EP3439774B1 - Mixing shaft - Google Patents

Description

The present invention relates to a mixing shaft with a tool holder and a mixing blade, in which a section of the mixing blade is fastened in a recess in the tool holder.

Mixers with one or more mixing shafts arranged perpendicular to the bottom of the mixing container are known. The mixing shafts often have a plurality of mixing blades which are arranged in a plurality of planes and extend radially outward from the longitudinal axis of the mixing shaft.

The mixing blades used as working tools are subject to wear and must therefore be replaced at certain intervals. It has been shown that the wear on the different mixing blades does not progress at the same speed. Mixing blades, which are covered by the mix with a higher layer height, wear significantly faster than mixing blades that are installed close to the surface of the mix.

It is known to screw the mixing blades directly onto the mixing tool shaft. Although this has the advantage that each mixing paddle can be mounted separately, it is disadvantageous that the fastening screws are exposed to wear and contamination from the mix, so that the mixing paddles can often no longer be easily removed from the tool holder after a long period of operation.

There are therefore already advanced systems for attaching mixing blades to a tool holder, in which the mixing blades are clamped centrally using mechanical or even hydraulic clamping devices. A disadvantage of these devices, however, is that the mechanical or hydraulic tensioning device results in increased construction costs. In addition, with these systems only all mixing blades can be released at the same time, i.e. even those mixing blades that should not be exchanged have to be loosened.

Mixing tools and shafts are known from the publication US 5,061,082 A , DE 2951014341 , WO 2011/115552 A1 , US 2007/076523 A1 , FR 2317011 A1 , US 2014/252142 A1 , EP 1 595 671 A1 and US 356571 A .

The present invention is therefore based on the object of providing a simple mixing shaft with a tool holder which reliably and reliably allows the individual exchange of individual mixing blades in a simple manner.

This object is achieved by a mixing shaft according to claim 1.

In other words, each mixing paddle is assigned its own clamping part, which, in the event that the mixing paddle is to be replaced, is released in order to detach the mixing paddle section from the tool holder.

The cutout has a first and a second cutout section, the mixing wing section being arranged in the first cutout section and the clamping part being at least partially arranged in the second cutout section.

For example, the clamping part can be completely accommodated in the second cutout section, so that the first cutout section is provided for receiving the mixing blade section and the second cutout section for receiving the clamping part. However, it is also possible that the mixing wing section in turn has a mixing wing section recess into which a part of the clamping part is inserted, so that the clamping part can also be partially arranged in the first recess section.

The clamping part and the mixing vane section are thus introduced into the recess next to one another in order to realize jamming of the mixing vane section in the recess.

According to the invention, the clamping part is supported both on the mixing wing section and on a wall of the second recess section, both clamping part and either the mixing wing section or the wall of the second recess section having wedge surfaces corresponding to one another.

Due to the corresponding wedge surfaces, which act like a ramp, the clamping part is pressed against the mixing wing section by inserting it. For example, the clamping part can be attached to the tool holder with the help of one, two or more screws. By tightening the screws, the clamping part is then drawn into the recess along the corresponding wedge surfaces, as a result of which the mixing blade section is clamped within the recess.

In a particularly preferred embodiment, the clamping part has a forcing thread, by means of which the clamping part can be pressed out of the recess again with the aid of a forcing screw. For example, the forcing thread can be arranged such that a Screw can be screwed into the forcing thread in such a way that the end of the screw facing away from the screw head is supported on a surface of the mixing shaft, for example on a surface of the tool holder, so that the clamping part is pressed out of the recess by turning the screw.

The wedge angle, i.e. the angle which the wedge surfaces form at a plane perpendicular to the longitudinal axis of the mixing shaft can in principle be chosen freely. A value greater than 7 ° has proven itself in practice. A slight self-locking is to be expected at this angle. If this is not desired, the wedge angle must be larger, e.g. at approx. 15 °.

According to the invention, the second recess section is arranged in the axial direction next to the first recess section. This has the advantage that no additional force is exerted by the mixing blade on the clamping part due to the expected torsional forces during use of the mixing shaft. In principle, the second recess section can be arranged in the axial direction both above and below the first recess section. In practice, it has proven useful if the second cutout section is arranged in the axial direction above the first cutout section, since then the assembly of the mixing blade section in the tool holder is easier to accomplish. The terms "above" and "below" refer to the intended working position of the mixing shaft. The end of the mixing shaft, which is located higher than the other end, is understood as the upper end. Therefore, if the second recess section is arranged above the first recess section, this means that the second recess section is arranged closer to the upper end of the mixing shaft than the first recess section.

In a preferred embodiment, means for fastening the mixing shaft to a motor shaft or a drive shaft are provided at the upper end of the mixing shaft.

In a further preferred embodiment, the tool holder consists of several tool holder disks, which are connected to the tool shaft, and a clamping device for bracing the tool holder disks in the axial direction. The mixing shaft thus consists of the tool shaft, the tool holder disks, the clamping device for the tool holder disks, the clamping device for the mixing blades and the mixing blades.

The recess is then arranged in at least one tool holder disk. Such an embodiment has the advantage that the mixing shaft has a modular structure and, depending on the desired length of the mixing shaft, other tool holder disks can simply be mounted on the shaft. For example, the shaft can have a hexagonal cross-section, while the tool holder disks have a hexagonal through-opening with which they pass the shaft can be pushed. Such a configuration has the advantage that the tool holder disks are positively connected to the shaft, so that the tool holder disks are rotated about their axis by rotating the shaft.

It is possible that the recess, i.e. the first recess section and the second recess section are arranged in the same tool holder disk.

In a preferred embodiment, a first part of the recess is arranged in a first tool holder disc and a second part of the recess in a second tool holder disc, the tool holder discs then being positioned next to one another in such a way that the first and the second part of the recess form the recess. It is particularly preferred if each tool holder disc has both a first and a second recess part, which are each intended to form a recess together with a second recess part or a first recess part of an adjacent positioned further tool holder disc.

Thus, although in this embodiment each tool holder disc has at least a first and a second recess part, these do not together form a recess in the same tool holder disc. Instead, the recess is first formed together with a corresponding recess part of an adjacent tool holder disk.

The recess can also be composed of more than two recess parts in different tool holder disks, so that the geometry of the recess can also be formed from more than two tool holder disks.

It is possible to design the parts of the cutout in such a way that the first part of the cutout forms the first cutout section and the second part of the cutout forms the second cutout section. However, this does not have to be the case.

In a further preferred embodiment, the clamping part is screwed to the tool shaft or preferably to the tool holder. If the clamping part is made of several parts, according to this embodiment at least part of the clamping part should be screwed to the tool shaft or preferably to the tool holder.

In a further preferred embodiment, a protective element is provided which is arranged in the second recess section and covers the clamping part. The protective element best closes the second recess section completely and without gaps, preferably also with respect to the mixing wing. The protective element can, for example, be a protective cap be, which can be made, for example, of a plastic or other easily removable material. The cutout should be as flush as possible with the outer contour of the tool holder, so that the protective cap is prevented from accidentally detaching from the cutout section during operation.

Alternatively, the recess can also be made with a hardening injection or casting compound, e.g. Silicone, can be closed.

In a further particularly preferred embodiment, the mixing blade section and the tool holder are connected to one another via a pin connection or another positive connection. For example, the mixing wing section can have a through opening, preferably with a circular cross section, and a pin can be arranged in the first recess section, which is connected to the tool holder. Then can be pushed with its through opening over the pin to attach the mixing wing section.

At high circumferential speeds of the mixing shaft, the positive connection prevents the mixing blades from coming out of the recess due to the centrifugal forces that occur when the clamping connection is reduced.

In a further preferred embodiment it is provided that the tool holder disk is substantially circular in cross section perpendicular to the axis of rotation, the positive connection, e.g. B. the pin of a pin connection is closer to the inner radius of the circular ring shape than the outer radius.

In a further preferred embodiment, in the event that the mixing wing section has an opening as part of the positive connection, it is provided that the clamping part at least partially covers this opening, the clamping part preferably completely covering the opening. On the one hand, this protects the opening against dust and, on the other hand, reduces the static friction between the clamping part and the mixing vane section, which makes assembly and disassembly of the mixing shaft easier.

In addition, a better clamping effect is achieved with this arrangement. Therefore, the clamping part is preferably arranged in the inserted state in such a way that it partially or best completely overlaps with the positive connection in a projection onto a plane perpendicular to the axis of rotation. In other words, the clamping part is arranged in the axial direction above or below the positive connection.

In a further preferred embodiment it is provided that the clamping part has a maximum extent in the circumferential direction which is greater than the maximum extent of the mixing wing section.

Especially in applications that require a plurality of mixing blades that are only slightly spaced in the axial direction, the smallest distance between the mixing blade section and the tool holder in the axial direction is smaller than the necessary displacement path of the mixing blade section in the axial direction in order to release the mixing blade from the positive connection.

To insert or remove the mixing blade from the tool holder, the mixing blade can then be tilted relative to a plane perpendicular to the axis of rotation. This tilting is possible due to the corresponding wedge surfaces. The mixing blades can be tilted, i.e. only by axial relative movement in relation to the tool holder.

Figur 1

eine perspektivische Ansicht einer erfindungsgemäßen Mischwelle,

Figur 1a

eine perspektivische Teilansicht der Ausführungsform von Figur 1,

Figur 2

einen Längsschnitt durch eine erfindungsgemäße Ausführungsform einer Mischwelle,

Figur 3

eine Draufsicht auf eine Werkzeughalterscheibe der Ausführungsform von Figur 1,

Figur 4

eine isometrische Detailansicht einer erfindungsgemäßen Mischwelle,

Figur 5

eine weitere isometrische Detailansicht einer erfindungsgemäßen Mischwelle,

Figur 6

eine Teilquerschnittsansicht der Ausführungsform von Figur 1,

Figur 7

eine perspektivische Vorderansicht eines Klemmteiles,

Figur 8

eine perspektivische Rückansicht des Klemmteiles von Figur 7,

Figur 9

einen Längsschnitt durch die Welle bei Verwendung von Halbrundnocken,

Figur 10

eine perspektivische Ansicht eines Mischflügels der Ausführungsform von Figur 9,

Figur 11

eine Teilschnittansicht einer zweiten Ausführungsform,

Figur 12

eine perspektivische Ansicht einer Verschlusskappe,

Figur 13

eine Explosionsansicht einer dritten Ausführungsform und

Figur 14

eine perspektivische Schnittansicht der dritten Ausführungsform.

Further advantages, features and possible uses will become clear from the following description of a preferred embodiment and the associated figures. Show it

Figure 1

2 shows a perspective view of a mixing shaft according to the invention,

Figure 1a

a partial perspective view of the embodiment of Figure 1 ,

Figure 2

2 shows a longitudinal section through an embodiment of a mixing shaft according to the invention,

Figure 3

a plan view of a tool holder disk of the embodiment of Figure 1 ,

Figure 4

2 shows an isometric detailed view of a mixing shaft according to the invention,

Figure 5

another detailed isometric view of a mixing shaft according to the invention,

Figure 6

a partial cross-sectional view of the embodiment of Figure 1 ,

Figure 7

a perspective front view of a clamping part,

Figure 8

a rear perspective view of the clamping part of Figure 7 ,

Figure 9

a longitudinal section through the shaft when using semicircular cams,

Figure 10

a perspective view of a mixing blade of the embodiment of Figure 9 ,

Figure 11

2 shows a partial sectional view of a second embodiment

Figure 12

a perspective view of a closure cap,

Figure 13

an exploded view of a third embodiment and

Figure 14

a perspective sectional view of the third embodiment.

Figure 1 shows a perspective view of a mixing shaft 1. The mixing shaft 1 has a tool holder, which in this embodiment consists of a plurality of tool holder disks 2. The tool holder disks 2 together form a cylindrical body which is rotated about its cylinder axis during operation. There are one over the outer surface of this cylinder A plurality of mixing blades 3 in front. These mixing blades 3 can have beveled edges 4, but do not have to. Therefore, some mixing blades 3 with corresponding beveled edges are shown in the figure, while other mixing blades do not have these edges.

The mixing shaft 1 has at its upper end a mounting flange 5 with which it can be attached to a corresponding drive shaft.

Protective caps 6 can be seen directly above or below the mixing blades 3. The protective caps 6 are inserted in corresponding recess sections of the tool holder disks 2 and are flush with them. The protective caps 6 can be made of plastic, for example.

In Figure 1a 10 is a partial perspective view of the embodiment of FIG Figure 1 shown. As well in Figure 1 as well in Figure 1a different mixing blade geometries are shown. As a rule, however, only a single geometry is used in a mixed wave. However, the figures are intended to illustrate that different geometries can be used in principle.

In addition, the protective caps 6 are shown partly above and partly below the mixing blades 3. As a rule, embodiments are preferred in which the protective caps are arranged either all above the mixing blades or all below the mixing blades.

The individual tool holder disks 2 are on a tool shaft 10 (in the Figures 1 and 1a not shown) arranged. In order to press the individual tool holder disks 2 onto one another, an upper annular closure disk 7, a clamping ring 8 and a plurality of clamping screws 9 are provided. An annular disk spring (not shown) is installed under the cover disk 7 and the upper edge of the uppermost tool holder disk 2. The clamping screws 9 can be fastened in corresponding threaded bores of the clamping ring 8 in such a way that they press the end plate 7 onto the package of the tool holder writing 2 and tension it. The plate spring generates a counterforce on the cover lens when it is tensioned to reliably prevent the clamping screws from loosening during operation. The tool holder disks are supported at the lower end of the tool shaft on a circular or annular closure disk 7 'screwed to the shaft.

Figure 2 shows a longitudinal section through the shaft 10 with a section through the clamping part 11. The tool holder disk 2 can also be seen here, which has a threaded bore 13. A clamping part 11 is screwed with the aid of the fastening screw 12 into the threaded bore 13 of the threaded holder disk 2. With the help of the clamping part 11, the mixing blade 3 is clamped within the tool holder. In order to contaminate the fastening screw 12, in particular its To avoid the screw head during operation, the recess in the tool holder disk is designed in such a way that the protective cap 6 can be introduced into the recess in such a way that it is essentially flush in order to prevent dirt from getting into the recess.

Figure 3 shows a plan view of a tool holder disc 2. The hexagonal recess 14, which serves to receive a correspondingly shaped tool shaft 10, can be clearly seen.

In the embodiment shown, the tool holder disk 2 shows two recesses, in each of which a section of a mixing blade 3 is inserted. In the embodiment shown, a mixing blade 3 has a circular opening through which a pin 15, which is connected to the tool holder disk 2, is guided.

The section of the other mixing blade 3, on the other hand, has two bulges on the left and right edges into which two pins 16, both of which are mounted on the tool holder disk, engage. The two different fastening systems in the figure, i.e. Fastening with a pin 15 or attachment with two pins 16, shown, is only for the purpose of illustration that different fastening systems can be used to produce a positive connection. As a rule, an embodiment in which only one of the two fastening systems is used is preferred in order to reduce the storage of the corresponding mixing blades. Only in the event that mixing blades of different geometries are used within the mixing shaft, different fastening systems can be used to identify the mixing blade geometry to ensure that the correct mixing blade geometry is always positioned in the correct recess. The pins, protrusions or recesses can also be part circular, e.g. semicircular cross section or another cross section.

In the Figure 4 a further isometric detailed view of a mixing shaft according to the invention is shown.

It can be seen here that the recess in the tool holder extends over two tool holder disks 2. The part of the recess which is arranged in the lower tool holder disk 2 comprises the first recess section. A section of the mixing blade 3 is positioned in this recess section. The second recess section is partially arranged in the part of the recess which is provided by the upper tool holder disk 2. The clamping part 11 is thus partially in the recess part provided by the lower tool holder disk and partially arranged in the recess part provided by the upper tool holder disk 2. In the embodiment shown, the protective cap 6 has a U-shape, a rib being arranged on the outside of a U-leg and engaging in a corresponding groove 18 which is arranged in the inner wall of the second cut-out section. The protective cap 6, which is preferably made of plastic, can then be clipped into the corresponding recess so that it engages in the groove 18. The protective cap can be pierced with a tool for removal and levered out of the recess.

The recess is stepped in the axial direction, i. H. the recess has a section with a smaller width in the circumferential direction and a section with a larger width in the circumferential direction. The width of the mixing wing section corresponds approximately to the smaller width, so that the mixing wing section can be inserted into the section with the smaller width. However, the height of the mixing wing section in the axial direction is somewhat greater than the height of the section with the smaller width, so that the mixing wing section protrudes somewhat into the section with the larger width.

This ensures that the clamping part 11 is supported on the mixing wing section and not on the upper side of the lower tool holder disk, in order to enable a secure, non-positive connection.

In Figure 5 a further isometric detailed view of a mixing shaft according to the invention is shown. In this embodiment, the mixing blade 3 has a through opening 15 into which a pin engages. In the embodiment shown here, the pin is formed in one piece with the tool holder disk 2.

Furthermore, the section through the clamping part 11 is selected in such a way that a further bore 17 with a subsequent pull-off thread 17 'can be seen. This bore 17 with forcing thread 17 'is only required for dismantling the clamping part 11. First the screws 12 are loosened. In order to push the clamping part 11 out of its position, a screw is screwed into the bore 17, the screw base of which is then pressed against the tool shaft 10, for example, in order to press the clamping part 11 radially outwards.

This becomes even clearer from the in Figure 6 Cross-sectional view shown through the clamping part 11. It can be seen here that the clamping part 11 is held on the tool holder disk 2 with the aid of the two fastening screws 12. The further bore 17/17 'can be used to press the clamping part 11 off the tool holder disk 2.

The Figures 7 and 8th show two perspective views of the clamping part 11. The clamping part 11 has an inclined wedge surface 19. By mounting the clamping part 11 on a tool holder disk 2, the clamping part 11 can be pressed radially inward with the aid of the fastening screws 12, which engage in the corresponding bores 20, so that the wedge surface 19, which abuts a corresponding wedge surface of the tool holder disk 2, the Section of the mixing blade clamped in the tool holder.

In Figure 9 a longitudinal section through the shaft is shown when using semicircular cams for fastening the mixing blade in the tool holder. A perspective view of the mixing blade 3 of this embodiment is shown in FIG Figure 10 shown. In this embodiment, the mixing blade 3 has two semicircular cams 21 which engage in corresponding bores 16 in the tool holder disk 2. In the embodiment shown, the cams are integrally connected to the mixing wing. In principle, the cams could instead be fastened to the tool holder disk 2, in which case the section of the mixing blade 3 would have to have corresponding bores or recesses for receiving the cams.

An alternative mounting option is in the isometric view of Figure 11 shown as a second embodiment of the invention. On the one hand, the wedge-shaped clamping part 11 is arranged below the mixing wing 3. On the other hand, a separate pin 21 is provided here, which engages both in a corresponding opening 15 in the mixing blade and in a corresponding opening 22 in the tool holder disk 2. The length of the pin section of the pin 21, which engages in the mixing blade 3, is chosen to be smaller than the height of the mixing blade 3 in order to enable easier removal or a more compact design of the tool holder disks. The clamping part 11 completely covers the through opening 22 in the mixing blade 3. In this embodiment, the smallest distance a between the mixing blade section 3 and the tool holder 2 in the axial direction is greater than the height b of the mixing blade section 3 in the axial direction. Alternatively, it can also be smaller. It can even be the smallest distance a between the mixing wing section and the tool holder in the axial direction smaller than the necessary displacement path c of the mixing wing section in the axial direction in order to detach the mixing wing from the positive connection.

Figure 12 shows a perspective view of the inside of the protective cap 6. It can be seen that the cap 6 has a rib 18 encircling three sides, which engages in corresponding grooves 19 in the tool holder disk 2. In addition, it has a recess 23 on the fourth edge in order to enable the gap to the mixing blade 3 to be as gap-free as possible.

Figure 13 shows an exploded perspective view of a third embodiment of the invention. Wherever possible, the same elements have been given the same reference numbers.

Two tool holder disks 2 are shown here by way of example, which together have a recess for receiving a mixing blade 3 and a clamping part 25, 26. The clamping part 25, 26 consists of a first part 25 and a second part 26. The two parts 25, 26 have wedge surfaces 27 which correspond to one another. The two parts 25, 26 are placed one on top of the other in such a way that the corresponding wedge surfaces 27 lie on one another. The second part 26 of the wedge element has a bore 29, which is designed here as a stepped bore. The first part of the clamping part 25 has a threaded bore 28. The second part 26 can be fastened to the first part 25 with the aid of a fastening screw 30. By tightening the screw 30, the first part 25 is pulled in the direction of the second part 26, so that it is displaced on the wedge surfaces 27 and the two-part wedge element 25, 26 expands in the axial direction, whereby the clamping effect is achieved.

As in Figure 14 As can be seen in a perspective sectional view, the second part 26 of the clamping part is fastened to the tool holder disk 2 with the aid of the fastening screw 12. The second part 26 of the clamping part is designed such that it is essentially flush with the circumferential surface of the tool holder disks 2. If the fastening screw 30 is now tightened or loosened, this leads to a relative movement of the first part of the clamping part 25 in the radial direction due to the force exerted by the fastening screw 30 and in the axial direction due to the wedge surfaces 27 which correspond to one another, whereby the wedge element in the axial direction " becomes thicker or thinner in order to clamp or loosen the mixing blade 3 within the recess in the tool holder disk 2.

In order to prevent the heads of the screws 12, 30 from becoming dirty during operation, plugs are introduced into the stepped bores.

Reference numerals

1

Mixing wave

2nd

Tool holder washers

3rd

Mixing blades

4th

beveled edges

5

Mounting flange

6

Protective caps

7

Cover lens

7 '

screwed lens

8th

Tension ring

9

Turnbuckles

10th

Tool shaft

11

Clamping part

12.30

Mounting screw

13.28

Tapped hole

14

hexagonal recess

15

pen

16

two pens

17.29

drilling

17 '

Forcing thread

18th

Groove / rib

19th

Wedge surface / groove

20

Holes

21

Cam / separate pin

22

corresponding opening

23

Recess

24th

Plug

25th

first part of a clamping part

26

second part of a clamping part

27

Wedge surfaces

Claims (13)

1. A mixing shaft comprising a tool holder and a mixing blade (3), wherein the tool holder has a recess in which a portion of the mixing blade (3) is fixed, wherein there is provided a clamping portion (11) fitted into the recess for fixing the mixing blade portion in the recess, wherein the clamping portion (11), the recess and the mixing blade portion are of such a configuration that a force-locking connection of the mixing blade (3) in the recess is implemented by means of the clamping portion (11), wherein the recess has a first and a second recess portion, wherein the mixing blade portion is arranged in the first recess portion and the clamping portion (11) is arranged at least partially in the second recess portion, wherein the tool holder has an axis of rotation and the mixing shaft (1) is adapted to be rotated about the axis of rotation, wherein the second recess portion is arranged in the axial direction beside the first recess portion,
   characterised in that the clamping portion (11) is supported both at the mixing blade portion and also at a wall of the second recess portion, wherein both the clamping portion (11) and also either the mixing blade portion or the wall of the second recess portion have mutually corresponding wedge surfaces (13), or
   the clamping portion (11) is of a two-part structure and the two parts of the clamping portion(25, 26) have mutually corresponding wedge surfaces (27).
2. A mixing shaft as set forth in claim 1 characterised in that the first part of the clamping portion (25) has a threaded bore and the second part of the clamping portion (26) has a through bore which are so arranged that the second part of the clamping portion (26) can be fixed to the first part of the clamping portion (25) by means of a screw which engages through the through bore in the second clamping portion (26) into the threaded bore in the first part of the clamping portion (25), so that the corresponding wedge surfaces (27) bear against each other, and the two parts of the clamping portion (25, 26) can be displaced relative to each other by rotation of the screw.
3. A mixing shaft as set forth in claim 1 characterised in that the tool holder comprises a tool shaft (10) and a plurality of tool holder disks (2) connected to the tool shaft (10), wherein the recess is arranged in at least one tool holder disk (2).
4. A mixing shaft as set forth in claim 3 characterised in that the recess comprises two recess parts, wherein the first recess part is arranged in a first tool holder disk (2) and the second recess part is arranged in a second tool holder disk (2), wherein the tool holder disks (2) are positioned in mutually juxtaposed relationship in such a way that the first and second recess parts form the recess.
5. A mixing shaft as set forth in claim 4 characterised in that each tool holder disk (2) has both a first and also a second recess part which are respectively provided together with a second recess part and a first recess part respectively of an adjacently positioned further tool holder disk (2) to form a recess.
6. A mixing shaft as set forth in one of claims 1 through 5 characterised in that the clamping portion (11) is screwed to the tool shaft (10) or preferably to the tool holder.
7. A mixing shaft as set forth in claim 6 characterised in that there is provided a protective element which is arranged in the second recess portion and covers the clamping portion (11), wherein the protective element completely closes the second recess portion, the protective element preferably being a protective cap (6).
8. A mixing shaft as set forth in one of claims 1 through 7 characterised in that the mixing blade portion and the tool holder are connected together by way of a positively locking connection and more specifically preferably by way of a pin connection.
9. A mixing shaft as set forth in claim 8 characterised in that the mixing blade portion has a through opening, preferably of circular cross-section, and arranged in the first recess portion is a pin connected to the tool holder, wherein for fixing the mixing blade portion same can be pushed with its through opening over the pin.
10. A mixing shaft as set forth in claim 8 or 9 when appendant to claim 5 characterised in that the tool holder disk is substantially in the form of a circular ring in a cross-section perpendicularly to the axis of rotation, wherein the positively locking connection is arranged closer to the inner radius of the circular ring shape than to the outer radius.
11. A mixing shaft as set forth in claim 9 or 10 characterised in that the mixing blade portion has an opening as part of the positively locking connection and the clamping portion (11) at least partially covers the opening, wherein preferably the clamping portion (11) completely covers the opening.
12. A mixing shaft as set forth in one of claims 1 through 11 characterised in that in the peripheral direction the clamping portion (11) is of a maximum extent greater than the maximum extent of the mixing blade portion.
13. A mixing shaft as set forth in one of claims 8 through 11 characterised in that the smallest spacing (a) between the mixing blade portion and the tool holder in the axial direction is less than the necessary displacement travel (c) of the mixing blade portion in the axial direction to release the mixing blade (3) from the positively locking connection.

Images