The present invention concerns a mixing device having a container for receiving mixing material, with an emptying opening being arranged in the bottom thereof, and a closure cover for closing the emptying opening. Such mixing devices are known. They frequently have a container rotatable about a container axis. In addition a rotatable mixing tool is frequently disposed in the interior of the container. In that arrangement the mixing tool is rotatable about a mixer shaft arranged parallel to the axis of rotation of the container, with for example mixing blades being fixed to the mixer shaft.
Such a mixing device is known for example from WO 2011/128435 A1.
The cylindrical mixing container 101 has a mixing tool 102 which is arranged eccentrically in the mixing container and which is mounted in overhung relationship, on a central shaft 103, with laterally arranged mixing blades 104 and a stationary wall/bottom scraper 105 mounted in overhung relationship vertically from above. Fixed to the lowermost blade plane of the mixing tool 102 are vertically downwardly projecting bottom blades 106 which operate at a small spacing relative to the surface of the container bottom.
The emptying opening 107 is disposed in the centre of the mixing container 101. The emptying opening 107 can be closed with a closure element in the form of a closure cover 108. In the illustrated embodiment the closure cover 108 is connected to a support arm 110 by way of a mounting fork and the mounting trunnion 119 and is thus pivotable about the pivot axis of the mounting trunnion 109. The support arm 110 is mounted rotatably by way of the pivot shaft 111. A return element (not shown) provides that the closure cover 108 assumes a given position relative to the support arm 110 if there are no external forces acting thereon.
When the emptying opening 107 is closed, that is to say the closure cover 108 is positioned within the emptying opening 107, the closure cover 108 ends flush with the bottom of the container. That forms a flat bottom surface, on which the mixing material is moved. That ensures efficient thorough mixing of all the material to be mixed, as above the closure cover there is no dead space which is not reached by the bottom blades 106.
The requirement for the closure cover to end flush with the container bottom gives rise to difficulty in terms of the configuration and guidance of the closure cover.
Basically the closure cover would have to be moved linearly downwardly to open the emptying opening. The consequence of that however would be that, by virtue of the arrangement of the emptying opening in the bottom of the container, the mixing material would flow over all edge surfaces of the closure cover and would possibly even foul the drive of the closure cover. It is however not possible for the closure cover to be pivoted laterally out of the emptying opening by virtue of the substantially cylindrical or frustoconical contact surfaces of the closure cover and the emptying opening.
For that reason the drive of the closure cover that is shown in
Finally it is necessary to provide in the discharge box space for the closure cover in the opened position, at which the closure cover impedes as little as possible the mixing material flowing out of the emptying opening. That means that a corresponding amount of space has to be provided for the closure cover.
Taking the described state of the art as the basic starting point the object of the present invention is therefore to provide a mixing device, the emptying opening of which can be opened and closed easily and in space-saving fashion.
According to the invention that object is attained in that the closure cover comprises two closure cover portions which can be reciprocated relative to each other between a closed position in which the two closure cover portions are in contact with each other and together form the closure cover and an opened position in which the two closure cover portions are spaced from each other so that an opening is formed between the two closure cover portions for removal of the mixing material from the container.
The two-part configuration of the closure cover provides that the required space for positioning of the closure cover in the opened position is better distributed so that overall the mixing devices can be of a more compact structure. In addition at no point during the rest or motion phase do the closure cover portions pass upwardly out of the plane of the mixing container bottom so that at no point can a collision occur with the mixing tool or the bottom blades fixed thereto with the closure cover.
In a preferred embodiment both closure cover portions can be pivoted about a pivot axis to reciprocate them between the closed position and the opened position, wherein preferably both closure cover portions are pivotable about the same pivot axis.
The pivotal movement about a pivot axis facilitates motion guidance of the closure cover portions.
In a further preferred embodiment the two closure cover portions each have a contact surface, wherein the two contact surfaces are in contact with each other in the closed position, wherein provided in at least one contact surface and preferably both contact surfaces is a recess in which an elastic sealing element is arranged.
That makes it possible for the emptying opening to be reliably closed in the closed position and discharge of mixing material through a gap formed between the closure cover portions is prevented.
A further preferred embodiment provides that the elastic sealing element is of such a dimension that it projects beyond the contact surface so that it is elastically deformed in the closed position. That measure enhances the sealing integrity of the closure cover. That is advantageous in particular when a reduced pressure is to be maintained in the mixing container during the mixing operation.
A further preferred embodiment provides that the recess is in the form of a groove extending over the entire contact surface. In that case preferably the recess is deeper and/or wider at the ends of the groove, wherein the elastic sealing element is designed to correspond to the recess so that it is thicker and/or deeper at its end regions than in a central region connecting the two end regions. A sealing element extending over the entire contact surface improves sealing integrity. By virtue of the fact that in the regions in which the contact surfaces of the closure cover portions meet the edge surfaces of the emptying opening the sealing element is of a greater volume, sealing integrity is improved precisely in those regions. By virtue of the fact that the recess is of a configuration corresponding thereto a positively locking connection is provided between the sealing element and the closure cover portion. In addition the sealing element can also be glued in the recess in order for example to completely prevent it becoming detached during operation.
A further preferred embodiment provides that the closure cover portions can be moved into a cleaning position which is between the open position and the closed position, wherein there is provided at least one cleaning nozzle so oriented that cleaning agent supplied by way of the cleaning nozzle can be sprayed on to the contact surfaces of the closure cover portions in the cleaning position. By virtue of the two-part structure of the closure cover mixing material passes on to the contact surfaces of the closure cover portions. It is therefore necessary for the contact surfaces to be cleaned at regular intervals. That is best achieved if the closure cover portions are in a position in which the two contact surfaces are spaced from each other, but are not yet arranged in the opened position. That intermediate position is referred to as the cleaning position.
A further preferred embodiment provides that each closure cover portion has a pivotal arm, by way of which the closure cover portion is connected to a drive element arranged on the pivot axis, wherein preferably each closure cover portion has a support arm, by way of which the closure cover portion is supported on the drive element of the other closure cover portion.
This embodiment has the advantage that the pivot axis can be moved into the discharge opening region of the mixing material. In that case the pivot axis does not need to be arranged in the region of the emptying opening. The support arm is therefore helpful for sufficiently stabilising the closure cover portion.
A preferred embodiment provides that each closure cover portion is of a substantially semicircular cross-section so that in the closed position that gives a closure cover of circular cross-section. In principle a configuration involving an exactly semicircular cross-section is possible. In practice however it has been found that the edge surfaces of the closure cover portions are advantageously rounded off in the region of the transition to the contact surface so that the closure cover portions do not have an exactly semicircular cross-sectional shape.
The closure cover portions preferably have an inner surface which with the emptying opening closed is arranged within the container, an outer surface which with the emptying opening closed is arranged outside the container, and an edge surface which with the emptying opening closed is arranged opposite an edge surface of the emptying opening.
In a further preferred embodiment the closure cover portions, the emptying opening and the pivot axis are of such a configuration and arrangement that a point arranged furthest away from the pivot axis on the inner surface or the edge surface of the closure cover portions describes a circle in the pivotal movement, wherein the closure cover portions are arranged within the circle and the edge surfaces of the emptying opening are arranged outside the circle.
By virtue of that measure the closure cover portions only have to be rotated about the pivot axis to close the emptying opening. The emptying opening is of such a configuration and arrangement that the edge surfaces of the emptying opening cannot collide with the closure cover during the pivotal movement.
In principle a gap can remain between the edge surfaces of the closure element and the edge surfaces of the emptying opening even in the closed position of the closure element within the emptying opening, the gap width however should be less than the smallest grain size of the mixing material to be processed, to prevent the mixing material from flowing out of the mixing container in the closed position of the closure element.
A preferred embodiment provides that the emptying opening and the closure cover portions have mutually corresponding edge surfaces which come into contact with each other when the closure element is positioned in the emptying opening.
That measure ensures that no gap remains between the emptying opening and the closure cover in the closed position of the closure cover.
A further preferred embodiment provides that the edge surfaces of the closure cover are of a curved configuration such that they lie on a notional sphere and the centre point of the notional sphere lies on the pivot axis.
Particularly preferably the closure cover ends flush with the bottom so that a flat bottom surface is afforded when the closure cover is positioned in the emptying opening.
Such a configuration of the edge surfaces is similar to the structure of spherical segment valve members. Spherical segment valve members serve as a shut-off member within dosing and feed lines. It will be noted however that in the case of the spherical segment valve members the movable valve members are of a spherical segment shape, that is to say not only the contact surfaces which come into contact with a corresponding valve seat are of a curved configuration, but the entire valve member is in the shape of a spherical cap. Apart from the fact that such a valve member is not to be viewed as a closure cover, it also does not permit a flat arrangement in the container bottom by virtue of the cap shape.
The configuration according to the invention has the advantage that the closure cover can be easily pivoted about the pivot axis to close or open the emptying opening.
A further preferred embodiment provides that the emptying opening and the closure cover portions have mutually corresponding edge surfaces which come into contact with each other when the closure cover portions are in the closed position, wherein the edge surfaces of the closure cover portions are of a curved configuration such that they lie on a notional sphere, wherein the centre point of the notional sphere is on the pivot axis. This embodiment has the advantage that the closure cover portions can be easily rotated about the pivot axis as the mutually corresponding surfaces lie on the surface of a notional sphere. The two-part configuration of the closure cover also ensures that, upon opening of the closure cover, the closure cover does not pass into the interior of the container.
In a further preferred embodiment there is provided at least one abutment element which limits the movement of the closure cover portions in the direction of the closed position so that both closure cover portions bear against the abutment element in the closed position.
Further advantages, features and possible uses of the present invention will be apparent from the description hereinafter of a preferred embodiment and the accompanying Figures in which:
The configuration of the state of the art shown in
The emptying opening 5 is in the centre of the mixing container 1. The emptying opening can be closed with the closure element in the form of a closure cover 6′, 6″. The mixing container bottom 7 can be seen here. As can be seen in particular from
The container bottom 7 rotates together with the container about an axis of rotation 8. The two closure cover portions 6′ 6″ are rotated about a pivot axis 9 for opening and closing the closure cover 6′, 6″. So that this is possible the emptying opening and the closure cover portions preferably have mutually corresponding edge surfaces curved in such a way that they lie on a notional sphere so that, for opening or closing the emptying opening, the closure cover portions can be pivoted about a pivot axis on which the centre point of the notional sphere lies.
In general disposed in the mixing container arranged above the mixing container bottom 7 is mixing material which, when the closure cover 6′, 6″ is opened, as shown in
A lift device 12, 13 is also arranged connected to the stationary system, for example in the mixer base, in which the corresponding mixer is positioned. In the illustrated example four lift stroke pistons 13 are arranged in the corresponding chambers within the piston housing 12. In per se known manner the fluid chambers formed by the lift pistons 13 can be acted upon with pressure fluid within the piston housing 12 in order to reciprocate the lift piston 13 within the housing 12 between its two extreme positions shown for example in
The lift piston 13 is connected to a first lift element portion 14. When the lift device 12, 13 is actuated the lift element portion 14 can be moved upwardly and downwardly together with the list piston 13. The lift element comprises the first lift element 14 and the second lift element 15. The two lift element portions 14, 15 are rotatable relative to each other by way of a rotary bearing 16. As the first lift element 14 is fixed to the lift piston 13, that is arranged in the stationary system, that is to say it does not rotate together with the mixing container. The second lift element portion 15 in turn is connected to the mixing material discharge 10 so that it rotates together with same and the mixing container when the container is driven. The first lift element portion and the second lift element portion are so arranged that they are connected together in positively locking relationship in the direction of the linear movement of the lift device 12, 13, which means that, when the first lift element 14 is moved from the lower position shown in
As can be seen in particular from
The closure cover portions are shown in
In the illustrated embodiment the emptying opening is circular so that the two closure cover portions are substantially semicircular and together form a circle corresponding to the circular shape of the emptying opening.
Alternatively, in the region in which the two closure cover portions 6′, 6″ meet the emptying opening could differ from the circular shape and could have corresponding inwardly projecting abutment elements. In that case the shape of the closure cover portions 6′, 6″ should also differ from the circular shape in the region of the abutment elements.
Number | Date | Country | Kind |
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10 2018 106 192.7 | Mar 2018 | DE | national |
Filing Document | Filing Date | Country | Kind |
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PCT/EP2019/055871 | 3/8/2019 | WO | 00 |