and towards the mixing part (6), the locking part ( 33) being configured to displace the closure part (27) towards the mixing part (6) and in the direction of translation (D1) during a rotation of the locking part (33) from the release position to the locking position.

7. The milk frothing device (2) according to claim 6, wherein the locking part (33) includes a bearing face (36) which extends transversely to the direction of translation (D1), said bearing face (36) being configured to displace the closure part (27) towards the mixing part (6) and in the direction of translation (D1) during a rotation of the locking part (33) from the release position to the locking position.

8. The milk frothing device (2) according to any one of claims 3 to 7, wherein the locking part (33) and the closure part (27) form a subset.

9. The milk frothing device (2) according to any one of claims 1 to 8, wherein the junction area is planar, and the direction of translation (D1) is substantially perpendicular to the junction area.

10. The milk frothing device (2) according to any one of claims 1 to 9, wherein the main flow conduit (15) includes a section restriction (16) forming a milk and air suction system based on the Venturi effect.

11. The milk frothing device (2) according to any one of claims 1 to 10, wherein the mixing chamber (13) is of the cyclonic type and extends vertically, the main flow conduit (15) opening into an upper part of the mixing chamber (13) and the outlet orifice (14) being located in a lower part of the mixing chamber (13).

12. The milk frothing device (2) according to any one of claims 1 to 11, which includes a milk reservoir (4) comprising an upper opening (5), the mixing part (6) being arranged at the upper opening (5).

13. The milk frothing device (2) according to claim 12, wherein the holding system (32) is configured to removably fasten the mixing part (6) and the closure part (27) to the milk reservoir (4).

14. The milk frothing device (2) according to claim 12 or 13, wherein the mixing part (6) and the closure part (27) are configured to close the milk reservoir (4) and to be removable with respect to the milk reservoir (4).

15. The milk frothing device (2) according to any one of claims 12 to 14, wherein the closure part (27) includes a filling opening (28) and a flap (31) movable between an open position in which the flap (31) at least partially releases the filling opening (28) and enables an introduction of milk into the milk reservoir (4) and a closed position in which the flap (31) at least partially seals the filling opening (28).

16. An automatic coffee machine (3) including a hot water / vapor outlet nozzle, a boiler producing hot water and / or vapor to feed said hot water / vapor outlet nozzle, and a milk frothing device (2) according to any one of claims 1 to 15, the hot water / vapor inlet orifice (21) of the milk frothing device (2) being connected to the hot water / vapor outlet nozzle.