EP0399878A1 - Mixer with movable protection screen - Google Patents

Abstract

Mixer comprising a removable bowl (20), a bowl support (22), a head (14) especially with a tool-carrier plate (40) on which a tool (44) is mounted, a body (12) comprising a device (16) for raising and lowering the bowl support, consisting of at least one vertically oriented column (24) integrally fastened to the bowl support and of a mechanism (28, 30 and 32) for driving this column in translation between two positions, high and low, along its lengthwise axis, as well as a movable protective screen (18), characterised in that this screen is movable in translation or in rotation about an axis between a closed position and a open position and in that this screen is connected to this column by driving means so that the high and low positions of this column correspond to the closed and open positions of the screen respectively. <IMAGE>

Description

The present invention relates to a mixer with removable bowl and bowl support comprising a movable protective screen.

In different industries such as baking, pastry, or more generally the food industry, there are mixers comprising a frame, itself composed of a head and a body, the head being oriented at 90 ° relative to to the body so that the axis of the tool is vertical. The body generally ensures the stability of the assembly, and includes the motorization while the head plays the role of transmitting the driving force to the tool. The material to be worked is generally contained in a removable bowl which is housed in a bowl support so that the open face of the bowl is in a horizontal plane. Furthermore, the bowl support is connected to an up and down device making it possible to bring the removable bowl and therefore the material it contains, up to the tool so that this material can be worked by this tool. The up and down system generally comprises two columns oriented vertically and both integral with the bowl support, at least one of these two columns being able to be driven in translation along its longitudinal axis by an appropriate device of irreversible nature in the working position such than ball screw, rack and pinion, or simply cam and operating lever.

In this type of mixer there is therefore a possibility of access to the bowl by the user at any time since the bowl does not come into contact with the head and the latter is generally of dimensions smaller than those of the bowl. Such a device could therefore present a danger to the user taking into account this possibility of introduction between the tool and the bowl, for example by the hand of the user. In addition, an element external to the mixer can be housed between the head and the bowl, which would cause damage to the mixer.

Also, these mixers are provided with a mobile protective screen intended to prevent access to the bowl during the working phase of the tool.

Different types of screen are known depending on whether they are retractable over the head by pivoting about a horizontal axis in the same way as a visor or whether they are pivotable around an axis oriented vertically so as to be folded around the mixer head. These screens are generally metallic grids.

In addition, these mobile screens are provided with safety devices generally comprising a contactor which stops the machine or prevents its operation when the screen is in the open position.

Such screens do provide the desired protection, but they have a certain number of drawbacks and in particular that of requiring a specific and independent manipulation which is only carried out after the complete preparation of the mixer.

The object of the present invention is to propose a mixer with a mobile protective screen, the installation of which is automatic and simultaneous with the placing in the working position of the removable bowl, the screen prohibiting any operation of this mixer when it is not not in place, whose installation is done in masked time and whose the screen provides total protection of the removable bowl opening and removes the specific electrical safety devices on the screen.

For this purpose, the mixer comprises a removable bowl, a bowl support, a head with in particular a tool-holder plate on which a tool is mounted, a body comprising a device for raising and lowering the bowl support, consisting of at least a column oriented vertically and integral with the bowl support and a drive mechanism in translation of this column between two high and low positions along its longitudinal axis, as well as a movable protective screen and is characterized in that this screen is movable in translation or in rotation about an axis between a closed position and an open position and in that this screen is connected to this column by drive means so that the high and low positions of this column correspond respectively to closed and open positions of the screen.

According to another characteristic, the mixer comprises a screen having at least one rod mounted to slide relative to the head and oriented parallel to the column of the device rises and falls.

According to a variant of the invention, the mixer comprises two columns and a screen with two rods and is characterized in that it comprises two transverse bars which connect the columns to one another and the rods to each other and that the ends of the lever are slidably mounted relative to these two transverse bars.

• - la figure 1 représente une vue en perspective d'un mélangeur selon l'invention avec un écran de protection mobile en translation par levier, en position hors service,
• - la figure 2 représente le mélangeur de la figure 1 dans la position de travail,
• - la figure 3 représente une variante du mélangeur des figures 1 et 2 et plus particulièrement une variante du montage du levier,
• - la figure 4 représente une autre variante de levier avec gorges,
• - la figure 5 représente une variante de levier à fourches avec liaisons souples,
• - la figure 6 représente une variante du mélangeur à écran mobile en rotation sur lui-même autour d'un axe vertical avec commande à poulies et câble, et
• - la figure 7 représente une variante du mélangeur à écran mobile en rotation autour d'un axe horizon­tal à commande par chaîne.

The invention will now be described in detail with reference to the accompanying drawings in which:

• FIG. 1 represents a perspective view of a mixer according to the invention with a movable protective screen in translation by lever, in the out-of-service position,
• - Figure 2 shows the mixer of Figure 1 in the working position,
• FIG. 3 represents a variant of the mixer of FIGS. 1 and 2 and more particularly a variant of the mounting of the lever,
• FIG. 4 represents another variant of lever with grooves,
• FIG. 5 represents a variant of a fork lever with flexible connections,
• FIG. 6 represents a variant of the mixer with a screen movable in rotation about itself around a vertical axis with pulley and cable control, and
• - Figure 7 shows a variant of the mobile screen mixer rotating around a horizontal axis controlled by chain.

In Figure 1 there is shown a mixer 10 comprising a body 12 and a head 14, the head 14 being disposed at 90 ° to the longitudinal axis of the body 12. In this Figure 1 there is also shown a device for raising and lowering 16 , a movable screen 18 and a removable bowl 20 resting on the bowl support 22.

The body 12 of the mixer 10, truncated in the drawing generally rests on the ground. Inside the body is provided the up and down device 16 which comprises two columns 24 movable in translation along their longitudinal axis 26 by sliding through the head. The drive in translation proper of these columns along their longitudinal axis comprises two links 28 and 30 hinged together at one of their ends, the second end of the link 28 being secured to an operating lever 32, mounted to rotate relative to an axis perpendicular to the plane comprising the link while the second end of the link 30 is pivotally mounted on the column 24 around an axis perpendicular to the plane containing this same rod 30.

These columns 24 are integral with the bowl support 22 by their lower end so as to drive this bowl support during their translation along the axes 26.

Furthermore, a position detector 34 is provided comprising a control part 36 intended to cooperate with the housing 38 formed on the column, the position of this housing 38 on the column 24 being such that the mixer can only operate when this column 24 is in the high position and the control piece 36 cooperates with the housing 38.

The head 14 of the mixer which plays the role of angle transmission and which receives the motive force generated by the drive motors generally arranged in the body of the mixer, comprises a motor shaft (not shown) intended to drive a carrier plate tool 40, itself supporting a planetary device 42 so as to give the tool 44 an epicyclic movement. The head 14 also supports the protective screen 18 which comprises a protective grid 46 consisting for example of a welded mesh, and two rods 48 integral with the mesh, the upper part of which is oriented vertically and parallel to the columns 24. These rods 48 are slidably mounted across the head 14. The ends of the two columns 24 and the two rods 48 are each provided with a protruding lug 50 which cooperates with oblong holes 52 formed in levers 54 which connect the lug of a rod 48 to the lug of a column 24, the pivot axis 56 of these levers 54 being oriented perpendicular to the plane containing the stem-column pairs.

FIG. 2 shows a mixer identical to that of FIG. 1 in the working position in which the working tool 44 is driven in rotation by the tool-holder plate 40 while the screen has been lowered in the direction arrow 58 simultaneously with the movement of the bowl in the direction of arrow 60 and that the lever 32 has been actuated in the direction of arrow 62.

The contactor 36 is then in a position such that the mixer can operate. Each lever 54 has pivoted about its axis of rotation.

FIG. 3 shows a mixer 10 identical to the previous mixer comprising columns 24 and rods 48. However, in this variant the two columns 24 and the two rods 48 are connected together by transverse bars 64 and 66 arranged substantially at the upper end of these columns and rods, a single lever 68 being pivotally mounted around a shaft 70 whose longitudinal axis coincides with axis 56, the lever 68 having its ends mounted free sliding through the bars 64 and 66.

In this variant also the screen has been modified in the sense that instead of the trellis proposed in FIGS. 1 and 2, this screen includes hand holding a plate of substantially truncated cone shape, not perforated so as to ensure a certain hermeticity of the assembly during the working phase.

FIG. 4 shows a variant of a lever 72 with a double fork nested between two transverse bars 74, 76 connecting the columns 24 and the rods 48.

The arms of the lever 72 include at their ends recesses 78 to allow nesting, the depth of these recesses being sufficient to compensate for the variations in distance between the transverse bars without disengagement.

In FIG. 5, a variant of connection of the lever 72 with the transverse bars 74, 76 is shown, in which the arms of the lever are fixed to these transverse bars by means of flexible connections of the silent-block type 80.

The operation of such a mixer is now described with reference to FIGS. 1 and 2.

In the rest position as shown in Figure 1 the lever 32 is generally oriented towards the rear so that the columns 24 are in the low position, which therefore also brings the bowl support 22 in the low position. The bowl 20 can be placed on the bowl support after taking the precaution of introducing the tool 44 into the bowl through its upper opening.

When the columns 24 are in the low position, the lever 54 whose pivot axis is arranged between these columns 24 and the rods 48 causes the same rods to rise in the high position, these rods driving the trellis constituting the screen to the top. In the example shown, the truncated cone shape of this screen allows it to come close to the lower part of the head by its small base while its large base is located substantially at the height of the planetary device 42. Thus in the position of rest, the planetary device 42 and its tool 44 remain accessible since the screen is retracted in the upper part.

Referring to FIG. 2, the lever 32 having been actuated in the direction of the arrow 62, the two links 28 and 30 convert this movement of rotation of the lever into a translation of the columns 24 which has a triple function to reconnect the position detector 34, to mount the bowl support and the bowl, therefore the material it contains, at the height of the tool so that this material is worked and finally, to simultaneously cause the lowering of the screen 18 by translational movement of the rods 48 opposite to the translational movement of the columns 24. The position detector 34 does not allow the mixer to be started until the housing 38 reaches the control part 36, which corresponds to a movement of the screen such that its large base comes close to the upper opening of the bowl 20.

The translational movement in opposite directions of the columns 24 and the rods 48 is obtained by the fact that the pivot axis 56 is disposed between the columns and the rods. The oblong holes 52 therefore allow the lever 54 to slide relative to the lugs 50, which moreover makes it possible to compensate for the variations in distance between the lugs 50 of the rods and those of the columns 24.

The operation of the variants represented in FIGS. 3, 4 and 5 is identical, the single lever and the double transverse bar, or the fork, being able to prove to be useful in certain embodiments of mixers within which the implantation of two lateral levers s turns out to be impossible. In this variant, it is possible to compensate for the variations in distance which separates the two transverse bars by sliding the lever through these same transverse bars or by flexible connections.

It is also possible to provide a variant in which the screen has the profile of the head and of larger dimensions so as to come into the retracted position around this head.

In FIGS. 6 and 7, two alternative embodiments of the mobile screen have also been shown.

In Figure 6, the screen 18 is movable in rotation about a vertical axis 82 coincident with the axis of rotation of the tool holder plate. In addition, it includes an access opening 83.

Each column 24 carries a rack 84 which cooperates with a pinion 86 integral with a shaft 88, oriented perpendicular to the column, on which is fixed a pulley 90. In the variant with two columns shown, two pulleys 90 and 92 are provided which are driven in the same direction synchronously by the column racks. A cable 93 connects the two pulleys together and this cable is integral with the screen so that it passes around the axis of rotation 82.

Furthermore, the cable is wound in one direction on the first pulley and in the opposite direction on the second.

The operation is as follows: when the device rises and falls is actuated, the columns 24 rise which causes the rotation of the two pulleys, the cable then winds up on one and unwinds on the other causing the rotation of the screen on itself around the axis 82 substantially a half-turn. The bowl rises and the access opening 83 in the frontal position when stopped is oriented towards the frame of the mixer which prevents access.

In FIG. 7, the protective screen 18 is completed by a fixed screen 94. The screen 18 is movable relative to a horizontal axis perpendicular to the column 24. A first pinion 96 is integral with the operating lever 32 of the mechanism drive.

The movable screen 18 comprises two rods, the ends of which at the top are rotatably mounted relative to the head of the mixer. One of the rods is integral with a second pinion 98 connected to the first by a chain 100.

The operation of this variant is as follows: when the operating lever 32 is actuated, it rotates the first pinion which rotates the second pinion by the chain 100. The rod 97 rotates relative to its end. The various drive ratios are such that the movable screen 18 completes the fixed part 94 so as to ensure continuity of the screen, when the bowl is in the high position.

The pinion 96 can also be integral with another coaxial pinion (not shown) driven by a rack carried by the column 24.

Such a mixer provided with this mobile safety screen allows the automatic positioning of this screen in position above the removable bowl. We also understand that the operation of the mixer is made impossible until the screen is not perfectly in place. It is completely impossible to access the position detector to block it artificially; as for foreign bodies such as dust, grease, oil, flour and others, they cannot hinder the proper functioning of the position detector.

The connections between the screen, the columns, the bowl support being mechanical only the non-mounted bowl support prevents the screen from lowering, but in this case the mixer cannot operate.

The user does not have to worry about the setting up of this screen since it is automatic and is done by the operation of the bowl rise control lever, operation in any case necessary.

Claims (11)

1. Mixer comprising a removable bowl (20), a bowl support (22), a head (14) with in particular a tool-holder plate (40) on which a tool (44) is mounted, a body (12) comprising a device (16) up and down of the bowl support, consisting of at least one column (24) oriented vertically and integral with the bowl support and a drive mechanism (28, 30 and 32) in translation of this column between two high and low positions along its longitudinal axis, as well as a movable protective screen (18) characterized in that this screen is movable in translation or in rotation about an axis between a closed position and an open position and in that this screen is connected to this column by drive means so that the high and low positions of this column correspond respectively to closed and open positions of the screen. 2. Mixer according to claim 1 characterized in that the screen is movable in translation along an axis parallel to the column (24) and in that the drive means comprise at least one pivoting lever (54, 72) whose l one of the ends is articulated relative to the screen and the other end of which is connected to the column (24) of the device rises and falls, the pivot axis (56) of the lever being located between the screen and the column so that the screen and the column move in translation in opposite directions. 3. Mixer according to claim 1 or 2 characterized in that the screen (18) comprises at least one rod (48) slidably mounted relative to the head (14) and oriented parallel to the column (24). 4. Mixer according to any one of the preceding claims, characterized in that the lever (54) comprises at each end a hole (52) oblong oriented along the longitudinal axis of the lever intended to cooperate with two lugs (50) projecting together one of the column (24) and the other of the rod (48). 5. Mixer according to any one of claims 1 to 3, characterized in that the pivoting lever (72) is double fork. 6. Mixer according to claim 5 characterized in that the ends of the forks include flexible joints. 7. Mixer according to any one of claims 1 to 3 comprising two columns (24) and a screen (18) with two rods (48) characterized in that two transverse bars (64, 66) connect, while remaining pivoting, one, the columns between them and the other, the rods between them and in that the ends of the lever (68) are slidably mounted relative to these two transverse bars. 8. Mixer according to any one of the preceding claims, characterized in that the screen (18) has a suitable profile in the upper part of the head and in the lower part of the bowl. 9. Mixer according to claim 1 characterized in that the screen is movable in rotation about an axis parallel to the column (24), centered relative to the bowl and comprises an opening (83) and in that the means d drive comprise two pulleys (90, 92) each provided with a coaxial pinion, cooperating with a rack (84) carried by the column (24), and a cable (93) disposed around the screen and fixed to it, the ends of which are wound in different directions on these pulleys so that the cable unwinds from a pulley and s rolls up on the other to cause the screen to rotate and make its opening (83) accessible. 10. Mixer according to claim 1 characterized in that the screen is movable in rotation about an axis perpendicular to the column (24), located at the top of this screen and in that the drive means comprise two pinions integral with the same shaft, the first of which cooperates with a rack carried by the column (24) and the second cooperates with a chain (100) which itself cooperates with a third pinion (98) integral with the screen and coaxial with the axis of rotation of this screen so that the chain causes the screen to rotate about its axis to retract it up. 11. Mixer according to claim 10 characterized in that the two pinions are replaced by a single pinion (96) integral with the operating lever (32) of the drive mechanism which cooperates with the chain (100).

Images