Abstract:
A mixing device for mixing liquid, flowable or powder-form materials, having a first component that is mounted in a rotatable manner on a frame, a second component mounted in a rotatable manner on the first component, a drive unit for generating a rotary movement of the first component, and a deflecting unit for transferring and deflecting the rotary movement of the first component to the second component in such a manner that the direction of rotation of the first component is opposite to the direction of rotation of the second component, the second component having at least one vacuum box which can be evacuated when in operation and in which there is at least one container for the materials that are to be mixed.

Description:
FIELD OF THE INVENTION 
     The invention refers to a mixing device for mixing liquid, flowable or powder-form materials, having a first component that is mounted in a rotatable manner, a second component mounted in a rotatable manner on the first component, a drive unit for generating a rotary movement of the first component, and a deflecting unit for transferring and deflecting the rotary movement of the first component to the second component in such a manner that the direction of rotation of the first component is opposite to the direction of rotation of the second component. 
     BACKGROUND 
     A mixing device of this type is known from DE 101 43 439 A1. The mixing device described there is a “speed mixer” in which the substances being mixed are mixed under vacuum in single-use trays, glass vials or syringes. However, the containers used in such mixing devices do not have walls that are sufficiently rigid or strong, with the result that they are often deformed or even completely destroyed during the evacuation process. 
     Mixing under vacuum thus presents difficulties when using mixing devices of the prior art described above. 
     SUMMARY OF THE INVENTION 
     The purpose of the present invention is to develop a mixing device of prior art as given above in such a way that it can also be used for mixing processes carried out under vacuum. 
     The purpose is fulfilled in that the second component has at least one vacuum box which is connected during operation to an evacuation device, and in which there is placed at least one container for the materials that are to be mixed. 
     Using the mixing device of the invention it is possible to place not only a container containing the materials that are to be mixed, but also the space surrounding the container, under vacuum. This in turn means that the containers used remain intact during the mixing process. 
     A benefit is that the container is made to fit in the vacuum box. The “customised” positioning of a container in the vacuum box means that the containers are subjected to only small amounts of stress during the mixing process. 
     In one embodiment of the present invention, the second component is in the form of a vacuum box. In a different embodiment, the second component is a mixing beaker, inside which the vacuum box is positioned in a removable manner. Unlike the first embodiment, the mixing device of the invention in the second embodiment can also be used without the vacuum box. In the first embodiment the entire second component would have to be replaced by a different second component with a mixing beaker. 
     It is also beneficial for the vacuum box to have a transparent lid. By this means it is possible to observe the inserted container during the mixing process. 
     Other benefits are given in the characteristics of the other sub-claims. 
     In one aspect, there is provided mixing device for mixing liquid, flowable or powder-form materials, having a first component that is mounted in a rotatable manner on a frame, a second component mounted in a rotatable manner on the first component, a drive unit for generating a rotary movement of the first component, and a deflecting unit for transferring the rotary movement of the first component to the second component in such a manner that the direction of rotation of the first component is opposite to the direction of rotation of the second component, the second component having at least one vacuum box with a box extension which can be evacuated when in operation and in which there is at least one container for the materials that are to be mixed, the container closed by a container lid and fitted in the vacuum box in such a way that, upon evacuation of the vacuum box, a negative pressure is generated exclusively in a free space of the box extension between the vacuum box and the container lid. 
     One embodiment of the present invention is described in greater detail below by means of the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  shows a side view in diagram form of a first and second component in accordance with the present invention. 
         FIG. 2  shows a side view in diagram form of a deflecting device in accordance with the present invention. 
         FIG. 3  is an exploded view in diagram form of a second component in the form of a mixing beaker, the vacuum box and a container, in accordance with the present invention. 
         FIG. 4  is a cross-section in diagram form through the second component as shown in  FIG. 1 , with the vacuum box and container inserted. 
     
    
    
     DETAILED DESCRIPTION 
     In  FIG. 1  the top area of a mixing device  1  is shown in side view in diagram form. A first component  5  in the form of a rotary arm is mounted on a frame  3  so that it is able to rotate, and has an axis of rotation D 1 . The rotary arm  5  is located in a non-rotating manner on the shaft  7  of a drive unit (not shown), which can be integrated into the frame  3 . The axis of rotation of the shaft coincides with the axis of rotation D 1 , and is also designated D 1  below. 
     A V-belt pulley  9  is mounted on the frame  3  on a frame surface  3 . 1  opposite the rotary arm  5  so that it is unable to rotate. The V-belt pulley  9  has an opening through it (not shown) for the shaft  7  and is positioned concentrically to the axis of rotation D 1  of the shaft  7  with a radial effective surface  9 . 1  which has V-shaped indentations. The securing of the V-belt pulley  9  to the surface  3 . 1  is effected by bolting a base area  9 . 2  to the frame  3 . However, any other means of securing known in prior art can also be used. 
     The rotary arm  5  can have any basic shape required. In the present embodiment, the rotary arm  5  has two side pieces  5 . 1  and  5 . 2 . The side piece  5 . 1  extends in a perpendicular plane through the axis of rotation D 1 , with a main axis at an angle—the setting angle—of between 0 and 90° radially to the axis of rotation D 1  of the shaft  7 . A second component  11  is mounted so that it is able to rotate on a surface  5 . 3  of the side piece  5 . 1 , which surface is suitably angled and is aligned perpendicular to the vertical plane; the second component has an axis of rotation D 2 . 
     The second component  11  is in the form of a mixing beaker for holding mix material. Because of the angled position of the side piece  5 . 1  there is an angular relationship between the axis of rotation D 1  of the first component  5  and the axis of rotation D 2  of the second component  11 . At its base—i.e. at the end of the second component  11  that is opposite to the surface  5 . 3  of the side piece  5 . 1 —the periphery of the second component  11  is made in the form of a V-belt pulley  13  and is thus connected to the second component  11  in a non-rotating manner. The V-belt pulley  13  has a radial effective area  13 . 1  that is concentric with the axis of rotation D 2  and has V-shaped indentations. 
     A first axial deflector element  15  is positioned on the rotary arm  5  at the side of the side piece  5 . 1 , and is mounted on the rotary arm  5  in a rotatable manner. In the present embodiment the axis of rotation of the first deflector element  15  lies parallel to the axis of rotation D 1 . The first deflector element  15  has a radial smooth effective area  15 . 1  concentric to its axis of rotation, which area lies in a horizontal plane with the effective area  9 . 1  of the V-belt pulley  9 . Not visible in  FIG. 1 , there is a second axial deflector element  15  behind the first axial deflector element  15  that is exactly the same as the first axial deflector element  15  and is positioned in the same relation to the V-belt pulley  9  and the effective area  9 . 1  of the latter. The two deflector elements  15  are positioned symmetrically to the V-belt pulley  9 . When viewed from the top, an imaginary connection of the axes of rotation of the two deflector elements  15  and the axis of rotation D 1  form an equilateral triangle, the imaginary connection between the two axes of rotation of the deflector elements  15  forming the base side of this triangle. 
     On the underside of the rotary arm  5  in the area of the side piece  5 . 2  there is also a radial deflector element  17 . In the present embodiment the radial deflector element  17  has an essentially horizontal axis of rotation and a radial smooth effective area that is concentric with it. The radial effective area meets, at one point, an imaginary horizontal centre plane of the effective area  9 . 1  of the V-belt pulley  9 . In  FIG. 1  a second axial deflector element  17  is positioned directly behind the radial deflector element  17  on the other side of the rotary arm  5 . This second axial deflector element  17  is exactly the same as the axial deflector element  17  illustrated, and is positioned in the same relation to the V-belt pulley  9  and the effective area  9 . 1  of same. The two radial deflector elements  17  are positioned symmetrically to the axis of rotation D 1 . 
       FIG. 2  shows, in diagram form, the deflection mechanism. The deflection mechanism is formed by a deflection device which in the present embodiment is made up of the first V-belt pulley  9 , the two axial deflector elements  15 , the two radial deflector elements  17  and the V-belt pulley  13 . These components of the deflection device are connected effectively to one another by means of a flexible belt element  19  in the form of a V-belt. The wedges of the continuous V-belt  19  engage with the indentations of the effective area  9 . 1  of the V-belt pulley  9 , and the belt runs with its smooth side around part of the periphery of the effective areas  15 . 1  of the two axial deflector elements  15  and, also with its smooth side, round part of the periphery of the effective area  17 . 1  of the radial deflector elements  17 , and finally runs with its wedged side round part of the periphery of the effective area  13 . 1  of the V-belt pulley  13 . As the rotary arm  5  rotates about the axis of rotation D 1 , the rotary movement is transferred via the deflector device to the second component  11 , the mixing beaker, in the opposite direction of rotation. 
       FIG. 2  shows the axes of rotation D 1  and D 2  in their angular relationship to each other, and the diameters of the components of the deflector device. By the appropriate choice of the angular relation between D 1  and D 2  and by the appropriate choice of the diameters, different rotational speeds can be set, depending on the material to be mixed, without changing the fundamental structure. By using the deflector device of the present invention as described, there is regularly a gearing down of the rotational speed of the first component  5  to the second component  11 . However, in theory it is also possible in suitable cases to design the deflector device in such a way that a gearing up process takes place. It is also possible for the deflector device to have more than two axial and/or radial deflector elements  15 ,  17 . There can also be additional deflector devices between the axial deflector devices  15  and the radial deflector devices  17  and between the radial deflector devices  17  and the V-belt pulley  13 , the effective areas of which additional devices taking up angular positions between those of the effective areas  15 . 1 ,  17 . 1  and  13 . 1  in order to support and guide the V-belt  19 . 
     A turntable  21  is positioned on the upper side of the rotary arm  5  ( FIG. 1 ) and has an opening into which the second component  11  partly engages. 
       FIG. 3  shows, in diagram form, an exploded view of the second component  11  of the invention with its separate parts. 
     The second component  11  is in the form of a mixing beaker, into which is inserted a vacuum box  23 . In the preferred embodiment illustrated, the vacuum box  23  is made to be an exact fit for the mixing beaker  11  or the interior of the mixing beaker  11  ( FIG. 4 ). Into the vacuum box there is inserted a container  25  which, in the present embodiment, is in the form of a bucket. The container  25  contains a material that is to be mixed (not shown), and can be closed by means of a lid  25 . 1 . 
     The vacuum box  23  can be closed by means of a box lid  23 . 1  In the embodiment shown, the box lid  23 . 1  is transparent or clear, but in different embodiments can also be opaque. 
     The box lid  23 . 1  has a central opening  23 . 2  into which can be inserted, in a sealed manner, a connector  27  for a vacuum tube. The connector  27  can be joined up to a tube (not shown) or similar that creates a connection to an evacuation device (not shown). 
     In  FIG. 4  the components described in  FIG. 3  are shown in their assembled state. 
     The second component  11  has a base  11 . 1  and at least one component side wall  11 . 2 . On its inner side the component side wall  11 . 2  has a number of component shoulders  11 . 3 , each of which lies in a plane A, B parallel to the base  11 . 1 . At its open end the component side wall  11 . 2  forms a flange  11 . 4 , in which there can be openings  11 . 5  for securing devices (not shown) for different inserts. The component shoulders  11 . 3  and the flange  11 . 4  form a supporting surface for the vacuum box  23 . 
     The vacuum box  23  also has a base  23 . 3  and at least one box side wall  23 . 4 . The number of box side walls  23 . 4  is the same as the number of component side walls  11 . 2  of the second component  11 . Where the geometrical shape is circular, as in the present case, there is thus only one component side wall  11 . 2  and one box side wall  23 . 4 . 
     The box side wall  23 . 4  has box shoulders  23 . 5  on the inside and corresponding box overhangs  23 . 6  (see also  FIG. 3 ) on the opposite outer surface; in the assembled state as shown in  FIG. 4  each of these lies in the same plane A, B as one of the component shoulders  11 . 3 . The dimensions of the box overhangs  23 . 6  are complementary to the component shoulders  11 . 3 , so that the box overhangs  23 . 6  on the outside of the vacuum box  23  lie exactly on the shoulders  11 . 3  on the inner wall of the second component when the vacuum box  23  is inserted into the second component  11 . 
     In its top part the vacuum box  23  has a box extension  23 . 7  with an outer surface that lies exactly against an outer surface of the flange  11 . 4 . At its open end  23 . 9  the box extension  23 . 7  forms, on the inside, an extension shoulder  23 . 10  on which the vacuum lid  23 . 1  lies to form a seal during operation. 
     A container  25  in the form of a bucket is placed into the vacuum box  23 . The container  25  also has a base side  25 . 2  and at least one container side wall  25 . 3 . In the case of the container  25  also, the number of container side walls  25 . 3  is the same as the number of component side walls  11 . 2 . The container side wall  25 . 3  does not sit perpendicular on the base side  25 . 2 , but at an angle a that in cross-section is slightly greater than 90°. As a result, the container  25  has a smaller cross-sectional width at the base than at the lid side. It can be seen in  FIG. 4  that the container side wall  25 . 3  goes upwards from the base  25 . 2  at such an angle a that the container side wall  25 . 3  lies up against the inside wall of the vacuum box  23  at the level of the box shoulders  23 . 5  and at the start of the box extension  23 . 7 . In its inserted state the container  25  extends with its container lid  25 . 1  peripherally into the larger space of the box extension  23 . 7 , albeit with a space towards the inside wall of the box extension  23 . 7 . An open space remains also between the container lid  25 . 1  and the box lid  23 . 1 . By means of the vacuum tube connector  27  and the evacuation device (not shown) that is connected to it, negative pressure is created in the open space of the box extension  23 . 7  around the container lid  25 . 1 , the level of which pressure can be set at the evacuation device. 
     Because of the exactly-fitting position of the container  25  in the vacuum box  23 , and of the latter in turn in the second component  11 , the negative pressure has very little effect on the shaping of the container  25 . 
     In alternative embodiments the second component  11  can also be made directly as a vacuum box  23 , so that it is not necessary to make the second component in the form of a mixing beaker.