CUTTING PICK AND MOUNTING ASSEMBLY

Abstract

To alleviate the problem associated with wear of either the shank of the cutting pick or the surface defining the cutting pick mounting hole, a cutting pick and mounting assembly is provided including a cutting pick having a shank and a cutting tip, a cutting pick mounting hole extending through a support surface within which the shank of the cutting pick is received such that the cutting tip projects from the hole; an inner sleeve having a cutting pick opening within which the shank of the cutting pick extends; an outer sleeve having an inner sleeve opening within which the inner sleeve and the shank of the cutting pick extend; wherein the shank, the inner sleeve and the outer sleeve are positioned concentrically within the cutting pick mounting hole.

Description

CROSS-REFERENCE TO PRIOR APPLICATION

This application claims priority to Australian Application No. 2008230023 filed Oct. 20, 2008, which is incorporated by reference herein.

FIELD OF THE INVENTION

The present invention relates to cutting tools used for mining and excavation purposes. The present invention has been developed principally for use in the mining of ore and in that use, typically underground ore mining. It will therefore be convenient to describe the invention in relation to that use although it will be readily appreciated that the invention could be employed for any mining or excavation operation to which its function is suitable.

BACKGROUND OF THE INVENTION

Equipment used to mine or excavate in hard earth can include rotary cutters in which a rotating drum that carries a plurality of projecting cutting bits or picks is brought into engagement with an earth face. The picks bite into the earth face as they rotate with the drum to impact against and to dislodge or fragment earth from the face. Picks employed for this purpose generally have a hard tungsten carbide tip that is fixed, usually by brazing, to a steel shank. The tip of the pick can be either of the insert or the cap style. The insert style pick has an elongate tip member anchored within a bore in the leading end of the shank which projects outwardly from the shank. The cap style pick involves the tip having a broader base than the insert style tip and the base is located and brazed into a relatively shallow recess in the leading end of the shank. The present invention is applicable to either of these forms of pick.

Picks of the above kind are typically mounted to a cutting assembly, such as a rotating drum, by way of a cutting pick mounting hole extending through a block secured to the drum or through an external surface of the drum into which the shank of the cutting pick is inserted and retained. With the shank of the cutting pick inserted into the mounting hole, the cutting tip extends outwardly therefrom for engagement with an earth face. In use, the cutting tip bites into the earth face as the drum rotates to impact against and dislodge or fragment earth from the face. This action results in a significant amount of force being translated through the cutting tip and the shank of the cutting pick into the cutting pick mounting hole of the rotating drum.

Furthermore, the cutting pick usually is rotatably mounted within the mounting hole to permit the pick to wear more evenly, but movement of pick within the mounting hole is such that over time the shank of the cutting pick and/or the surface of the mounting hole can wear. Over time the wear may be extensive and result in the shank of the cutting pick being worn to the extent that the shank may break or alternatively the surface of the mounting hole may wear to the extent that it may no longer effectively be able to retain the shank of the cutting pick therewithin.

The discussion of the background to the invention herein is included to explain the context of the invention. This is not to be taken as an admission that any of the material mentioned is considered prior art.

SUMMARY

To alleviate the problem associated with wear of either the shank of the cutting pick or the surface defining the cutting pick mounting hole, the present invention provides a cutting pick and mounting assembly including a cutting pick having a shank and a cutting tip, a cutting pick mounting hole extending through a support surface within which the shank of the cutting pick is received such that the cutting tip projects from the hole; an inner sleeve having a cutting pick opening within which the shank of the cutting pick extends; an outer sleeve having an inner sleeve opening within which the inner sleeve and the shank of the cutting pick extend; wherein the shank, the inner sleeve and the outer sleeve are positioned concentrically within the cutting pick mounting hole.

The arrangement between the shank, the inner sleeve, the outer sleeve and the mounting hole is such that upon the cutting pick being subjected to a load which tends to cause movement of the cutting pick relative to the mounting hole, that movement can cause movement of the inner sleeve relative to the outer sleeve. Movement of the cutting pick and the cutting pick shank relative to the mounting hole can cause movement of the inner sleeve relative to the outer sleeve, whereby either or both of the sleeves can wear sacrificially instead of the cutting pick, the shank of the cutting pick and/or the cutting pick mounting hole. Consequently, an advantage of the invention is that wear of the cutting pick mounting hole and/or the cutting pick or the shank of the cutting pick upon movement of the cutting pick and the shank of the cutting pick relative to the mounting hole can be reduced.

In one form, the outer sleeve remains substantially stationary relative to the cutting pick mounting hole such that in use when the cutting pick engages an earth face, any axial or lateral movement of the cutting pick relative to the mounting hole results in sacrificial wearing of the inner sleeve and/or the outer sleeve rather than wear occurring in the shank of the cutting pick or the surface of the cutting pick mounting hole.

One purpose of sacrificial wearing of the inner sleeve and/or the outer sleeve is to reduce or eliminate the amount of wear encountered by parts of the cutting pick which would normally encounter wear as a result of relative movement of the cutting pick and the mounting hole and in particular the shank of the cutting pick. Another purpose is to reduce the amount of wear encountered in sections of the cutting pick mounting hole which would normally wear as a result of relative movement of the cutting pick and the mounting hole. Thus, the above arrangement is particularly advantageous in extending the useful life of the cutting pick and the cutting pick mounting hole and in turn the useable life of the cutting assembly, such as a cutter support and a rotary cutter or any other form of cutter, or of a piece of mining or excavation equipment incorporating one or more of the cutting pick and mounting assemblies disclosed herein.

Another advantage of the cutting pick and mounting assemblies disclosed herein is that the outer sleeve can be used to fill a gap between a radially outwardly facing surface of the shaft of the inner sleeve and the facing surface of the cutting pick mounting hole which may result over time due to wearing of the surface of the cutting pick mounting hole. As the gap becomes larger then outer sleeves of greater thicknesses can be used to fill or take up the gap.

In one form, the outer sleeve is a substantially annular member having an inner surface that defines the inner sleeve opening and that is configured to face a facing surface of the inner sleeve. The outer sleeve can also have an outer surface that is configured for face to face contact with a facing surface of the cutting pick mounting hole.

The outer sleeve can include at least one hole extending partially or fully between the inner surface and the outer surface for facilitating the removal of the outer sleeve either from around the inner sleeve or from within the cutting pick mounting hole, such as by a suitable tool that engages the hole.

In one form, the outer sleeve is substantially cylindrical. The outer sleeve can be formed out of a sheet of metal which is rolled into a substantially annular configuration.

The outer sleeve can include a longitudinal slit to enable the diameter of the inner sleeve opening to be expanded or contracted. The longitudinal slit can extend in substantially the same direction as a longitudinal axis of the inner sleeve opening of the outer sleeve.

In one form, the inner sleeve is a substantially annular member having an inner surface that defines the cutting pick opening and is configured for face to face contact with the shank of the cutting pick and an outer surface that is configured to face the outer sleeve.

In another form, the inner sleeve includes a pair of longitudinally spaced apart ridges on the outer surface for retaining the inner sleeve within the inner sleeve opening of the outer sleeve by abutting against opposite ends of the outer sleeve.

The cutting pick and mounting assembly can further include a first recess in one of the inner sleeve or the cutting pick mounting hole for receiving a locking element for releasably locking the inner sleeve within the cutting pick mounting hole.

In another form, the assembly can include a recess on one of the inner sleeve or the shank of the cutting pick for receiving a locking element for releasably locking the cutting pick within the inner sleeve.

In one form, the inner sleeve includes a shaft and a shoulder at one end of the shaft surrounding the cutting pick opening. The shoulder can be configured for abutment with the cutting pick to prevent or restrict axial movement of the cutting pick relative to the inner sleeve when the shank of the cutting pick is inserted within the cutting pick opening of the inner sleeve. The shoulder can also be configured for abutment with a surface surrounding the cutting pick mounting hole to limit the extent to which the shaft of the inner sleeve and/or the outer sleeve is insertable into the cutting pick mounting hole.

The shoulder can have a first surface which is annular and oriented transversely to a longitudinal axis of the cutting pick opening for abutment with a flanged portion of the cutting pick shank.

The shoulder can have a second surface which is annular and oriented transversely to a longitudinal axis of the cutting pick opening for facing a surface surrounding the opening of the cutting pick mounting hole. The second surface can include at least one protuberance for abutment with the surface surrounding the cutting pick mounting hole. The surface which extends circumferentially around the shoulder can be of a tapering annular form.

The outer sleeve can be independently positionable within the cutting pick mounting hole for subsequently receiving the inner sleeve and the shank of the cutting pick through the inner sleeve opening thereof.

The outer sleeve can be configured to receive the inner sleeve through the inner sleeve opening in a snap-fit locking engagement.

The invention also provides an inner sleeve configured for use in the cutting pick and mounting assembly of any one of the forms set out above.

The invention also provides a cutting pick having a shank which is positioned within a cutting pick opening of an inner sleeve for use in the cutting pick and mounting assembly of any one of the forms set out above. The cutting pick can have a cutting tip fixed to one end of the shank which projects from the shank and which is of a material that is harder than the material of the shank.

The invention also provides an outer sleeve configured for use in the cutting pick and mounting assembly of any one of the forms set out above.

The invention also provides a mounting assembly comprising an outer sleeve positioned within a cutting pick mounting hole of a cutting pick support, for use in the cutting pick and mounting assembly of any one of the forms set out above.

The invention also provides a cutting pick configured for use in the cutting pick and mounting assembly of any one of the forms set out above.

The invention also provides a wear sleeve for use in a cutting pick and mounting assembly of a cutting assembly, the wear sleeve including a substantially annular member having a radially inwardly facing surface that defines a longitudinally extending cutting pick opening for receiving a shank of a cutting pick therethrough and an opposite radially outwardly facing surface that includes a pair of longitudinally spaced apart ridges.

Further aspects and concepts will become apparent to those skilled in the art after considering the following description and claims in conjunction with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

In the accompanying drawings, which are incorporated in and constitute a part of the specification, embodiments of the invention are illustrated, which together with a general description of the invention given above, and the detailed description below serve to exemplify embodiments of the invention;

FIG. 1 is a perspective view of an inner sleeve and an outer sleeve of a cutting pick and mounting assembly wherein the inner sleeve is fitted within an inner sleeve opening of an outer sleeve in a snap fit locking engagement.

FIG. 2 is a perspective view of the inner sleeve of FIG. 1.

FIG. 3 is a side view of the inner sleeve and the outer sleeve of FIG. 1 wherein the inner sleeve is fitted within the inner sleeve opening of the outer sleeve in a snap fit locking engagement.

FIG. 4 is a side view of a cross section of the inner sleeve and the outer sleeve of FIG. 1 taken along the section line 4-4 in FIG. 3.

FIG. 5 is a side view of the inner sleeve of FIG. 1.

FIG. 6 is a side view of a cross section of the inner sleeve of FIG. 1 taken along the section line 6-6 in FIG. 5.

FIG. 7 is a perspective view of the outer sleeve of FIG. 1.

FIG. 8 is a top view of the outer sleeve of FIG. 1.

FIG. 9 is a side view of a cross-section of the cutting pick and mounting assembly.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring to FIGS. 1 to 9 there is shown a cutting pick and mounting assembly 5 (See FIG. 9), and components thereof, in accordance with an embodiment of the invention disclosed herein. The cutting pick and mounting assembly 5 is mounted to a cutting pick mounting block 2 to form part of a cutting assembly which can include a rotary cutter, or any other form of cutter, of a piece of mining or excavation equipment (not shown).

The cutting pick and mounting assembly 5 includes a cutting pick 10, an inner sleeve 30 and an outer sleeve 40. The cutting pick 10 includes a shank 12 that is receivable within a cutting pick opening 32 within the inner sleeve 30. The inner sleeve 30 is receivable within an inner sleeve opening 42 within the outer sleeve 40 which in turn is receivable within a cutting pick mounting hole 20 extending through a support surface 24 of the cutting pick mounting block 2. Accordingly, the shank 12, the inner sleeve 30 and the outer sleeve 40 are positioned concentrically within the cutting pick mounting hole 20. The cutting pick and mounting assembly 5 is advantageous in that the arrangement between the shank 12, the inner sleeve 30, the outer sleeve 40 and the mounting hole 20 is such that upon the cutting pick 10 being subjected to a load which tends to cause movement of the cutting pick 10 relative to the mounting hole 20, that movement causes movement of the inner sleeve 30 relative to the outer sleeve 40. Movement of the cutting pick 10 and the shank 12 relative to the mounting hole 20 causes movement of the inner sleeve 30 relative to the outer sleeve 40, whereby the inner sleeve 30 and/or the outer sleeve 40 can wear sacrificially instead of the cutting pick 10, or the shank 12 thereof, and/or a surface 22 defining the cutting pick mounting hole 20. The provision of the outer sleeve 40 can also provide the advantage of preventing abrasion and/or wearing of the surface 22 of the cutting pick mounting hole 20. Consequently, an advantage of the cutting pick and mounting assembly 5 is that wear of the cutting pick mounting hole 20 and/or the cutting pick shank 12 upon movement of the cutting pick shank 12 relative to the mounting hole 20 can be reduced.

Another advantage of the provision of the outer sleeve 40 is that the outer sleeve 40 can facilitate filling in of any space between the surface 22 of the cutting pick mounting hole 20 and the inner sleeve 30 which can arise as a result of abrasion and/or wearing of the surface 22. Other advantages of forms of the invention disclosed herein will be apparent in view of the following detailed description.

Referring to FIG. 1 there is shown the inner sleeve 30 with the outer sleeve 40 fitted thereto. The inner sleeve 30 is an annular member made up of a substantially cylindrically shaped shaft 39 with a shoulder 50 at one end. The shaft 39 has the cutting pick opening 32 extending longitudinally therethrough. The shaft 39 also has a radially outwardly facing substantially cylindrical surface 36 and a radially inwardly facing substantially cylindrical surface 34 wherein the radially inwardly facing surface 34 defines the cutting pick opening 32 within of the shaft 39. The shoulder 50 is integrally formed at one end of the shaft 39. The shoulder 50 thus forms a flange at the top of the inner sleeve 30. The shoulder 50 has a first or upper annular shaped surface 52 which faces away from the shaft 39 and an opposite second or lower annular surface 54 which faces towards the shaft 39. The shoulder 50 farther includes an annular lateral surface 58 which extends between the upper surface 52 and the lower surface 54. The lateral surface 58 is partially tapered towards the upper annular surface 52 of the shoulder 50 and the lateral surface 58 extends around the circumference of the shoulder 50.

As shown in FIGS. 1, 3, 4 and 9 the shaft 39 of the inner sleeve 30 with the outer sleeve 40 fitted thereto is insertable into the cutting pick mounting hole 20 of the rotary cutter, or any other form of cutter, of the mining or excavation equipment. When the inner sleeve 30 with the outer sleeve 40 fitted thereto is inserted into the cutting pick mounting hole 20, the lower surface 54 of the shoulder 50 faces towards the supporting surface 24 surrounding the cutting pick mounting hole 20. The lower surface 54 of the shoulder 50 also includes a pair of protuberances 56 on radially opposite sides of the shaft 39. The protuberances 56 project downwardly from the lower surface 54 of the shoulder 50 such that when the shaft 39 of the inner sleeve 30 with the outer sleeve 40 fitted thereto is inserted into the cutting pick mounting hole 20, the protuberances 56 abut against the surface 24 surrounding the cutting pick mounting hole 20 to limit the extent to which the shaft 39 of the inner sleeve 30 and/or the outer sleeve 40 is insertable into the cutting pick mounting hole 20. Alternatively, the outer sleeve 40 can be fitted independently within the cutting pick mounting hole 20 and the shaft 39 of the inner sleeve 30 subsequently fitted within the inner sleeve opening 42 of the outer sleeve 40 and thereby fitted within the cutting pick mounting hole 20.

The radially outwardly facing surface 36 of the shaft 39 of the inner sleeve 30 includes a first recess 35. The recess 35 is in the form of a radial groove which extends circumferentially about the radially outwardly facing surface 36 of the shaft 39 to form an annular groove therein. The first recess 35 is configured to receive a first locking element 25 which in the embodiment illustrated in FIG. 9 is in the form of a locking ring. The locking element fits within the first recess 35 and projects radially outwardly from the first recess 35 and the radially outwardly facing surface 36 of the shaft 39. The first locking element 25 has a diameter which is greater than the diameter of the cutting pick mounting hole 20 and/or the diameter of the inner sleeve opening 42 of the outer sleeve 40. Thus, the first locking element 25 is unable to pass through the inner sleeve opening 42 of the outer sleeve 40 and/or the cutting pick mounting hole 20 when the first locking element 25 is fitted to the first recess 35 after the shaft 39 of the inner sleeve 30 is fitted within the outer sleeve 40 and within the cutting pick mounting hole 20. The first locking element 25 can be removably fitted to first recess 35 to releasably lock the shaft 39 of the inner sleeve 30 within the cutting pick mounting hole 20. The first locking element 25 can take any suitable form as long as it achieves the function of inter-engaging with the first recess 35 to releasably lock the inner sleeve 30 within the cutting pick mounting hole 20. The first locking element 25 can be a biased or sprung locking member such as a ring or a U-shaped member.

As illustrated in FIG. 9, the shank 12 of the cutting pick 10 has a cutting tip 14 fixed to one end of the shank 12 which projects from the shank 12 and which is made of a material that is harder than the material of the shank 12. For example, the material forming the shank can be a cast metal. However, the material forming the cutting tip 14 is preferably made out of a material that is relatively harder than the material forming the shank 12 of the cutting pick 10. For example, the material forming the cutting tip 14 can be formed out of silicon carbide (SiC), an oxide of aluminium (Al₂O₃), a titanium alloy, titanium nitride (TiN), silicon carbide diamond composite (SiC-D), cubic boron nitride, tool steel or other like materials. These materials can be formed as a composite material with other suitable materials or they can be provided as an outer layer or layers over a suitable base to form the cutting tip 14. The cutting tip 14 can be either of the insert or cap type. The cap type is illustrated in FIG. 9. The cap type involves the cutting tip 14 having a shorter axial length than in the insert type. The cutting tip 14 in both instances is mounted within a bore 15 which is within one end of the shank 12 of the cutting pick 10. The cutting tip 14 is brazed within the bore 15 to maintain it securely therewithin. The shank 12 of the cutting pick 10 is a substantially cylindrically shaped solid rod made of any suitable material such as a metal alloy.

As can be seen in FIG. 9, the shank 12 of the cutting pick 10 is insertable within the cutting pick opening 32 within the inner sleeve 30. The radially outwardly facing cylindrically shaped surface 13 of the shank 12 is configured for face to face contact with the radially inwardly facing surface 34 of the inner sleeve 30 when the shank 12 of the cutting pick 10 is inserted within the shank the cutting pick opening 32 of the inner sleeve 30. The radially inwardly facing surface 34 of the shaft 39 of the inner sleeve 30 includes a second recess 37. The second recess 37 is in the form of an annular groove in the radially inwardly facing surface 34 of the shaft 39. The radially outwardly facing surface 13 of the shank 12 of the cutting pick includes a recessed annular groove 17. The second recess 37 and/or the annular groove 17 are configured to receive a second locking element 16. The second locking element 16 can be fitted between the second recess 37 and the annular groove 17 to lock the shank 12 of the cutting pick 10 within the cutting pick opening 32 within the inner sleeve 30. The second locking element 16 can be a biased or sprung locking member such as a ring or a U-shaped member. Accordingly, the second locking element 16 can be sprung or otherwise resiliently mounted such that when the shank 12 of the cutting pick 10 is inserted in the cutting pick opening 32 of the inner sleeve 30 the second locking element 16 can be depressed within the annular groove 17 in the radially outwardly facing surface 13 of the shank 12 so as to enter the cutting pick opening 32. When the shank 12 has been sufficiently inserted within the cutting pick opening 32 of the inner sleeve 30 the second locking element 16 can resiliently project into the second recess 37 to releasably lock the shank 12 of the cutting pick 10 within the cutting pick opening 32 of the inner sleeve 30.

The cutting pick 10 includes a flanged portion 11 atop the shank 12 of the cutting pick 10 configured for abutment with the upper surface 52 of the shoulder 50 to prevent or restrict axial movement of the cutting pick 10 relative to the inner sleeve 30 when the shank 12 of the cutting pick 10 is inserted within the cutting pick opening 32 of the inner sleeve 30. In particular, the flanged portion 11 abuts against the upper surface 52 of the shoulder 50 to prevent the shank 12 of the cutting pick 10 passing entirely within the cutting pick opening 32 of the inner sleeve 30.

As shown in FIGS. 1, 3, 4, 7, 8 and 9, the outer sleeve 40 is an annular member that has a substantially cylindrical overall shape. The outer sleeve 40 is formed out of a sheet of any suitable material such as steel, a metal alloy or any other suitable material which can be rolled into an annular or tubular shape. Alternatively, the outer sleeve 40 can be molded or extruded into an annular or tubular shape. The outer sleeve 40 includes a radially outwardly facing surface 46 and a radially inwardly facing surface 44. Accordingly, the radially inwardly facing surface 44 defines the inner sleeve opening 42 which extends from the lower end 41 to the upper end 43 of the outer sleeve 40. Furthermore, the outer sleeve 40 includes a longitudinal slit 48 which extends from a lower end 41 to an upper end 43 of the outer sleeve 40.

As shown in FIGS. 1 to 6 and 9 the inner sleeve 30 includes first and second ridges 31, 33 on the radially outwardly facing surface 36 of the shaft 39. The first and second ridges 31, 33 are longitudinally spaced apart from each other and from the first recess 35 on the radially outwardly facing surface 36 of the inner sleeve 30 with the second ridge 33 located immediately adjacent to the lower surface 54 of the shoulder 50 and the protuberance 56 of the shoulder 50. The first ridge 31 has a sloping surface 31a and an opposite abutting surface 31b. The sloping surface 31a of the first ridge 31 faces away from the shoulder 50 while the abutting surface 31b faces towards the shoulder 50. Thus, when the shaft 39 of the inner sleeve 30 is inserted within the inner sleeve opening 42 of the outer sleeve 40 the upper end 43 or the lower end 41 of the annular outer sleeve 40 meets and slides over the sloping surface 31a of the first ridge 31. The outer sleeve 40 is configured to enable the shaft 39 of the inner sleeve 30 to be inserted within the inner sleeve opening 42 such that the radially inwardly facing surface 44 of the outer sleeve 40 faces the radially outwardly facing surface 36 of the shaft 39 of the inner sleeve 30. By including the longitudinal slit 48 which extends from the lower end 41 to the upper end 43 the diameter of the inner sleeve opening 42 of the outer sleeve 40 can be expanded slightly to enable the upper end 43, the lower end 41 and the radially inwardly facing surface 44 of the outer sleeve 40 to slide over the sloped surface 31a of the first ridge 31. This is because the first ridge 31 of the radially outwardly facing surface 36 of the shaft 39 of the inner sleeve 30 has a slightly larger diameter than the diameter of the inner sleeve opening 42 of the outer sleeve 40 in its unexpanded state. Similarly, the second ridge 33 also has a slightly larger diameter than the diameter of the inner sleeve opening 42 of the outer sleeve 40 in its unexpanded state. After the radially inwardly facing surface 44 of the outer sleeve 40 has slid over the sloped surface 31a of the first ridge 31 the outer sleeve 40 is positioned between the first ridge 31 and the second ridge 33 on the radially outwardly facing surface 36 of the inner sleeve 30 with the upper end 43 of the outer sleeve abutting against the second ridge 33 and the lower end 41 abutting against the abutting surface 31b of the first ridge 31. Thus, the outer sleeve 40 is releasably retained between the longitudinally spaced apart first and second ridges 31, 33 on the radially outwardly facing surface 36 of the shaft 39 of the inner sleeve 30.

As will be appreciated, the cutting pick and mounting assembly 5 in the assembled configuration involves the shank 12 of the cutting pick 10 being inserted within the cutting pick opening 32 of the inner sleeve 30 and being releasably retained or locked therewithin. The shaft 39 of the inner sleeve 30 is inserted within the inner sleeve opening 42 of the outer sleeve 40 and is releasably retained therewithin. The cutting pick 10, the shaft 39 of the inner sleeve 30 and the outer sleeve 40 are inserted in their assembled configuration within the cutting pick mounting hole 20 and are releasably retained therewithin by the interaction between the first recess 35 on the shaft 39 of the inner sleeve 30 and the first locking element 25 in the manner described above.

Accordingly, as shown in FIG. 9, the radially outwardly facing surface 46 of the outer sleeve 40 is in face to face engagement with the surface 22 defining the cutting pick mounting hole 20. When the cutting pick and mounting assembly 5 is in use and the cutting pick 10 is brought into engagement with an earth face and the cutting pick and mounting assembly 5 is moved relative to the earth face the cutting pick 10 and the shank 12 thereof are subjected to axial and/or lateral movement relative to the cutting pick mounting hole 20. The axial and/or lateral movement of the cutting pick 10 relative to the cutting pick mounting hole 20 is transmitted through the inner sleeve 30 as axial and/or lateral and/or rotational movement thereof relative to the cutting pick mounting hole 20. The outer sleeve 40 which surrounds the shaft 39 of the inner sleeve remains substantially stationary relative to the cutting pick mounting hole 20 such that movement of the inner sleeve 30 relative to the cutting pick mounting hole 20 results in movement of the inner sleeve 30 relative to the outer sleeve 40. Movement of the inner sleeve 30 relative to the outer sleeve 40 results in the radially outwardly facing surface 36 of the inner sleeve 30 and the radially inwardly facing surface 44 of the outer sleeve 40 rubbing against each other which causes friction and/or abrasion therebetween. Thus, the inner sleeve 30 and/or the outer sleeve 40 are sacrificially worn as a result of the friction and/or abrasion therebetween.

The purpose of this sacrificial wearing of the inner sleeve 30 and/or the outer sleeve 40 is to reduce the amount of wear encountered by the cutting pick 10 and in particular the shank 12 thereof and to reduce the amount of wear encountered by the cutting pick mounting hole 20 and in particular the surface 22 defining the cutting pick mounting hole 20. Thus, the above arrangement is particularly advantageous in extending the usable life of the cutting pick 10 and the cutting pick mounting hole 20 and in turn the useable life of the cutting assembly, such as a rotary cutter or any other form of cutter, of a piece of mining or excavation equipment incorporating one or more of the cutting pick mounting holes 20.

Another advantage of the above arrangement is that the outer sleeve 40 can fill a gap between the radially outwardly facing surface 36 of the shaft 39 of the inner sleeve 30 and the surface 22 defining the cutting pick mounting hole 20 which may result over time due to wearing of the surface 22 defining the cutting pick mounting hole 20.

The invention has been described herein with reference to preferred embodiments. Modification and alteration may occur to persons skilled in the art upon reading and understanding this specification. It is intended to include all such modifications and alterations in so far as they fall within the scope of the following claims or equivalence thereof.

Although the present invention has been described in connection with preferred embodiments thereof, it will be appreciated by those skilled in the art that additions, deletions, modifications, and substitutions not specifically described may be made without department from the spirit and scope of the invention as defined in the appended claims.

Claims

1. A cutting pick and mounting assembly, comprising: a cutting pick having a shank and a cutting tip, a cutting pick mounting hole extending through a support surface within which the shank of the cutting pick is received such that the cutting tip projects from the hole;an inner sleeve having a cutting pick opening within which the shank of the cutting pick extends;an outer sleeve having an inner sleeve opening within which the inner sleeve and the shank of the cutting pick extend;wherein the shank, the inner sleeve and the outer sleeve are positioned concentrically within the cutting pick mounting hole.

2. The cutting pick and mounting assembly of claim 1, wherein the outer sleeve is a substantially annular member having a radially inwardly facing surface that defines the inner sleeve opening and that is configured to face a facing surface of the inner sleeve and a radially outwardly facing surface that is configured for face to face contact with a facing surface of the cutting pick mounting hole.

3. The cutting pick and mounting assembly of claim 2, wherein the outer sleeve includes at least one hole extending between the inwardly facing surface and the outwardly facing surface for facilitating the removal of the outer sleeve either from around the inner sleeve or from within the cutting pick mounting hole.

4. The cutting pick and mounting assembly according to claim 1, wherein the outer sleeve is substantially cylindrical.

5. The cutting pick and mounting assembly according to claim 1, wherein the outer sleeve includes a longitudinal slit to enable the diameter of the inner sleeve opening to be expanded or contracted.

6. The cutting pick and mounting assembly of claim 5, wherein the longitudinal slit extends in substantially a same direction as a longitudinal axis of the inner sleeve opening of the outer sleeve.

7. The cutting pick and mounting assembly according to claim 1, wherein the outer sleeve is formed out of a sheet of metal which is rolled into a substantially annular configuration.

8. The cutting pick and mounting assembly according to claim 1, wherein the inner sleeve is a substantially annular member having a radially inwardly facing surface that defines the cutting pick opening and is configured for face to face contact with the shank of the cutting pick and a radially outwardly facing surface that is configured to face a facing surface of the outer sleeve.

9. The cutting pick and mounting assembly of claim 8, wherein the inner sleeve further includes a pair of longitudinally spaced apart ridges on the radially outwardly facing surface for retaining the inner sleeve within the inner sleeve opening of the outer sleeve by abutting against opposite ends of the outer sleeve.

10. The cutting pick and mounting assembly of claim 1, further including a first recess in one of the inner sleeve or the cutting pick mounting hole for receiving a locking element for releasably locking the inner sleeve within the cutting pick mounting hole.

11. The cutting pick and mounting assembly of claim 1, further including a recess on one of the inner sleeve or the shank of the cutting pick for receiving a locking element for releasably locking the cutting pick within the inner sleeve.

12. The cutting pick and mounting assembly of claim 1, wherein the inner sleeve includes a shaft and a shoulder at one end of the shaft surrounding the cutting pick opening.

13. The cutting pick and mounting assembly of claim 12, wherein the shoulder has a first surface which is annular and oriented substantially transversely to a longitudinal axis of the cutting pick opening for abutment with a flanged portion of the cutting pick shank.

14. The cutting pick and mounting assembly of claim 12, wherein the shoulder has a second surface which is annular and oriented substantially transversely to a longitudinal axis of the cutting pick opening for facing a surface surrounding the cutting pick mounting hole.

15. The cutting pick and mounting assembly of claim 14, wherein the second surface of the shoulder includes at least one protuberance for abutment with the surface surrounding the cutting pick mounting hole.

16. The cutting pick and mounting assembly of claim 12, wherein a tapering annular surface extends circumferentially around the shoulder.

17. The cutting pick and mounting assembly of claim 1, wherein the outer sleeve is independently positionable within the cutting pick mounting hole for subsequently receiving the inner sleeve and the shank of the cutting pick through the inner sleeve opening thereof.

18. The cutting pick and mounting assembly of claim 1, wherein the outer sleeve is configured to receive the inner sleeve through the inner sleeve opening in a snap-fit locking engagement.

19. An inner sleeve configured for use in the cutting pick and mounting assembly of claim 1.

20. A cutting pick having a shank which is positioned within a cutting pick opening of an inner sleeve for use in the cutting pick and mounting assembly of claim 1.

21. An outer sleeve configured for use in the cutting pick and mounting assembly of claim 1.

22. A mounting assembly in which an outer sleeve is positioned within a cutting pick mounting hole for use in the cutting pick and mounting assembly of claim 1.

23. A cutting pick configured for use in the cutting pick and mounting assembly of claim 1.

24. A wear sleeve for use in a cutting pick and mounting assembly of a cutting assembly, comprising: a substantially annular member having a radially inwardly facing surface that defines a longitudinally extending cutting pick opening for receiving a shank of a cutting pick therethrough and an opposite radially outwardly facing surface that includes a pair of longitudinally spaced apart ridges.