Electric cooker with stirring blade for cooking food

Abstract

To provide an electric cooker that is compact and inexpensive while achieving sufficient stirring of food in a cooking tank of the electric cooker.SOLUTION: An electric cooker (2) comprises: a frame (3) comprising a cooking tank (4); a stirring blade (7) comprising at least one stirring arm (8) configured to stir food in the cooking tank (4); and a magnetic drive system (11) comprising an outer periphery ring (12) extending around the cooking tank (4), a first permanent magnetic device fixed to the outer periphery ring (12), a second permanent magnetic device that is fixed to a tip part (9) of the stirring arm (8) and is configured to cooperate with the first permanent magnetic device, and a drive motor (16) configured to perform rotation drive around the cooking tank (4) on the outer periphery ring (12). The magnetic drive system (11) is configured to perform rotation drive on the stirring arm (8) when the drive motor (16) performs rotation drive on the outer periphery ring (12) in the case that the second permanent magnetic device (20) is placed so as to face the first permanent magnetic device (18).SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] FIELD OF THEINVENTION The present invention relates generally to electric cookers, such as pressure cookers or electric pressure cookers, for cooking food with or without pressure. [Background technology]

[0002] Patent Document 1: - a cooking vessel configured to receive food to be cooked; - an impeller rotatably mounted within the cooking vessel, the impeller having a central portion and a plurality of agitating arms extending from the central portion and configured to agitate food contained within the cooking vessel; - a magnetic drive system configured to drive the agitator blade in rotation; - a heating device arranged below the cooking vat and configured to heat the cooking vat; The present invention discloses an electric cooker comprising:

[0003] The magnetic drive system of the above electric cooker comprises a permanent magnet arranged in the center of the stirring blade and a rotating magnetic field generating unit arranged below the bottom wall of the cooking vessel and therefore in close proximity to the heating device.

[0004] Such a configuration of the magnetic drive system allows for rotational driving of the agitator impeller without the need for a drive shaft extending through the bottom wall of the cooking vessel, thereby avoiding sealing problems at the bottom wall level of the cooking vessel. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] International Publication No. 2015 / 129254 Brochure Summary of the Invention [Problem to be solved by the invention]

[0006] However, in order to place the rotating magnetic field generating unit close to the heating device and the permanent magnet close to the rotation axis of the stirring blade, it is necessary to enlarge the rotating magnetic field generating unit and the permanent magnet so that a sufficient magnetic torque can be transmitted to the stirring blade. Such an increase in size of the magnetic drive system significantly increases the size and cost of the electric cooker.

[0007] In cases where the configuration of the electric cooker does not allow for a large magnetic drive system, or where it is desirable to minimize the cost of raw materials for manufacturing, such as magnets, the magnetic torque transmitted to the impeller may be insufficient to adequately stir the food contained in the cooking vessel, and the impeller may become detached.

[0008] The present invention aims to overcome all or some of these disadvantages. [Means for solving the problem]

[0009] The technical problem underlying the present invention is, inter alia, to provide a compact and low-cost electric cooker while providing sufficient stirring of the food contained in the cooking vessel of the electric cooker.

[0010] Therefore, the present invention provides an electric cooker, comprising: - a housing having a cooking vessel configured to contain food to be cooked; - an impeller rotatably mounted within the cooking vessel, the impeller having at least one agitating arm configured to agitate food contained within the cooking vessel, the agitating arm having a tip portion configured to extend adjacent to or into contact with a side wall of the cooking vessel; - a magnetic drive system configured to rotatably drive the agitator blade, the magnetic drive system comprising: a perimeter wheel extending around a side wall of the cooking vessel; a first permanent magnetic device secured to the perimeter wheel; a second permanent magnetic device secured to a distal end portion of the agitator arm and configured to cooperate with the first permanent magnetic device; and a drive motor configured to rotatably drive the perimeter wheel around the side wall of the cooking vessel. Equipped with The magnetic drive system relates to an electric cooker configured such that when a second permanent magnetic device is placed opposite the first permanent magnetic device, the drive motor rotatably drives the outer circumferential wheel to rotatably drive the stirring blade.

[0011] Such a configuration of the magnetic drive system, in particular the arrangement of the first permanent magnetic device relative to a peripheral wheel arranged around the side wall of the cooking vessel, can transmit a high magnetic torque to the agitator blade (especially compared to the magnetic torque generated at the level of the agitator blade's rotation axis), thereby enabling efficient rotation of the agitator blade, even when there is a large amount of food in the cooking vessel.

[0012] Furthermore, such an arrangement of the first permanent magnetic device and the second permanent magnetic device enables the first permanent magnetic device and the second permanent magnetic device to be miniaturized, thereby reducing the size and manufacturing costs of the magnetic drive system while still providing sufficient rotational drive for the stirring blade.

[0013] Furthermore, by placing the first permanent magnetic device on the outer periphery, when the electric cooker is equipped with a heating device arranged under the cooking vessel, the first permanent magnetic device can be moved away from the heating device, thereby generating a stronger magnetic field. In fact, the magnetic attraction force generated by the permanent magnet decreases with increasing temperature. The same is true for the second permanent magnetic device configured to cooperate with the first permanent magnetic device. However, if it is not desired to apply a stronger magnetic field, the first permanent magnetic device and the second permanent magnetic device can be made even smaller, thereby further reducing the manufacturing cost of the magnetic drive system.

[0014] In addition, the electric cooker may have one or more of the following features, either alone or in combination:

[0015] According to one embodiment, the first permanent magnetic device and the second permanent magnetic device are configured such that when the first permanent magnetic device and the second permanent magnetic device are placed opposite each other, the first permanent magnetic device and the second permanent magnetic device exert a magnetic attraction force on each other.

[0016] The first and second permanent magnetic devices, due to their opposing polarity arrangement, exert a magnetic attraction on each other, thereby rotating the stirring blades when the outer wheel rotates, thereby causing stirring of the contents of the cooking vessel.

[0017] According to one embodiment of the present invention, the plurality of first permanent magnetic devices and the plurality of second permanent magnetic devices are arranged such that each first permanent magnetic device and each complementary second permanent magnetic device exert a magnetic attraction force on each other.

[0018] According to one embodiment of the invention, the first permanent magnetic device comprises one or more first permanent magnets, suitably distributed on a peripheral ring with an angular offset between each other.

[0019] According to one embodiment of the invention, the second permanent magnetic device comprises the same number of magnets as the first permanent magnetic device.

[0020] According to another embodiment of the invention, the first permanent magnetic device and the second permanent magnetic device are arranged in such a way that the magnetic attraction force exerted by the first permanent magnetic device and the second permanent magnetic device placed opposite the first permanent magnetic device has a component capable of pressing the stirring arm against the bottom wall of the cooking vat.

[0021] According to one embodiment of the present invention, the first permanent magnetic device is positioned adjacent to the bottom wall of the cooking vat.

[0022] According to an embodiment of the present invention, the first permanent magnetic device is vertically offset with respect to the bottom wall of the cooking vat.

[0023] According to one embodiment of the present invention, the tip portion of the stirring arm has a storage compartment for the second permanent magnetic device, which makes it possible to add the second permanent magnetic device to the stirring arm after the stirring blade is manufactured, making it easier to manufacture the stirring blade.

[0024] According to one embodiment of the invention, the storage compartment is closed.

[0025] According to one embodiment of the invention, the second permanent magnetic device is disposed within an insert that is removably mounted within the receiving compartment.

[0026] According to one embodiment, the second permanent magnetic device is inserted into the agitator arm following an overmolding step of the second permanent magnetic device.

[0027] According to one embodiment, the first permanent magnetic device comprises a single first permanent magnet and the second permanent magnetic device comprises a single second permanent magnet, the first permanent magnet and the second permanent magnet have magnetization axes oriented approximately radially relative to the axis of rotation of the outer ring or the axis of rotation of the blades, and the first permanent magnet and the second permanent magnet are arranged with opposite polarity.

[0028] According to one embodiment of the present invention, the first permanent magnetic device comprises two first permanent magnets having magnetization axes oriented approximately radially relative to the axis of rotation of the outer ring, the first permanent magnets being arranged with opposite polarity, and the second permanent magnetic device comprises two second permanent magnets having magnetization axes oriented radially relative to the axis of rotation of the blades, the second permanent magnets being arranged with opposite polarity, the two first permanent magnets of the first permanent magnetic device being arranged opposite one of the two second permanent magnets of the second permanent magnetic device, each with opposite polarity.

[0029] According to one embodiment, half of the pole gap distance between two permanent magnets of the second permanent magnetic device is greater than the pole gap between one second permanent magnet of the second permanent magnetic device and one first permanent magnet of the first permanent magnetic device.

[0030] According to one embodiment, the magnetic drive system includes a plurality of first permanent magnetic devices fixed to a peripheral wheel and angularly offset from one another.

[0031] In another configuration, the first permanent magnetic device and the second permanent magnetic device could exert a repulsive force on each other. The first permanent magnetic device would then be located upstream of the second permanent magnetic device in the direction of rotation of the circumferential wheel and the blades. In such an embodiment, an additional device would be required, configured to hold the blades on the bottom of the cooking vat. Such an additional device would have the function of allowing only one degree of freedom, namely rotation, which means, among other things, holding them on the bottom of the vat.

[0032] In such an embodiment of the invention, the cooking vessel comprises an alignment piece extending from a bottom wall of the cooking vessel and configured to cooperate with the stirring blade to center the stirring blade within the cooking vessel, and / or the electric cooker comprises a movable central magnet positioned below a center portion of the cooking vessel and arranged to attract a central portion of the blade including a ferromagnetic portion.

[0033] According to one embodiment of the present invention, the agitator comprises a plurality of agitator arms, e.g., two or three, configured to agitate food contained within a cooking vessel, each agitator arm having a tip portion configured to extend adjacent to or in contact with a side wall of the cooking vessel.

[0034] According to one embodiment, at least two of the plurality of arms have different shapes.

[0035] In this way, the shape of one arm can be optimized for mixing smaller food items and the shape of another arm can be optimized for mixing larger food items.

[0036] According to one embodiment of the present invention, the agitator arms are angularly offset from one another, which allows the agitator blades to be concentric with the cooking vat, thereby eliminating the need for a centering block on the bottom wall of the cooking vat.

[0037] According to one embodiment of the invention, the stirring arms are regularly spaced apart from one another. Advantageously, the stirring arms are regularly distributed around the rotation axis of the stirring blade.

[0038] According to one embodiment of the invention, the impeller comprises three stirring arms regularly distributed around the rotation axis of the impeller.

[0039] According to one embodiment of the present invention, the impeller is of one piece construction.

[0040] According to one embodiment, the magnetic drive system includes a plurality of second permanent magnetic devices, each fixed to a tip of the agitator arm, which significantly increases the magnetic torque transmitted to the agitator blade and achieves concentric rotation of the agitator blade within the cooking vat, thereby preventing the first and second permanent magnetic devices from "de-magnetizing" when a large amount of food is mixed.

[0041] Advantageously, the number of first permanent magnetic devices is equal to or greater than the number of agitator arms. According to one embodiment of the invention, the tip portion of each agitator arm is equipped with a second permanent magnetic device. According to another embodiment of the invention, the number of second permanent magnetic devices is less than the number of agitator arms, and only some of the agitator arms are equipped with a second permanent magnetic device at their tip portion. According to yet another embodiment of the invention, only the tip portion of one agitator arm is equipped with a second permanent magnetic device.

[0042] According to an embodiment of the present invention, the number of the first permanent magnetic devices is the same as the number of the second permanent magnetic devices.

[0043] According to one embodiment of the present invention, the first permanent magnetic device is configured to cooperate with the second permanent magnetic device to center the stirring blade within the cooking vessel.

[0044] According to one embodiment of the present invention, the first permanent magnetic devices are configured to cooperate with the second permanent magnetic devices such that each of the second permanent magnetic devices automatically aligns with the complementary first permanent magnetic device when the impeller is placed in the cooking vat, such that when the impeller is inserted into the cooking vat, the second permanent magnetic devices on the agitator arms are attracted by the first permanent magnetic devices on the outer ring, thereby automatically locking each agitator arm into place.

[0045] According to one embodiment of the present invention, the number of the first permanent magnetic devices fixed to the peripheral wheel is different from the number of the second permanent magnetic devices, for example greater than the number of the second permanent magnetic devices.

[0046] According to one embodiment of the present invention, each second permanent magnetic device is configured to cooperate with a complementary first permanent magnetic device.

[0047] According to one embodiment of the present invention, the peripheral ring has a number of teeth distributed on the peripheral surface of the peripheral ring.

[0048] According to one embodiment of the present invention, the magnetic drive system includes a pinion gear in rotational communication with an output shaft of a drive motor, the teeth of the outer ring being adapted to mesh with a set of teeth on the pinion gear.

[0049] According to an embodiment of the present invention, the drive motor is arranged on the outer periphery of the side wall of the cooking vat, so that when the electric cooker is equipped with a heating device, the drive motor can be located away from the heating device.

[0050] According to another embodiment of the invention, the drive motor is arranged below the bottom of the cooking vat.

[0051] According to one embodiment of the present invention, the drive motor has an axis of rotation that is positioned approximately parallel to the central axis of the peripheral wheel.

[0052] According to another embodiment of the invention, the drive motor is arranged below the cooking vat, which allows the electric cooker to have a different design.

[0053] According to one embodiment of the invention, the drive motor has an axis of rotation that is generally transverse to the central axis of the peripheral wheel.

[0054] According to one embodiment of the present invention, the electric cooker comprises a heating device arranged in the housing, e.g., configured to heat the cooking vessel at least by conduction, and the peripheral ring is vertically offset with respect to the heating device, such that one or more first permanent magnetic devices can be offset with respect to the heating device, thereby preserving the magnetic attraction that the or each first permanent magnetic device exerts on a complementary second permanent magnetic device. The heating device can include, e.g., a resistive heater.

[0055] According to one embodiment of the invention, the heating device is arranged below the bottom wall of the cooking vat.

[0056] According to one embodiment of the present invention, the peripheral ring is closer to the bottom wall of the cooking vessel than the access opening of the cooking vessel.

[0057] According to one embodiment of the invention, the electric cooker comprises a lid element movable between an open position, in which the lid allows access to the cooking vat, and a closed position, in which the lid prevents access to the cooking vat. The lid may be, for example, pivotally attached to the housing.

[0058] According to one embodiment of the invention, the stirring blade is removable.

[0059] According to one embodiment of the invention, the bottom wall of the cooking vessel is generally smooth.

[0060] According to one embodiment of the invention, the electric cooker comprises a support arranged to slidably support the peripheral ring. Advantageously, the support comprises a number of bearing elements on which the peripheral ring rests. According to a variant embodiment of the invention, the support could comprise a ball bearing, a roller bearing or a plain bearing.

[0061] According to one embodiment of the invention, the agitator blade comprises a single agitator arm.

[0062] According to one embodiment of the invention, the wings are equipped with specific features to minimize friction between the wings and the bottom and / or edges of the cooking vat.

[0063] Such special elements may include inserts made from materials with a low coefficient of friction, such as silicone, and low coefficient of friction coatings, such as polytetrafluoroethylene, commonly referred to by the abbreviation PTFE.

[0064] According to one embodiment, the side wall of the cooking vessel has an internal protrusion, and the tip portion of the stirring blade is arranged to straddle the internal protrusion.

[0065] According to one embodiment of the present invention, the electric cooker is an electric pressure cooker, such as an electric pressure cooker or a multi-function electric pressure cooker.

[0066] The present invention relates to a method of using an electric cooker as described above, comprising the steps of: - inserting an agitator blade inside the cooking vessel; - generating a pressure in the cooking vessel that is higher than atmospheric pressure; - rotating the agitator blade by a magnetic drive system; The present invention further covers uses including:

[0067] This method allows the user to homogenize the contents of the cooking vessel when the electric cooker is in a pressurized operating mode without having to directly touch the contents of the cooking vessel. [Brief description of the drawings]

[0068] The invention will be better understood on reading the following description with reference to the attached drawing, which represents one embodiment of this electric cooker by way of non-limiting example. [Figure 1] 1 is a longitudinal section through an electric cooker according to the invention; [Diagram 2] FIG. 2 is a partial top view of the electric cooker of FIG. 1. [Diagram 3] FIG. 2 is a schematic diagram of an arrangement of a first permanent magnetic device and a second permanent magnetic device of a magnetic drive system. [Figure 4] A contour diagram of the end of the agitator blade and a portion of the side wall of the cooking tank. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0069] 1 and 2 show an electric cooker 2, more particularly an electric pressure cooker such as an electric pressure cooker or a multi-function electric pressure cooker.

[0070] The electric cooker 2 comprises a housing 3 with a cooking vessel 4 configured to contain food to be cooked, and a lid (not shown) movable between an open position, in which the lid allows access to the cooking vessel 4, and a closed position, in which the lid prevents access to the cooking vessel 4. According to the illustrated embodiment, the cooking vessel 4 has a substantially circular transverse cross section.

[0071] The electric cooker 2 further comprises a heating device 5 arranged in the housing 3 and adapted to heat the cooking vat 4 by conduction. However, other types of heating could also be envisaged, in particular heating by induction or radiation. The heating device 5 is, for example, a resistive heater and can advantageously be arranged below the bottom wall 6 of the cooking vat 4.

[0072] The electric cooker 2 also comprises a stirring impeller 7 that is removable and rotatably mounted within the cooking vessel 4. According to the illustrated embodiment, the stirring impeller 7 is of one piece construction and comprises a number of stirring arms 8, for example three stirring arms 8, configured to stir the food contained in the cooking vessel 4.

[0073] The stirring arms 8 are angularly offset relative to one another. Advantageously, the stirring arms 8 are regularly distributed around the rotation axis A of the stirring blade 7.

[0074] More specifically, each agitator arm 8 has a tip portion 9 configured to extend adjacent to or in contact with an inner surface of a sidewall 10 of the cooking vessel 4 .

[0075] The electric cooker 2 further comprises a magnetic drive system 11 configured to drive the stirring blade 7 in rotation.

[0076] The magnetic drive system 11 comprises a peripheral wheel 12 which extends around the side wall 10 of the cooking vat 4 and is vertically offset with respect to the heating device 5. Advantageously, the central axis of the peripheral wheel 12 substantially overlaps with the axis of rotation of the stirring blade 7 and is substantially vertical when the electric cooker 2 is placed on a horizontal table.

[0077] The peripheral ring 12 has a number of teeth 13 distributed on its peripheral surface. Advantageously, the peripheral ring 12 is closer to the bottom wall 6 of the vat 4 than an access opening 14 of the vat 4 through which food to be placed in the vat 4 can pass. However, any other configuration is still possible, such as one in which the peripheral ring 12 is closer to the access opening 14 of the vat 4 than to the bottom wall 6 of the vat 4, in particular in cases where the lid is provided with heating means.

[0078] The electric cooker 2 further comprises a support 15 arranged to slidably support the peripheral wheel 12. Advantageously, the support 15 comprises a number of balls on which the peripheral wheel 12 rests. A ball bearing, a roller bearing or a plain bearing may also be provided. It is even conceivable that the support 15 and the peripheral wheel 12 simply come into contact and slide against each other, with preference being given to using two materials with low coefficients of friction.

[0079] The magnetic drive system 11 also comprises a drive motor 16 configured to drive the periphery wheel 12 in rotation about the side wall 10 of the cooking vat 4. The drive motor 16 is advantageously located on the outer surface of the side wall 10 of the cooking vat 4 and has an axis of rotation substantially parallel to the central axis of the periphery wheel 12. It is also conceivable that the drive motor 16 is located below the cooking vat 4 depending on the desired size for the electric cooker 2.

[0080] According to the illustrated embodiment, the magnetic drive system 11 comprises a pinion gear 17 rotatably connected to the output shaft of the drive motor 16 and having a row of teeth configured to mesh with the teeth 13 of the outer ring 12.

[0081] The magnetic drive system 11 comprises a plurality of first permanent magnetic devices 18 fixed to the peripheral wheel 12 and angularly offset with respect to each other. Each of the first permanent magnetic devices 18 can be, for example, located adjacent to the bottom wall 6 of the cooking vat 4 or vertically offset with respect to the bottom wall 6 of the cooking vat 4.

[0082] According to one embodiment of the present invention, the peripheral ring 12 comprises a number of internal compartments 19, angularly offset from one another, in each of which a first permanent magnetic device 18 is disposed. Each internal compartment 19 can be configured, for example, to open at the top surface of the peripheral ring 12, allowing the first permanent magnetic device 18 to be inserted into said internal compartment 19 after the peripheral ring 12 is manufactured. The first permanent magnetic device can also be overmolded into the peripheral ring 12 during injection molding.

[0083] The magnetic drive system 11 further comprises a plurality of second permanent magnetic devices 20 configured to be disposed within the cooking vat 4.

[0084] Each of the second permanent magnetic devices 20 is fixed to the tip portion 9 of the complementary agitator arm 8. The tip portion 9 of each agitator arm 8 thus has a receiving compartment in which the complementary second permanent magnetic device 20 is accommodated. Advantageously, the second permanent magnetic device 20 associated with each agitator arm 8 could also be arranged in an insert removably mounted in the complementary receiving compartment. According to an embodiment of the invention, each receiving compartment is hermetically sealed. The second permanent magnetic device 20 could also be overmolded therein beforehand during injection molding of the agitator arm 8.

[0085] According to the embodiment shown, the number of second permanent magnetic devices 20 is the same as the number of agitator arms 8 and the number of second permanent magnetic devices 20 is the same as the number of first permanent magnetic devices 18 .

[0086] The first permanent magnetic device 18 and the second permanent magnetic device 20 are arranged in a configuration such that when each first permanent magnetic device 18 is placed opposite a complementary second permanent magnetic device 20, the first permanent magnetic device 18 exerts a magnetic attraction force on the complementary second permanent magnetic device 20. The magnetic drive system 11 is thus configured to rotate the agitator arm 8 when the drive motor 16 rotates the circumferential wheel 12, when each second permanent magnetic device 20 is placed opposite a complementary first permanent magnetic device 18.

[0087] According to one embodiment of the present invention, the first permanent magnetic device 18 and the second permanent magnetic device 20 are arranged such that the mutual magnetic attraction force acting between each first permanent magnetic device and each second permanent magnetic device placed opposite it includes a component that is approximately radial to the rotation axis A of the agitator blade 7.

[0088] In addition, the first permanent magnetic device 18 and the second permanent magnetic device 20 are arranged so that the mutual magnetic attraction force acting between each of the first permanent magnetic devices and each of the second permanent magnetic devices 20 placed opposite the first permanent magnetic device 18 has a component that can press each of the stirring arms 8 against the bottom wall 6 of the cooking tank 4.

[0089] Advantageously, the first permanent magnetic device 18 is configured to cooperate with the second permanent magnetic device 20 to center the stirring blade 7 within the cooking vessel 4 when the stirring blade 7 is placed within the cooking vessel 4, and further to automatically bring each of the second permanent magnetic devices 20 into a position opposite the complementary first permanent magnetic device 18.

[0090] According to the illustrated embodiment, each first permanent magnetic device 18 comprises two first permanent magnets 18a, 18b having magnetization axes oriented approximately radially with respect to the axis of rotation A of the peripheral wheel 12, the first permanent magnets 18a, 18b being arranged with opposite polarity.

[0091] On the other hand, the second permanent magnetic device 20 comprises two second permanent magnets 20a, 20b having magnetization axes oriented radially relative to the rotation axis A of the agitator blade 7, the second permanent magnets 20a, 20b being arranged to have opposite polarity.

[0092] The two first permanent magnets 18a, 18b of the first permanent magnetic device 18 are arranged to face one of the two second permanent magnets 20a, 20b of the second permanent magnetic device 20 with opposite polarity.

[0093] As shown in FIG. 3, the distance of the pole gap e' between the two second permanent magnets 20a, 20b of the second permanent magnetic device 20 is equal to or greater than half the pole gap e between one second permanent magnet 20a, 20b of the second permanent magnetic device 20 and one first permanent magnet 18a, 18b of the first permanent magnetic device 18. This minimizes the leakage magnetic flux between the two second permanent magnets 20a, 20b. However, if they are not equal, the distance of the pole gap e' should not be much greater than half the pole gap e between one second permanent magnet 20a, 20b of the second permanent magnetic device 20 and one first permanent magnet 18a, 18b of the first permanent magnetic device 18. This is because the magnetic flux may otherwise form an additional loop for the same second permanent magnets 20a, 20b. The best compromise is for the pole gap e' between the two second permanent magnets 20a, 20b of the second permanent magnetic device 20 to be equal to half the pole gap e between one second permanent magnet 20a, 20b of the second permanent magnetic device 20 and one first permanent magnet 18a, 18b of the first permanent magnetic device 18.

[0094] To still maximize the effective magnetic flux between the first magnetic device 18 and the second magnetic device 20, a laminated core may be provided with the magnet face of each permanent magnetic device 18, 20 facing away from the magnets of the other permanent magnetic device 18, 20.

[0095] Such a laminated core can further reduce the volume of the magnet when the volume of the inner section 19, i.e., the storage section, is kept constant.

[0096] On the other hand, the pole gap e'' between the two first permanent magnets 18a, 18b of the first permanent magnetic device 18 is obtained by maintaining the same deviation angle as the deviation angle α between the two second permanent magnets 20a, 20b of the second permanent magnetic device 20. These deviation angles are measured at the level of the rotation axis A of the stirring blade 7 between two secants passing through the centers of the first permanent magnets 18a, 18b of the first permanent magnetic device 18 and the second permanent magnets 20a, 20b of the second permanent magnetic device 20.

[0097] By doing so, the magnetic flux of the two second magnets 20a, 20b of the second permanent magnetic device 20 can be directed toward the first permanent magnets 18a, 18b of the first permanent magnetic device 18, and conversely, the magnetic flux of the two first magnets 18a, 18b of the first permanent magnetic device 18 can be directed toward the second permanent magnets 20a, 20b of the second permanent magnetic device 20, preventing the magnetic flux from forming a loop around the same permanent magnet.

[0098] Such a configuration of each first permanent magnetic device 18 and each second permanent magnetic device 20 can strengthen the attraction between the first permanent magnetic device 18 and the complementary second permanent magnetic device 20, thereby increasing the torque transmitted to the stirring impeller 7. Indeed, when the two second permanent magnets 20a, 20b of one second permanent magnetic device 20 are positioned opposite the complementary first permanent magnetic device 18, particularly when they are axially aligned with the two complementary first permanent magnets 18a, 18b, the magnetic circuit formed by the two first permanent magnets 18a, 18b and the two complementary second permanent magnets 20a, 20b has a low energy for the magnetic flux to form a loop.

[0099] According to an alternative embodiment of the invention not shown, each first permanent magnetic device 18 and each second permanent magnetic device 20 could comprise only one first permanent magnet and only one second permanent magnet, respectively.

[0100] The first permanent magnets 18a, 18b of the first permanent magnetic device 18 and the second permanent magnets 20a, 20b of the second permanent magnetic device 20 may be made of neodymium, ferrite, or the like.

[0101] According to another embodiment of the invention, not shown, at least two of the arms have different shapes.

[0102] In this way, the shape of one arm can be optimized for mixing smaller food items, while the shape of another arm can be optimized for mixing larger food items.

[0103] As shown in FIG. 4, the side wall of the cooking tank 4 has an internal protrusion 10a, and the tip portion of the mixing blade 7 is arranged to straddle the internal protrusion 10a.

[0104] The inner protrusion 10a enables the stirring blade 7 to properly perform its stirring function.

[0105] The operation of the electric cooker 2 according to the present invention will now be briefly described.

[0106] When carrying out a recipe requiring stirring of the food to be cooked, the consumer inserts the stirring impeller 7 into the cooking vessel 4. The second permanent magnetic device 20 at the tip portion 9 of the stirring arm 8 is attracted by the first permanent magnetic device 18 of the peripheral wheel 12, so that the stirring impeller 7 can be automatically centered in the cooking vessel 4. After the food is subsequently placed in the cooking vessel 4, the drive motor 16, which is automatically powered during the cooking and / or browning phases of the food, according to the sequence of the selected recipe, rotates the peripheral wheel 12 via the pinion 17. The stirring arm 8 is then driven to rotate by the magnetic cooperation of the first permanent magnetic device 18 and the second permanent magnetic device 20.

[0107] According to one embodiment of the present invention not shown, the agitator 7 comprises a single agitator arm 8, and the cooking vessel 4 comprises an alignment piece extending from the bottom wall 6 of the cooking vessel 4 and configured to cooperate with the agitator 7 to center the agitator 7 within the cooking vessel 4.

[0108] Therefore, the user may use the electric cooker 2 as described above, - inserting the stirring blade 7 into the cooking tank 4; - generating a pressure higher than atmospheric pressure in the cooking vessel 4; - driving the impeller 7 in rotation by means of a magnetic drive system 11; The use of the present invention includes the following:

[0109] This method allows the user to homogenize the contents of the cooking vessel 4 when the electric cooker 2 is in a pressurized operating mode without having to directly touch the contents of the cooking vessel 4.

[0110] Naturally, the invention is in no way limited to the embodiments described and shown purely by way of example: modifications are still possible, especially in terms of the arrangement of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

[0111] As such, the first permanent magnetic device 18 may comprise a permanent magnet arranged to interact with a ferromagnetic material that may be comprised by a plurality of second permanent magnetic devices 20, or vice versa.

[0112] The first permanent magnetic device 18 may simultaneously comprise a permanent magnet arranged to interact with the ferromagnetic bodies of the plurality of second permanent magnetic devices 20 and a ferromagnetic body arranged to interact with the permanent magnets of the plurality of second permanent magnetic devices 20.

Claims

1. An electric cooker (2), a housing (3) equipped with a cooking tank (4) adapted to contain the food to be cooked, - an impeller (7) rotatably mounted within said cooking vessel (4), said impeller (7) comprising at least one agitator arm (8) configured to agitate food contained within said cooking vessel (4), said agitator arm (8) comprising a tip portion (9) configured to extend adjacent to or in contact with a side wall (10) of said cooking vessel (4); a magnetic drive system (11) configured to drive the stirring blade (7) in rotation, the magnetic drive system (11) comprising a peripheral ring (12) extending around the side wall (10) of the cooking vessel (4), a first permanent magnetic device (18) fixed to the peripheral ring (12), a second permanent magnetic device (20) fixed to the tip portion (9) of the stirring arm (8) and configured to cooperate with the first permanent magnetic device (18), and a drive motor (16) configured to drive the peripheral ring (12) in rotation around the side wall (10) of the cooking vessel (4); Equipped with the magnetic drive system (11) is configured such that, when the second permanent magnetic device (20) is placed opposite the first permanent magnetic device (18), the magnetic drive system (11) rotates the stirring blade (7) when the drive motor (16) rotates the outer circumferential wheel (12); The electric cooker (2), wherein the first permanent magnetic device (18) comprises two first permanent magnets (18a, 18b) having magnetization axes oriented approximately radially with respect to the rotation axis (A) of the outer circumferential wheel (12), the first permanent magnets (18a, 18b) being arranged to have opposite polarities, and the second permanent magnetic device (20) comprises two second permanent magnets (20a, 20b) having magnetization axes oriented radially with respect to the rotation axis (A) of the stirring blade (7), the second permanent magnets (20a, 20b) being arranged to have opposite polarities, and the two first permanent magnets (18a, 18b) of the first permanent magnetic device (18) are arranged opposite to one of the two second permanent magnets (20a, 20b) of the second permanent magnetic device (20) with opposite polarities.

2. 2. The electric cooker (2) according to claim 1, wherein the first permanent magnetic device (18) comprises a plurality of first permanent magnets (18a, 18b) suitably distributed on the peripheral wheel (12) with an angular offset between each other.

3. 3. The electric cooker (2) according to claim 1 or 2, wherein the second permanent magnetic device (20) comprises the same number of magnets as the first permanent magnetic device (18).

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

5. 5. The electric cooker (2) according to any one of claims 1 to 4, wherein the first permanent magnetic device (18) comprises a single first permanent magnet (18a) and the second permanent magnetic device (20) comprises a single second permanent magnet (20a), the first permanent magnet (18a) and the second permanent magnet (20a) have magnetization axes oriented approximately radially with respect to the rotation axis (A) of the outer circumferential wheel (12) or the rotation axis of the stirring blade (7), and the first permanent magnet (18a) and the second permanent magnet (20a) are arranged with opposite polarity.

6. 2. The electric cooker (2) according to claim 1, wherein a distance of a pole gap (e') between the two second permanent magnets (20a, 20b) of the second permanent magnetic device (20) is equal to or greater than half of a pole gap (e) between one second permanent magnet (20a, 20b) of the second permanent magnetic device (20) and one first permanent magnet (18a, 18b) of the first permanent magnetic device (18).

7. 7. The electric cooker (2) according to any one of claims 1 to 6, wherein the magnetic drive system (11) comprises a plurality of the first permanent magnetic devices (18) fixed to the peripheral wheel (12), the first permanent magnetic devices (18) being angularly offset from one another.

8. The electric cooker (2) according to any one of claims 1 to 7, wherein the stirring blade (7) comprises a plurality of stirring arms (8) configured to stir food placed in the cooking tank (4), each of the stirring arms (8) having a tip portion (9) configured to extend in close proximity to or in contact with the side wall (10) of the cooking tank (4).

9. The electric cooker (2) according to claim 8, wherein at least two of the plurality of arms have different shapes.

10. The electric cooker (2) according to claim 8 or 9, wherein the magnetic drive system (11) comprises a plurality of second permanent magnetic devices (20), each of which is fixed to the tip portion (9) of the stirring arm (8).

11. The electric cooker (2) according to claim 7 or 10, wherein the number of the first permanent magnetic devices (18) is equal to or greater than the number of the stirring arms (8).

12. The electric cooker (2) of claim 11, wherein the first permanent magnetic device (18) is configured to cooperate with the second permanent magnetic device (20) such that each of the second permanent magnetic devices (20) automatically comes into a position opposite a complementary first permanent magnetic device (18) when the stirring blade (7) is placed in the cooking tank (4).

13. 13. The electric cooker (2) according to any one of the preceding claims, wherein the drive motor (16) is arranged on the outer periphery of the side wall (10) of the cooking vat (4) or beneath the bottom of the cooking vat (4).

14. An electric cooker (2) as described in any one of claims 1 to 13, wherein the side wall (10) of the cooking tank (4) has an internal protrusion (10a), and the tip portion (9) of the stirring blade (7) is arranged to straddle the internal protrusion (10a).

15. A method of using an electric cooker (2) according to any one of claims 1 to 14, comprising the steps of: - inserting the stirring blade (7) inside the cooking tank (4); - generating a pressure above atmospheric pressure in said cooking vessel (4); - driving said impeller (7) in rotation by said magnetic drive system (11); Usage including.

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