Mixing machine and its liner

Abstract

A mixing machine 1 comprising a mixing head 3 having element(s) for connecting to a receptacle to form a mixing container. The mixing head 3 is pivotably supported in a frame 2 such that the mixing container can pivot for the mixing process. The mixing head 3 has at least one rotationally driven mixing tool whose drive shaft 23 extends through the wall of the mixing head 3. The mixing head 3 has a double wall with a perforated inner wall 8. The perforations form a fluid path from the chamber surrounded by the inner wall 8 to the intermediate wall chamber 10. The intermediate wall chamber 10 is connected to a pressure adjustment device for adjusting the pressure. A flexible liner 15 is arranged in the mixing head 3 on its inner surface, which liner 15 can be fixed to the inner wall 8 of the mixing head by applying a vacuum.

Claims

1. A mixing machine comprising: a mixing head having with one or more elements for connecting it to a receptacle forming a closed mixing container for containing a material to be mixed; which mixing head is pivotably supported opposite a frame such that the mixing container can pivot for carrying out the mixing process; the mixing head having at least one rotationally driven mixing tool with a drive shaft extending through the wall of the mixing head; the mixing head having a double wall, wherein the inner wall of the double-wall construction is perforated to fluidly connect to an intermediate wall chamber between the inner wall and the outer wall; the intermediate wall chamber is connected to a pressure adjustment device for adjusting the pressure in the intermediate wall chamber; a flexible liner in the mixing head jacketing its inner surface made available by the inner wall; and which liner can be fixed to the inner wall of the mixing head by a vacuum applied in the intermediate wall chamber.

2. The mixing machine of claim 1, wherein the liner has a radially outward projecting circumferential flange on its end facing away from the bottom of the mixing head.

3. The mixing machine of claim 2, wherein a circumferential connection continuation is formed on the flange of the liner, the connection continuation engages in a circumferential groove of an annular body closing the intermediate wall chamber, wherein the flange of the liner simultaneously serves as a seal between the mixing head and a mixing receptacle connected thereto.

4. The mixing machine of claim 1, further comprising the liner having an opening surrounded by an annular body in an area of its bottom from admitting a sealing sleeve to admit a drive shaft having a mixing tool which is held by a clamping ring on the bottom of the mixing head.

5. The mixing machine of claim 4, wherein the clamping ring for holding the annular body of the liner is a radially outward projecting flange of the sealing sleeve extending through the bottom of the mixing head.

6. The mixing machine of claim 1, wherein the intermediate wall chamber can be loaded with excess pressure with the pressure adjustment device.

7. The mixing machine of claim 1, wherein the liner is manufactured from an elastic or rubbery elastic polymer.

8. The mixing machine of claim 7, wherein the inner wall of the liner is provided with an adhesion-minimizing coating and/or is provided with such a surface structuring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic, perspective view of a mixing machine with a mixing container containing a material to be mixed on the mixing head of the mixing machine in the mixing position,

(2) FIG. 2 is a schematic cross section through the mixing head of the mixing machine of FIG. 1 shown without mixing tools and with a liner set in it,

(3) FIG. 3 is an enlarged detailed view of the section of the mixing head characterized in FIG. 2,

(4) FIG. 4 is a perspective inside view of the mixing head without the inserted liner,

(5) FIG. 5 is a perspective view of the liner set into the mixing head of the mixing machine of FIG. 1, and

(6) FIG. 6 is an enlarged and more detailed section from the bottom of the mixing head in the area of its perforation for running a drive shaft for a mixing tool through it.

(7) Before explaining the disclosed embodiment of the present invention in detail, it is to be understood that the invention is not limited in its application to the details of the particular arrangement shown, since the invention is capable of other embodiments. Exemplary embodiments are illustrated in referenced figures of the drawings. It is intended that the embodiments and figures disclosed herein are to be considered illustrative rather than limiting. Also, the terminology used herein is for the purpose of description and not of limitation.

DETAILED DESCRIPTION

(8) A mixing machine 1 for industrial purposes comprises a machine frame 2 on which a mixing head 3 is pivotably supported. The pivot shaft of the mixing head 3 is made recognizable by the reference numeral S in FIG. 1. The mixing head 3 can be pivoted through at least 180 by a drive 4 about its pivot shaft S. In the exemplary embodiment shown, the pivotability of the mixing head 3 serves the purpose that in its position rotated through 180 in comparison to the view in FIG. 1 a mixing container 5 can be moved as a container containing mixing material to the mixing head 3 and can be connected to the latter in order to then be able to pivot the unit formed from mixing container 5 and mixing head 3the actual mixing receptacleinto the position of the mixing head 3 shown in FIG. 1. In this position the mixing head 3 of the mixing machine 1 is at the bottom so that the material contained in the mixing container 5 falls onto the tools arranged in the mixing head 3. This position represents the mixing position of the mixing head 3 of the mixing machine 1.

(9) The mixing head 3 of the exemplary embodiment shown comprises 2 tools that are driven in the exemplary embodiment shown by an electromotor 6, 7.

(10) In the exemplary embodiment shown in the figures the mixing head 5 with its mixing tools is designed like the mixing head according to the exemplary embodiment of the FIGS. 1 to 3 in EP 2 460 581 A1. To this extent the descriptions of the mixing head that refer to EP 2 460 581 A1 are made subject matter of these comments and are used to describe the mixing head 3 of the exemplary embodiment shown by this explicit reference to the above-cited patent.

(11) FIG. 2 shows the mixing head 3 of the mixing machine 1 by itself and without the mixing tools arranged in it and including the drive shafts driving the tools. The mixing head 3 is constructed as a double wall and comprises an inner wall 8 and an outer wall 9 enclosing the inner wall 8 with a space between them. In the exemplary embodiment shown the outer wall 9 surrounds the inner wall like a box. An intermediate wall chamber 10 is formed between the inner wall 8 and the outer wall 9. The intermediate wall chamber 10 is sealed against the outside environment. To this end an annular body 11 shown in FIG. 2 to connect the inner wall 8 to the lower closure of the outer wall 9. The annular body 11 also forms a connection flange as a support against which the connection flange of the mixing container 5 is pressed with its connection flange for forming a mixing receptacle. The intermediate wall chamber 10 serves in the mixing head 3 as a collector for a fluid, typically ambient air. The intermediate wall chamber 10 can be loaded with a vacuum or an excess pressure. To this end the intermediate wall chamber 10 is connected via a connection 12 and a connection line to a pressure adjustment device in a manner not shown in detail. The pressure prevailing in the intermediate wall chamber 10 can be adjusted with this device.

(12) Openings 13, 14 sealed from the intermediate wall chamber 10 allow entrance of the drive shafts of the mixing tools not shown in the figure. In the mixing head 3 of the mixing machine 1, a rotationally driven, bottom-cleaning tool is arranged through the opening 13 while the opening14 serves for the drive shaft of a mixing tool that rotates more rapidly and is responsible for the actual mixing.

(13) The chamber enclosed by the inner wall 10 forms, together with the hollow chamber of a mixing container connected to the mixing head 3, the hollow mixing chamber. The inside of the inner wall 8 is jacketed with a flexible liner 15. The arrangement of the liner 15 on the inner wall 8 can be recognized in the enlarged view of FIG. 3.

(14) The inner wall 8 is perforated and carries in the manner of a grid perforation 16 distributed over its entire surface with which the intermediate wall chamber 10 is connected to the hollow chamber enclosed by the inner wall 8 (see also FIG. 4). The liner 15 of the exemplary embodiment shown is manufactured from a rubber material like a sheet and carries on its side facing the hollow chamber an adhesion-reducing coating which is constructed in the exemplary embodiment shown as a PTFE coating. The liner 15 typically comprises a Shore hardness A between 50 and 70 and therefore has a material elasticity corresponding approximately to those of a motor vehicle tire. This means that the liner 15 has a certain material elasticity. The liner 15 carries an outwardly projecting radial circumferential flange 17 on its end associated with the annular body 11. A connection continuation 18 in the manner of a lever edge is formed on the flange 17 and engages into a circumferential groove 19 of the annular body 11. In the exemplary embodiment shown the groove 19 is formed by an offset in the annular body 11 and the outside of the inner wall 8. The connection continuation 18 facing away from the contact side of the annular body 11 is frictionally held in the groove 19. This ensures that the liner 15 remains in the position shown in the FIGS. 2 and 3 even if no mixing container is connected to the mixing head 3. The liner 15 has a corresponding inherent stability so that it retains is shape shown in the FIGS. 2 and 3 even without additional measures and does not fall into the hollow chamber surrounded by the inner wall 8 even if no vacuum is present in the intermediate wall chamber 10.

(15) In order to completely fix the liner 15 on the inner wall 8 the intermediate wall chamber 10 is loaded with a certain vacuum, for example 0.3-0.5 bar under ambient pressure. As a result of the sealing of the intermediate wall chamber 10 against the environment the liner 15 is attracted by suction onto the inside of the inner wall 8 by this measure. This ensures that the liner 15 remains in contact in its proper position with the inside of the inner wall 8 even in a mixing operation. The liner 15 and the side facing the hollow chamber are sufficiently wear-resistant for the material to be mixed with the mixing head 3.

(16) FIG. 5 shows the liner 15, whose geometry is adapted to the geometry of the inside of the inner wall 8. The liner 15 comprises corresponding perforations at those positions at which the drive shafts or other means, for example sensors, engage into the hollow chamber surrounded by the inner wall 8.

(17) FIG. 6 shows an enlarged sectional view of the area of the opening 13 for running the drive shaft for a mixing tool through the bottom of the mixing head 3 and through the liner 15 arranged in it. The related opening of the liner is surrounded by annular body 20 formed on the other components of the liner 15. The annular body 20 can comprise a steel inserter for reinforcement. The annular body 20 is constructed for engaging into a recess 21 of the bottom of the mixing head 3. A sealing sleeve 22 is inserted into the opening 13 of the mixing head 3. This sleeve seals the drive shaft 23 with fixing tool on the free end. Several shaft seals are held on the inside in the sealing sleeve 22. The sealing sleeve 22 itself comprises a radially outward projecting flange 24 which is fastened by several screws 25 on the bottom of the mixing head 3. The flange 24 is arranged on the side of the sealing sleeve 22 on the inside of the mixing head 3 and comprises an offset 26 on the outer surface. The offset overlaps a complementary offset of the annular body 20 of the liner 15. The annular body 20 is connected when the sealing sleeve is mounted to the bottom of the mixing head 3 by this overlapping of the flange 24 with its projection formed by the offset 26.

(18) The drive shafts running through the openings 13, 14 are sealed against the openings 13, 14 by a slot seal so that they are washed with gas from the outside toward the inside. As a result, the internal pressure in the mixing receptacle is slowly raised during the mixing process so that the fixing of the liner on the inside of the inner wall 8 is additionally supported by this.

(19) After a first mixing phase the mixing head 3 is pivoted back into its base position so that the mixing head 3 is again located at the top to remove not sufficiently mixed deposits of material in the area of the inside of the mixing head 3 at the end of the mixing process. To ensure any deposit of material that were not thoroughly mixed fall back into the mixed material the intermediate wall chamber 10 is loaded with a certain excess pressure in comparison to the pressure present in the mixing receptacle, for example 0.3-0.5 bar. This lifts the liner 15 off the inside of the inner wall 8, deforming it on account of its flexibility. As a result of this milling-like deformation, adhering deposits of material are loosened and fall back into the material contained in the mixing container. The mixing process is subsequently continued. Material that fell into the mixing material and was not yet sufficiently mixed is thoroughly mixed in the continuation of the mixing process. If deposits of material should be repeatedly observed they are then now thoroughly mixed mixing material.

(20) In addition, it is advantageous when using a liner, as was presented in the previous exemplary embodiment, that this liner can be readily provided with adhesion-minimizing coatings, in any case in a much simpler manner than in the case of a steel surface.

(21) The liner 15 can remain in the mixing head 3 during a cleaning of the mixing head 3. Generally, when cleaning of the mixing head 3 the mixing tools are removed from the mixing head 3. This allows for the possibility when cleaning the mixing head of replacing the liner 15. If it is to be expected that a batch of mixing material with the same material composition is to be mixed again, such a liner 15 removed from the mixing head 3 does not need to be cleaned. If a mixing batch is again mixed that corresponds to the one that was mixed with the liner 15, this liner can also be inserted uncleaned into the mixing head 3. This not only reduces the time necessary for a cleaning of the mixing head 3 but also reduces the associated costs and reduces the use of cleaning liquid and reduces the amount of cleaning liquid to be disposed.

(22) Even if the liner 15 consists of a material which is resistant to wear regarding the mixing material to be mixed in the described exemplary embodiment, the claimed concept can also be used in order to introduce friction into the mixing material. The liner is then manufactured from such a material or has a coating consisting of such a material and facing into the hollow mixing chamber.

(23) While a number of exemplary aspects and embodiments have been discussed above, those of skill in the art will recognize certain modifications, permutations, additions and sub-combinations therefore. It is therefore intended that the following appended claims hereinafter introduced are interpreted to include all such modifications, permutations, additions and sub-combinations are within their true spirit and scope. Each apparatus embodiment described herein has numerous equivalents.

(24) The terms and expressions which have been employed are used as terms of description and not of limitation, and there is no intention in the use of such terms and expressions of excluding any equivalents of the features shown and described or portions thereof, but it is recognized that various modifications are possible within the scope of the invention claimed. Thus, it should be understood that although the present invention has been specifically disclosed by preferred embodiments and optional features, modification and variation of the concepts herein disclosed may be resorted to by those skilled in the art, and that such modifications and variations are considered to be within the scope of this invention as defined by the appended claims. In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. The above definitions are provided to clarify their specific use in the context of the invention.

LIST OF REFERENCE NUMERALS

(25) 1 Mixing machine 2 Machine frame 3 Mixing head 4 Pivoting drive 5 Mixing container 6 Electromotor 7 Electromotor 8 Inner wall 9 Outer wall 10 Intermediate wall chamber 11 Annular body 12 Connection 13 Perforation 14 Perforation 15 Liner 16 Perforation 17 Flange 18 Connection continuation 19 Groove 20 Annular body 21 Recess 22 Sealing sleeve 23 Drive shaft 24 Flange 25 Screw 26 Offset S Pivot shaft