FR2997282A1 - Mixer rod for use in e.g. plunging mixer for crushing food materials immersed in liquid, has protection cover comprising peripheral wall whose internal surface has edges provided on sides of slot and radially shifted relative to each other - Google Patents

Abstract

The rod (10) has a protection cover (12) whose lower end is opened, and peripheral wall (13) whose internal surface forms a mixing chamber around a working tool (5) e.g. knife. The tool is driven in rotation around an axis by a motor. The peripheral wall comprises a slot (16) defining a passage of a mixing flow generated by rotation of the working tool across the peripheral wall. The internal surface of the peripheral wall comprises opposite edges (13B, 13C) on sides of the slot, where the edges are radially shifted with respect to each other. An independent claim is also included for an electric household apparatus.

Description

B.1262 MIXING FOOT PROVIDED WITH A PARTICULAR SHAPE PROTECTIVE BELL AND HOUSEHOLD MIXER PROVIDED WITH SUCH MIXING FOOT The present invention relates to the general technical field of household mixers of the plunge type and relates more particularly to a foot of mixing for grinding food materials immersed in a liquid. Such mixing stands are well known and commonly used. They are usually removably coupled to a housing containing a motor and comprise a protective bell enclosing a mixing tool integral with a shaft whose upper end is coupled to an output shaft of the engine. Driven at high speed, the tool is dipped inside the food to be prepared and it cuts, mixes, emulsifies, etc. It is known, from EP 0 682 904, a mixing stand having a protective bell open at its lower end and having a peripheral wall delimiting a mixing chamber around a tool driven in rotation by a motor, the peripheral wall. having a plurality of vertical slots evenly distributed around the perimeter of the peripheral wall, each slot defining a space for the passage of a mixing stream generated by the rotation of the tool.

Such a mixing desk allows effective mixing of food but has the disadvantage of requiring a manual movement of the mixer by the user to unmixed areas to obtain a homogeneous mixture of all the food in the container . The invention which follows aims to overcome these disadvantages by providing a mixing foot to obtain a homogeneous mixing of food in the container without the need to move the mixing foot carefully over the entire volume of the container. Another object of the present invention is to provide a mixing foot having a simple shape for easy cleaning.

The object of the invention is achieved by a mixing foot comprising a protective bell open at its lower end and having a peripheral wall whose inner surface forms a mixing chamber around a working tool, such as a knife, for to be rotated about an axis X by a motor, the peripheral wall having at least one slot defining a space for the passage through the peripheral wall of a mixing stream generated by the rotation of the tool of work, characterized in that the inner surface of the peripheral wall comprises, on either side of the slot, two facing edges which are offset radially relative to each other. Such a mixing stand has the advantage of having an optimized mixing flow ensuring in particular a better transfer of food between the inside and the outside of the protective bell for greater grinding efficiency. According to another characteristic of the invention, the two opposite edges are offset radially so that the mixing flow at the outlet of the slot travels along the outer surface of the peripheral wall. According to another characteristic of the invention, the two edges on each side of the slot respectively constitute a trailing edge and a leading edge which are successively scanned by the mixing stream, the trailing edge being further away from the center of the slot. the protection bell as the leading edge.

According to another characteristic of the invention, the peripheral wall has a plurality of slots. According to another characteristic of the invention, the slot has a rectilinear shape and extends in length in a plane passing through the axis X of rotation. According to yet another characteristic of the invention, the slot opens on a lower edge of the peripheral wall. According to yet another characteristic of the invention, the slot extends in the longitudinal direction of the X axis near the lower edge of the peripheral wall and has a curved shape in its upper part. According to yet another characteristic of the invention, the slot extends over more than half the height of the peripheral wall and preferably over more than two thirds of its height.

According to yet another characteristic of the invention, the mixing chamber of the protective bell is delimited in its upper part by an upper wall comprising raised fins. According to yet another characteristic of the invention, the lower edge of the protective bell has longitudinal protuberances elevating the peripheral wall of the protective bell. According to yet another characteristic of the invention, the working tool is centered in the protection bell. According to yet another characteristic of the invention, the working tool is integral with a drive shaft passing through the upper part of the protection bell, the protective bell being surmounted by a tubular shaft enclosing the shaft of drive and comprising an upper end provided with coupling means with a motor housing. According to yet another characteristic of the invention, the peripheral wall envelopes more than 50% of the periphery of the working tool. In this way, the mixing chamber around the working tool is essentially closed when the protective bell is applied against the bottom of a container. According to yet another characteristic of the invention, the protection bell has an axis of symmetry coincident with the axis X of rotation of the working tool. The invention also relates to a household appliance comprising a housing enclosing an electric motor, characterized in that the apparatus comprises a mixing stand as previously described.

The aims, aspects and advantages of the present invention will be better understood from the description given hereinafter of several particular embodiments of the invention, given by way of non-limiting example, with reference to the accompanying drawings in FIG. which: Figure 1 is a side view of a household mixer provided with a mixing foot according to a first embodiment of the invention; Figures 2 and 3 are perspective views of the mixing stand of Figure 1; - Figure 4 is a bottom view of the mixing foot of Figure 2; - Figures 5 and 6 are respectively a perspective view and a bottom view of a mixing foot according to a second embodiment of the invention; - Figure 7 is a perspective view of an alternative embodiment of the mixing foot of Figures 5 and 6; FIG. 8 is a perspective view of another alternative embodiment of the mixing stand of FIGS. 5 and 6.

Only the elements necessary for the understanding of the invention have been represented. To facilitate the reading of the drawings, the same elements bear the same references from one figure to another. FIG. 1 represents a household mixer comprising a housing 1 enclosing a motor 2, shown schematically in dashed lines, arranged along the longitudinal axis of the housing 1, the motor 2 having an output shaft 3 passing through an opening made in the lower part of the housing 1, the output shaft 3 being provided at its lower end with a rotary drive 4. On the lower part of the housing 1 is mounted a mixing stand 10 comprising a tubular shaft 11 advantageously made of stainless steel or plastic, the tubular shaft 11 having an upper part comprising a coupling piece for the removable mounting of the mixing pad on the casing 1. The lower part of the mixing pad comprises a protective bell 12 enclosing a working tool 5, advantageously constituted by a knife advantageously comprising four curved blades distributed at 90 ° to each other, the working tool 5 being driven in rotation by a shaft 6 whose upper end comes to couple with the rotary drive 4 of the housing 1 when the mixing foot 10 is coupled to the housing 1, the shaft 6 being advantageously centered in the protective bell 12 and extending longitudinally along an axis X inside the tubular shaft 11. According to FIGS. 2 to 4, the protective bell 12 is open at its lower end and has a peripheral wall 13 whose internal surface forms a mixing chamber around the working tool 5, the peripheral wall 13 enveloping more than 50% of the periphery of the working tool 5 so as to form a substantially closed chamber when the protective bell 12 is applied against the bottom of a container. The mixing chamber is delimited, in its upper part, by an upper wall 14, of circular contour, having the shape of a dome of diameter similar to the diameter of the working tool 5, and in its lower part, by the lower edge 13A of the peripheral wall 13, the latter extending in a plane perpendicular to the axis X. In accordance with Figure 3, the upper wall 14 of the mixing chamber comprises a central sleeve 15 projecting enclosing a guide bearing of the shaft 6, not shown in the figures, the shaft 6 passing through the central sleeve 15 and having a lower end on which the working tool 5 is fixed, the working tool 5 being advantageously at a distance of the order of 2 cm from the upper wall 14 and at a distance of about 1 cm from the plane passing through the lower edge 13A of the peripheral wall 13. For example, the protective bell 12 has a globally ar rounded, flared from the upper wall 14 to the lower edge 13A, and advantageously has a height of about 3 cm between the lower edge 13A and the upper wall 14, with a diameter of about 4.6 cm at the level of the upper wall 14 and a diameter of about 7 cm at the lower edge 13A. More particularly according to the invention, the peripheral wall 13 comprises at least one slot 16 defining a space for the passage of the mixing stream generated by the rotation of the working tool 5, the peripheral wall 13 comprising, on both sides other of the slot 16, two edges 13B, 13C opposite which are offset radially relative to each other by a distance dl so that the mixing flow generated by the rotation of the work tool 5 in the direction of the arrow R runs substantially tangentially to the outer surface of the peripheral wall 13 at the exit of the slot 16. In the first embodiment of the invention illustrated in Figures 1 to 4, the peripheral wall 13 comprises four slots 16 distributed at 900 from each other, the slots 16 extending longitudinally to the mixing base 10 over the entire height of the peripheral wall 13, from the lower edge 13A to the top wall 14, thus dividing the wall peripheral 13 in four identical lobes. Each slot 16 advantageously has a transverse width d2 of the order of 2 to 3 mm, the edges 13B, 13C opposite each slot 16 being offset radially by a distance dl of the order of 4 to 5 mm. In this way the two edges 13B, 13C on each side of the slots 16 constitute respectively a trailing edge 13B and a leading edge 13C which are successively scanned by the mixing flow illustrated by the arrows F in FIG. 13B leakage being further away from the center of the protective bell 12 than the leading edge 13C so that small food carried by the mixing stream can escape naturally through the radial space of the slot 16 , the food size larger than the width dl slots 16 being maintained inside the protective bell 12 to be mixed by the working tool 5. The resulting mixing foot has the advantage of a very high mixing efficiency by the presence of the slots 16 directing the mixing flow tangentially to the outer surface of the peripheral wall 13 of the protective bell 12, which allows to create an optimal flow of circulation between the food present inside the protective bell 12 and the food present outside the protective bell 12. There is thus a strong improvement in the stirring especially when the mixing foot 10 is placed in a container containing food materials immersed in a large volume of liquid, the user does not need to move the mixing pad 10 in each of the unmixed areas of the container to obtain a good mixing efficiency. FIGS. 5 and 6 illustrate a mixing stand 20 according to a second embodiment of the invention in which only the shape of the protective bell has been modified, the other elements remaining identical to the elements described in the first embodiment.

In this embodiment, the mixing pad 20 comprises a protective bell 22, open at its lower end, comprising a peripheral wall 23 whose inner surface forms a mixing chamber around the working tool 5, this enclosure of mixing being delimited in its upper part by a smooth upper wall 24 having a circular contour of diameter similar to the diameter of the working tool 5. More particularly according to this second embodiment, the peripheral wall 23 is provided with four slots 26 of curved shape, each having a width d2 of the order of 4 mm, the four slots 26 opening on a lower edge 23A of the protective bell being oriented perpendicular to the latter and then extending in an arc of substantially the entire circle height of the peripheral wall 23, the slots 26 ending in an upper end extending substantially parallel to the inferior edge 23A of the peripheral wall 23.

The portion of the peripheral wall 23 located under each of the four slots 26 thus defines a lobe which is slightly curved towards the inside of the protection bell 22, as can be seen in FIG. 6, so that the wall peripheral 23 comprises, on either side of each slot 26, two facing edges 23B, 23C which are offset radially from one another by a distance dl of the order of 4 to 5 mm. In this way, the mixing flow generated by the rotation of the working tool 5 in the direction of the arrow R travels substantially tangentially to the outer surface of the peripheral wall 23 at the outlet of the slot 26, as illustrated. by the arrows F in FIG.

The mixing foot 20 thus produced has a different aesthetic from that of the first embodiment but makes it possible, like the mixing foot 10 according to the first embodiment, to obtain an optimized circulation flow making it possible to repress the mixed feeds present. inside the protective bell 22 to the outside of the protection bell 22, which allows for greater mixing efficiency. FIG. 7 illustrates a mixing stand 30 according to an alternative embodiment of the mixing stand of FIGS. 5 and 6, in which the mixing stand 30 differs from the mixing stand 20 according to the second embodiment only by the presence of four longitudinal protuberances 23D at the lower edge 23A of the protection bell 22, these protuberances 23D advantageously having a height of the order of 5 mm and raising the peripheral wall 23 so as to reduce the suction effect generated in the enclosure during the rotation of the working tool 5. Indeed, the elevation of the lower edge 23A of the peripheral wall 23, between each protrusion 23D, allows to pass a large flow to the mixing chamber when the foot mixer 30 is applied to the bottom of a container, thereby reducing the vacuum generated within the mixing chamber, this flow being then partly rejected through the slots 2 6 of the protection bell 22. FIG. 8 illustrates a mixing stand 40 according to another alternative embodiment of the mixing stand of FIGS. 5 and 6 in which the mixing stand 40 differs from the mixing stand 20 according to the second embodiment embodiment only by the presence of radial fins 24A on the upper wall 24 of the protective bell 22, these fins 24A disturbing the circular flow generated naturally close to the upper wall 24 during the rotation of the work tool 5 to return this flow of traffic to the center of the mixing chamber and the work tool 5 for greater mixing efficiency. The mixing foot produced according to the different modes or embodiments described above thus has the advantage of providing an excellent mixing efficiency, especially for food materials disposed in large amounts of liquid, ensuring a strong mixing of food, providing thus high efficiency and optimal performance even when the mixing stand is not moved in all areas of the container. Such a mixing desk thus makes it possible to obtain an excellent mixing result even if the user does not bother to move the mixing desk over the entire volume of the container. In addition, the mixing feet described above have the advantage of having a protective bell with a simple shape, facilitating the cleaning of the mixing stand. Of course, the invention is not limited to the described and illustrated embodiments which have been given by way of example. Modifications are possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention. Thus, in an alternative embodiment not shown, the shape of the protective bell may be oblong and the working tool may be eccentric in the protective bell.

Thus, in another variant embodiment, the mixing foot may be integral with the motor housing. Thus, in an alternative embodiment not shown, the protection bell of the mixing foot according to the first embodiment may also include longitudinal protuberances elevating the lower edge of the peripheral wall to limit the suction effect.

Claims (15)

REVENDICATIONS1. A mixing pad (10; 20; 30; 40) comprising a protective bell (12; 22) open at its lower end and having a peripheral wall (13; 23) whose inner surface forms a mixing chamber around a working tool (5), such as a knife, intended to be rotated about an axis (X) by a motor (2), said peripheral wall (13; 23) having at least one slot (16; 26) defining a space for the passage through the peripheral wall (13; 23) of a mixing flow generated by the rotation of the working tool (5), characterized in that the inner surface of the peripheral wall (13) 23) comprises, on both sides of the slot, two edges (13B, 13C; 23B, 23C) opposite which are offset radially with respect to each other. 2. mixing foot (10; 20; 30; 40) according to claim 1, characterized in that the two edges (13B, 13C; 23B, 23C) opposite are offset radially so that the mixing flow at the exit of the slot (16; 26) runs along the outer surface of the peripheral wall (13; 23). 3. mixing foot (10; 20; 30; 40) according to any one of claims 1 to 2, characterized in that the two edges (13B, 13C; 23B, 23C) on each side of the slot (16; 26) respectively constitute a trailing edge (13B; 23B) and a leading edge (13C; 23C) which are successively scanned by the mixing stream and that the trailing edge (13B; 23B) is further away from the center of the protective bell (12; 22) as the leading edge (13C; 23C). 4. mixing foot (10; 20; 30; 40) according to any one of claims 1 to 3, characterized in that the peripheral wall (13; 23) has a plurality of slots (16; 26). 5. mixing foot (10) according to any one of claims 1 to 4, characterized in that the slot (16) has a rectilinear shape and extends in length in a plane passing through the axis (X) of rotation. 6. Mixing foot (10; 20; 30; 40) according to any one of claims 1 to 5, characterized in that the slot (16; 26) opens on a lower edge (13a; 23A) of the peripheral wall ( 13; 23). 7. mixing foot (20; 30; 40) according to claim 6, characterized in that the slot (26) extends in the longitudinal direction of the axis (X) near the lower edge (23A) of the peripheral wall (23) and has a curved shape in its upper part. Mixing foot (10; 20; 30; 40) according to one of Claims 6 to 7, characterized in that the slot (16; 26) extends over more than half the height of the wall. peripheral (13; 23) and preferentially over more than two thirds of its height. 9. Mixing foot (40) according to any one of claims 1 to 8, characterized in that the mixing chamber of the protective bell (22) is delimited in its upper part by an upper wall (24) comprising fins (24A) in relief. Mixing foot (30) according to any one of claims 1 to 9, characterized in that the lower edge (23A) of the protective bell has longitudinal protuberances (23D) elevating the peripheral wall (23) of the protective bell. Mixing foot (10; 20; 30; 40) according to one of Claims 1 to 10, characterized in that the working tool (5) is centered in the protective bell (12; 22). 12. mixing foot (10; 20; 30; 40) according to any one of claims 1 to 11, characterized in that the working tool (5) is integral with a traversing drive shaft (6). the upper part of the protective bell (12; 22), the protective bell (12; 22) being surmounted by a tubular shaft (11) enclosing the drive shaft (6) and comprising an upper end provided with coupling means with a housing (1) motor. 13. mixing foot (10; 20; 30; 40) according to any one of claims 1 to 12, characterized in that the peripheral wall (13; 23) envelops more than 50% of the periphery of the work tool. (5). 14. mixing foot (10; 20; 30; 40) according to any one of claims 1 to 13, characterized in that the protective bell (12; 22) has an axis of symmetry coincident with the axis (X ) of rotation of the working tool (5). 15. Domestic appliance comprising a housing (1) enclosing an electric motor (2), characterized in that said apparatus comprises a mixing stand (10; 20; 30; 40) according to any one of claims 1 to 14.