Milk frothing device

Abstract

A frothing assembly (21) for frothing milk in a container (11) is disclosed. The assembly (21) comprises: a body (25); a motor (33) fixed to the body and having an output shaft (34), the output shaft (34) being rotatably driven about a longitudinal axis (35) of the shaft (34); a frothing device (36) rotatably driven by the shaft (34) and immersed in the milk in the container (11); and a perforated member (43) at least partially surrounding the frothing device (36) and separated from the frothing device (36) by a gap (44), wherein rotation of the frothing device (36) causes the milk in the gap (44) to move and causes the milk to move through the perforated member (43) to circulate back through the container (11) and the gap (44) to cause the milk to froth.

Description

Technical Field

[0001] The present invention relates to milk frothing or texturizing, and more particularly to mechanical texturizing or frothing. Background Art

[0002] Texturizing creates bubbles for milk. Heated and texturized milk is needed to make popular drinks such as cappuccino and latte.

[0003] The main benefit of mechanical texturizing over steam texturizing is the resulting milk flavor. Steam tends to add some moisture to the milk, which dilutes it, and the high temperatures can destroy some of the milk's natural sweetness. Using a whisk to create a vortex, which pulls air into the milk, certainly has some advantages.

[0004] Milk frothing devices are known from the following publications: Foremost BV, publication US 2012 / 0017778 (milk frother), Aerolatte Limited, patent number US 6,558,035 (electric stirrer), Chinese patent CN 201683731 (fully automatic milk frother), Green Lane Designs, US8726790 (milk frothing device) and Tito Ciusti, GB604048A (improvements in or relating to pasteurization and boiling devices).

[0005] The disadvantage of devices that steam texturize the milk is that the temperature of the milk is poorly controlled and the milk is diluted. The disadvantage of "beater" type devices is that the milk may not be frothed or textured to the desired degree.

[0006] Purpose of the Invention

[0007] An object of the present invention is to overcome or substantially ameliorate at least one of the above disadvantages. Summary of the invention

[0008] A frothing assembly for frothing milk in a container is disclosed, the assembly comprising:

[0009] main body;

[0010] an electric motor fixed to the body and having an output shaft, rotatably driving the output shaft about a longitudinal axis of the shaft;

[0011] a frothing device rotatably driven by the shaft and immersed in the milk in the container; and

[0012] a perforated member at least partially surrounding the foaming device and spaced apart from the foaming device by a gap;

[0013] wherein rotation of the frothing device causes movement of milk in the gap and causes the milk to move through the perforated member, circulating back through the container and the gap to cause frothing of the milk.

[0014] Preferably, the frothing means comprises a plurality of blades, the blades being angularly spaced about the axis and having a direction of extension away from the axis including a radial component.

[0015] Preferably, the extension direction also includes an angular component.

[0016] Preferably, each of said blades is generally flat.

[0017] Preferably, the perforated member has an end providing a plurality of channels through which milk can pass.

[0018] Preferably, the end portion is at least partially coextensive with the blade in the axial direction.

[0019] Preferably, the end portion is substantially coextensive with the blade in the axial direction.

[0020] Preferably, the foaming device and the perforated member provide an assembly which is detachable relative to the motor.

[0021] Preferably, the gap is annular and is 0.5 to 1.00 mm.

[0022] Preferably, the gap is about 0.5 mm.

[0023] Also disclosed herein is a milk frother comprising a base for supporting an upper container and to which the frothing assembly is attached.

[0024] Preferably, the milk frother further comprises a rod fixed to extend upwardly from the base, and the frothing assembly is attached to the base.

[0025] Preferably, the position of the foaming component on the rod is adjustable in the longitudinal direction to adjust the height of the foaming device relative to the container.

[0026] Preferably, the motor is located above the perforated member, the perforated member extending downwardly from the motor to be at least partially immersed in milk in the container.

[0027] Preferably, the base comprises means for heating milk in the container.

[0028] Preferably, the base comprises a temperature sensor for detecting the temperature of the container, and thereby the temperature of the milk.

[0029] Preferably, the foamer comprises a circuit for controlling the motor and receiving a signal from the sensor and controlling the heater.

[0030] Preferably, the circuit activates the motor to rotate the frothing device at a rotation speed of about 5,500 rpm to about 13,500 rpm.

[0031] Preferably, the circuit activates the motor to rotate the frothing device at a rotational speed of about 13,500 rpm for a period of time, and then at a rotational speed of about 9,500 rpm for another period of time.

[0032] The present invention also discloses a milk frothing device for frothing milk in a container, the milk frothing device comprising:

[0033] a base assembly for supporting the container, the base assembly including a fluid source; and

[0034] a foaming assembly attached to the base assembly, the foaming assembly comprising:

[0035] main body;

[0036] an electric motor fixed to the body and having an output shaft rotatably driven about a longitudinal axis of the output shaft, the output shaft including a hollow passage in communication with the fluid source;

[0037] a frothing device rotatably driven by the shaft and immersed in the milk in the container; and

[0038] a perforated member at least partially surrounding the foaming device and spaced apart from the foaming device by a certain gap, the perforated member being in communication with the hollow passage of the output shaft,

[0039] wherein rotation of the frothing device causes movement of milk in the gap and causes milk to move through the perforated member, circulating back through the container and the gap to cause milk frothing; and

[0040] Thereby, the fluid source is operable to dispense fluid through the hollow passage and the perforated member.

[0041] The present invention also discloses a milk frothing device for frothing milk in a container, the milk frothing device comprising:

[0042] a base assembly having a body for supporting the container; and

[0043] a foaming assembly at least partially mounted in the body of the base assembly, the foaming assembly comprising:

[0044] an electric motor having an output shaft, the output shaft being rotatably driven about a longitudinal axis of the shaft;

[0045] a frothing device rotatably driven by the shaft and immersed in the milk in the container; and

[0046] a perforated member at least partially surrounding the foaming device and spaced apart from the foaming device by a gap;

[0047] wherein rotation of the frothing device causes movement of milk in the gap and causes the milk to move through the member, circulating back through the container and the gap to cause frothing of the milk. BRIEF DESCRIPTION OF THE DRAWINGS

[0048] Preferred forms of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which:

[0049] Figure 1 is a schematic partial cross-sectional side view of a first embodiment of a milk frother;

[0050] Figure 2 yes Figure 1 A schematic isometric view of a frothing assembly of a milk frother;

[0051] Figure 3 yes Figure 2 A schematic front view of a foaming component;

[0052] Figure 4 yes Figure 1 Another schematic cross-sectional side view of a milk frother of FIG.

[0053] Figure 5 yes Figure 1 Another cross-sectional side view of the milk frother;

[0054] Figure 6 yes Figure 1 A schematic cross-sectional side view of a container for use in a milk frother with a portion of a frothing assembly;

[0055] Figure 7 yes Figure 6 A schematic bottom plan view of the lower portion of the foaming component;

[0056] Figure 8 yes Figure 1 A schematic cross-sectional side view of a modification of a foaming component;

[0057] Fig. 9 yes Figure 8 Another schematic cross-sectional side view of a foaming component;

[0058] Fig.10 yes Figure 1A schematic cross-sectional side view of a modification of a foaming component;

[0059] Fig.11 yes Fig.10 A schematic bottom plan view of a foaming component;

[0060] Fig.12 yes Figure 1 A schematic cross-sectional side view of a modification of a foaming component;

[0061] Fig.13 yes Fig.12 A schematic bottom plan view of a foaming component;

[0062] Fig.14 yes Figure 1 A schematic isometric view of a modification of a foaming component;

[0063] Fig.15 yes Fig.14 A schematic isometric view of a foaming component;

[0064] Fig.16 yes Figure 1 A schematic cross-sectional side view of a modification of a foaming component;

[0065] Fig.17 yes Fig.16 A schematic cross-sectional side view of a foaming component;

[0066] Fig.18 yes Figure 1 A schematic cross-sectional side view of a modification of a foaming component;

[0067] Fig.19 yes Fig.18 A schematic cross-sectional side view of a portion of a foaming component;

[0068] Fig. 20 yes Fig.18 A schematic cross-sectional side view of a portion of a foaming component;

[0069] Fig.21 yes Figure 1 A schematic side view of a modification of a foaming component;

[0070] Fig. 22 yes Fig.21 A schematic cross-sectional side view of a foaming component;

[0071] Fig.23 is a schematic partial cross-sectional side view of a second embodiment of a milk frother;

[0072] Fig.24 yes Fig.23 A schematic partial cross-sectional side view of a modification of a foaming component;

[0073] Fig.25 yes Fig.23 A schematic cross-sectional side view of a first embodiment of a cleaning device for a milk frother;

[0074] Fig.26 yes Fig.25 A schematic isometric view of a cleaning device;

[0075] Fig. 27 yes Fig.25 Another schematic cross-sectional side view of a cleaning device;

[0076] Fig.28 yes Fig.25 Another schematic isometric view of a cleaning device;

[0077] Fig.29 yes Fig.25 Another schematic cross-sectional side view of a cleaning device;

[0078] Fig.30 yes Fig.25 Another schematic isometric view of a cleaning device;

[0079] Fig.31 yes Fig.23 A schematic cross-sectional side view of a second embodiment of a cleaning device for a milk frother;

[0080] Fig.32 yes Fig.31 A schematic isometric view of a cleaning device;

[0081] Fig.33 yes Fig.32 Another schematic cross-sectional side view of a cleaning device;

[0082] Fig.34 yes Fig.31 Another schematic isometric view of a cleaning device;

[0083] Fig.35 yes Fig.31 Another schematic cross-sectional side view of a cleaning device;

[0084] Fig.36 yes Fig.31 Another schematic isometric view of a cleaning device;

[0085] Fig.37 is a schematic partial cross-sectional side view of a third embodiment of a milk frother;

[0086] Fig.38 yes Fig.25 A schematic isometric view of a foaming device and a container;

[0087] Fig.39 and Fig.40 yes Fig.25 A schematic isometric view of a milk frother;

[0088] Fig.41 is a schematic partial cross-sectional side view of a fourth embodiment of a milk frother;

[0089] Fig.42 and Figure 43 Fig.29 A schematic isometric view of a milk frother;

[0090] Fig.44 is a schematic partial cross-sectional side view of a fifth embodiment of a milk frother; and

[0091] Fig.45 and Fig.46 yes Fig.32 Schematic isometric view of a milk frother. DETAILED DESCRIPTION

[0092] In the attached figure Figures 1 to 7 In FIG. 1 , a first embodiment of a milk frother 10 is schematically depicted. The milk frother 10 comprises a container (tank) 11 which will receive milk 12 for frothing the milk.

[0093] The milk frother 10 comprises a base assembly 13 providing a housing 14 in which an induction coil 15 is mounted to heat the container 11 and the milk 12 .

[0094] A temperature sensor 16 is also mounted in the housing 14 to sense the temperature of the container 11 (and hence the milk 12) and to provide a signal indicative of the temperature.

[0095] Also mounted in the housing 14 is a user interface 17 , which a user can manipulate to control the milk frother 10 .

[0096] The interface 17 is operably associated with a microprocessor and control circuit 18 which operates the induction coil 15 and receives the signal generated by the temperature sensor 16 .

[0097] Circuitry 18 also operates fan 19 to flow air through housing 14 to cool components located therein.

[0098] The milk frothing assembly 21 is supported on a rod 20 fixed to the base assembly 13. The assembly 21 is also electrically connected to the circuit 18 through an electrical conduit 22 so as to be controlled by the circuit 18.

[0099] Assembly 21 is mounted on pole 20 so as to be height-adjustable in direction 23 relative to container 11 resting on base assembly 13 .

[0100] Rod 20 (such as Figure 2 best shown) includes an upwardly extending slot 24 which provides height adjustment for the assembly 21.

[0101] Assembly 21 is attached to rod 20 by mounting 25. Mounting 25 includes a sleeve 26 slidable on rod 20 in direction 23. Rod 20 passes through sleeve 16 so that mounting 25 slidably moves along rod 20 to maintain assembly 21 in the orientation shown.

[0102] The sleeve 26 has a plurality of threaded holes 27 that receive stop members (threaded fasteners) 28. The stop members 28 pass through the slots 24 and engage the lower ends 29 of the slots 24 to position the assembly 21 at a desired height. By engaging the stop members 28 in a selected one of the holes 27, the height can be adjusted because the holes 27 are arranged at different heights, i.e., different positions in the direction of the slots 24.

[0103] The mount 25 also includes a body 31 extending generally horizontally from the sleeve 26 attached thereto.

[0104] Pivotally mounted on the body 31 is a lock 30 for angular movement about a generally horizontal axis (i.e., generally perpendicular to the direction 23 and perpendicular to the axis of the rod 20). The lock 30 can engage a flange or step 32 of the sleeve 26 to hold the foaming component 21 in place. Figure 1 The latch position in the raised position shown (as shown Figure 1 32 and a release position spaced apart from the step 32 so that the assembly 21 can be moved to a lowered position determined by the position of the stop member 28 engaged with the end 29.

[0105] The foaming assembly 21 includes a motor 33 connected to the conduit 22 so as to receive power therefrom and be controlled by the circuit 18. The motor 33 rotatably drives the shaft 34 about its longitudinal axis 35 so as to have a rotation speed of about 5,500 rpm to about 13,500 rpm. The shaft 34 operates a foaming device 36. The foaming device 36 includes a central longitudinal shaft 37, which is provided with an impeller 38 at its lower end. In this embodiment, the impeller 38 includes a plurality of blades 39 fixed to the shaft 37 so as to rotate therewith. The shaft 37 is fixed to the shaft 34 so as to be driven about the axis 35. The blades 39 are angularly spaced about the axis 35. The device 36 has the same rotation speed as the motor 33. Preferably, the circuit 18 controls the motor 33 to rotate 34 and therefore the device 36 at a rotation speed of about 9,500 rpm for a first period of time and then at a rotation speed of about 13,500 rpm for a second period of time.

[0106] Preferably, the blades 39 have a direction of extension away from the axis 37 that includes a radial component. More preferably, the blades 39 also have a direction of extension away from the axis 37 that also includes an angular component. In the longitudinal direction, the blades 39 are generally parallel to the axis 35. Preferably, the blades are generally planar and are inclined at an acute angle 41 to a radius 40. Preferably, the blades 39 are equiangularly spaced about the axis 35.

[0107] Impeller 38 is driven in a rotational direction 42 , with each blade being inclined at an angle 41 from an adjacent radius 40 along direction 42 .

[0108] The frothing assembly 21 includes a perforated member 43 surrounding the impeller 38. In this embodiment, the perforated member 43 is cylindrical in configuration and is spaced apart from the radially outer ends of the blades 39 by a gap 44. Thus, there is an annular space 45 surrounding the impeller 38. The member 43 has a lower end 82. The member 43 has a lower end 82 with a plurality of radial passages 83 through which the milk flows. However, there is milk shear between the impeller 38 and the member 43 to at least assist in frothing the milk.

[0109] When using the above-described milk frother 10, the motor 33 is driven at an angular speed of 5,500 rpm to 13,500 rpm, wherein the impeller 38 has four blades 39. The container 11 is cylindrical in construction so as to have a diameter 46 and the milk has a depth 47. Preferably, the lower end of the frothing device 36 is spaced from the base 48 of the container 11 by a depth 49. Preferably, the member 43 has a diameter 50 and the impeller 38 has a diameter 51. Preferably, the blades 39 have a longitudinal length 52 in the direction 23. The blades 39 are generally coextensive with the portion 82 in the direction of the axis 35.

[0110] Preferably, depth 47 is approximately equal to inner diameter 46. Preferably, length 52 is 1 / 4 to 1 / 6 of diameter 51. Preferably, the depth is 1 / 2 to 1 / 6 of depth 47. Preferably, diameter 51 is four to eight times greater than gap 44, most preferably six times greater than gap 44. Preferably, gap 44 is about .5 to about 1.00 mm, most preferably about .5 mm. Preferably, angle 41 is 20° to 30°, and most preferably about 25°.

[0111] like Figure 6 As shown, milk frothing assembly 21 circulates milk 12 in container 11. Specifically, assembly 21 causes circulation so that the milk moves angularly about axis 35 in direction 42. However, assembly 21 also circulates the milk to form annular vortices 80 and 81. Vortices 80 and 81 are annular relative to axis 35, wherein the milk moves along Figure 6Specifically, the milk is moved outwardly from the perforated end 82 of the member 43, thereby having a radial component and a longitudinal component relative to the axis 35. The circulation of the milk 12 also provides for the milk to be transported upwardly toward the gap 44 from a location adjacent to the base 48 and generally in the center of the container 11. When engaged with the blades 39, the milk is moved radially outwardly through the passage 83 to circulate again.

[0112] exist Figure 8 and 9 In the embodiment of the present invention, the shaft 37, the member 43 and the impeller 38 are removable from the motor 33 as an assembly. Fixed to the motor 33 is a latch assembly 53, which includes an inner sleeve 54 having a plurality of holes 55 each accommodating a spherical element 56. The elements 56 are captively located in their respective holes 55, which are radially movable between inner and outer positions relative to the axis 35. These positions are determined by a slider 57. The slider 57 has a plurality of recesses 58 in which the elements 56 are received. The slider 57 is urged in a direction 59 by a spring 60 so as to urge the elements 56 radially inwardly. The member 43 has an annular groove 44 at its upper end in which the elements 56 are received to keep the assembly of the member 43, the shaft 37 and the rotor 38 attached to the motor 33 and in driving engagement with the shaft 34. When the slider 57 is in the upper position, the slider 57 holds the elements 56 in the groove 44, thereby keeping the member 43 fixed to the motor 33. However, when the slider 57 is moved downward (opposite to the direction 59), the element 58 is allowed to move radially outward. Thus, from the moment the user grasps and moves the component 43 downward, the element 56 leaves the groove 44 and allows the component 43 to be removed from the motor 33.

[0113] exist Fig.10 and Fig.11 In the embodiment of the invention, the frothing device 36 is provided with a temperature sensor 61 which provides a signal indicative of the temperature of the milk 12. The sensor 61 communicates with the circuit 18 so that the circuit 18 can best adapt the operation of the induction coil 58 and the froth machine 56 in terms of duration, temperature and operating speed to optimize the production of frothed milk.

[0114] exist Fig.12 and Fig.13 In the embodiment of the present invention, the temperature sensor 61 is enclosed in the chamber 62, and Fig.10 and Fig.11 In the embodiment of FIG. 6 , the temperature sensor 61 protrudes outward from the cavity 62. Fig.14 and Fig.15In the embodiment of the invention, the latch assembly 53 has been modified. In this embodiment, the latch assembly 53 is a "twist lock". In this embodiment, there is a sleeve 63 fixed to the motor 33, the sleeve 63 having an angularly extending slot 64 terminating in a recess 65. The slot 64 extends angularly about the axis 35, while the recess 65 extends in the direction of the axis 35. The assembly of the shaft 37, member 44 and rotor 38 is provided with a cylindrical portion 66 having a relatively radially extending protrusion 67 which is received in the slot 64 and angularly moved along it to engage in the recess 65 to securely attach the assembly of the member 43 and shaft 37 drivingly connected to the shaft 34 and fixed to the motor 33. Angular movement of the cylindrical member 66 in a direction 68 engages the sleeve 66 relative to the motor 33, while angular movement in a direction opposite to the direction 68 disengages the sleeve 66 from the motor 33.

[0115] exist Fig.16 and Fig.17 In the embodiment of the present invention, the assembly of member 44, shaft 37 and impeller 38 is again releasably secured to motor 33 by a latch assembly 53. In this embodiment, latch assembly 53 includes an elastic ring 69 that is radially compressible relative to axis 35 to a retracted position to remove member 43 relative to motor 33, and radially compressible to a radially outer position (e.g., Fig.16 33), wherein the ring 69 engages in an annular groove 70 of a protrusion 71 fixed to the motor 33. When extended into the annular groove 70, the member 43 is fixed to the motor 33. A butterfly 72 is fixed to the protrusion 71, and the butterfly 72 is pushed inwardly by the user to cause the ring 69 to compress and release the member 43. The ring 69 is resiliently urged outwardly to engage in the annular groove 70.

[0116] exist Fig.18 , Fig.19 and Fig. 20 In the embodiment of the present invention, the latch assembly 73 includes a pair of opposed angularly movable pawls 73 fixed to the motor 33 and angularly movable toward the axis 35 to engage and disengage the member 43. The member 43 has an enlarged end 74, which is provided with an annular groove or a spaced groove 75, and the distal end of the pawl 73 is engaged in the groove. The pawl 73 is moved radially inward relative to the axis 35 by the user engaging the butterfly 76 and moving it inward, so that the pawl 73 is moved radially inwardly to disengage from the recess 75.

[0117] exist Fig. 20 and Fig.21In the embodiment of the present invention, the lock assembly 53 has an annular lock member 76 that projects radially inward to engage in an annular recess 77 in the upper end of the member 43. The user grasps the sleeve 78 and moves the sleeve 78 in a direction parallel to the axis 35 to move the member 76 radially relative to the recess 77 for engagement and disengagement. Fig. 22 In the embodiment, the component 76 is held in the recess 77 by the sleeve 78. If the sleeve 78 moves downward in the direction 79, the component 76 moves radially outward under its own elasticity, thereby leaving the recess 77 to remove the component 43 relative to the motor 33.

[0118] Fig.23 and Fig.24 A second embodiment of a milk frother 100 is shown that operates in substantially the same manner as the milk frother 10 described above, with like reference numerals being used to indicate like features. In this embodiment, the milk frother 100 includes a fluid pump 185 and a fluid source mounted in the housing 114 and operably associated with the circuit 118. It should be understood that the fluid source is a fluid tank 186 mounted in the housing 114, or alternatively a mains fluid supply external to the housing 114. The milk frother 100 also includes a fluid sensor 187 mounted in the housing 114 and operably associated with the circuit 118. An air pump 188, an air pressure sensor 189, and switches 190, 191 also operably associated with the circuit 118 are also mounted in the housing 114. The circuit 118 and the motor 133 of the frothing assembly 121 are powered by a power supply 184 within the housing 114.

[0119] Fluid pump 185 is connected to a fluid source (i.e., fluid tank 186 or a mains fluid supply) and fluid sensor 187. Fluid is added to fluid tank 186 through an opening (not shown) in housing 114. Circuitry 118 also operates fluid sensor 187 to detect the amount of fluid within fluid tank 186 and alert a user via user interface 117 if the detected amount of fluid is low.

[0120] The circuit 118 operates the air pump 188 to draw air from an opening (not shown) in the side wall of the housing 114. The air pump 188 is connected to an air pressure sensor 189 to detect the amount of air drawn into the air pump 188. It is contemplated that the circuit 118 may additionally include other forms of sensors, such as a speed sensor, to detect the motor speed of the air pump 188 and predict the amount of air drawn into the air pump 188.

[0121] The fluid pump 185 is connected to the hollow passage 192 of the central longitudinal axis 137 of the frothing device 136 via a fluid conduit 193. The hollow passage 192 includes an opening connected to the impeller / rotor 138. The air pump 188 is also connected to the hollow passage 192 via an air conduit 194. After the milk frothing device 100 is used, the circuit 118 operates the fluid pump 185 and the air pump 188 to pump fluid and air (separately or simultaneously) into the hollow passage 192 so as to purge and thereby clean the inner and outer surfaces of the impeller / rotor 138. It will be understood that in other embodiments (not shown), the hollow passage 192 of the central longitudinal axis 137 is directly connected to a fluid source (e.g., directly connected to the fluid tank 186 or connected to a mains fluid supply via a manually operated valve). When connected to a mains fluid supply, the valve is operable to introduce fluid from the mains fluid supply into the hollow passage 192 to purge and thereby clean the inner and outer surfaces of the impeller / rotor 138.

[0122] It should be appreciated that control of the fluid sensor 187 , the pressure sensor 189 , the fluid pump 185 , and the air pump 188 is facilitated by switches 190 and 191 .

[0123] exist Fig.24 In the embodiment of the present invention, the circuit 118, fluid pump 185, fluid tank 186, fluid sensor 187, air pump 188, air pressure sensor 189, and switches 190, 191 are mounted in a housing 195 and located above the motor 133 and the foaming device 136, rather than in the housing 114 of the base assembly 113. In this embodiment, the fluid pump 185 is connected to a fluid reservoir 196 located outside the housing 195. The power source 184 is also located outside the housing 195.

[0124] exist Figures 25 to 30 , a first embodiment of a cleaning device 197 of a milk frother 100 is schematically depicted. The cleaning device 197 is mounted to the perforated member 143 of the frothing device 136. The cleaning device 197 comprises a container 197a, which is mounted to the perforated member 143 by an associated cover 197b. The cover 197b is removably engaged with the container 197a by a snap-fit ​​engagement. The container 197a is adapted to receive and contain a fluid (e.g., water or a cleaning solution). The frothing device 136 is operable to agitate the fluid contained in the container 197a, thereby cleaning the inner and outer surfaces of the impeller / rotor 138 and the surface of the perforated member 143.

[0125] exist Figure 31 to Figure 36, a second embodiment of a cleaning device 198 of a milk frother 100 is schematically depicted, which functions in substantially the same manner as the cleaning device 197 described above. However, in this embodiment, the cleaning device 198 comprises an outer container 198a, an associated cover 198b and an inner container 198c. The inner container 198c is mounted within the outer container 198a and comprises a plurality of protrusions 198d extending radially inwardly from the wall of the inner container 198c. The inner container 198c also comprises a plurality of perforations 198e arranged in a spatial relationship with the plurality of protrusions 198d. The plurality of protrusions 198d can engage with the perforated member 143. Both the inner container 198c and the outer container 198a are adapted to receive and contain fluids.

[0126] The inner container 198c includes a base 198f and a plurality of base protrusions 198g extending upwardly from the base 198f. The plurality of base protrusions 198g can engage with the impeller 138 of the foaming device 136. The engagement of the base protrusions 198g and the operation of the impeller 138 cause the inner container 198c to also rotate about the longitudinal axis 135 of the shaft 134. The rotation creates friction between the protrusions 198d and the perforated member 143, so that the protrusions 198d act in a manner similar to the bristles on a brush. This action, combined with the agitation of the fluids within the inner and outer containers 198c and 198a, promotes cleaning of the inner and outer surfaces of the impeller 138.

[0127] Figures 37 to 40 A third embodiment of a milk frother 200 is shown which also operates in substantially the same manner as the milk frothers 10 and 100 described above, with like reference numerals being used to indicate like features. However, in this embodiment of the milk frother 200, a frothing assembly 221 is located within a housing 214 of a base assembly 213, rather than being supported on the rod 120 of the first and second embodiments of the milk frothers 10 and 100 described above.

[0128] The frothing assembly 221 includes a motor 233 that rotatably drives the shaft 234 about its longitudinal axis 235, thereby having a rotation speed of about 5,500 to 13,500 rpm, the same as the milk frothers 10 and 100 described above. An impeller 238 is coupled to the shaft 234, thereby being driven about the axis 235. The impeller 238 includes a plurality of protrusions 239 angularly spaced about the axis 235.

[0129] In this embodiment, the base 201 of the container 211 includes a channel 202 formed therein. The channel 202 is defined by a hollow space surrounded by a cylindrical wall 203, which is formed with an external thread 204 at its upper end. The milk frother 200 includes a perforated member 243 having an internal thread 205 corresponding to the external thread 204 of the channel 202, thereby allowing the perforated member 243 to be tightened onto the channel 202 of the container 211. The hollow space of the channel 202 accommodates an impeller 238. An agitator member 206 is attached to the impeller 238, and the agitator member 206 has a protrusion 207 corresponding to the protrusion 239 of the impeller 238 to provide a sliding fit therebetween. A bearing 208 and a washer 209 are also coupled to the impeller 238 to provide balance and structural integrity for the impeller 238 and the agitator member 206 while the drive shaft 234 rotates.

[0130] like Fig.39 and 40 As best shown, the container 211 includes a plurality of recesses 250 that correspond to a plurality of protrusions 251 on the housing 214 of the base assembly 213 to provide a yellow fit when the container 211 is mounted on the housing 214. A temperature sensor 252 and a weight sensor 253 are mounted on the protrusions 251. An induction coil 254 is also mounted in the housing 214 of the base assembly 213 (see FIG. Fig.37 ), which is connected to the circuit 218 to provide heat to the base 201, thereby providing heat to the container 211 to heat the milk 12 therein.

[0131] Figure 41 to Figure 4 3 shows a third embodiment of a milk frother 300 having a generally similar structure to the milk frother 200 described above, wherein like reference numerals are used to indicate like features. However, in this embodiment of the milk frother 300, the housing 314 of the base assembly 313 includes external threads 355 that correspond to internal threads 356 of an attachment 357 attached to the container 311. The corresponding external and internal threads 355 and 356 allow the container 311 to be screwed onto the housing 314 of the base assembly 313 and secured thereto.

[0132] Figures 44 to 46 A fourth embodiment of a milk frother 400 is shown, which again has a generally similar structure to the milk frothers 200 and 300 described above, with like reference numerals used to indicate like features. However, in this embodiment of the milk frother 400, the housing 414 of the base assembly 413 includes a recess 458 sized to receive a portion of the container 411 therein. The recess 458 includes a sidewall 459 in which an additional induction coil 421 is positioned to provide additional heating of the milk 12 within the container 211.

Claims

1. A frothing assembly for frothing milk in a container, the assembly comprising: main body; an electric motor fixed to the body and having an output shaft rotatably driven in a rotational direction about a longitudinal axis of the shaft; a frothing device rotatably driven by the shaft and immersed in the milk in the container; and a cylindrical perforated member at least partially surrounding the frothing device and separated from the frothing device by a gap, wherein the perforated member has an end portion providing a plurality of radial channels through which milk can pass, and wherein the end portion terminates with an opening along the longitudinal axis, wherein rotation of the frothing means is adapted to cause movement of milk in the gap and through the perforated member to circulate back through the container and the gap to cause frothing of the milk, and wherein the frothing means comprises a plurality of generally planar blades angularly spaced about the axis, wherein the generally planar blades are generally parallel to the longitudinal axis and have extension directions inclined at an acute angle in the direction of rotation away from the axis to a radial direction, wherein each of the plurality of planar blades is spaced apart along the longitudinal axis. 2 . The foaming component of claim 1 , wherein the end portion is at least partially coextensive with the blade in the axial direction.

3. The foaming component of claim 1, wherein the end portion is substantially coextensive with the blade in the axial direction.

4. A foaming assembly according to any one of claims 1 to 3, wherein the foaming device and perforated member provide an assembly that is detachable relative to the motor.

5. The foaming component according to any one of claims 1 to 3, wherein the gap is annular and is 0.5 to 1.00 mm. The foaming component according to claim 5 , wherein the gap is about 0.5 mm.

7. A milk frother comprising a base for supporting an upper container and to which a frothing assembly according to any one of claims 1 to 6 is attached.

8. The foamer of claim 7, further comprising a rod fixed to extend upwardly from the base, the foaming assembly being attached to the base.

9. The foamer of claim 8, wherein the position of the foaming assembly on the rod is longitudinally adjustable to adjust the height of the foaming device relative to the container.

10. The frother of claim 9, wherein the motor is located above the perforated member, the perforated member extending downwardly from the motor to be at least partially immersed in the milk in the container.

11. The frother of claim 10, wherein the base includes a heater for heating milk in the container.

12. A frother according to claim 11, wherein the base comprises a temperature sensor for detecting the temperature of the container, and hence the temperature of the milk.

13. The foamer of claim 12, further comprising a circuit for controlling the motor and receiving a signal from the temperature sensor and controlling the heater.

14. The foamer of claim 13, wherein the circuit activates the motor to rotate the foaming device at a rotational speed of about 5500 rpm to about 13,500 rpm.

15. The foamer of claim 14, wherein the circuit activates the motor to rotate the foaming device at a rotational speed of about 13,500 rpm for a period of time and then at a rotational speed of about 9,500 rpm for another period of time.

16. A milk frother for frothing milk in a container, the milk frother comprising: a base assembly for supporting the container, the base assembly including a fluid source; and a foaming assembly attached to the base assembly, the foaming assembly comprising: main body; a motor fixed to the body and having an output shaft rotatably driven about a longitudinal axis of the output shaft, the output shaft including a hollow passage in communication with the fluid source; a frothing device rotatably driven by the shaft and immersed in the milk in the container; and a cylindrical perforated member at least partially surrounding the frothing device and separated from the frothing device by a gap, the perforated member communicating with the hollow passage of the output shaft, wherein the perforated member has an end portion providing a plurality of radial passages through which milk can pass, and wherein a distal end of the end portion has an opening along the longitudinal axis, wherein rotation of the frothing means is adapted to cause movement of milk in the gap and through the perforated member to circulate back through the container and the gap to cause frothing of the milk, and wherein the frothing means comprises a plurality of generally planar blades angularly spaced about the axis, wherein the generally planar blades are generally parallel to the longitudinal axis and have an extension direction inclined at an acute angle to a radial direction away from the axis, wherein each of the plurality of planar blades is spaced apart along the longitudinal axis; and Thereby, the fluid source is operable to dispense fluid through the hollow passage and the perforated member.

17. A milk frother for frothing milk in a container, the milk frother comprising: a base assembly having a body for supporting the container; and a foaming assembly at least partially mounted in the body of the base assembly, the foaming assembly comprising: an electric motor having an output shaft rotatably driven about a longitudinal axis of the shaft; a frothing device rotatably driven by the shaft and immersed in the milk in the container; and a cylindrical perforated member at least partially surrounding the frothing device and spaced apart from the frothing device by a gap, wherein the perforated member has an end portion providing a plurality of radial passages through which milk can pass, and wherein the end portion terminates with an opening along the longitudinal axis; wherein rotation of the frothing device is adapted to cause movement of milk in the gap and through the member to circulate back through the container and the gap to cause frothing of the milk, and wherein the frothing device comprises a plurality of generally planar blades angularly spaced about the axis, wherein the generally planar blades are generally parallel to the longitudinal axis and have an extension direction inclined at an acute angle to a radial direction away from the axis, wherein each of the plurality of planar blades is spaced apart along the longitudinal axis.

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