US20120062017A1

US20120062017A1 - Two piece tool holder assembly

Info

Publication number: US20120062017A1
Application number: US12/880,344
Authority: US
Inventors: Martin Maushart; Michael Enste; Thomas Jürgen Chudowski
Original assignee: Kennametal Inc
Current assignee: Kennametal Inc
Priority date: 2010-09-13
Filing date: 2010-09-13
Publication date: 2012-03-15
Also published as: DE102011111868A1; CN102433828A; ZA201106423B; AU2011213863A1

Abstract

A tool holder assembly on a rotating unit, e.g. drum of an earth strata cutting assembly, includes a base mountable to the rotating unit and a removable member mounted to the base and having a support block for carrying an earth strata cutting tool. The base includes an upright member. In one aspect, the removable member substantially encloses the upright member and the removable member includes a V-shaped surface engaging a V-shaped surface of the upright member for a close tolerance fit. In another aspect, the removable member partially encloses the upright member and the removable member includes a circular surface engaging a circular surface of the upright member for a close tolerance fit.

Description

FIELD OF THE INVENTION

The invention pertains to a tool holder assembly for carrying a cutting tool. More specifically, the invention pertains to a two piece tool holder assembly comprising a base fixedly mountable to a rotating unit of a cutting assembly and a removable member connected to the base for carrying the cutting tool.

BACKGROUND

Examples of an earth strata cutting assembly include a continuous mining machine and a continuous road milling machine. These machines typically include a plurality of rotatable cutting drums that are advanced so as to engage the earth strata e.g. coal in a sediment layer or asphalt, concrete or stone in a road and cut or rip the same into fragments. Typically, the rotatable cutting drums include a plurality of cutting tools that impinge upon the material so as to break it into fragments.
Various types of cutting tools are known and, for example, may take the form of an elongated body round in cross section and symmetrical about a central axis with a cylindrical supporting shank at one end and with the other end generally tapering inwardly to a point in which is mounted a cemented carbide wear resistant element or tip. The portion of the cutting tool immediately rearward of the point is usually conical and as the cutting tool is used and rotates in use, the body of the cutting tool adjacent the hard cemented carbide insert experiences significant wear. In addition, the tool holder and the block or base which receives the tool holder include cooperating exposed surface areas which are subjected to substantial loads as the cutting tool is used. Because of the loads involved, the exposed surface areas can experience wear. While the cutting tool and the tool holder can be replaced relatively easy when they are worn out, rapid wear of the block, which is usually welded in place on the rotatable cutting drum, is a serious problem because the block is normally expected to remain in good condition for the life of several cutting tools.
There is a need to provide a tool holder assembly for an earth-strata cutting assembly that overcomes limitations and disadvantages of known tool holder assemblies.

SUMMARY

The invention generally provides a tool holder assembly for carrying a cutting tool on a rotating unit of an earth strata cutting assembly. The tool holder assembly includes a base fixedly mountable to the rotating unit; and a removable member mounted on the base and comprising a support block constructed and arranged to carry the cutting tool. The base includes an upright member and a planar member supporting the upright member. The removable member is constructed and arranged to substantially enclose the upright member and abut against the planar member of the base.
In one aspect, the upright member of the base includes a tapered upper surface, the removable member includes a corresponding tapered surface adjacent the tapered upper surface of the upright member; and the upright member and the removable member are constructed and arranged to be secured together through a close tolerance fit. A retaining element extends through apertures in the removable member and in the upright member of the base for ensuring and maintaining a secure connection of the removable member to the base. The removable member includes a wedge-like body angularly supporting the support block at a desired angle of attack and two spaced apart side walls joined together by a mediate portion to form an open area that receives the upright member of the base. The upright member further includes spaced apart side walls, an arcuate surface at a first end, and a V-shaped surface at an opposed second end, and the mediate portion of the wedge-like body of the removable member includes a V-shaped surface corresponding to the V-shaped surface of the upright member of the base. The arcuate surface of the upright member of the base is constructed and arranged to receive a shank of a cutting tool when the cutting tool is carried by the support block of the removable member. The upright member of the base and the wedge-like body of the removable member are wedged together through a close tolerance fit and the V-shaped surface of the upright member engages the V-shaped surface of the wedge-like body of the removable member.
In a further aspect of the present invention, the tool holder assembly comprises a base comprising an upright member and a planar member supporting the upright member and a removable member which is constructed and arranged to partially enclose the upright member of the base.
In other aspects of the invention, the upright member of the base and the removable member are constructed and arranged to be secured together through a close tolerance fit. A retaining element extends through an aperture in the removable member and an aperture in the upright member of the base for ensuring and maintaining a secure connection of the removable member to the base. The removable member further includes a wedge-like body angularly supporting the support block at a desired angle of attack and comprising spaced apart sidewalls joined together by a mediate portion and forming an open area for receiving the upright member of the base; and one of the spaced apart sidewalls of the removable member extends a partial depth of the removable member. The upright member of the base comprises spaced-apart side walls, a flat surface at a first end, and a curved surface at the opposed second end; the mediate portion of the wedge-like body of the removable member comprises a curved surface corresponding to and engaging the curved surface of the upright member of the base; and the flat surface of the upright member of the base is constructed and arranged to receive a flat surface of a cutting tool when the cutting tool is carried by the support block of the removable member. The upright member of the base and the wedge-like body of the removable member are wedged together through a close tolerance fit with at least the curved surface of the upright member engaging the curved surface of the wedge-like body of the removable member. The upright member of the base further includes an arcuate member extending along a surface of one of the sidewalls concentric to the aperture of the upright member and outwardly into the open area formed by the spaced apart sidewalls of the removable member.
These and various other aspects and advantages will be apparent from the following drawings and detailed description.

DRAWINGS

FIG. 1 is a schematical representation of a portion of a cutting assembly (e.g., an earth strata cutting assembly), in accordance with an aspect of the invention.

FIG. 2 is a perspective view of an assembled two-piece tool holder assembly, in accordance with an aspect of the invention.

FIG. 3 is a perspective, exploded view of the two-piece tool holder assembly of FIG. 2, in accordance with an aspect of the invention.

FIG. 3A is a view taken along lines 3A-3A of FIG. 3, in accordance with an aspect of the invention.

FIG. 4 is a perspective view of an assembled two-piece tool holder assembly, in accordance with a further aspect of the invention.

FIG. 5 is a perspective, exploded view of the two-piece tool holder assembly of FIG. 4, in accordance with an aspect of the invention.

FIG. 5A is a view taken along lines 5A-5A of FIG. 5, in accordance with an aspect of the invention.

DETAILED DESCRIPTION

Referring to the drawings, FIG. 1 is a schematical representation of a portion of a cutting assembly (e.g., an earth strata cutting assembly), generally designated as 10. Cutting assembly 10 includes a rotatable cutting drum 14 having a plurality of cutting tool assemblies 16 arranged thereon. The cutting drum 14 is operatively connected to a motor 20 that drives the rotatable cutting drums 14. Cutting tool assemblies 16 may include a two-piece tool holder assembly, as will be described herein, and a cutting tool (e.g. conical bit cutting tools as are generally known) received therein.
Referring to FIGS. 2 and 3, there is illustrated a two-piece tool holder assembly 24, in accordance with an aspect of the invention. The two-piece tool holder assembly includes a base 26 and a removable member 28. Base 26 is constructed to be fixedly mounted by, for example, welding to a rotating unit such as, for example, the rotatable cutting drums 14 shown in FIG. 1. The removable member 28 is mounted on base 26 and includes a cylindrical support block 30 having a bore 32 for carrying a cutting tool (not shown). The support block 30 may be fixedly mounted by, for example, welding to the removable member 28.
Still referring to FIGS. 2 and 3, the base 26 includes a planar member 34 and an upright member 36. The removable member 28 substantially covers or encloses upright member 36 of base 26. In one aspect, planar member 34 may be in the form of a wedge wherein planar member 34 has an upper surface 38 that tapers downwardly from a first end 40 to an opposed second end 42. Similarly, removable member 28 may be in the form of a wedge, that is, removable member 28 comprises a wedge-like body 44 that has an upper surface 46 that tapers downwardly from a first end 48 to an opposed second end 50. As particularly shown in FIG. 2, when removable member 28 is mounted on base 26, this wedge-form structure of tool holder assembly 24 causes support block 30 and therefore a cutting tool when mounted in bore 32 of support block 30 to be positioned at a designed angle of attack when tool holder assembly 24 is mounted to the rotatable cutting drum 14.
Still referring to FIGS. 2 and 3, in one aspect the upright member 36 of base 26 has a length that is less than the length of planar member 34 and has a width that is less than the width of planar member 34. The removable member 28 of tool holder assembly 24 has a length that substantially equals the length of planar member 34 and has a width that is less than the width of planar member 34 so that when removable member 28 is mounted on upright member 36 ledges 54 and 56 are formed. In one aspect, the ledges 54 and 56 provide a surface area for applying leverage to the base 26 for separating base 26 and removable member 28 and to assist with removing the bit or cutting tool as desired.
Referring particularly to FIG. 3, upright member 36 is also in the form of a wedge. That is, upright member 36 has a wedge-like body 52 having an upper surface 55 that tapers downwardly from a first end 57 to an opposed second end 59. The upper surface 55 will be adjacent the upper surface 46 which has a similar taper. Referring to upright member 36, first end 57 may have an arcuate surface 64 with spaced apart end walls 66 and 68 and the opposed second end 59 may have a V-shaped surface 70. As shown in FIGS. 3 and 3A, the wedge-like body 44 of removable member 28 further includes two spaced apart side walls 72 and 74 at the first end 48. The side walls 72 and 74 are joined together at the opposed second end 50 by a mediate portion 76. The mediate portion 76 has a V-shaped surface 78 that corresponds to the V-shaped surface 70 of upright member 36. The spaced apart side walls 72 and 74 form an open area 79. When removable member 28 is positioned on base 26 to enclose upright member 36, the V-shaped surface 78 of mediate portion 76 of removable member 28 engages the V-shaped surface 70 of upright member 36 and the arcuate surface 64 of first end 56 of upright member 36 is received in the open area 79 such that the end walls 66 and 68 of arcuate surface 64 abut against an inner surface of spaced apart side walls 72 and 74
As can be appreciated, when a cutting tool such as for example, a rotatable cutting tool having a cylindrical shank is carried by support block 30 of removable body 28, the cylindrical shank will abut against arcuate surface 64 of upright member 36 such that removable body 28 is wedged against upright member 36 and against the upper surface 38 of planar member 34. However, it will be appreciated that the surface 64 may have shapes and configurations other than arcuate.
Still referring to FIGS. 2 and 3, upright member 36 further includes an aperture 80 that extends there through. Similarly, the spaced apart side walls 72 and 74 of removable member 28 each comprise an aperture (one of which is shown at reference numeral 82). Even though not shown, the corresponding aperture of side wall 72 is in alignment with the aperture 82 of side wall 74. When removable member 28 is mounted onto upright member 36, aperture 80 of upright member 36 is in alignment with the apertures 82 of sidewalls 72 and 74. A retaining element 84 is inserted through apertures 80 and 82 to force upright member 36 in a close tolerance fit within the open area 79 of removable member 28 and to ensure a secure connection of removable member 28 to upright member 36. Retaining element 84 may comprise, for example, a bolt, a roll pin or a wedged element.
It will be appreciated that even though removable member 28 and upright member 36 have a close tolerance fit and is retained via retaining element 84, that the impact forces involved by the cutting tool carried in support block 30 of removable member 28 against the earth strata during the cutting process will initially and continually force removable member 28 onto upright member 36 such that removable member 28 will be wedged onto upright member 36 and against planar member 34, and that retaining element 84 only ensures and maintains a secure connection between removable member 28 and upright member 36.
FIGS. 4 and 5 illustrate an additional two-piece tool holder assembly 90, in accordance with another aspect of the invention. Specifically, the two-piece tool holder assembly 90 comprises a base 92 and a removable member 94. Base 92 is constructed to be fixedly mounted by, for example, welding to a rotating unit such as, for example, the rotatable cutting drum 14 shown in FIG. 1. The removable member 94 is mounted on base 92 and includes a cylindrical support block 96 having a bore 98 for carrying a cutting tool (not shown). The support block 96 may be fixedly mounted by, for example, welding to removable member 94.
Still referring to FIGS. 4 and 5, base 92 comprises a planar member 100 and an upright member 102. In one aspect, the removable member 94 partially covers or encloses upright member 102 of base 92 so that the upright member 102 is protected from wear.
Planar member 100 is in the form of a wedge that is, planar member 100 has an upper surface 104 that tapers downwardly from a first end 106 to an opposed second end 108. Similarly, removable member 94 is in the form of a wedge, that is, removable member 94 comprises a wedge-like body 110 that has a first upper surface 112 that extends into a second upper surface 113 that tapers downwardly from a first end 114 to an opposed second end 116. As particularly shown in FIG. 4, when removable member 94 is mounted on base 92, this wedge-form structure of tool holder assembly 90 positions support block 96 and therefore a cutting tool in bore 32 of support block 96 at a designed angle of attack when tool holder assembly 90 is mounted onto the rotatable cutting drum 14 as shown in FIG. 1.
Referring again to FIGS. 4 and 5, in one aspect the upright member 102 of base 92 has a length that is less than the length of planar member 100 and has a width that is less than the width of planar member 100. As shown particularly in FIG. 4, removable member 94 of tool holder assembly 90 has a length that is substantially the same length as planar member 100 and has a width that is less than the width of planar member 100 so that when removable member 94 is mounted on upright member 102 ledges 118 and 120 are formed.
Still referring to FIGS. 4 and 5, upright member 102 is also in the form of a wedge. That is, upright member 102 has a wedge-like body 122 having an upper surface 124 that tapers downwardly from a first end 126 to an opposed second end 128 and spaced-apart side walls 130 and 132. Referring to upright member 102, first end 126 has a flat surface 134 and the opposed second end 128 has a curved surface 136. As shown in FIG. 5A, the wedge-like body 110 of removable member 94 further includes two spaced apart side walls 138 and 140 at the first end 114 which are joined together at the opposed second end 116 by a mediate portion 142. Mediate portion 142 has an outwardly curved surface 144 that corresponds to the outwardly curved surface 136 of upright member 102. The side wall 138 extends the full depth of removable member 94 while sidewall 140 extends a partial depth of removable member 94. The spaced apart side walls 138 and 140 of removable member 94 forms an open area 143 for receiving upright member 102. Side wall 138 provides wear protection for upright member 102.
Referring to FIGS. 4, 5 and 5A, when removable member 94 is positioned on base 92 to enclose upright member 102, the curved surface 144 of mediate portion 142 of removable member 94 engages the curved surface 136 of upright member 102. The flat surface 134 of first end 126 of upright member 102 is received in the open area 143 formed by spaced apart side walls 138 and 140 of removable member 94 such that portions of flat surface 134 abut against inner surfaces of spaced apart side walls 138 and 140 of removable member 94.
As can be appreciated, when a cutting tool such as for example, a rotatable cutting tool having a shank is carried by support block 96 of removable member 94, the shank of the cutting tool will abut against flat surface 130 of upright member 102 such that removable member 94 is wedged against upright member 102 and against the upper surface of planar member 100. It will be appreciated that the surface 130 may have other shapes and configurations besides being flat, e.g. surface 130 may by curved or arcuate.
Still referring to FIGS. 4 and 5, upright member 102 further comprises an aperture 150 that extends there through. Similarly, sidewall 138 of removable member 94 comprises an aperture 152. When removable member 94 is mounted onto upright member 102, aperture 150 of upright member 102 is in alignment with aperture 152 of sidewall 140. As best shown in FIG. 4, a retaining element 154 is inserted through apertures 150 and 152 to position and force upright member 102 in a close tolerance fit within the open area 143 of removable member 94 and to ensure a secure connection of removable member 94 with upright member 102. Retaining element 154 may comprise, for example, a bolt, a roll pin or a wedged element.
It is to be appreciated, that even though removable member 94 and upright member 102 have a close tolerance fit and is retained via retaining element 154, that the impact forces involved by the cutting tool carried in support block 96 of removable member 94 against the earth strata during the cutting process will initially and continually force removable member 94 onto upright member 102 such that removable member 94 will be wedged onto upright member 102 and against planar member 100, and that retaining element 154 ensures and maintains a secure connection between removable member 94 and upright member 102.
Still referring to FIGS. 4 and 5, upright member 102 further comprises a member 160 (which may be generally arcuate) which extends along the outer surface of side wall 130 of upright member 102 and concentric to aperture 150 of upright member 102. This member 160 at least partially encircles retaining element 154 to provide wear protection to the retaining element 154.
The implementation described above and other implementations are within the scope of the described invention and the following claims.

Claims

What is claimed is:

1. A tool holder assembly for carrying a cutting tool on a rotating unit of an cutting assembly, comprising:

a base fixedly mountable to the rotating unit, wherein the base comprises an upright member and a planar member supporting the upright member; and

a removable member mounted on the base and including a support block constructed and arranged to carry the cutting tool, wherein the removable member is constructed and arranged to substantially enclose the upright member and abut against the planar member of the base.

2. The tool holder assembly of claim 1, wherein the upright member of the base comprises a tapered upper surface and the removable member comprises a corresponding tapered surface adjacent the tapered upper surface of the upright member.

3. The tool holder assembly of claim 2, wherein the upright member and the removable member are constructed and arranged to be secured together through a close tolerance fit.

4. The tool holder assembly of claim 3, further comprising a retaining element extending through the removable member and the upright member of the base for removably connecting the removable member to the base.

5. The tool holder assembly of claim 2, wherein at least the removable member comprises a wedge-like body angularly supporting the support block at a desired angle of attack.

6. The tool holder assembly of claim 5, wherein the wedge-like body of the removable member comprises two spaced apart side walls joined together by a mediate portion and forming an open area that receives the upright member of the base.

7. The tool holder assembly of claim 6:

wherein the upright member of the base comprises spaced apart side walls, an arcuate surface at a first end, and a V-shaped surface at an opposed second end;

wherein the mediate portion of the wedge-like body of the removable member comprises a V-shaped surface corresponding to the V-shaped surface of the upright member of the base; and

wherein the arcuate surface of the upright member of the base is constructed and arranged to receive a shank of a cutting tool when the cutting tool is carried by the support block of the removable member.

8. The tool holder assembly of claim 7, wherein the upright member of the base and the wedge-like body of the removable member are wedged together through a close tolerance fit and wherein the V-shaped surface of the upright member engages the V-shaped surface of the wedge-like body of the removable member.

9. The tool holder assembly of claim 8:

wherein the upright member of the base further comprises an aperture;

wherein the spaced apart side walls of the wedge-like body of the removable member each comprise an aperture which are in alignment with the aperture of the upright member when the removable member is positioned on the upright member, and

wherein the tool holder assembly further comprises a retaining element extending through the aperture of the upright member and each aperture of the spaced apart side walls of the wedge-like body of the removable member in order to removably secure the removable member to the base of the tool holder assembly.

10. A tool holder assembly for carrying a cutting tool on a rotating unit of an cutting assembly, comprising:

a removable member mounted on the base and including a support block constructed and arranged to carry the cutting tool, wherein the base comprises an upright member and a planar member supporting the upright member and wherein the removable member is constructed and arranged to partially enclose the upright member of the base.

11. The tool holder assembly of claim 10, wherein the upright member of the base and the removable member are constructed and arranged to be secured together through a close tolerance fit.

12. The tool holder assembly of claim 11, further comprising a retaining element extending through the removable member and the upright member of the base for removably connecting the removable member to the base.

13. The tool holder assembly of claim 10, wherein the removable member further comprises a wedge-like body angularly supporting the support block at a desired angle of attack.

14. The tool holder assembly of claim 13:

wherein the wedge-like body of the removable member comprises spaced apart sidewalls joined together by a mediate portion and forming an open area for receiving the upright member of the base; and

wherein one of the spaced apart sidewalls of the removable member extends a partial depth of the removable member.

15. The tool holder assembly of claim 14:

wherein the upright member of the base comprises spaced-apart side walls, a flat surface at a first end, and a curved surface at the opposed second end;

wherein the mediate portion of the wedge-like body of the removable member comprises a curved surface corresponding to and engaging the curved surface of the upright member of the base; and

wherein the flat surface of the upright member of the base is constructed and arranged to support a surface of a cutting tool when the cutting tool is carried by the support block of the removable member.

16. The tool holder assembly of 15, wherein the upright member of the base and the wedge-like body of the removable member are wedged together through a close tolerance fit with at least the curved surface of the upright member engaging the curved surface of the wedge-like body of the removable member.

17. The tool holder assembly of claim 16;

wherein the upright member of the base further comprises an aperture;

wherein one of the spaced apart side walls of the wedge-like body of the removable member comprises an aperture which is in alignment with the aperture of the upright member when the removable member is positioned on the upright member; and

wherein the tool holder assembly further comprises a retaining element extending through the aperture of the upright member and the aperture of one of the spaced apart sidewalls of the wedge-like body of the removable member in order to removably connect the removable member to the base of the tool holder assembly.

18. The tool holder assembly of claim 17, wherein the upright member of the base further comprises an arcuate member extending along a surface of one of the sidewalls concentric to the aperture of the upright member and outwardly into the open area formed by the spaced apart sidewalls of the removable member.