An electric cooking appliance for cooking food, including stirring blades

Abstract

The present invention provides an electric cooking appliance (2), comprising: a housing (3) including a cooking container (4); a stirring blade (7) having at least one stirring arm (8) configured to stir food received in the cooking container (4); and a magnetic drive system (11) including a peripheral crown gear (12) extending around the cooking container (4), a first permanent magnet device fastened to the peripheral crown gear (12), a second permanent magnet device fastened to an end (9) of the stirring arm (8) and configured to cooperate with the first permanent magnet device, and a drive motor (16) configured to drive the peripheral crown gear (12) to rotate around the cooking container (4), the magnetic drive system (11) being configured to drive the stirring arm (8) to rotate when the second permanent magnet device is placed opposite the first permanent magnet device and when the drive motor (16) drives the peripheral crown gear (12) to rotate.

Description

Technical Field

[0001] The present invention generally relates to an electric cooking appliance for cooking food with or without pressure, such as a pressure cooker or an electric pressure cooker. Background Art

[0002] Document WO2015 / 129254 discloses an electric cooking appliance, which includes:

[0003] - a cooking container configured to receive food to be cooked,

[0004] - a stirring blade rotatably movably mounted in the cooking container, the stirring blade having a central portion and a plurality of stirring arms extending from the central portion and configured to stir the food received in the cooking container,

[0005] - a magnetic drive system configured to drive the stirring blade to rotate, and

[0006] - a heating device disposed below the cooking container and configured to heat the cooking container.

[0007] The magnetic drive system of the above electric cooking appliance includes a permanent magnet disposed at the central portion of the stirring blade and a rotating magnetic field generating unit disposed below the bottom wall of the cooking container and thus close to the heating device.

[0008] This configuration of the magnetic drive system enables the stirring blade to be driven to rotate without the need for a drive shaft extending through the bottom wall of the cooking container, thus avoiding sealing problems at the bottom wall of the cooking container.

[0009] However, the position of the rotating magnetic field generating unit is close to the heating device, and the position of the permanent magnet is close to the rotation axis of the stirring blade, which requires the rotating magnetic field generating unit and the permanent magnet to be very large in size to ensure satisfactory magnetic torque transmission to the stirring blade. Such a large-sized magnetic drive system significantly increases the volume and cost of the electric cooking appliance.

[0010] If the configuration of the electric cooking appliance does not allow the magnetic drive system to be very large in size, or if it is desired to minimize the manufacturing cost of raw materials (such as magnets), the magnetic torque transmitted to the stirring blade may be insufficient to ensure satisfactory stirring of the food received in the cooking container. The stirring blade may also become disengaged. Summary of the Invention

[0011] The present invention aims to remedy all or some of these drawbacks.

[0012] The technical problem of the present invention is particularly to provide a compact and cost-reasonable electric cooking appliance while ensuring satisfactory stirring of the food received in the cooking container of such an electric cooking appliance.

[0013] To this end, the present invention relates to an electric cooking appliance, which comprises:

[0014] - A housing, which includes a cooking container configured to receive food to be cooked,

[0015] - A stirring blade rotatably and movably mounted in the cooking container, the stirring blade having at least one stirring arm configured to stir the food contained in the cooking container, the stirring arm having an end configured to extend near or in contact with the side wall of the cooking container, and

[0016] - A magnetic drive system configured to drive the stirring blade to rotate, the magnetic drive system including a peripheral crown gear extending around the side wall of the cooking container, a first permanent magnet device fastened to the peripheral crown gear, a second permanent magnet device fastened to the end of the stirring arm and configured to cooperate with the first permanent magnet device, and a drive motor configured to drive the peripheral crown gear to rotate around the side wall of the cooking container,

[0017] The magnetic drive system is configured to drive the stirring blade to rotate when the second permanent magnet device is positioned opposite the first permanent magnet device and when the drive motor drives the peripheral crown gear to rotate.

[0018] This configuration of the magnetic drive system, in particular the setting of the first permanent magnet device on the peripheral crown gear provided around the side wall of the cooking container, enables a high magnetic torque to be transmitted to the stirring blade (especially compared to the magnetic torque generated on the rotation axis of the stirring blade), thereby ensuring efficient rotation of the stirring blade, including when a large amount of food is contained in the cooking container.

[0019] In addition, this setting of the first and second permanent magnet devices enables the sizes of the first and second permanent magnet devices to be reduced, thereby reducing the volume and manufacturing cost of the magnetic drive system while ensuring satisfactory rotational drive of the stirring blade.

[0020] In addition, when the electric cooking appliance is equipped with a heating device provided below the cooking container, the position of the first permanent magnet device is on the periphery, so that the first permanent magnet device can be away from the heating device, and thus a stronger magnetic field can be generated. This is because the magnetic attraction force generated by the permanent magnet decreases with the increase in temperature. The same applies to the second magnetic device configured to cooperate with the first permanent magnet device. However, if a stronger magnetic field is not desired, it is possible to further reduce the sizes of the first and second permanent magnet devices, thereby further reducing the manufacturing cost of the magnetic drive system.

[0021] In addition, the electric cooking appliance may also have one or more of the following features individually or in combination.

[0022] According to an embodiment, the first permanent magnet device and the second permanent magnet device are configured such that when the first permanent magnet device and the second permanent magnet device are placed opposite to each other, the first permanent magnet device and the second permanent magnet device exert a magnetic attraction force on each other.

[0023] Since the first and second magnetic devices are arranged opposite to each other with opposite magnetic poles, they exert a magnetic attraction force on each other, which enables the stirring blade to rotate when the outer crown gear rotates, thereby allowing the contents of the cooking container to be stirred.

[0024] According to an embodiment of the present invention, the first permanent magnet device and the second permanent magnet device are arranged such that each first permanent magnet device and each complementary second permanent magnet device are configured to exert a magnetic attraction force on each other.

[0025] According to an embodiment of the present invention, the first permanent magnet device includes one or more first permanent magnets, which are distributed on the outer crown gear in an angularly offset manner relative to each other if necessary.

[0026] According to an embodiment of the present invention, the second permanent magnet device includes the same number of magnets as the first permanent magnet device.

[0027] According to another embodiment of the present invention, the first permanent magnet device and the second permanent magnet device are arranged such that the mutual magnetic attraction force exerted by the first permanent magnet device and the second permanent magnet device placed opposite to the first permanent magnet device includes a component for pressing the stirring arm against the bottom wall of the cooking container.

[0028] According to an embodiment of the present invention, the first permanent magnet device is disposed close to the bottom wall of the cooking container.

[0029] According to an embodiment of the present invention, the first permanent magnet device is vertically offset relative to the bottom wall of the cooking container.

[0030] According to an embodiment of the present invention, the end of the stirring arm has a receiving groove for accommodating the second permanent magnet device. These arrangements enable the second permanent magnet device to be added to the stirring arm after the stirring blade is manufactured, thereby facilitating the manufacture of the stirring blade.

[0031] According to an embodiment of the present invention, the receiving groove is sealed.

[0032] According to an embodiment of the present invention, the second permanent magnet device is disposed in a plug that is removably mounted in the receiving groove.

[0033] According to an embodiment of the present invention, after the step of overmolding the second permanent magnet device, the second permanent magnet device is inserted into the stirring arm.

[0034] According to an embodiment, the first permanent magnet device has a single first permanent magnet, the second permanent magnet device has a single second permanent magnet, the first permanent magnet and the second permanent magnet have magnetization axes that are substantially radially oriented with respect to the rotation axis of the outer crown gear or the rotation axis of the blade, and the first permanent magnet and the second permanent magnet are arranged with opposite magnetic poles.

[0035] According to an embodiment of the present invention, the first permanent magnet device includes two first permanent magnets, whose magnetization axes are substantially radially oriented with respect to the rotation axis of the outer crown gear and are arranged with opposite magnetic poles, the second permanent magnet device includes two second permanent magnets, whose magnetization axes are radially oriented with respect to the rotation axis of the blade and are arranged with opposite magnetic poles, and each of the two first permanent magnets of the first permanent magnet device is arranged to be opposite and have opposite magnetic poles to one of the two second permanent magnets of the second permanent magnet device.

[0036] According to an embodiment, half of the air gap distance between the two second permanent magnets of the second permanent magnet device is greater than the air gap between the second permanent magnet of the second permanent magnet device and the first permanent magnet of the first permanent magnet device.

[0037] According to an embodiment, the magnetic drive system includes a plurality of first permanent magnet devices that are fastened to the outer crown gear and are angularly offset from each other.

[0038] According to another configuration, the first permanent magnet device and the second permanent magnet device can exert a repulsive force on each other. Then, the first permanent magnet device will be arranged upstream of the second permanent magnet device in the rotation direction of the outer crown gear and the blade. Such an embodiment also requires an additional device that is configured to hold the blade on the bottom of the cooking container. This additional device has the function of allowing only one degree of freedom of rotation, which particularly means being held on the bottom of the container.

[0039] According to such an embodiment of the present invention, the cooking container includes a centering pin that extends from the bottom wall of the cooking container and is configured to cooperate with the stirring blade to center the stirring blade in the cooking container, and / or the electric cooking appliance includes a movable central magnet that is arranged below the central region of the cooking container and is arranged to attract the central portion of the blade including a ferromagnetic part.

[0040] According to an embodiment of the present invention, the stirring blade includes a plurality of stirring arms, such as two or three stirring arms, which are configured to stir the food contained in the cooking container, and each stirring arm has an end portion that is configured to extend near or in contact with the side wall of the cooking container.

[0041] According to an embodiment, at least two of the plurality of arms have different shapes.

[0042] This arrangement enables the shape of one arm to be optimized for stirring small-sized food and the shape of another arm to be optimized for stirring larger-sized food.

[0043] According to an embodiment of the present invention, the stirring arms are angularly offset relative to each other. These arrangements enable the stirring blades to be positioned concentrically relative to the cooking vessel, so that there is no need to provide centering pins on the bottom wall of the cooking vessel.

[0044] According to an embodiment of the present invention, the stirring arms are regularly spaced apart relative to each other. Advantageously, the stirring arms are regularly distributed around the rotation axis of the stirring blades.

[0045] According to an embodiment of the present invention, the stirring blade has three stirring arms that are regularly distributed around the rotation axis of the stirring blade.

[0046] According to an embodiment of the present invention, the stirring blade is integral.

[0047] According to an embodiment of the present invention, the magnetic drive system includes a plurality of second permanent magnet devices, each of which is fastened to the end of a corresponding stirring arm. These arrangements make it possible to significantly increase the magnetic torque transmitted to the stirring blade and also ensure the concentric rotation of the stirring blade in the cooking vessel, thus avoiding possible "magnetic separation" between the first and second permanent magnet devices when stirring a large amount of food.

[0048] Advantageously, the number of the first permanent magnet devices is advantageously equal to or greater than the number of the stirring arms. According to an embodiment of the present invention, the end of each stirring arm is equipped with a second permanent magnet device. According to another embodiment of the present invention, the number of the second permanent magnet devices is less than the number of the stirring arms, and only the ends of some of the stirring arms are equipped with second permanent magnet devices. According to yet another embodiment of the present invention, only the end of one stirring arm is equipped with a second permanent magnet device.

[0049] According to an embodiment of the present invention, the number of the first permanent magnet devices is the same as the number of the second permanent magnet devices.

[0050] According to an embodiment of the present invention, the first permanent magnet device is configured to cooperate with the second permanent magnet device to center the stirring blade in the cooking vessel.

[0051] According to an embodiment of the present invention, the first permanent magnet device is configured to cooperate with the second permanent magnet device so that when the stirring blade is disposed in the cooking vessel, each second permanent magnet device is automatically positioned opposite a complementary first permanent magnet device. Thus, when the stirring blade is inserted into the cooking vessel, the second permanent magnet devices located on the stirring arms are attracted by the first permanent magnet devices provided on the peripheral crown gear, and the respective stirring arms can be automatically positioned.

[0052] According to an embodiment of the present invention, the number of the first permanent magnet devices fastened to the peripheral crown gear is different from the number of the second permanent magnet devices, and is, for example, greater than the number of the second permanent magnet devices.

[0053] According to an embodiment of the present invention, each second permanent magnet device is configured to cooperate with a complementary first permanent magnet device.

[0054] According to an embodiment of the present invention, the outer crown gear includes a plurality of teeth distributed on the outer surface of the outer crown gear.

[0055] According to an embodiment of the present invention, the magnetic drive system includes a pinion rotatably coupled to the output shaft of the drive motor, and the teeth of the outer crown gear are configured to mesh with the teeth provided on the pinion.

[0056] According to an embodiment of the present invention, the drive motor is disposed on the periphery of the side wall of the cooking container. When the electric cooking appliance is equipped with a heating device, this arrangement enables the drive motor to be away from the heating device.

[0057] According to another embodiment, the drive motor is disposed below the bottom of the cooking container.

[0058] According to an embodiment of the present invention, the drive motor has a rotation axis that is positioned substantially parallel to the central axis of the outer crown gear.

[0059] According to another embodiment, the drive motor is disposed below the cooking container. This arrangement gives the electric cooking appliance another design.

[0060] According to an embodiment of the present invention, the drive motor has a rotation axis that is positioned substantially transverse to the central axis of the outer crown gear.

[0061] According to an embodiment of the present invention, the electric cooking appliance has a heating device disposed in the housing and configured to heat the cooking container, for example, at least by conduction, and the outer crown gear is vertically offset relative to the heating device. These arrangements enable one or more first permanent magnet devices of the heating device to be offset, so as to maintain the magnetic attraction force exerted by the first permanent magnet device or each first permanent magnet device on the complementary second permanent magnet device. For example, the heating device may include a resistive heating element.

[0062] According to an embodiment of the present invention, the heating device is disposed below the bottom wall of the cooking container.

[0063] According to an embodiment of the present invention, the outer crown gear is closer to the bottom wall of the cooking container than the entrance of the cooking container.

[0064] According to an embodiment of the present invention, the electric cooking appliance has a lid element that is movable between an open position and a closed position. In the open position, the lid allows access to the cooking container, and in the closed position, the lid prevents access to the cooking container. The lid may be pivotally mounted on the housing, for example.

[0065] According to an embodiment of the present invention, the stirring blade is removable.

[0066] According to an embodiment of the present invention, the bottom wall of the cooking container is generally smooth.

[0067] According to an embodiment of the present invention, the electric cooking appliance has a support portion configured to slidably support an outer crown gear. Advantageously, the support portion includes a plurality of rolling elements on which the outer crown gear rests. According to a variant of the embodiment of the present invention, the support portion may include a ball bearing, a roller bearing or a bearing.

[0068] According to an embodiment of the present invention, the stirring blade has a single stirring arm.

[0069] According to an embodiment, the blade includes specific elements for minimizing the friction between the blade and the bottom and / or edge of the cooking container.

[0070] Such specific elements may include inserts made of a material with a low coefficient of friction (such as silicone) or a low coefficient of friction coating (such as polytetrafluoroethylene, commonly abbreviated as PTFE).

[0071] According to an embodiment, the side wall of the cooking container has an inner boss, and the end of the stirring blade is arranged to span the inner boss.

[0072] According to an embodiment of the present invention, the electric cooking appliance is an electric pressure cooking appliance, such as an electric pressure cooker or an electric pressure multi-cooker.

[0073] The present invention also relates to a method of using an electric cooking appliance as described above, comprising the following steps:

[0074] - Inserting the stirring blade into the cooking container;

[0075] - Generating a pressure greater than atmospheric pressure in the cooking container,

[0076] - Driving the stirring blade to rotate by a magnetic drive system.

[0077] When the electric cooking appliance is in the pressure operation mode, this method enables the contents of the cooking container to be homogenized without the user directly intervening in the contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0078] The present invention will be clearly understood by reference to the following description, which is given by way of example and not limitation, with reference to the schematic drawings showing embodiments of such an electric cooking appliance.

[0079] Figure 1 is a longitudinal sectional view of an electric cooking appliance according to the present invention.

[0080] Figure 2 is Figure 1 a partial top view of the electric cooking appliance in

[0081] Figure 3 It is a schematic diagram of the arrangement of the first permanent magnet device and the second permanent magnet device of the magnetic drive system.

[0082] Figure 4 It is a contour map of the end of the stirring blade and a part of the side wall of the cooking container. Detailed implementation

[0083] Figure 1 and Figure 2 shows an electric cooking appliance 2, in particular an electric pressure cooking appliance, such as an electric pressure cooker or an electric pressure multi-functional cooker.

[0084] The electric cooking appliance 2 includes a housing 3 having a cooking container 4 configured to receive food to be cooked, and a lid (not visible in the figure) that can be moved between an open position and a closed position. In the open position, the lid allows access to the cooking container 4, and in the closed position, the lid prevents access to the cooking container 4. According to the embodiment shown in the figure, the cooking container 4 has an approximately circular cross-section.

[0085] In addition, the electric cooking appliance 2 has a heating device 5 that is provided in the housing 3 and configured to heat the cooking container 4 by conduction. However, other types of heating can be considered, such as by induction or radiation. For example, the heating device 5 can include a resistive heating element and is advantageously provided below the bottom wall 6 of the cooking container 4.

[0086] The electric cooking appliance 2 also has a detachable stirring blade 7 that is rotatably movably mounted in the cooking container 4. According to the embodiment shown in the figure, the stirring blade 7 is integrally constructed and has a plurality of stirring arms 8, such as three stirring arms 8, which are configured to stir the food contained in the cooking container 4.

[0087] The stirring arms 8 are angularly offset from each other. Advantageously, the stirring arms 8 are regularly distributed around the rotation axis A of the stirring blade 7.

[0088] More particularly, each stirring arm 8 has an end 9 that is configured to extend near or in contact with the inner surface of the side wall 10 of the cooking container 4.

[0089] The electric cooking appliance 2 also includes a magnetic drive system 11 that is configured to drive the stirring blade 7 to rotate.

[0090] The magnetic drive system 11 includes a peripheral crown gear 12 that extends around the side wall 10 of the cooking container 4 and is vertically offset relative to the heating device 5. Advantageously, the central axis of the peripheral crown gear 12 substantially coincides with the rotation axis of the stirring blade 7 and is substantially vertical when the electric cooking appliance 2 is placed on a horizontal support.

[0091] The outer crown gear 12 has a plurality of teeth 13 distributed on the outer surface of the outer crown gear 12. Advantageously, the outer crown gear 12 is closer to the bottom wall 6 of the cooking vessel 4 than the inlet 14 of the cooking vessel 4, and food can be introduced into the cooking vessel 4 through the inlet 14. However, any other configuration is possible, for example, in the case where the lid includes a heating member, the outer crown gear 12 is closer to the inlet 14 of the cooking vessel 4 than the bottom wall 6 of the cooking vessel 4.

[0092] The electric cooking appliance 2 further includes a support portion 15 configured to slidably support the outer crown gear 12. Advantageously, the support portion 15 includes a plurality of balls, and the outer crown gear 12 is supported on these balls. It is also possible to provide ball bearings, roller bearings or bearings. It is also conceivable to simply bring the support portion 15 and the outer crown gear 12 into contact and slide them on each other, thus facilitating the use of two materials with a low coefficient of friction.

[0093] The magnetic drive system 11 further includes a drive motor 16 configured to drive the outer crown gear 12 to rotate around the side wall 10 of the cooking vessel 4. The drive motor 16 is advantageously provided on the periphery of the side wall 10 of the cooking vessel 4 and has a rotation axis substantially parallel to the central axis of the outer crown gear 12. Depending on the volume designed for the electric cooking appliance 2, it is also conceivable to provide the drive motor 16 below the cooking vessel 4.

[0094] According to the embodiment shown in the figure, the magnetic drive system 11 has a pinion 17 which is rotatably coupled to the output shaft of the drive motor 16 and has teeth configured to mesh with the teeth 13 of the outer crown gear 12.

[0095] The magnetic drive system 11 includes a plurality of first permanent magnet devices 18 which are fastened to the outer crown gear 12 and are angularly offset relative to each other. Each first permanent magnet device 18 can be provided, for example, close to the bottom wall 6 of the cooking vessel 4 or vertically offset relative to the bottom wall 6 of the cooking vessel 4.

[0096] According to an embodiment of the invention, the outer crown gear 12 has a plurality of internal grooves 19 which are angularly offset relative to each other, and a first permanent magnet device 18 is provided in each internal groove. For example, each internal groove 19 can lead to the upper surface of the outer crown gear 12 and can be configured to allow the insertion of the first permanent magnet device 18 into the internal groove 19 after the manufacture of the outer crown gear 12. The first permanent magnet device 18 can also be overmolded into the outer crown gear 12 during injection molding.

[0097] The magnetic drive system 11 further includes a plurality of second permanent magnet devices 20 configured to be provided in the cooking vessel 4.

[0098] Each second permanent magnet device 20 is fastened to the end 9 of the complementary stirring arm 8. For this purpose, the end 9 of each stirring arm 8 has a receiving groove in which the complementary second permanent magnet device 20 is received. Advantageously, the second permanent magnet device 20 associated with each stirring arm 8 can be provided in a plug-in part removably mounted in the complementary receiving groove. According to an embodiment of the invention, each receiving groove is sealed. The second permanent magnet device 20 can also be overmolded into the stirring arm 8 during injection molding.

[0099] According to the embodiment shown in the figure, the number of second permanent magnet devices 20 is the same as the number of stirring arms 8, and the number of second permanent magnet devices 20 is the same as the number of first permanent magnet devices 18.

[0100] The first permanent magnet device 18 and the second permanent magnet device 20 are arranged such that when the first permanent magnet device 18 is placed opposite the complementary second permanent magnet device 20, each first permanent magnet device 18 is configured to exert a magnetic attraction force on the complementary second permanent magnet device 20. Thus, the magnetic drive system 11 is configured to drive the stirring arm 8 to rotate when each second permanent magnet device 20 is placed opposite the complementary first permanent magnet device 18 and when the drive motor 16 drives the peripheral crown gear 12 to rotate.

[0101] According to an embodiment of the invention, the first and second permanent magnet devices 18, 20 are arranged such that the mutual magnetic attraction force exerted between each first permanent magnet device 18 and each second permanent magnet device 20 placed opposite each other includes a substantially radial component with respect to the rotation axis A of the stirring blade 7.

[0102] Furthermore, the first and second permanent magnet devices 18, 20 are arranged such that the mutual magnetic attraction force exerted between each first permanent magnet device 18 and each second permanent magnet device 20 placed opposite the first permanent magnet device 18 includes a component for pressing the corresponding stirring arm 8 against the bottom wall 6 of the cooking container 4.

[0103] Advantageously, the first permanent magnet device 18 is configured to cooperate with the second permanent magnet device 20 to place the stirring blade 7 at the center of the cooking container 4 and, when the stirring blade 7 is disposed in the cooking container 4, automatically position each second permanent magnet device 20 opposite the complementary first permanent magnet device 18.

[0104] According to the embodiment shown in the figure, each first permanent magnet device 18 includes two first permanent magnets 18a, 18b, the magnetization axes of which are substantially radially oriented with respect to the rotation axis A of the peripheral crown gear 12 and are arranged with opposite magnetic poles.

[0105] The second permanent magnet device 20 then has two second permanent magnets 20a, 20b, the magnetization axes of which are radially oriented with respect to the rotation axis A of the stirring blade 7 and are arranged with opposite magnetic poles.

[0106] Each of the two first permanent magnets 18a, 18b of the first permanent magnet device 18 is arranged to face one of the two second permanent magnets 20a, 20b of the second permanent magnet device 20 and have opposite magnetic poles.

[0107] As Figure 3 shown, the distance of the air gap e' between the two second permanent magnets 20a, 20b of the second permanent magnet device 20 is greater than or equal to half of the air gap e between the second permanent magnets 20a, 20b of the second permanent magnet device 20 and the first permanent magnets 18a, 18b of the first permanent magnet device 18. Therefore, the leakage flux between the two second permanent magnets 20a, 20b is minimized. However, in the case of inequality, the distance of the air gap e' should not be too large, exceeding half of the air gap e between the second permanent magnets 20a, 20b of the second permanent magnet device 20 and the first permanent magnets 18a, 18b of the first permanent magnet device 18, otherwise the magnetic flux may further circulate back to the same second permanent magnets 20a, 20b. The best compromise is that the distance of the air gap e' between the two second permanent magnets 20a, 20b of the second permanent magnet device 20 is equal to half of the air gap e between the second permanent magnets 20a, 20b of the second permanent magnet device 20 and the first permanent magnets 18a, 18b of the first permanent magnet device 18.

[0108] To further maximize the useful magnetic flux between the first magnetic device 18 and the second magnetic device 20, stacked metal sheets can be placed against one side of each magnet of one of the permanent magnet devices 18, 20 and opposite to the magnets of the other permanent magnet device 18, 20.

[0109] With the same internal groove volume or the same receiving groove volume, such stacked metal sheets can save more magnet volume.

[0110] The air gap e'' between the two first permanent magnets 18a, 18b of the first permanent magnet device 18 is generated by maintaining the same angular distance as the angular distance α between the two second permanent magnets 20a, 20b of the second permanent magnet device 20, and these angular distances are measured between two straight lines that intersect at the rotation axis A of the stirring blade 7 and pass through the centers of the first and second permanent magnets 18a, 18, 20a, 20b of the first and second permanent magnet devices 18, 20 respectively.

[0111] These settings enable the magnetic flux of the second permanent magnets 20a, 20b of the second permanent magnet device 20 to be directed towards the first permanent magnets 18a, 18b of the first permanent magnet device 18, and vice versa, thus preventing the magnetic flux from circulating back to the same permanent magnet.

[0112] This configuration of the first permanent magnet device 18 and the second permanent magnet device 20 can increase the attraction between the first permanent magnet device 18 and the complementary second permanent magnet device 20, thereby increasing the torque transmitted to the stirring blade 7. In fact, when the two second permanent magnets 20a, 20b of the second permanent magnet device 20 are positioned opposite the first complementary permanent magnet device 18, especially axially centered with respect to the two complementary first permanent magnets 18a, 18b, the two first permanent magnets 18a, 18b and the two complementary second permanent magnets 20a, 20b form a magnetic circuit with less energy for magnetic flux circulation.

[0113] According to a variant of an embodiment of the invention not shown in the figures, each first permanent magnet device 18 and each second permanent magnet device 20 may respectively comprise a single first permanent magnet and a single second permanent magnet.

[0114] The first and second permanent magnets 18a, 18b, 20a, 20b of the first and second permanent magnet devices 18, 20 may be made of neodymium or ferrite.

[0115] According to another embodiment of the invention not shown in the figures, at least two of the plurality of arms have different shapes.

[0116] This arrangement allows the shape of one arm to be optimized for stirring small-sized foods and the shape of another arm to be optimized for stirring larger-sized foods.

[0117] In addition, as Figure 4 shown, the side wall of the cooking container 4 has an inner boss 10a, and the end of the stirring blade 7 is arranged to span the inner boss 10a.

[0118] This inner boss 10a enables the stirring blade 7 to correctly perform its stirring function.

[0119] The operation of the electric cooking appliance 2 according to the invention is briefly described below.

[0120] When a consumer wants to prepare a recipe that requires stirring the food to be cooked, the consumer inserts the stirring blade 7 inside the cooking container 4. The second permanent magnet device 20 located at the end 9 of the stirring arm 8 is attracted by the first permanent magnet device 18 of the peripheral crown gear 12 and automatically centers the stirring blade 7 in the cooking container 4. Then, the food is introduced into the cooking container 4, and during the cooking phase and / or coloring phase of the food, in accordance with the step-by-step sequence of the selected recipe, the drive motor 16 is automatically powered and drives the peripheral crown gear 12 to rotate via the pinion 17. Due to the magnetic cooperation between the first and second permanent magnet devices 18, 20, this drives the stirring arm 8 to rotate.

[0121] According to an embodiment of the present invention not shown in the figures, the stirring blade 7 has a single stirring arm 8, and the cooking container 4 has a centering pin that extends from the bottom wall 6 of the cooking container 4 and is configured to cooperate with the stirring blade 7 to center the stirring blade 7 in the cooking container 4.

[0122] Therefore, the user can implement the usage method of the electric cooking appliance 2 as described above, which includes the following steps:

[0123] - Insert the stirring blade 7 inside the cooking container 4;

[0124] - Generate a pressure greater than atmospheric pressure in the cooking container 4,

[0125] - Drive the stirring blade 7 to rotate through the magnetic drive system 11.

[0126] When the electric cooking appliance 2 is in the pressure operation mode, this method enables the contents of the cooking container 4 to be homogenized without the user directly intervening in the contents.

[0127] Of course, the present invention is not limited to the described and shown embodiments, which are provided only as examples. In particular, there may be some modifications in the constitution of various elements or by the substitution of equivalent techniques, which do not depart from the protection scope of the present invention.

[0128] Therefore, the first permanent magnet device 18 may include a permanent magnet arranged to interact with the ferromagnetic element of the second permanent magnet device 20, and vice versa.

[0129] The first permanent magnet device 18 may include a permanent magnet arranged to interact with the ferromagnetic element of the second permanent magnet device 20 and a ferromagnetic element arranged to interact with the permanent magnet of the second permanent magnet device 20.

Claims

1. An electric cooking appliance (2), comprising: - A housing (3) comprising a cooking vessel (4) configured to receive food to be cooked, - A stirring blade (7) rotatably movably mounted in the cooking vessel (4), the stirring blade (7) having at least one stirring arm (8) configured to stir the food received in the cooking vessel (4), the stirring arm (8) having an end (9) configured to extend near or in contact with the side wall (10) of the cooking vessel (4), and - A magnetic drive system (11) configured to drive the stirring blade (7) to rotate, the magnetic drive system (11) including a peripheral crown gear (12) extending around the side wall (10) of the cooking vessel (4), a first permanent magnet device (18) fastened to the peripheral crown gear (12), a second permanent magnet device (20) fastened to the end (9) of the stirring arm (8) and configured to cooperate with the first permanent magnet device (18), and a drive motor (16) configured to drive the peripheral crown gear (12) to rotate around the side wall (10) of the cooking vessel (4), The magnetic drive system (11) is configured to drive the stirring blade (7) to rotate when the second permanent magnet device (20) is positioned opposite the first permanent magnet device (18) and when the drive motor (16) drives the peripheral crown gear (12) to rotate, The first permanent magnet device (18) includes two first permanent magnets (18a, 18b) distributed on the peripheral crown gear (12) in an angularly offset manner relative to each other, their magnetization axes being substantially radially oriented relative to the rotation axis (A) of the peripheral crown gear (12), and the magnetic poles being arranged oppositely. The second permanent magnet device (20) includes two second permanent magnets (20a, 20b) on the same stirring arm (8), their magnetization axes being radially oriented relative to the rotation axis (A) of the stirring blade (7), and the magnetic poles being arranged oppositely. Each of the two first permanent magnets (18a, 18b) of the first permanent magnet device (18) is arranged opposite and with opposite magnetic poles to one of the two second permanent magnets (20a, 20b) of the second permanent magnet device (20), The distance of the air gap (e') between the two second permanent magnets (20a, 20b) of the second permanent magnet device (20) with opposite magnetic poles is greater than or equal to half of the air gap (e) between the second permanent magnets (20a, 20b) of the second permanent magnet device (20) and the two first permanent magnets (18a, 18b) of the first permanent magnet device (18) with opposite magnetic poles.

2. The electric cooking appliance (2) according to claim 1, wherein, The first permanent magnet device (18) and the second permanent magnet device (20) are arranged such that the mutual magnetic attraction force exerted by the first permanent magnet device (18) and the second permanent magnet device (20) placed opposite the first permanent magnet device (18) includes a component for pressing the stirring arm (8) against the bottom wall (6) of the cooking vessel (4).

3. The electric cooking appliance (2) according to claim 1 or 2, wherein, The magnetic drive system (11) includes a plurality of first permanent magnet devices (18) that are fastened to the peripheral crown gear (12) and are angularly offset relative to each other.

4. The electric cooking appliance (2) according to claim 1 or 2, wherein, The stirring blade (7) has a plurality of stirring arms (8) configured to stir the food received in the cooking container (4), and each stirring arm (8) has an end (9) configured to extend near or in contact with the side wall (10) of the cooking container (4).

5. The electric cooking appliance (2) according to claim 4, wherein, At least two of the plurality of arms have different shapes.

6. The electric cooking appliance (2) according to claim 4, wherein, The magnetic drive system (11) includes a plurality of second permanent magnet devices (20), and each second permanent magnet device (20) is fastened to the end (9) of a corresponding stirring arm (8).

7. The electric cooking appliance (2) according to claim 3, wherein, The number of the first permanent magnet devices (18) is advantageously equal to or greater than the number of the stirring arms (8).

8. The electric cooking appliance (2) according to claim 7, wherein, The first permanent magnet devices (18) are configured to cooperate with the second permanent magnet devices (20) so that when the stirring blade (7) is disposed in the cooking container (4), each second permanent magnet device (20) is automatically positioned opposite a complementary first permanent magnet device (18).

9. The electric cooking appliance (2) according to claim 1 or 2, wherein, The drive motor (16) is disposed on the periphery of the side wall (10) of the cooking container (4) or below the bottom of the cooking container (4).

10. The electric cooking appliance (2) according to claim 1 or 2, wherein, The side wall (10) of the cooking container (4) has an inner boss (10a), and the end (9) of the stirring blade (7) is arranged to span the inner boss (10a).

11. A method of using the electric cooking appliance (2) according to any one of claims 1 to 10, comprising the following steps: - Insert the stirring blade (7) inside the cooking container (4); - Generate a pressure greater than atmospheric pressure in the cooking container (4), - Drive the stirring blade (7) to rotate through the magnetic drive system (11).

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