MIXING DEVICE WITH CLOSURE ELEMENT

Abstract

Mixing device having a container rotatable about container axis, with emptying opening being arranged in the bottom thereof, rotatable mixing tool arranged in the interior of the container, and closure element for closing the emptying opening. The closure element can be pivoted about a pivot axis for opening and closing the emptying opening. With the emptying opening closed, the closure element has inner surface arranged within the container, outer surface arranged outside the container, and edge surface arranged opposite an edge surface of the emptying opening. The closure element, emptying opening and 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 describes a circle in the pivotal movement, wherein the closure element is arranged within the circle and the edge surfaces of the emptying opening are arranged outside the circle.

Claims

1. A mixing device having a container rotatable about a container axis for receiving mixing material, with an emptying opening being arranged in the bottom thereof, a rotatable mixing tool arranged in the interior of the container, and a closure element for closing the emptying opening, wherein the closure element can be pivoted about a pivot axis for opening and closing the emptying opening, wherein the closure element has 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, wherein the closure element, 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 element describes a circle in the pivotal movement, wherein the closure element is arranged within the circle and the edge surfaces of the emptying opening are arranged outside the circle.

2. The mixing device according to claim 1, wherein the emptying opening and the closure element have mutually corresponding edge surfaces which come into contact with each other when the closure element is positioned in the emptying opening.

3. The mixing device according to claim 2, wherein the edge surfaces of the closure element 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.

4. The mixing device according to claim 1, wherein the closure element ends flush with the bottom so that a flat bottom surface is afforded when the closure element is positioned in the emptying opening.

5. The mixing device according to claim 1, wherein the mixing tool has a mixer shaft arranged parallel to the axis of rotation of the container and a positioning device for rotational positioning of the mixer shaft relative to the emptying opening.

6. The mixing device according to claim 5, wherein the mixing tool has at least one bottom blade or mixing element projecting in the direction of the container bottom.

7. The mixing device according to claim 5, wherein the positioning device has a device for determining the rotational position of the mixer shaft.

8. The mixing device according to claim 7, wherein the device for determining the rotational position of the mixer shaft has cams arranged on the mixer shaft or on drive elements fixed thereto, and cam followers co-operating with the cams.

9. The mixing device according to claim 5, wherein the positioning device is of such a configuration that it can stop the rotary movement of the mixer shaft and/or the rotary movement of the mixing container.

10. The mixing device according to claim 1, wherein the closure element is in the form of a closure cover.

Description

[0031] 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:

[0032] FIG. 1 shows a plan view of a mixing container of the state of the art,

[0033] FIG. 2 shows a lateral section through the mixing device and the mixing container fitted therein as shown in FIG. 1, and

[0034] FIG. 3 shows an embodiment according to the invention of a mixing device. FIGS. 1 and 2 show a structure from the state of the art, that has already been described hereinbefore.

[0035] FIG. 3 shows a diagrammatic sectional view of an embodiment according to the invention of the mixing device.

[0036] As far as possible the same reference numerals are used for the same elements. Here too there is a cylindrical mixing container 1 rotatable about an axis of rotation. A mixing tool having a mixing shaft 3 is arranged in the interior of the mixing container 1. Fixed to the mixing shaft 3 is a disc-shaped mixing tool 19 with axially upwardly projecting pins and with bottom blades 6 projecting in the direction of the container bottom.

[0037] The mixing shaft 3 is driven by a motor 21 by way of a V-belt. For that purpose a V-belt pulley 16 is fixed to the mixing shaft 3. Arranged on the V-belt pulley 16 are magnets 17 which can be detected with a suitable sensor 18. In the illustrated example the magnets 17 are arranged in the same plane in which both the axis of rotation of the mixing shaft 3 and also the bottom blade 6 are arranged.

[0038] As also shown by way of example in FIG. 3 the corresponding magnets 17 can also be arranged directly on the mixing shaft 3. The sensors 18 are read by a controller 20 which in turn drives the motor 21.

[0039] The container bottom has an emptying opening 7. A closure cover 13 is arranged in the emptying opening 7. The closure cover 13 and the emptying opening 7 have mutually corresponding edge surfaces which come into contact with each other when the closure cover is positioned in the emptying opening 7 as shown in FIG. 3. It will be seen that the closure cover 13 ends flush with the bottom of the container so that this affords a flat bottom surface.

[0040] The edge surfaces of the closure cover 13 are of a curved configuration such that they lie on a notional sphere. The closure cover 13 can be pivoted about a pivot axis 14 for opening and closing the emptying opening 7. The centre point of the notional sphere is on the pivot axis 14. The consequence of this is that the closure cover 13 can be pivoted about the pivot axis 14 without having to be previously moved out of the emptying opening 7. In that case the edge surfaces of the closure cover 13 move on the notional sphere 15. FIG. 3 shows a situation in which the closure cover 13 would collide with a bottom blade 6 in a pivotal movement about the pivot axis 14.

[0041] Therefore, before the closure cover 13 is pivoted about the pivot axis 14, the position of the mixing shaft 3 is detected by way of the magnets 17 and the sensors 18 and the movement of the mixing shaft 3 is controlled in such a way that the bottom blades 6 are moved out of the region of the pivotal movement of the closure cover 13 so that the closure cover 13 can then be opened or closed without any risk. Instead of the magnets 17 and the sensors 18, as already described hereinbefore, it would also be possible to fit suitable cams and cam followers or any other sensors and corresponding counterpart members which make it possible to detect the rotational position of the shaft.