REGULATION OF WISKING OF A FOOD SUBSTANCE

Abstract

A machine (1) has: a tank (10) having a cavity (10′) for containing and processing a batch of liquid food substance; a stirring tool (15) in the cavity (10′) having a stirring surface (151) for imparting a mechanical effect on said food substance in the cavity (10′) to froth the food substance; an actuator configured to rotate the stirring tool (15) in the cavity (10); and a control unit configured to control the actuator so that the rotational speed of the stirring tool (15) is changeable. The control unit has a mode in which the actuator is controlled by the control unit so that: during a first phase (501) of processing the batch, the stirring tool (15) is rotated below a low frothing rotational speed (511); and thereafter during a second phase (502) of processing said batch, the rotational speed (512) of the stirring tool (15) is increased from the low frothing rotational speed (511) to above a high frothing rotational speed (513); and thereafter during a third phase (503) of processing said batch, the stirring tool (15) is rotated above the high frothing rotational speed (513).

Claims

1. A machine comprising: a tank having a cavity for containing and processing a batch of liquid food substance; a stirring tool in the cavity having a stirring surface for imparting a mechanical effect on the food substance in the cavity to froth the food substance; an actuator configured to rotate the stirring tool in the cavity; and a control unit configured to control the actuator so that the rotational speed of the stirring tool is changeable, the control unit has a mode in which the actuator is controlled by the control unit so that: during a first phase of processing the batch, the stirring tool is rotated below a low frothing rotational speed; and thereafter during a second phase of processing the batch, the rotational speed of the stirring tool is increased from the low frothing rotational speed to above a high frothing rotational speed; and thereafter during a third phase of processing the batch, the stirring tool is rotated above the high frothing rotational speed.

2. The machine of claim 1, wherein the control unit is configured in the mode such that the second phase is engaged after at least one of: a predetermined period of time corresponding to the first phase, such as a period of time in the range of 10 to 45 sec.; and a resistance against rotation of the stirring tool has increased while the stirring tool has been rotated below the low frothing rotation speed by at least 10%.

3. The machine of claim 1, wherein the control unit is configured in the mode to control the actuator so as to drive during a start-up phase the stirring tool from rest, at a rotational speed of zero, to reach the first phase within a period of time in the range of 2 to 25 sec.

4. The machine of claim 1, wherein during the second phase in the mode, the rotational speed of the stirring tool is increased from the low rotational speed to reach the third phase within a period of time in the range of 5 to 30 sec.

5. The machine of claim 1, wherein in the mode: during the first phase, the rotational speed is maintained within a span of 3 or 5% of the low rotational speed immediately below the low rotational speed ; and/or during the third phase the rotational speed is maintained within a span of 2 to 4% of the high rotational speed immediately above the high rotational speed; and/or the first and third phases lasting for a cumulated period of time that is in the range of: 45 to 90 sec.; and/or 50 to 95% of a total length of time of imparting a mechanical effect with the stirring tool on said-the batch in the cavity; and a total length of time of imparting a mechanical effect with the stirring tool on the batch in the cavity being in the range of 60 to 120 sec.

6. The machine of claim 1, wherein the high rotational speed and the low rotational speed have a ratio that is in the range of 1.02 to 5.

7. The machine of claim 1, wherein: the low rotational speed is in the range of 10 to 50 Hz; and/or the high rotational speed is in the range of 15 to 75 Hz.

8. The machine of claim 1, wherein the control unit has a different mode in which the actuator is controlled by the control unit so that: during an initial phase of processing the batch, for instance an initial phase lasting a period of time in the range of 0.5 to 15 sec., stirring tool is rotated from zero to a constant frothing rotational speed; and thereafter during a main phase of processing the batch, for instance a main phase lasting a period of time in the range of 50 to 250 sec., the rotational speed of the stirring tool is maintained substantially at the constant rotational speed; and thereafter during an end phase of processing the batch, for instance an end phase lasting a period of time in the range of 0.5 to 10 sec., the rotational speed of the stirring tool is allowed to drop to zero.

9. The machine of claim 1, which comprises a base supporting the tank, the base containing the actuator and the control unit.

10. The machine of claim 9, wherein the base has an upright outside gripping surface, located under the tank and seizable by an adult human hand such that the base with the supported tank can be carried and displaced single-handed by seizure of the upright outside gripping surface, the tank extending horizontally beyond the outside gripping surface.

11. The machine of claim 10, which has a foot that has a bottom side configured to be placed on a substantially horizontal external support surface, such as a surface formed by a table or a shelf, during processing of the batch of liquid food substance, and to support the base during such processing.

12. The machine of claim 11, wherein the base is removably mounted to the foot, the base and the foot having a connection that is configured to: inhibit or prevent relative pivoting of the base and the foot about an axis extending along the external support surface during such processing; and/or conduct electric power from the foot into the base; and/or be connectable in a plug and socket fashion.

13. The machine of claim 11, wherein the foot extends horizontally beyond the outside gripping surface.

14. The machine of claim 1, wherein the stirring tool comprises a homogenising device for homogenizing the batch of liquid food substance during thermal conditioning thereof.

15. The machine of claim 1, which has a central upright axis along which at least one of the tank, the cavity, and when present the base and/or the foot, extends, the cavity and, when present, the base and/or the foot having a shape of revolution about the central upright axis such as a cylindrical and/or conical shape and/or spherical shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0099] The invention will now be described with reference to the schematic drawings, wherein:

[0100] FIG. 1 is a perspective side view of a machine having a tank on a base and foot, a stirring tool, an actuator and control unit configured according to the invention;

[0101] FIG. 2 is a perspective side view of the machine of FIG. 1 in which the tank and the base have been separated from the foot;

[0102] FIG. 3 is a cross-sectional perspective view of the machine shown in FIG. 1;

[0103] FIG. 4 is a graph showing the control of the actuator and the rotational speed of the stirring tool over time in an advantageous mode of the control unit of the machine of FIG. 1; and

[0104] FIG. 5 is a graph showing the control of the actuator and the rotational speed of the stirring tool over time in a different mode of the control unit of the machine of FIG. 1.

DETAILED DESCRIPTION

[0105] An exemplary embodiment of a machine 1 according to the invention is illustrated in FIGS. 1 to 3. FIGS. 4 and 5 illustrate two possible modes of the machine's control unit to operate the machine's stirring tool.

[0106] Machine 1 has a tank 10 with a cavity 10′ for containing and processing a batch of liquid food substance, such as milk or a milk-based substance. Tank may have an access opening that is covered by a removable lid 12, e.g. via a seal 13.

[0107] Machine 1 has a stirring tool 15 in cavity 10′. Tool 15 has a stirring surface 151 for imparting a mechanical effect on the food substance in cavity 10′ to froth the food substance. Stirring tool 15 may be driven from outside the tank 10. Stirring surface 151 can be formed by a helicoidal spring and/or an undulated plate and/or a plurality of radial frothing wings.

[0108] Machine 1 includes an actuator configured to rotate stirring tool 15 in cavity 10′. The actuator may be magnetically coupled to stirring tool 15, e.g. via a tank side wall and/or a bottom wall and/or top wall.

[0109] Machine 1 has a control unit configured to control the actuator so that the rotational speed of stirring tool 15 is changeable. For instance, the control unit includes a processor and/or a controller and/or a user-interface 26, e.g. a user-interface 26 at an outside housing 2.

[0110] Stirring tool 15 may have an upright extending elongated part 16. Part 16 may be topped with a radial protruding element 161 such as a ball.

[0111] Stirring tool 15 can have an upright arched part 162, such as an arched part, located above stirring surface 151. For instance, upright arched part 162 is located below upright extending elongated part 16.

[0112] Stirring tool 15 may have a connection part 163 for connection with a connection part 17 of tank 10 to position stirring tool 15 in tank 10. Connection parts 163,17 may form a plug and socket arrangement and/or magnetic connecting parts. Connection parts 163,17 may be configured to position stirring tool 15 on a central upright axis 1′ in cavity 10′ or in parallel to axis 1′.

[0113] The control unit has a mode in which the actuator is controlled by the control unit so that: [0114] during a first phase 501 of processing the batch, stirring tool 15 is rotated below a low frothing rotational speed 511; and thereafter [0115] during a second phase 502 of processing the batch, rotational speed 512 of stirring tool 15 is increased from the low frothing rotational speed 511 to above a high frothing rotational speed 513; and thereafter [0116] during a third phase 503 of processing the batch, stirring tool 15 is rotated above the high frothing rotational speed 513.

[0117] The control unit can be configured to control a voltage supply 50′ and/or a current supply and/or a frequency of a power supply to the actuator to adjust the frothing rotational speed 50 of stirring tool 15.

[0118] Further to the control unit and to the actuator, such machine 1 may be free of any thermal conditioner or may comprise a thermal conditioner 23 that is controlled by the control unit to produce substantially no heat in cavity 10′ in the above mentioned mode during first, second and third phases 501,502,503, such as during a total length of time of imparting a mechanical effect with stirring tool 15 on the batch in cavity 10′, such as a total length of time of processing the batch in cavity 10′.

[0119] The control unit may be configured in the above mentioned mode such that second phase 502 is engaged after at least one of: a predetermined period of time corresponding to the first phase 501, such as a period of time in the range of 10 to 45 sec., such as 15 to 35 sec., e.g. 20 to 25 sec.; and a resistance against rotation of stirring tool 15 has increased while stirring tool 15 has been rotated below the low frothing rotation speed 511 by at least 10%, such as at least 20%, for instance at least 30%, e.g. at least 40%.

[0120] The control unit is configured in the above mentioned mode to control the actuator so as to drive during a start-up phase 500 stirring tool 15 from rest, at a rotational speed 50 of zero, to reach first phase 501 within a period of time in the range of 2 to 25 sec., such as 5 to 20 sec, e.g. 10 to 15 sec. Stirring tool 15 may be driven during start-up phase 500 at a rotational speed 510 that is increased from zero to above the low frothing rotational speed 511 to then drop to below the low frothing rotational speed 511, such as: to less than 15%, e.g. less than 10%, above the low frothing rotational speed 511; and/or for a period of time above the low frothing rotational speed 511 of less than 10 sec., e.g. less than 6 sec.

[0121] During the second phase 502, rotational speed 50 of stirring tool 15 is increased from low rotational speed 511 to reach third phase 503 within a period of time in the range of 5 to 30 sec., such as 10 to 20 sec, e.g. 12 to 16 sec. Stirring tool 15 may be driven during second phase 502 at a rotational speed 512 that is increased from the low frothing rotational speed 511 to above the high rotational speed 513 to then drop towards high rotational speed 513, such as: increased to less than 10%, e.g. less than 5%, above high rotational speed 513; and/or for a period of time above the low frothing rotational speed 511 of less than 10 sec., e.g. less than 6 sec.

[0122] During first phase 501, rotational speed 50 can be maintained within a span of 3 or 5% of low rotational speed 511 immediately below low rotational speed 511.

[0123] During third phase 503, rotational speed can be maintained within a span of 2 to 4% of high rotational speed 513 immediately above high rotational speed 513.

[0124] First and third phases 501,503 may last for a cumlated period of time that is in the range of: 45 to 90 sec., such as 50 to 80 sec., for instance 55 to 70 sec., e.g. 60 to 65 sec.; and/or 50 to 95%, such as 55 to 80%, for instance 60 to 70%, of a total length of time of imparting a mechanical effect with stirring tool 15 on the batch in cavity 10′, such as a total length of time of processing the batch in cavity 10′.

[0125] A or the above mentioned total length of time of imparting a mechanical effect with stirring tool 15 on the batch in cavity 10′ can be in the range of 60 to 120 sec., such as 70 to 110 sec., for instance 80 to 100 sec., e.g. 85 to 95 sec.

[0126] High rotational speed 513 and low rotational speed 511 may have a ratio that is in the range of 1.02 to 5, such as 1.05 to 2.5, for instance 1.1 to 1.7, e.g. 1.13 to 1.2.

[0127] Low rotational speed 511 may be in the range of 10 to 50 Hz, such as 15 to 40 Hz, for instance 20 to 35 Hz, e.g. 25 to 30 Hz.

[0128] High rotational speed 513 can be in the range of 15 to 75 Hz, for instance 20 to 65 Hz, such as 25 to 50 Hz, e.g. 30 to 35 Hz.

[0129] The control unit can have a different mode in which the actuator is controlled by the control unit so that: [0130] during an initial phase 500a of processing the batch, for instance an initial phase 500a lasting a period of time in the range of 0.5 to 15 sec. such as 2 to 12 sec. e.g. 4 to 9 sec., stirring tool 15 is rotated from zero to a constant frothing rotational speed 511a; and thereafter [0131] during a main phase 501a of processing the batch, for instance a main phase 501a lasting a period of time in the range of 50 to 250 sec. such as 75 to 175 sec. e.g. 100 to 140 sec, rotational speed 50 of stirring tool 15 is maintained substantially at constant rotational speed 511a, e.g. at constant rotational speed 511a or within a range of less than 5% such as less than 2% of constant rotational speed 511a above and/or below constant rotational speed 511a, optionally constant rotational speed 511a being substantially equal to low rotational speed 511 or in the range of 10 to 50 Hz such as 15 to 40 Hz, for instance 20 to 35 Hz, e.g. 25 to 30 Hz; and thereafter [0132] during an end phase 502a of processing the batch, for instance an end phase 500a lasting a period of time in the range of 0.5 to 10 sec. such as 1.5 to 7.5 sec. e.g. 3 to 5 sec., rotational speed 50 of stirring tool 15 is allowed to drop to zero.

[0133] Tank 10 may be associated with a thermal conditioner 23 controlled by the control unit that, in such different mode, controls thermal conditioner 23 to generate heat in cavity 10′ so as to heat the batch of liquid food substance such as milk or a milk-based substance, e.g. to a temperature in the range of 55 to 70° C. e.g. 60 to 65° C.

[0134] Machine 1 may include a base 20 supporting tank 10. Base 10 may contain the actuator and the control unit and optionally a or the above mentioned thermal conditioner 23. Thermal conditioner 23 may be associated with a tank side wall and/or a bottom wall configured to emit thermal energy into and/or absorb thermal energy from cavity 10′. The thermal conditioner may comprise at least one of a resistor e.g. a thick film resistor 23, an induction, a thermocouple and a heat pump.

[0135] Base 20 can have an upright outside gripping surface 21, e.g. a textured or striated or corrugated or undulated or ruled or even surface to facilitate hand gripping, located under tank 10 and seizable by an adult human hand such that base 20 with supported tank 10 can be carried and displaced single-handed by seizure of the upright outside gripping surface 21. Tank 10 can extend horizontally beyond outside gripping surface 21. Outside gripping surface 21 may be at least substantially vertical, for instance vertical or inclined thereto by an angle of less than 15 deg., for instance less than 10 deg., such as less than 5 deg., e.g. less than 2.5 deg.

[0136] Tank 10 may have an outer horizontal tank perimeter.

[0137] Tank 10 can extend horizontally beyond outside gripping surface 21 over a predominant part of its tank perimeter, e.g. over more than 50 or more than 75% of its perimeter, such as over substantially the entire perimeter, e.g. above 90 or 95% of the perimeter.

[0138] The perimeter can have a circumference in the range of 15 to 70 cm, for instance 20 to 60 cm, such as 25 to 50 cm, e.g. 30 to 40 cm.

[0139] Tank 10 may have an upright outer tank surface 11 and cavity 10′ may have a height 11′. The outer horizontal perimeter may extend along outer tank surface 11. Outer tank surface 11 may be located horizontally beyond outside gripping surface 21 over substantially its entire tank perimeter over substantially the entire cavity height 11′. Upright outer tank surface 11 may be located horizontally beyond outside gripping surface 21 by a distance 21′ in the range of 0.5 to 10 cm, for instance 1 to 7 cm, such as 1.5 to 5 cm, e.g. 2 to 4 cm.

[0140] Upright outer tank surface 11 can be at least substantially vertical, for instance vertical or inclined thereto by an angle of less than 15 deg., such as less than 10 deg., e.g. less than 5 deg., for example less than 2.5 deg.

[0141] Machine 1 may include an outside housing 2 that forms upright outside gripping surface 21. Outside housing 2 may extend upright along at least part of the outer tank surface 11. Housing 2 can comprise a substantially horizontal and/or inclined intermediate portion 22, e.g. a straight or curved portion, extending from a top of upright outside gripping surface 21 to a bottom of upright outer tank surface 11, such as an inclined intermediate portion 22 having an inclination to a horizontal direction in the range of 15 to 75 deg., such as 20 to 70 deg., e.g. 40 to 60 deg.

[0142] Machine 1 can have a foot 30 that has a bottom side 31 configured to be placed on a substantially horizontal external support surface 3, such as a surface 3 formed by a table or a shelf, during processing of the batch of liquid food substance, and to support base 20 during such processing. Foot 30 may be assembled to or fixed to or integral with base 20.

[0143] Base 20 may be removably mounted to foot 30. Base 20 and foot 30 can have a connection 25,35.

[0144] Connection 25,35 can be configured to inhibit or prevent relative pivoting of base 20 and foot 30 about an axis extending along external support surface 3 during such processing. Connection 25,35 may be mechanical and/or magnetic.

[0145] Connection 25,35 may be configured to conduct electric power from foot 30 into base 20. For instance, foot 30 has an electric cord 32 for connection to an external power supply, such as to the mains.

[0146] Connection 25,35 can be configured to be connectable in a plug 35 and socket 25 fashion. For instance, connection 25,35 has a plug 35 part of foot 30 and a socket 25 part of base 20 or vice versa.

[0147] Foot 30 may extend horizontally beyond outside gripping surface 21, e.g. the foot extending horizontally up to or beyond tank 10. Foot 30 may extend horizontally beyond outside gripping surface 21 by a distance 21″ in the range of 0.5 to 15 cm, for instance 1 to 10 cm, such as 1.5 to 7 cm, e.g. 2 to 3 cm.

[0148] Upright outside gripping surface 21 can have a height 21′″ along which surface 21 is seizable by the human hand for carrying and supporting single-handed base 20 and tank 10, this height being of at least 3 cm, for instance in the range of 4 to 20 cm, such as 5 to 16 cm, e.g. 6 to 12 cm.

[0149] Cavity 10′ can have a volume that is greater than 200 ml, for instance in the range of 250 to 1250, such as in the range 300 to 1000 ml, e.g. in the range of 450 to 850 ml or 500 to 700 ml.

[0150] Cavity 10′ or an upright part 16 of stirring tool 15 may be associated with or comprise an indication arrangement 18,19 for assisting an appropriate filling of cavity 10′ with liquid food substance to form the batch prior to its processing in cavity 10′. For instance, the indication arrangement has an indicator 18, e.g. a high indicator 18, for a maximum level for thermally conditioning the batch without frothing and/or an indicator 19, e.g. a low indicator 19, for a maximum level of liquid food substance with or without thermal conditioning. The indicator may include at least one of a verbal sign 181,191, a sign e.g. a pictogram 182,192 of a corresponding stirring tool and a level sign 183,193.

[0151] Stirring tool 15 may have a homogenising device 182 for homogenizing the batch of liquid food substance during thermal conditioning thereof, such as a homogenising device with at least one radial homogenising arm, e.g. 2, 3 or 4 radial homogenising arms.

[0152] Machine 1 can have a or the above mentioned central upright axis 1′ along which at least one of tank 10, cavity 10′, and when present base 20 and/or foot 30, extends. At least one of tank 10, cavity 10′ and, when present, base 20 and/or foot 30 can have a shape of revolution about central upright axis 1′ such as a cylindrical and/or conical shape and/or spherical shape.