Industrial Mixing Machine

Abstract

An industrial mixing machine comprises a mixing head and at least one attachment means for attaching a mixing container, which contains a material to be mixed and is open on the attachment side, to the mixing head to form a closed mixing receptacle. The mixing head is pivotably mounted in relation to a frame as part of a pivotable assembly in such a way that the closed mixing receptacle formed from mixing head and mixing container is pivotable in relation to the frame to carry out the mixing process. The mixing head has at least one mixing tool, which is seated on a drive shaft extending through the mixing head and rotationally driven thereby, having multiple radial blades. The radial blades have a cross-sectional geometry according to which, starting from its maximum thickness, the blade thickness decreases in the rotational direction toward the rear blade end. In the section of decreasing blade thickness, the blade lower side is pitched more strongly with respect to the horizontal in the rotational direction than the blade upper side. An imaginary straight line connecting the rear end of the radial blades to their respective front end facing in the rotational direction is inclined in relation to the horizontal in the same direction as the inclination of the blade lower side in the section of decreasing thickness.

Claims

1. An industrial mixing machine, comprising: a mixing container for containing a material to be mixed, the mixing container open on an attachment side; a mixing head which attaches to the attachment side of the mixing container to form a closed mixing receptacle, the mixing head pivotably mounted in relation to a frame such that the mixing receptacle formed from mixing head and mixing container is pivotable in relation to the frame for carrying out a mixing process; wherein the mixing head has at least one mixing tool which is seated on a drive shaft engaging through a bottom of the mixing head and rotationally driven thereby, the mixing tool comprising multiple radial blades, each blade having a cross-sectional geometry according to which a blade thickness decreases through a section of the blade in a rotational direction toward a rear end of the blade starting from its maximum thickness; wherein, in the section of decreasing blade thickness, a lower side of the blade is pitched more strongly in the rotational direction with respect to the horizontal than an upper side of the blade, and an imaginary straight line connecting the rear end of the blade to a respective front end of the blade facing in the rotational direction is inclined in relation to the horizontal in the same direction as the inclination of the lower side of blade in the section of decreasing blade thickness.

2. The mixing machine of claim 1, wherein, at least in the section of decreasing blade thickness, the lower side of the blade is embodied as a flat surface.

3. The mixing machine of claim 2, wherein the entire lower side of the blade is embodied as a flat surface at least substantially.

4. The mixing machine of claim 1, wherein, in the section of decreasing blade surface, the upper side of the blade is embodied as a flat surface at least substantially.

5. The mixing machine of claim 1, wherein the radial blades are embodied mirror symmetrically to the imaginary straight line in cross-section.

6. The mixing machine of claim 1, wherein the inclination of the imaginary straight line between the respective rear end and the respective front end of the radial blade is inclined at an angle relative to the horizontal which is equal to or less than that at which the lower side of the blade is inclined in relation to the horizontal in the section of decreasing blade thickness.

7. The mixing machine of claim 1, wherein the front sides of the radial blades facing in the rotational direction are rounded.

8. The mixing machine of claim 7, wherein the front sides of the radial blades are rounded with a constant radius of curvature.

9. The mixing machine of claim 8, wherein the radial blades have their maximum thickness in a section of the rounded front sides.

10. The mixing machine of claim 1, wherein the front end of the radial blade facing in the rotational direction is formed by an edge guiding together the upper side of the blade with the lower side of the blade.

11. The mixing machine of claim 1, wherein the mixing tool has three radial blades.

12. The mixing machine of claim 1, wherein the outer ends of the radial blades each support an outer blade provided on the upper side of the blade.

13. The mixing machine of claim 12, wherein a front end of each outer blade extending away from the upper side of the radial blade is inclined opposite to the rotational direction of the mixing tool.

14. The mixing machine of claim 13, wherein a cross-sectional geometry of the outer blades corresponds to the cross-sectional geometry of the radial blades, wherein an outer blade side of each outer blade, which faces outward in a radial direction in the outer blades, corresponds to the lower side of the radial blades, and said outer blade side of the outer blades is pitched in relation to a cylindrical lateral surface in the same manner as the lower sides of the radial blades in relation to a horizontal.

15. The mixing machine of claim 14, wherein a pitch angle of the outer blade sides of the outer blades in relation to the cylindrical lateral surface is less than that at which the lower sides of the radial blades are pitched in relation to a horizontal.

16. The mixing machine of claim 12, wherein a cross-sectional geometry of the outer blades corresponds to the cross-sectional geometry of the radial blades, wherein an outer blade side of each outer blade, which faces outward in a radial direction in the outer blades, corresponds to the lower side of the radial blades, and said outer blade side of the outer blades is pitched in relation to a cylindrical lateral surface in the same manner as the lower sides of the radial blades in relation to a horizontal.

17. The mixing machine of claim 16, wherein a pitch angle of the outer blade sides of the outer blades in relation to the cylindrical lateral surface is less than that at which the lower sides of the radial blades are pitched in relation to a horizontal.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The present disclosure is described hereinafter on the basis of an example embodiments with reference to the appended figures, wherein:

[0020] FIG. 1 shows a perspective view of an industrial mixing machine;

[0021] FIG. 2 shows a view of the lower side of the head plate of the mixing head with a mixing tool supported thereon;

[0022] FIG. 3 shows a perspective view of the mixing tool alone;

[0023] FIG. 4 shows a side view of the mixing tool of FIG. 3, attached to the drive shaft extending through the head plate of the mixing head;

[0024] FIG. 5 shows an enlarged illustration of the cross-sectional geometry of the radial blades of the mixing tool of FIGS. 3 and 4;

[0025] FIG. 6 shows a view of the head plate of the mixing head corresponding to FIG. 2 with another mixing tool placed on the drive shaft; and

[0026] FIG. 7 shows a side view corresponding to FIG. 4 of the mixing tool of FIG. 6 seated on the drive shaft.

[0027] Before explaining the depicted embodiments, it is to be understood that the invention is not limited in application to the details of the particular arrangements shown, since the invention is capable of other embodiments. The embodiments and figures disclosed herein are to be considered illustrative rather than limiting.

DETAILED DESCRIPTION

[0028] Referring to FIG. 1, a mixing machine 1 is used for the industrial mixing of material located in a mixing container, for example, plastic granules. The mixing machine 1 has a frame 2, which is provided in the illustrated embodiment by two stands 3, 3.1. A container entrance 4 is located between the stands 3, 3.1 in the area of the bottom. The container entrance 4 is delimited laterally in the direction of each of the stands 3, 3.1 by a respective side wall 5, 5.1. In their upper section, the two stands 3, 3.1 are connected to one another via a pivotable assembly 6. The pivotable assembly 6 comprises a frame component 7, on each of whose two narrow sides a pivot shaft 8 is fastened. The pivot shaft 8 is mounted in the stands 3, 3.1. An electromotive drive 9, via which the pivotable assembly 6 can be pivoted around the axis of its pivot shaft 8, is located in the stand 3.

[0029] Two lifting devices 10, 10.1 designed as jackscrews are part of the pivotable assembly 6. The lifting devices 10, 10.1 are constructed identically. The basic structure of the lifting device 10 is described below. These statements apply similarly to the lifting device 10.1. The lifting device 10 has a lifting plate 11 as part of a lifting plate unit movable in the vertical direction by a spindle 12. A further plate, which has a chamfer towards the container flange, is located on the lifting plate. The container is thus centered during the lifting. The lifting plate unit is guided on a guide 13. The spindle 12 is driven by an electric motor. The lifting plate unit can be adjusted in the vertical direction by means of the spindle 12. It is shown in its lowermost position in FIG. 1. A locking lever 14, which can be pivoted around a vertical pivot axis from its base position shown in FIG. 1 in the direction of the mixing container receptacle, is furthermore part of the lifting plate unit. The pivoting of the locking lever 14 is used to lock a mixing container moved into the container entrance 4. The locking lever 4 acts against the outer wall of such a mixing container. The lifting device 10 is movable by means of an electric motor 15 as part of the pivotable assembly 6 in the direction of the longitudinal extension of the pivot axis of the pivotable assembly 6. The electric motor 15 drives a spindle drive for this purpose.

[0030] The pivotable assembly furthermore comprises a mixing head, of which its upper side (outer side) can be seen in FIG. 1.

[0031] The mixing head 16 having the two lifting devices 10, 10.1 is gimbal-mounted within the frame component 7. By means of a pivot drive S, the mixing head 16 with its two lifting devices 10, 10.1 can be pivoted about a rotational axis extending transversely to the pivot axis of the frame component 7. As a result, the mixing head 16 can be pivoted around two axes perpendicular to one another during operation of the mixing machine 1. This permits a mixing process to be carried out in which a mixing container attached to the mixing head 16 executes a multidimensional pendulum movement.

[0032] Part of the mixing head 16 is a head plate 17 forming a bottom of the rotated mixing receptacle in closing the mixing container interior. A drive shaft 18 extends through the head plate 17 and is driven by an electric motor 32 (see also FIG. 2). A mixing tool 19 is seated on the drive shaft 18 at a distance to the upper side of the head plate 17 forming the bottom of the closed mixing receptacle when rotated. The mixing tool 19 is a bladed tool with three radial blades 20, 20.1, 20.2. The radial blades 20, 20.1, 20.2 are attached to the hub 21 of the mixing tool 19 at the same angular distance from one another. The radial blades 20, 20.1, 20.2 are all constructed identically. Each radial blade 20, 20.1, 20.2 has an outer blade 22, 22.1, 22.2 on its radial outer end, each attached to the blade upper side. The attachment of the outer blades 22, 22.1, 22.2 is shown schematically in the figures. In practice, the radial blade will be embodied continuously having a slight radius between the two blade sections.

[0033] FIG. 2 shows the inner lateral surface 23 of a mixing container, which is attached to the mixing head 16 and is otherwise not shown in greater detail. It is used to visualize the radial outer distance of the outer blades 22, 22.1, 22.2 from the inside of a mixing container represented by the lateral surface.

[0034] FIG. 3 shows the mixing tool 19 alone in a perspective view. The cross-sectional geometry of the radial blades 20, 20.1, 20.2 is already clear from this illustration. This is explained below with reference to FIGS. 4 and 5 on the basis of the radial blade 20. The radial blade 20the same applies to the two other radial blades 20.1, 20.2has a wedge-shaped cross-sectional geometry facing opposite to the rotational direction with a rounded end face facing in the rotational direction. The rotational direction of the mixing tool 19 is indicated in these figures by a block arrow.

[0035] FIG. 5 shows the cross-sectional profile of the radial blade 20 in an enlarged view, without the outer blade 22 formed on the end thereof. The radial blade 20 is pitched in relation to a horizontal H, specifically with an inclination direction in the direction toward the head plate 17 of the mixing head 16 in the rotational direction. In the illustration, it is in the horizontal plane. This plane is also, independently of the current spatial orientation of the head plate, the plane which is spanned perpendicularly to the rotational axis of the mixing tool 19. In the spatial orientation of the cross-sectional geometry of the radial blade 20 shown in the figures, the straight blade lower side 24, which is thus embodied without additional contours, encloses an angle of approximately 25 with the horizontal H. The blade upper side 25 is also embodied to be straight and in the illustrated embodiment is inclined in the same direction as the blade lower side 24, but only by a few degrees. The inclination of the blade upper side 25 is also apparent on the radial blade 20.2 in the illustration of FIG. 4 of the mixing tool 19, in which view the radial blade 20.2 is shown from its front side and, in this perspective, the blade upper side rising due to its inclination is visible. The straight sections of the blade lower side 24 and the blade upper side 25 represent the section of the radial blade 20, the thickness of which decreases from its maximum thickness in the direction toward the rear blade end 26.

[0036] Due to the described pitch, the rear end of the radial blade 20 provided by the blade end 26 is at a higher level in relation to a vertical than the front end of the straight section of the blade upper side 25 facing in the rotational direction. The blade lower side 24 and blade upper side 25, which are embodied as straight without additional contours, are brought together at the blade end 26 due to their different inclination. The blade lower side 24 encloses an angle of approximately 20 with the blade upper side 25. Facing in the rotational direction, the front face 27 of the radial blade 20 is embodied as rounded, with a constant radius of curvature in the illustrated embodiment. It is essential in the design of the cross-sectional geometry of the radial blade 20 that a straight line G connecting the blade end 26 to the front blade end facing in the rotational direction is inclined in the same direction as the inclination of the blade lower side 24. In the illustrated embodiment, the inclination of this straight line G, at approximately 12, is less by approximately half than the inclination of the blade lower side 24 in relation to the horizontal H. The radial blade 20 is constructed mirror symmetrically with respect to the plane in which the straight line G is located. The plane in which the straight line G is located is the central longitudinal plane of the radial blade 20.

[0037] During a rotation of the mixing tool 19 in the rotational direction shown in the figures, material to be mixed incident on the curved front face 27 above its apex is guided in the vertical direction upward to the blade upper side 25. As a result, the material to be mixed receives an upwardly oriented moment in the vertical direction, which is assisted by the pitch of the blade upper side 25 inclined in the rotational direction. Due to this, the material to be mixed through which the radial blade 20 is moved is raised upward in the vertical direction in the manner of a shovel or accelerated away from the radial blade 26. At the same time, material to be mixed located below its apex facing in the rotational direction is moved due to the rounded front face 27 in the vertical direction to the head plate 17. However, the pitch of the blade lower side 24, against the background of the material to be mixed displaced by the radial blade 20, causes a certain negative pressure in the space below the radial blade, which enlarges toward the blade end 26, due to which material to be mixed located below the blade lower side 24 of the radial blade 20 is pulled upward and engaged by the following radial blade 20.2 and receives a further moment conveying the material to be mixed particles upward in the vertical direction via its blade upper side. This special mode of operation is the reason for the intensive mixing of material to be mixed using the mixing tool 19.

[0038] The outer blade 22 on the radial blade 20 shows the same cross-sectional geometry as the radial blade 20 and the same blade pitch in relation to the lateral surface 23 of a mixing container. As is apparent from the top view of FIG. 2, the blade side 28 facing outward in the radial direction is also pitched in relation to the lateral surface 23 like the blade lower side 24 in relation to the horizontal H. The pitch angle of the blade side 28 of the outer blade 22 with the lateral surface 23 is a few degrees smaller in the illustrated embodiment than the pitch angle of the blade lower side 24 in relation to the horizontal H.

[0039] FIG. 6 shows a further mixing tool 19.1, which is basically constructed like the mixing tool 19 of the preceding figures. The mixing tool 19.1 differs in the specific cross-sectional geometry of its radial blades 29, 29.1, 29.2 from that of the mixing tool 19. The cross-sectional geometry of these radial blades 29, 29.1, 29.2 can be seen more clearly in the side view of the mixing tool 19.1 in FIG. 7. The cross-sectional geometry of the radial blade 29this also applies to the two other radial blades 29.1, 29.2differs from that of the radial blade 20 in that the blade lower side 30 is embodied as straight as a whole and the blade lower side 30 thus corresponds to the imaginary straight line which connects the blade end to the front end. The blade upper side 31 has a straight rear section, by which the section of decreasing thickness is defined starting from the maximum thickness of the radial blade 29. This radial blade 29 has its greatest thickness (distance from blade lower side 30 ) to the blade upper side 31 set back somewhat further from its front end in relation to the radial blade 20. At this point, the blade upper side 31 is embodied as rounded to form an apex and guided on the front side to the blade lower side 30 to form an edge.

[0040] During a rotation of the mixing tool 19.1, material to be mixed is exclusively conveyed upward and thus away from the head plate 17 by the radial blade 29. In this mixing tool 19.1, during operation more material to be mixed, which is not engaged by the radial blade 29 and is located below its movement path in the direction to the head plate 17, is swirled up, since no components of material to be mixed are displaced by the radial blade 29 in the direction toward the head plate 17, in contrast to the radial blade 20.

[0041] The invention has been described on the basis of example embodiments. Without leaving the scope of the appended claims, persons skilled in the art will recognize further options, modifications, permutations, additions, combinations and sub-combinations for implementing the invention, without having to explain them in greater detail herein. The appended claims should therefore be interpreted to include all such options, modifications, permutations, additions, combinations and sub-combinations. Each embodiment described herein has numerous equivalents. Terms and expressions herein are used as terms and expressions of description and not of limitation, and there is no intention in the use thereof to exclude any equivalents of the features shown or described, or portions thereof.

TABLE-US-00001 LIST OF REFERENCE SIGNS 1 mixing machine 2 frame 3, 3.1 stand 4 container entry 5, 5.1 side wall 6 pivotable assembly 7 frame component 8 pivot axis 9 drive unit 10, 10.1 lifting device 11 lifting plate 12 spindle 13 guide 14 locking lever 15 electric motor 16 mixing head 17 head plate 18 drive shaft 19 mixing tool 20, 20.1, 20.2 radial blade 21 hub 22, 22.1, 22.2 outer blade 23 lateral surface 24 blade lower side 25 blade upper side 26 blade end 27 front face 28 blade side 29, 29.1, 29.2 radial blade 30 blade lower side 31 blade upper side 32 electric motor G straight line H horizontal S pivot drive angle angle