CUTTING CROWN MOUNTING

Abstract

A cutting crown fixing for positively locking and non-rotatable fixing of a cutting crown to a holder associated therewith of a comminuting apparatus, in particular a rotor of a comminuting apparatus, including a cutting crown, a cutting crown holder associated with the cutting crown, a screw bolt and a thread insert having a head portion and a shaft portion, wherein the thread insert has a female thread complementary to the male thread of the screw bolt and the cutting crown holder has a through passage for receiving the screw bolt, and in the installed position the thread insert is arranged in positively locking relationship in the axial and tangential direction in a holding opening of the cutting crown associated therewith. The cutting crown holder according to the invention is distinguished in that the positively locking configuration of a peripheral surface of the thread insert relative to the holding opening of the associated cutting crown extends over the entire longitudinal extent of the thread insert, wherein the thread insert is of a rotationally symmetrical configuration over the longitudinal extent of the head portion for providing an axial positively locking relationship with the holding opening and at least over a longitudinal portion has a conical peripheral surface which in the installed position corresponds to a conical receiving portion of complementary configuration of the holding opening and the thread insert in the region of the longitudinal extent of the shaft portion is of a non-rotationally symmetrical configuration for providing a rotational positively locking relationship with the holding opening.

Claims

1-13. (canceled)

14. A cutting crown fixing for positively locking and non-rotatable fixing of a cutting crown to a holder associated therewith of a comminuting apparatus, in particular a rotor of a comminuting apparatus, including a cutting crown, a cutting crown holder associated with the cutting crown, a screw bolt and a thread insert having a head portion and a shaft portion, wherein the thread insert has a female thread complementary to the male thread of the screw bolt and the cutting crown holder has a through passage for receiving the screw bolt, and in the installed position the thread insert is arranged in positively locking relationship in the axial and tangential direction in a holding opening of the cutting crown associated therewith, wherein the positively locking configuration of a peripheral surface of the thread insert relative to the holding opening of the associated cutting crown extends over the entire longitudinal extent of the thread insert, wherein the thread insert is of a rotationally symmetrical configuration over the longitudinal extent of the head portion for providing an axial positively locking relationship with the holding opening and at least over a longitudinal portion has a conical peripheral surface which in the installed position corresponds to a conical receiving portion of complementary configuration of the holding opening and the thread insert in the region of the longitudinal extent of the shaft portion is of a non-rotationally symmetrical configuration for providing a rotational positively locking relationship with the holding opening.

15. The cutting crown fixing as set forth in claim 14, wherein the holding opening extends from a surface, in particular a cutting surface of the cutting crown, to a surface opposite thereto.

16. The cutting crown fixing as set forth in claim 14, wherein the head portion of the thread insert in the longitudinal direction has a cylindrical portion which in the installed position faces towards the cutting surface of the cutting crown and which is adjoined in coaxial orientation by the conical portion.

17. The cutting crown fixing as set forth in claim 14, wherein along the longitudinal extent of its shaft portion the thread insert has a variable spacing in respect of its peripheral surface perpendicularly to the axis of its screw thread.

18. The cutting crown fixing as set forth in claim 14, wherein in the installed position in the longitudinal extent of its shaft the thread insert is free of positively locking engagement in the axial direction relative to associated portions of the holding opening.

19. The cutting crown fixing as set forth in claim 14, wherein the thread insert is arranged in fixed relationship for example by means of clamping, producing a press fit, staking or gluing in the holding opening of the cutting crown.

20. The cutting crown fixing as set forth in claim 14, wherein in the installed position at a front end portion facing at least towards a cutting surface of the associated cutting crown the thread insert has an end face which continuously extends and/or supplements the at least one cutting surface of the cutting crown to avoid chips which are misdirected by edges.

21. The cutting crown fixing as set forth in claim 14, wherein in the installed position at a front end portion facing towards at least one cutting surface of the associated cutting crown the screw bolt has an end face which continuously extends and/or supplements the end face of the thread insert and therewith the at least one cutting surface of the cutting crown to avoid chips which are misdirected by edges.

22. The cutting crown fixing as set forth in claim 14, wherein the female thread of the thread insert is in the form of a blind hole thread.

23. The cutting crown fixing as set forth in claim 14, wherein the thread insert and the associated cutting crown are made from mutually different materials, wherein the material of the thread insert is of higher ductility than the material of the cutting crown.

24. The cutting crown fixing as set forth in claim 14, wherein the shaft of the thread insert in a section transversely to the longitudinal axis has at least a plurality of polygonal portions, in particular a closed polygonal shape, wherein corners of the polygon can be rounded.

25. The cutting crown fixing as set forth in claim 14, wherein the thread insert and the associated cutting crown in the relative installed position are subjected to a heat treatment to set a predetermined final strength of the cutting crown.

26. The cutting crown fixing as set forth in claim 14, wherein the longitudinal extent of the head portion of the thread insert is at least 30%, in particular at least 35% of the overall longitudinal extent of the thread insert.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0030] The invention is described hereinafter by the description of an embodiments together with modifications with reference to the accompanying Figures in which:

[0031] FIG. 1 shows a sectional view with two partial sections which are displaced relative to each other through 90° of an embodiment of a cutting crown fixing according to the invention as a perspective side view;

[0032] FIG. 2 shows the view of FIG. 1 as an exploded view;

[0033] FIG. 3A shows a perspective side view looking on to the shaft of the thread insert of the cutting crown fixing of FIGS. 1 and 2;

[0034] FIG. 3B shows a perspective side view of the thread insert of FIG. 3A looking on to the head of the thread insert;

[0035] FIG. 3C shows a front view on to the thread insert of FIG. 3A looking on to the shaft; and

[0036] FIG. 3D shows a side view of the thread insert of FIG. 3A.

DETAILED DESCRIPTION

[0037] FIG. 1 shows a perspective view of a cutting crown fixing 1 according to the invention in a sectional view with two partial sections displaced through 90° relative to each other, the section line formed by two section planes extending coaxially through the axis A of a screw bolt 4. The cutting crown fixing according to the invention includes a cutting crown holder 3 to which a cutting crown 2 is fitted, wherein inserted at the end of the cutting crown, that is remote from the cutting crown holder, is a thread insert 5 which in the installed position is screwed to the screw bolt 4 for axially securing the cutting crown 2 to the cutting crown holder 3.

[0038] In the described embodiment the cutting crown holder 3 can be adapted for fixing to a comminuting rotor of a comminuting or shredding apparatus, in particular by welding. In general a multiplicity of such cutting crown fixings 1 are mounted on the comminuting rotor over the entire working width thereof and frequently peripherally displaced. By way of example such a comminuting rotor can have respective rib-like recesses into which a respective cutting crown holder 3 having contact surfaces complementary to the recess is inserted and welded to the rotor in such a way that a worn cutting crown can be replaced by releasing the described screw connection.

[0039] FIG. 2 shows an exploded view of the components of FIG. 1 relating to the configuration of the cutting crown fixing 1 according to the invention. At its end facing towards the cutting crown 2 the cutting crown holder 3 has a contact surface 31 which here is flat for bearing against a contact surface 23 of the cutting crown 2, that is of a complementary configuration. Between its opposite ends the cutting crown holder 3 has a passage or bore 30 through which the screw bolt 4 in the installed state extends with its bolt thread 41, wherein in the described embodiment the length of the bolt thread 41 corresponds to the sum of the length of the passage 30 in the cutting crown holder 3 and the length of the holding opening 25 in the cutting crown 2 and the holder opening 25 extends between the flat contact surface 23 and the oppositely disposed end face or surface which here represents a cutting surface 21.

[0040] In the described embodiment the holding opening 25 is in the form of a positively locking surface over its entire longitudinal extent in relation to the outside peripheral surfaces of the thread insert 5.

[0041] In the described embodiment the thread insert 5 has a thread 56 extending therethrough, of a complementary configuration to the bolt thread 41 of the screw bolt 4. The head region of the thread insert 5 with an axial extent Lk is here of a purely rotationally symmetrical configuration and, starting from the head end 57 of the thread insert 5, includes a purely cylindrical portion 51, adjoined by a cone portion 52, the axial end of which is adjoined by the shaft portion 53 over an axial extent Ls. To provide an axial positively locking relationship with the cutting crown the latter, starting from the cutting surface 21, to provide the holding opening 25, firstly has a purely cylindrical delimitation surface 22a which is adjoined by a conical delimitation surface 22b in a complementary configuration with the cone 52 of the thread insert. The shaft portion 53 of the axial length s of the thread insert 5 is of a complementary configuration to the delimitation surface 22c of the cutting crown 2, in the present case in cross-section in the form of a polygon shape with rounded corners, at which the edges of the polygon blend into each other. In the described embodiment the length of the holding opening 25 is adapted to or is identical to the overall height of the thread insert 5, that is to say the sum Ls and Lk. In the described embodiment the outer peripheral surface of the shaft 53 is of a complementary configuration to the delimitation surface 22c of the cutting crown 2 so that that longitudinal portion involves a rotational positively locking relationship between the thread insert 5 and the cutting crown 2 in the installed position. In particular it can be provided that the delimitation surface 22c of the holding opening 25 and in a complementary fashion the outer peripheral surface of the shaft 53 over the entire longitudinal extent thereof are of a substantially identical cross-section perpendicularly to the longitudinal direction so that in this described embodiment in the installed position of the components a purely axial positively locking relationship is present over the axial distance Lk and a purely torsional, that is to say rotational, positively locking relationship between the cutting crown 2 and the female thread 5 is present over the axial length Ls.

[0042] In an embodiment (not shown) it can also be provided that the radial extent of the outer peripheral surface of the shaft 53 changes in the longitudinal direction and the delimitation surface 22c also in a correspondingly complementary fashion so that in this embodiment the axial portion Ls involves both a torsional and also an axial positively locking relationship between the cutting crown 2 and the thread insert 5.

[0043] In particular the positively locking configuration of the cutting crown 2 and therewith also the configuration, complementary thereto, of the holding opening in the cutting crown can be seen in greater detail from the views in FIGS. 3a-d showing different views of the thread insert 5 of the described cutting crown fixing according to the invention. It can be seen in particular from FIG. 3c that, in the cross-section perpendicular to the axis, the outer peripheral surface of the shaft 53 in the described embodiment is composed of a multiplicity of curved surface portions 59a-f occurring in succession in the peripheral direction. As the successive peripheral surfaces are of different radii of curvature this results in a rotational positively locking relationship between those peripheral surfaces and the longitudinal portion Ls of the holding opening 25 of the cutting crown, that is of a complementary configuration to the peripheral surface of the shaft 53, see FIGS. 1 and 2.

LIST OF REFERENCES

[0044] 1 cutting crown fixing [0045] 2 cutting crown [0046] 3 cutting crown holder [0047] 4 screw bolt [0048] 5 thread insert [0049] 20a,b,c cutting edge [0050] 21 cutting surface [0051] 22a,b,c delimitation surface [0052] 23 contact surface [0053] 25 holding opening [0054] 30 passage [0055] 31 contact surfaces [0056] 32 bolt head receiving means [0057] 32 bolt head [0058] 40 bolt thread [0059] 41 head [0060] 50 cylindrical portion [0061] 52 cone, conical portion [0062] 53 shaft, shaft portion [0063] 54 peripheral surface [0064] 56 thread [0065] 57 end face [0066] 59a-f peripheral surface portion of the shaft [0067] A axis [0068] Lk head length [0069] Ls shaft length