U.S. patent application number 12/795186 was filed with the patent office on 2011-07-07 for cutting pick and mounting assembly.
This patent application is currently assigned to Sandvik Intellectual Property AB. Invention is credited to Keith SLEEP, Steven Weaver.
Application Number | 20110163591 12/795186 |
Document ID | / |
Family ID | 42138810 |
Filed Date | 2011-07-07 |
United States Patent
Application |
20110163591 |
Kind Code |
A1 |
SLEEP; Keith ; et
al. |
July 7, 2011 |
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.
Inventors: |
SLEEP; Keith; (Manly,
AU) ; Weaver; Steven; (Fletcher, AU) |
Assignee: |
Sandvik Intellectual Property
AB
Sandviken
SE
|
Family ID: |
42138810 |
Appl. No.: |
12/795186 |
Filed: |
June 7, 2010 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12582175 |
Oct 20, 2009 |
|
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|
12795186 |
|
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Current U.S.
Class: |
299/104 |
Current CPC
Class: |
E21C 35/197
20130101 |
Class at
Publication: |
299/104 |
International
Class: |
E21C 35/197 20060101
E21C035/197; E21C 35/183 20060101 E21C035/183 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 20, 2008 |
AU |
2008230023 |
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.
Description
CROSS-REFERENCE TO PRIOR APPLICATION
[0001] This application claims priority to Australian Application
No. 2008230023 filed Oct. 20, 2008, which is incorporated by
reference herein.
FIELD OF THE INVENTION
[0002] 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
[0003] 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.
[0004] 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.
[0005] 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.
[0006] 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
[0007] 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.
[0008] 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.
[0009] 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.
[0010] 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.
[0011] 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.
[0012] 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.
[0013] 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.
[0014] 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.
[0015] 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.
[0016] 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.
[0017] 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.
[0018] 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.
[0019] 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.
[0020] 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.
[0021] 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.
[0022] 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.
[0023] 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.
[0024] The outer sleeve can be configured to receive the inner
sleeve through the inner sleeve opening in a snap-fit locking
engagement.
[0025] 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.
[0026] 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.
[0027] 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.
[0028] 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.
[0029] 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.
[0030] 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.
[0031] 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
[0032] 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;
[0033] 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.
[0034] FIG. 2 is a perspective view of the inner sleeve of FIG.
1.
[0035] 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.
[0036] 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.
[0037] FIG. 5 is a side view of the inner sleeve of FIG. 1.
[0038] 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.
[0039] FIG. 7 is a perspective view of the outer sleeve of FIG.
1.
[0040] FIG. 8 is a top view of the outer sleeve of FIG. 1.
[0041] FIG. 9 is a side view of a cross-section of the cutting pick
and mounting assembly.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0042] 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).
[0043] 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.
[0044] 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.
[0045] 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.
[0046] 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.
[0047] 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.
[0048] 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 (Al.sub.2O.sub.3), 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.
[0049] 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.
[0050] 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.
[0051] 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.
[0052] 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.
[0053] 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.
[0054] 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.
[0055] 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.
[0056] 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.
[0057] 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.
[0058] 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.
* * * * *