Note: Descriptions are shown in the official language in which they were submitted.
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SLEEVE FOR REVERSIBLE CUTTING TOOL
FIELD
[0001] The present disclosure relates generally to cutting tools. More
specifically,
the present disclosure relates to reversible cutting tools incorporating a
shield over
an exposed retainer. Also, the present disclosure relates to the combination
of a
reversible cutting tool and a sleeve and/or block holder system, to apparatus
including such combinations and to a sleeve per se and to a shield per se.
BACKGROUND
[0002] In the discussion of the background that follows, reference is made
to
certain structures and/or methods. However, the following references should
not be
construed as an admission that these structures and/or methods constitute
prior art.
Applicant expressly reserves the right to demonstrate that such structures
and/or
methods do not qualify as prior art.
[0003] A conventional cutting tool, such as a point attack bit for mining
and
construction, consists of one cutting end and one retention end. In operation,
the
retention end is positioned in a holder and the cutting end is applied against
material
to be mined, excavated, moved or so forth. Operation over time wears the
cutting
end. Once the cutting end is worn, a user removes the cutting tool and
replaces it
with a new or more serviceable cutting tool.
[0004] The removed worn cutting tool is typically discarded. However, even
though the cutting tool is worn at the cutting end, a majority of the
remaining portions
of the cutting tool are still intact, a large portion of the material of the
cutting tool,
e.g., the steel body, remains and non-cutting end portions of the cutting tool
are still
functional.
[0005] Also, for every removed cutting tool, a replacement cutting tool
must be
delivered to the machine. The replacement cutting tools are heavy and
cumbersome and transporting cutting tools can be difficult and costly,
particular
when delivery is to underground locations, such as in mining operations.
[0006] Reversible cutting tools are generally known: see, e.g., U.S. Patent
Nos.
3,342,531; 3,493,268; 3,519,309; and 5,810,102 and GB 1,117,112. Typically,
such
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cutting tools are secured in a bit holder by a retaining mechanism. These
retaining
mechanisms typically use a retaining device, variously and for example, a
retention
pin, a retention clip, a plunger or a keeper, associated with the bit holder
that
cooperates with a recess on a cutting tool inserted into a bore of the bit
holder and
that biases the cutting tool to be retained in the bit holder.
[0007] By its reversible construction, reversible cutting tools has a
recess
associated with each end of the tool. Thus, while one recess is inserted into
the bit
holder for retention, a second recess is exposed. This exposed recess is used
for
retention when that end is inserted into the bit holder. However, prior to its
use for
retention in the bit holder, the recess is exposed to wear during operation
when that
end of the cutting tool in used for mining or construction. Such wear can
detrimentally impact the retention of the cutting tool when the cutting tool
is
reversed.
SUMMARY
[0008] An exemplary embodiment of a disclosed double sided tool system to be
used on mining and construction equipment, for example, rotating drums,
wheels,
rotary cutters, or chains to cut soft and hard rock, has a cutting surface on
both ends
of the cutting tool. In operation, the cutting tool can be flipped around in
the tool
holder, e.g., a block system or a block and sleeve system, once one end is
worn to
expose the other end for use. A shield slides over the nose of the cutting
tool and
provides protection to the exposed recess and retainer while keeping the
removed
cutting material moving due to its free rotation around the nose of the
cutting tool.
The shield minimizes or prevents material from getting backed up and lodged in
the
recess. The shield stays on the cutting tool the same way a typical sleeve
would.
For example the shield is friction fit with the retainer, the shield has a
groove on the
inside for cooperation with a bumped retainer, or a combination of the two,
can be
used to hold the shield over the retainer while still allowing free rotation
on the
cutting tool. The shield is removed when the cutting tool is reversed.
[0009] The double-sided feature allows the cutting tool in essence to
behave as
two tools. Each end of the cutting tool has a dual purpose ¨ acting as a
retention
shank for half the cutting tool's life and acting as a cutting tip for the
other half of the
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cutting tool's life. Once the first end is worn, the user can extract the
cutting tool
from the holder and turn it so that the second end, that was previously used
to hold
the cutting tool inside the tool holder, is now the cutting end and the worn
end is now
the retention end.
[0010] An exemplary embodiment of a sleeve for inserting into a bore in a
block
holder of a cutting tool comprises a body with a bore longitudinally
therethrough from
a first end to a second end, the bore defining an inner surface, a shoulder on
the
first end, the shoulder having a contact face, and two grooves on the inner
surface
of the bore, wherein the two grooves are longitudinally spaced apart.
[0011] An exemplary embodiment of a combination comprises a reversible
cutting tool with two cutting ends, a block holder with a bore, and a sleeve
inserted
into the bore in the block holder, wherein the sleeve includes a body with a
bore
longitudinally therethrough from a first end to a second end, the bore
defining an
inner surface, a shoulder on the first end, the shoulder having a contact
face, and
two grooves on the inner surface of the bore, wherein the two grooves are
longitudinally spaced apart.
[0012] It is to be understood that both the foregoing general description
and the
following detailed description are exemplary and explanatory and are intended
to
provide further explanation of the invention as claimed.
BRIEF DESCRIPTION OF THE DRAWING
[0013] The following detailed description can be read in connection with
the
accompanying drawings in which like numerals designate like elements and in
which:
[0014] FIGS. 1A, 1B and 1C schematically illustrate various exemplary
embodiments of a cutting tool.
[0015] FIGS. 2A and 2B schematically illustrate various exemplary
embodiments
of a shield for a cutting tool.
[0016] FIG. 3A schematically illustrates, in an exploded view, an exemplary
embodiment of a cutting tool, a shield for a cutting tool and a sleeve and
FIG. 3B
schematically illustrates a cross-section of the assembled elements of FIG.
3A.
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[0017] FIG. 4A schematically illustrates, in an exploded view, an exemplary
embodiment of a cutting tool, a shield for a cutting tool and a sleeve and
FIG. 4B
schematically illustrates a cross-section of the assembled elements of FIG.
4A.
[0018] FIG. 5 is an isometric view of an assembled combination of a cutting
tool,
shield, optional sleeve and block holder.
DETAILED DESCRIPTION
[0019] FIGS. 1A-1C schematically illustrate various exemplary embodiments
of a
cutting tool. In FIGS. 1A-1C, a cutting tool 100 has a first cutting end 102
and a
second cutting end 104. A shoulder 106 is at the interface of the first
cutting end
102 and the second cutting end 104. The first cutting end 102, the shoulder
106
and the second cutting end 104 are arranged longitudinally along common axis
108.
A shield 110 is shown mounted on first cutting end 102, but can be removed
from
the first cutting end 102 and placed on the second cutting end 104.
[0020] Each cutting end on each cutting tool includes a cutting tip 120 at
a distal
end 122, a body portion 124, a recess 126 in the body portion 124 and a
retainer
128 positioned in the recess 126. The cutting tip 120 is typically formed of a
hard
material, such as a cemented carbide, and is mounted on the body portion 124
by a
suitable mounting technique, such as metallurgically bonding, brazing, and/or
soldering. The body portion is formed from a steel.
[0021] FIGS 1A-1C demonstrates the applicability of a shield to various
designs
of cutting ends. FIG. 1A shows a cutting end with conical transition 140 from
the
cutting tip 120 rearward toward the recess 126 and retainer 128 while FIG. 1B
shows a stepped arrangement 142. Also in FIG. 1B, the cutting end has a ring
144
of hard material, such as a cemented carbide. Retainers 128 of various forms
can
be used. For example, FIG. 1C shows a retainer 128 with a protrusion 130 on
the
outer surface that fits into a groove 132 in an inner surface of a bore of the
shield
110; FIGS. 1A and 16 show retainers 128 with a friction fit between the outer
surface of the retainer and the inner surface of the bore of the shield 110.
[0022] The retainers 128, which typically are formed of, for example, a
spring
steel, can have a slit 146 or other feature by which the retainer can
expand/contract
to fit around the body portion and into the recess and to accommodate the
shield
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being placed over the retainer. The retainer 128 on each of the first cutting
end 102
and the second cutting end 104 of the cutting tool 100 are rotatably mounted
in the
respective recess 126. For example, the retainer 128 in recess 126 can rotate
R in
either direction, but translation T is limited by the edges 148. The edges 148
are
wear areas. If the edges 148 wear too much during operation, then translation
T will
not be limited and the retainer 128 could slide off the cutting end of the
cutting tool.
As seen in comparing, for example, FIG. 1A and FIG. 1C, the recesses 126 for
different retainers 128 can have different sizes, e.g., lengths and depths.
[0023] It is contemplated that various combinations of the above features
of the
cutting end design, the retainers and the recesses may be included in the
disclosed
cutting tool and disclosed combinations, apparatus and methods. Further, some
embodiments of cutting tools have a first cutting end 102 that is a mirror
image of
the second cutting end 104, with a mirror plane 150 that is perpendicular to
the
common axis 108 and bisecting the shoulder 106, while other embodiments of
cutting tools can have different cutting ends, i.e., the cutting ends on one
cutting tool
are not mirror images. As an example of a non-mirror image cutting tool, some
applications such as trenching may use a first cutting end that is longer than
a
second cutting end, i.e., the first cutting end has a different gage length
than the
second cutting end. The first longer cutting end may be used for some aspects
of
the operation and then the shorter cutting end is used for other aspects, such
as
when excavation conditions become harder, e.g., the cutting material becomes
harder. If the excavation conditions become easier again, the cutting tool
cutting
ends may be switched again, with the longer cutting end being placed back into
operation.
[0024] FIGS. 2A and 2B schematically illustrate various exemplary
embodiments
of a shield for a cutting tool. The shield 200 has a frustum shape with a base
202, a
top 204 and a body 206. Special cases of the general frustum shape include a
conical frustum, a pyramidal frustum, and a spherical segment. Although
described
herein as a frustum, it should be understood that the general shape is that of
a
frustum and that special cases and minor variations while maintaining the
general
frustum shape of a portion of a solid which lies between two parallel planes
cutting
the solid are within the meaning of "frustum". Further, outer side edges of
the
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frustum can be planar, concave, convex or of a complex form or a combination
of
such forms. Finally, although described herein as a frustum shape, other
shapes of
the shield are contemplated and can be used including cylindrical shapes and
barrel
shapes.
[0025] The body 206 of the shield 200 has a bore 208 therethrough from the top
204 to the base 202. The bore 208 has an inner surface 210. The inner surface
210 includes a groove 212. The inner surface 210 and the groove 212 each
cooperate with outer surfaces of the retainer 128, and with the protrusion 130
on the
retainer 128, if present, fitting into the groove 212. The groove can take any
form.
For example, FIG. 2A shows the groove 212 as being part circular and FIG. 2B
shows the groove 212 as rectangular with radial or chamfered corners 214. Note
that, while the shield has a groove on the inner surface, the groove is not
necessarily
engaged by a corresponding feature on the retainer on the first cutting end in
all
embodiments. However, the inclusion of a groove in the shield adapts the
shield for
universal use with or without a protrusion on the retainer.
[0026] At the base end of the shield 200, the inner surface 210 of the bore
208
has a chamfered surface 216. The chamfered surface of the bore 208 assists in
forcing the retainer 128 into the bore 208 when the shield 200 is slipped over
the
cutting end.
[0027] At the base end of the shield 200, an outer edge 220 is chamfered. This
chamfered outer edge 220 provides a surface to receive a removal tool. For
example, prongs or bifurcated portions of a removal tool can be placed under
the
outer edge 220 and levered against the shoulder 106 to remove the shield 200.
A
similar chamfer on an outer edge 160 of the shoulder 106 (see FIGS. 1A-1C) is
similarly used with a suitable removal tool to allow placement of the removal
tool,
which is then levered against a surface of a sleeve or a block holder to
remove the
cutting tool from a bore of the sleeve or a bore of the block holder.
[0028] The shield can be made of a hard material, such as a steel or cemented
carbide. Alternatively, because it is a wear part and a consumable, the shield
can
be made of a plastic material, such as neoprene or other rubbers and
composites, or
a combination of such materials.
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[0029] FIG. 3A schematically illustrates, in an exploded view, an exemplary
embodiment of a cutting tool 300, a shield 302 for a cutting tool 300 and a
sleeve
304.
[0030] In FIG. 3A, the second cutting end 306 of the cutting tool 300 is
placed
into a bore 308 of the sleeve 304, typically until the shoulder 310 contacts
the sleeve
304, so that a friction fit is formed between the outer surface 312 of the
retainer 314
on the second cutting end 306 and the inner surface 316 of the bore 308 of the
sleeve 304. In the case where the retainer does not have a protrusion on the
outer
surface, as here, the inner surface of the bore of the sleeve can be
correspondingly
smooth, in this case without a corresponding groove. However, the use of a
bore
with an inner surface that is grooved is not precluded where the retainer is
without a
protrusion.
[0031] In FIG. 3A, the first cutting end 320 of the cutting tool 300
receives the
shield 302. The cutting tip 322 and body portion 324 of the first cutting end
320 are
placed into the opening 326 in the shield 302, typically until the base 328
contacts
the shoulder 310, so that a friction fit is formed between the outer surface
312 of the
retainer 314 on the first cutting end 320 and the inner surface 330 of the
opening
326 in the shield 302. In the case where the retainer does not have a
protrusion on
the outer surface, as here, the inner surface of the opening in the shield can
be
correspondingly smooth. However, the use of an opening in the shield with an
inner
surface that is grooved is not precluded where the retainer is without a
protrusion
and, indeed, a shield with a groove provides universality to both the smooth
retainer
and the retainer with a protrusion.
[0032] FIG. 3B schematically illustrates a cross-section of the assembled
components of FIG. 3A. In this view, the friction fit between the outer
surface of the
retainer on the second cutting end and the inner surface of the bore of the
sleeve
can be seen. Further, the friction fit between the outer surface of the
retainer on the
first cutting end and the inner surface of the opening in the shield can be
seen. Also
shown in FIG. 38, the shield covers the retainer as well as the wear edges of
the
recess.
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[0033] FIG. 4A schematically illustrates, in an exploded view, an exemplary
embodiment of a cutting tool 400, a shield 402 for a cutting tool 400 and a
sleeve
404.
[0034] In FIG. 4A, the second end 406 of the cutting tool 400 is placed
into a
bore 408 of the sleeve 404, typically until the shoulder 410 contacts the
sleeve 404,
so that a friction fit is formed between the outer surface 412 of the retainer
414 on
the second end 406 and the inner surface 416 of the bore 408 of the sleeve
404. In
the case where the retainer does have a protrusion 418 on the outer surface,
as
here, the inner surface of the bore of the sleeve can have a corresponding
groove
420.
[0035] In FIG. 4A, the first cutting end 422 of the cutting tool 400
receives the
shield 402. The cutting tip 424 and body portion 426 of the first cutting end
422 are
placed into the opening 428 in the shield 402, typically until the base 430
contacts
the shoulder 410, so that a friction fit is formed between the outer surface
412 of the
retainer 414 on the first cutting end 422 and the inner surface 432 of the
opening
428 in the shield 402. In the case where the retainer has a protrusion 418 on
the
outer surface, as here, the inner surface of the opening in the shield can
have a
corresponding groove 434.
[0036] Returning to the sleeve 404 shown in FIGS. 4A and 4B, two grooves on
the inner surface 416 of the bore 408 of the sleeve 404 are shown. The first
groove
420 accommodates features of the retainer 412 when the second end 406 of the
cutting tool 400 is inserted in the sleeve 404. An example of such a feature
is the
protrusion 418. The first groove is positioned toward a first end 436 of the
sleeve
404. The first end 436 of the sleeve 404 also has a shoulder 438 with a
contact
surface 440. When assembled in a block holder for a cutting tool, the contact
face
440 is oriented toward the body of the block holder and may or may not contact
the
block holder. In some exemplary embodiments, the first groove 420 is located
at
least partially above the plane defined by the contact surface 440, i.e.,
longitudinally
toward the first end 436 of the body 442 of the sleeve 404. In some
embodiments,
the first groove 420 is located completely above the plane defined by the
contact
surface 440. A second groove 444 accommodates features on or related to a
shank
of a conventional single-ended cutting tool and is suitable located along the
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=
longitudinal axis of the sleeve to accommodate mating with such features. The
second groove 444 is located further from the first end 436 of the sleeve 404
than is
the first groove 420. The second groove 444, for example, can be approximately
at
the longitudinal center of the bore 408 of the sleeve 404. Also, for example,
the
second groove 444 can be completely below the plane defined by the contact
surface 440. A sleeve 404 with two grooves 420, 444 as depicted in FIGS. 4A
and
4B can be a universal sleeve, because a two-ended cutting tool with a bumped
retainer utilizes the first groove 420 and a single ended cutting tool
utilizes the
second groove 444. Further, cutting tools with no features requiring a groove
can
also be used.
[0037] FIG. 4B schematically illustrates a cross-section of the assembled
elements of FIG. 4A. In this view, the friction fit between the outer surface
of the
retainer on the second cutting end and the inner surface of the bore of the
sleeve
can be seen as well as the fit between the protrusion on the retainer and the
groove
in the bore of the sleeve. Further, the friction fit between the outer surface
of the
retainer on the first cutting end and the inner surface of the opening in the
shield can
be seen as well as the fit between the protrusion on the retainer on the first
cutting
end and the groove in the inner surface of the shield. Also shown in FIG. 4B,
the
shield covers the retainer as well as the wear edges of the recess.
[0038] FIGS. 3B and 4B illustrate the continuous ballistic envelope of the
respective cutting ends when the shield is removably mounted on the respective
cutting end. For example and as illustrated in FIGS. 3B and 4B, a continuous
curve
350, 450 can be drawn from the most distal portion of the cutting tip to the
radially
most outermost portion of the shoulder. This curve 350, 450 has a ballistic or
ogive
shape, where the distal end of the cutting tip corresponds to the point of the
arch
352, 452 of the ogive. All of the surfaces of the first cutting end and the
shield, if
present, are within the envelope. In some embodiments, a portion of an outer
surface of the shield correlates to a portion of the envelope. Although shown
in
FIGS. 3B and 4B associated with the first cutting end, a similar curve is
associated
with the second cutting end when the cutting tool is reversed and the shield
is on the
second cutting end.
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[0039] FIG. 5 is an isometric view of a combination of a cutting tool 502,
shield
504, optional sleeve 506 and block holder 508. In the FIG. 5 view, the second
culling end of the cutting tool has been inserted into the sleeve 506 and is
not
visible. The sleeve 506 has been inserted into the block holder 508. Thus and
with
analogy to a single ended cutting tool, the second cutting end operates as a
type of
shank for the first cutting end, and when the reversible cutting tool is
reversed, the
first cutting end operates as a type of a shank for the second cutting end. In
the
FIG. 5 view, the shield 504 has not yet been mounted on the first cutting end
of the
cutting tool 502 and the retainer 510 on the first cutting end is visible.
[0040] The combination of FIG. 5 can be mounted on an apparatus for cutting.
For example, the block holder can be welded to a rotatable cutting element. An
exemplary embodiment of an apparatus for cutting comprises a rotatable cutting
element and the combination of a cutting tool, a shield, an optional sleeve
and a
block holder. The block holder is mounted on the rotatable cutting element. An
example of a rotatable cutting element is a drum of a wall excavating machine.
The
block holder is mounted on the rotatable cutting element by, for example,
welding.
The rotatable cutting element can itself be on a translatable or otherwise
movable
arm of the apparatus. An example of a suitable apparatus with a rotatable
cutting
element is a Sandvik Alpine Miner AM75.
[0041] An exemplary method of cutting material employs the apparatus for
cutting
to engage the cutting tool against material to be removed. As the cutting tool
moves
in contact with the material, some of the material is removed. The exemplary
method is applicable to mining, construction and excavating.
[0042] Another exemplary method of cutting material inserts a first cutting
end of
a cutting tool into a bore of a block holder on a rotatable cutting element of
an
apparatus for cutting or into a bore of a sleeve which is mounted in a block
holder on
a rotatable cutting element of an apparatus for cutting. The shield is then
mounted
on a second cutting end of the cutting tool. For example, the shield is
mounted by
application of manual force by, for example, a mallet. The apparatus is then
operated to cut material with the second cutting end of the cutting tool.
After the
second cutting end is worn, the shield is removed from the second cutting end
of the
cutting tool and the first end of the culling tool is removed from the bore of
the block
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holder. As previously discussed, a removal tool can be used to remove the
shield
and/or the cutting tool.
[0043] The second cutting end of the cutting tool is then inserted into a
bore of a
block holder on a rotatable cutting element of an apparatus for cutting or
into a bore
of a sleeve which is mounted in a block holder on a rotatable cutting element
of an
apparatus for cutting. The shield, preferably the same shield as previously
removed
from the second cutting end but optionally a different shield, is mounted on
the first
cutting end of the cutting tool. The first cutting end is then ready to cut
material.
[0044] In the exemplary methods, the first cutting end of the cutting tool
includes
a first cutting tip at a first distal end, a first body portion, a first
recess in the first
body portion and a first retainer positioned in the first recess, and the
second cutting
end of the cutting tool includes a second cutting tip at a second distal end,
a second
body portion, a second recess in the second body portion and a second retainer
positioned in the second recess.
[0045] Inclusion of the shield upon the second use of the cutting tool is
optional,
as the retainer and wear edges protected by the shield are no longer going to
be
used if the other cutting end of the cutting tool has already been used and
worn.
Generally, the shield enhances the durability of the double sided cutting
tool. By
placing the shield over the cutting tip and recess, the shield acts as
protection to the
recess and wear areas thereof so that these areas will still be intact as the
cutting tip
wears. The shield also protects the retainer optionally installed in the
recess. A
user can remove the shield once that side is worn and still have a fully
useable
recess and/or retainer for when one uses the opposite end of the cutting tool.
[0046] During operation to cut material, the free rotation of the shield
keeps the
limited material that does reach the inside of the shield from remaining
lodged inside
the shield. The rotation will help to break up any material. The shield freely
rotates
because the inner surface of the retainer is rotatable in the recess while the
shield is
friction fit or protrusion fit to the outer surface of the retainer. Also
during operation
to cut material, the shield helps the cutting tool to carry higher loads than
for a
cutting tool without a shield. This is because the shield is in contact with
the
shoulder of the cutting tool. Higher side impacts will be carried from the
cutting tip
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features of conventional sleeves used in sleeve and block holders.
[0049] Although 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 scope of the invention as defined in the appended claims
when purposively construed.
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