U.S. patent application number 15/095846 was filed with the patent office on 2016-10-13 for bit assembly for cutter head.
The applicant listed for this patent is Joy MM Delaware, Inc.. Invention is credited to John R. Frederick.
Application Number | 20160298453 15/095846 |
Document ID | / |
Family ID | 57030079 |
Filed Date | 2016-10-13 |
United States Patent
Application |
20160298453 |
Kind Code |
A1 |
Frederick; John R. |
October 13, 2016 |
BIT ASSEMBLY FOR CUTTER HEAD
Abstract
A bit assembly for a cutting drum includes a sleeve and a bit.
The sleeve includes shank portion, a flange positioned, and a bore
extending through the flange and the shank portion. The flange
includes a first end surface, a second end surface, and a sleeve
outer surface extending between the first end surface and the
second end surface. A portion of the sleeve outer surface
positioned adjacent the first end surface defines a sleeve profile.
The bit includes a cutting end, a shank, and a shoulder positioned
between the cutting end and the shank. The shank is positioned
within the bore, and the shoulder is positioned adjacent the first
end surface of the sleeve. A bit outer surface extending between
the cutting end and the shoulder. A portion of the bit outer
surface positioned adjacent the shoulder defines a bit profile that
corresponds to the sleeve profile.
Inventors: |
Frederick; John R.; (Allison
Park, PA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Joy MM Delaware, Inc. |
Wilmington |
DE |
US |
|
|
Family ID: |
57030079 |
Appl. No.: |
15/095846 |
Filed: |
April 11, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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62145603 |
Apr 10, 2015 |
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62202573 |
Aug 7, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
E21C 35/188 20200501;
E21C 35/18 20130101; E21C 35/197 20130101; E21C 25/10 20130101 |
International
Class: |
E21C 35/197 20060101
E21C035/197; E21C 25/10 20060101 E21C025/10 |
Claims
1. A bit assembly for a cutting drum, the bit assembly comprising:
a sleeve including shank portion, a flange positioned adjacent an
end of the shank portion, and a bore extending through the flange
and the shank portion, the flange including a first end surface, a
second end surface, and a sleeve outer surface extending between
the first end surface and the second end surface, a portion of the
sleeve outer surface positioned adjacent the first end surface
defining a sleeve profile; and a bit including a cutting end, a
shank, and a shoulder positioned between the cutting end and the
shank, at least a portion of the shank positioned within the bore
of the sleeve, the shoulder positioned adjacent the first end
surface of the sleeve, the bit further including a bit outer
surface extending between the cutting end and the shoulder, a
portion of the bit outer surface positioned adjacent the shoulder
defining a bit profile that corresponds to the sleeve profile.
2. The bit assembly of claim 1, wherein an imaginary surface
aligned with a contour of the sleeve profile and extending beyond
the first end of the sleeve is aligned with a contour of the bit
profile.
3. The bit assembly of claim 1, wherein the bit profile defines a
first frustoconical shape and the sleeve profile defines a second
frustoconical shape, the first frustoconical shape and the second
frustoconical shape having an identical, constant slope.
4. The bit assembly of claim 1, wherein the entire length of the
sleeve outer surface defines the sleeve profile, and wherein the
entire length of the bit outer surface defines the bit profile.
5. The bit assembly of claim 1, wherein an end surface of the bit
shoulder is spaced apart from the first end surface of the sleeve
by a gap.
6. The bit assembly of claim 1, wherein the bit is freely rotatable
relative to the sleeve about a bit axis extending along the
shank.
7. The bit assembly of claim 1, wherein the sleeve profile is a
first end sleeve profile, a portion of the sleeve outer surface
positioned adjacent the second end surface defining a second end
sleeve profile, the bit assembly further comprising: a holder
including a holder end surface, an opening positioned on the holder
end surface, and a holder outer surface, the opening receiving the
shank portion of the sleeve, the holder end surface positioned
adjacent the second end surface of the flange, a portion of the
holder outer surface positioned adjacent the holder end surface
defining a holder profile, the holder profile corresponding to the
second end sleeve profile.
8. The bit assembly of claim 1, wherein the bit includes a bit body
and an insert, the bit body extending between a body end and the
shoulder, the bit including an aperture positioned adjacent the
body end, the insert positioned at least partially within the
aperture and including a tip, wherein the bit profile is a shoulder
end bit profile, a portion of the bit outer surface positioned
adjacent the body end defining a body end bit profile, wherein the
insert includes an insert outer surface, at least a portion of the
insert outer surface defining an insert profile that corresponds to
the body end bit profile.
9. The bit assembly of claim 1, wherein the shank extend along a
bit axis, wherein the shoulder includes a shoulder edge and a first
inclined surface extending along the shoulder edge around the
perimeter of the shoulder, the first inclined surface forming a
first acute angle relative to the bit axis, wherein the first end
surface of the flange includes a flange edge and a second inclined
surface extending along the flange edge around the perimeter of the
first end surface, the second inclined surface forming a second
acute angle relative to the bit axis, wherein the first inclined
surface and the second inclined surface are positioned adjacent one
another such that the first acute angle and the second acute angle
form a combined wedge angle.
10. The bit assembly of claim 1, wherein the shank extends along a
bit axis, wherein the shoulder includes an edge defining a
perimeter, a first surface, and a second surface, the first surface
positioned adjacent the edge and radially between the edge and the
bit axis, the second surface positioned adjacent the first surface
and radially between the first surface and the bit axis, the first
surface and the second surface extending along the length of the
perimeter, wherein the first surface is inclined at a first angle
relative to the bit axis and the second surface is inclined at a
second angle relative to the bit axis.
11. A cutter head for an industrial machine, the cutter head
comprising a drum supported for rotation about a drum axis; and a
plurality of bit assemblies, each bit assembly supported on the
drum and including, a sleeve including shank portion, a flange
positioned adjacent an end of the shank portion, and a bore
extending through the flange and the shank portion, the flange
including a first end surface, a second end surface, and a sleeve
outer surface extending between the first end surface and the
second end surface, a portion of the sleeve outer surface
positioned adjacent the first end surface defining a sleeve
profile; and a bit including a cutting end, a shank, and a shoulder
positioned between the cutting end and the shank, at least a
portion of the shank positioned within the bore of the sleeve, the
shoulder positioned adjacent the first end surface of the sleeve,
the bit further including a bit outer surface extending between the
cutting end and the shoulder, a portion of the bit outer surface
positioned adjacent the shoulder defining a bit profile that
corresponds to the sleeve profile.
12. The cutter head of claim 11, wherein the bit profile defines a
first frustoconical shape and the sleeve profile defines a second
frustoconical shape, the first frustoconical shape and the second
frustoconical shape having an identical, constant slope.
13. The cutter head of claim 11, wherein the entire length of the
sleeve outer surface defines the sleeve profile, and wherein the
entire length of the bit outer surface defines the bit profile.
14. The cutter head of claim 11, wherein an end surface of the bit
shoulder is spaced apart from the first end surface of the sleeve
by a gap.
15. The cutter head of claim 11, wherein the sleeve profile is a
first end sleeve profile, a portion of the sleeve outer surface
positioned adjacent the second end surface defining a second end
sleeve profile, each bit assembly further including, a holder
including a holder end surface, an opening positioned on the holder
end surface, and a holder outer surface, the opening receiving the
shank portion of the sleeve, the holder end surface positioned
adjacent the second end surface of the flange, a portion of the
holder outer surface positioned adjacent the holder end surface
defining a holder profile, the holder profile corresponding to the
second end sleeve profile.
16. The cutter head of claim 11, wherein the bit includes a bit
body and an insert, the bit body extending between a body end and
the shoulder, the bit including an aperture positioned adjacent the
body end, the insert positioned at least partially within the
aperture and including a tip, wherein the bit profile is a shoulder
end bit profile, a portion of the bit outer surface positioned
adjacent the body end defining a body end bit profile, wherein the
insert includes an insert outer surface, at least a portion of the
insert outer surface defining an insert profile that corresponds to
the body end bit profile.
17. A bit assembly configured to be secured to a cutting drum, the
bit assembly comprising: a bit including a cutting end, a shank,
and a shoulder positioned between the cutting end and the shank,
the bit further including a bit outer surface extending between the
cutting end and the shoulder, a portion of the bit outer surface
positioned adjacent the shoulder defining a bit profile; and a
holder including a holder end surface, an opening positioned on the
holder end surface, and a holder outer surface, the opening
receiving at least a portion of the shank, the holder end surface
facing toward the shoulder, at least a portion of the holder outer
surface positioned adjacent the holder end surface defining a
holder profile that corresponds to the bit profile.
18. The bit assembly of claim 17, further comprising a sleeve
including shank portion, a flange positioned adjacent an end of the
shank portion, and a bore extending through the flange and the
shank portion, the bore receiving the shank of the bit, the shank
portion positioned within the opening of the holder, the flange
positioned between the shoulder of the bit and the holder end
surface of the holder, the flange including a flange outer surface,
at least a portion of the flange outer surface defining a sleeve
profile that corresponds to the holder profile.
19. The bit assembly of claim 18, wherein the shank portion of the
sleeve extends along an axis, the flange including a first end
surface adjacent the holder end surface and a second end surface
adjacent the shoulder of the bit, the first end surface of the
flange including an edge and a first inclined surface extending
along the edge around the perimeter of the first end surface, the
first inclined surface forming a first acute angle relative to the
axis, wherein the holder end surface includes a holder edge and a
second inclined surface extending along the holder edge around the
perimeter of the holder end surface, the second inclined surface
forming a second acute angle relative to the axis, wherein the
first inclined surface and the second inclined surface are
positioned adjacent one another such that the first acute angle and
the second acute angle form a combined wedge angle.
20. The bit assembly of claim 17, wherein the bit includes a bit
body and an insert, the bit body including an aperture positioned
adjacent the first end of the bit, the insert positioned at least
partially within the aperture, the insert defining a tip, the
insert including an insert outer surface defining an insert profile
that is continuous with the bit profile.
21. The bit assembly of claim 17, wherein an imaginary surface
aligned with a contour of the holder profile and extending beyond
the holder end surface is aligned with a contour of the bit
profile.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims the benefit of and priority to
prior-filed, co-pending U.S. Provisional Application No.
62/145,603, filed Apr. 10, 2015, and U.S. Provisional Application
No. 62/202,573, filed Aug. 7, 2015. The entire contents of these
documents are hereby incorporated by reference herein.
BACKGROUND
[0002] The present application relates to cutting bits, and
particularly to a cutting bit assembly for an industrial
machine.
[0003] Conventional continuous mining machines, longwall mining
machines, and entry development machines include a cutter head
including multiple cutting bit assemblies. In some embodiments,
each cutting bit assembly includes a bit holder block coupled to a
rotating drum. The bit holder block also includes a slot. In some
embodiments, the slot receives a sleeve. The sleeve includes a bore
and an outer surface engaging the slot of the bit holder block. A
bit is secured within the bore of the sleeve.
SUMMARY
[0004] In one aspect, a bit assembly for a cutting drum includes a
sleeve and a bit. The sleeve includes shank portion, a flange
positioned adjacent an end of the shank portion, and a bore
extending through the flange and the shank portion. The flange
includes a first end surface, a second end surface, and a sleeve
outer surface extending between the first end surface and the
second end surface. A portion of the sleeve outer surface
positioned adjacent the first end surface defines a sleeve profile.
The bit includes a cutting end, a shank, and a shoulder positioned
between the cutting end and the shank. At least a portion of the
shank is positioned within the bore of the sleeve, and the shoulder
is positioned adjacent the first end surface of the sleeve. The bit
further includes a bit outer surface extending between the cutting
end and the shoulder. A portion of the bit outer surface positioned
adjacent the shoulder defines a bit profile that corresponds to the
sleeve profile.
[0005] In another aspect, a cutter head for an industrial machine
includes a drum supported for rotation about a drum axis and a
plurality of bit assemblies. Each bit assembly is supported on the
drum and includes a sleeve and a bit. The sleeve includes a shank
portion, a flange positioned adjacent an end of the shank portion,
and a bore extending through the flange and the shank portion. The
flange includes a first end surface, a second end surface, and a
sleeve outer surface extending between the first end surface and
the second end surface. A portion of the sleeve outer surface
positioned adjacent the first end surface defines a sleeve profile.
The bit includes a cutting end, a shank, and a shoulder positioned
between the cutting end and the shank. At least a portion of the
shank is positioned within the bore of the sleeve. The shoulder is
positioned adjacent the first end surface of the sleeve. The bit
further includes a bit outer surface extending between the cutting
end and the shoulder. A portion of the bit outer surface positioned
adjacent the shoulder defines a bit profile that corresponds to the
sleeve profile.
[0006] In yet another aspect, a bit assembly is configured to be
secured to a cutting drum and includes a bit and a holder. The bit
includes a cutting end, a shank, and a shoulder positioned between
the cutting end and the shank. The bit further includes a bit outer
surface extending between the cutting end and the shoulder. A
portion of the bit outer surface positioned adjacent the shoulder
defines a bit profile. The holder includes a holder end surface, an
opening positioned on the holder end surface, and a holder outer
surface. The opening receives at least a portion of the shank. The
holder end surface faces toward the shoulder. At least a portion of
the holder outer surface positioned adjacent the holder end surface
defines a holder profile that corresponds to the bit profile.
[0007] Other aspects will become apparent by consideration of the
detailed description and accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] FIG. 1 is a perspective view of a mining machine.
[0009] FIG. 2 is a perspective view of a portion of a cutter
head.
[0010] FIG. 3 is a perspective view of a cutting bit assembly.
[0011] FIG. 4 is a side view of the cutting bit assembly of FIG.
3.
[0012] FIG. 5 is an exploded view of the cutting bit assembly of
FIG. 3.
[0013] FIG. 6 is a side view of a cutting bit and sleeve.
[0014] FIG. 7 is an enlarged side view of area 7--7 of the cutting
bit and sleeve of FIG. 6.
[0015] FIG. 8 is a side view of a cutting bit assembly according to
another embodiment.
[0016] FIG. 9 is a top plan view of the cutting bit assembly of
FIG. 8.
DETAILED DESCRIPTION
[0017] Before any embodiments are explained in detail, it is to be
understood that the invention is not limited in its application to
the details of construction and the arrangement of components set
forth in the following description or illustrated in the following
drawings. The invention is capable of other embodiments and of
being practiced or of being carried out in various ways. Also, it
is to be understood that the phraseology and terminology used
herein is for the purpose of description and should not be regarded
as limiting. The use of "including," "comprising" or "having" and
variations thereof herein is meant to encompass the items listed
thereafter and equivalents thereof as well as additional items. The
terms "mounted," "connected" and "coupled" are used broadly and
encompass both direct and indirect mounting, connecting and
coupling. Further, "connected" and "coupled" are not restricted to
physical or mechanical connections or couplings, and can include
electrical or hydraulic connections or couplings, whether direct or
indirect. Also, electronic communications and notifications may be
performed using any known means including direct connections,
wireless connections, etc.
[0018] FIG. 1 illustrates a mining machine, such as a continuous
miner 10, including a frame 14 that is supported for movement
(e.g., by tracks 18). The continuous miner 10 further includes a
boom 22 and a cutter head 26 supported on the boom 22. In the
illustrated embodiment, the frame 14 also includes a collecting
mechanism or gathering head 30 and a conveyor 34 extending from a
first or front end of the frame 14 toward a second or rear end of
the frame 14. In the illustrated embodiment, the gathering head 30
includes a pair of rotating arms 38 that engage cut material below
the cutter head 26 and direct the cut material onto the conveyor
34. The conveyor 34 transports the cut material along a
longitudinal axis of the frame 14, from the area below the cutter
head 26 to a second conveyor (not shown) positioned proximate the
second end of the frame 14.
[0019] The boom 22 includes one end pivotably coupled to the frame
14 and another end supporting the cutter head 26. The boom 22 is
pivotable about a pivot axis 54 that is generally transverse to the
longitudinal axis of the frame 14. The boom 22 is pivoted by a pair
of actuators 58 that are coupled between the frame 14 and the boom
22. In the illustrated embodiment, the actuators 58 are hydraulic
jacks or cylinders.
[0020] As shown in FIG. 2, the cutter head 26 is formed as an
elongated drum 62 including cutting bit assemblies 66 secured to an
outer surface of the drum 62. In the illustrated embodiment, the
outer surface of the drum 62 includes multiple pedestals 68, and
each cutting bit assembly 66 is secured to one of the pedestals 68.
The drum 62 defines a drum axis 70 (FIG. 1) that is generally
parallel to the pivot axis 54 of the boom 22, and the drum 62 is
rotatable about the drum axis 70.
[0021] FIGS. 3-5 illustrate a cutting bit assembly 72 according to
one embodiment. Although the cutting bit assemblies 66 illustrated
in FIG. 2 are different from the cutting bit assembly 72, it is
understood that multiple cutting bit assemblies 72 could be
positioned on the cutting drum 62 in a similar manner.
[0022] Each cutting bit assembly 72 includes a bit 74, a sleeve 78,
and a holder or holder block 82. The block 82 includes a bore or
opening 86 (FIG. 5), and the sleeve 78 is received within the
opening 86. The block 82 has an end surface or forward surface 90
and an outer surface 92. A portion of the outer surface 92
immediately adjacent the forward surface 90 defines a holder
profile. In the embodiment of FIGS. 3-5, the holder profile has a
generally cylindrical shape. In other embodiments, the holder
profile may have a frustoconical shape. In still other embodiments,
the holder profile may have another shape. Also, the block 82 may
incorporate a nozzle aperture (not shown) for supporting a fluid
spray nozzle. The nozzle can provide a spray envelope that
encompasses a portion of the bit 74.
[0023] The sleeve 78 includes an elongated shank portion 94 (FIG.
5) and a flange 96. In the illustrated embodiment, the shank
portion 94 has a generally cylindrical shape and is positioned
within the opening 86 of the block 82. The flange 96 includes a
first end surface or forward surface 98 and a second end surface or
rear surface 100. The rear surface 100 of the flange 96 is
positioned adjacent the forward surface 90 of the holder block 82.
In the illustrated embodiment, the rear surface 100 of the flange
96 abuts or contacts at least a portion of the forward surface 90
of the holder block 82. The flange 96 also includes an outer
surface 102 extending between the forward surface 98 and the rear
surface 100. The outer surface 102 of the flange 96 defines a
sleeve profile. In the illustrated embodiment, the sleeve profile
has a frustoconical shape. In other embodiments, the sleeve profile
may have other shapes, such as a curved shape having a non-linear
taper. The sleeve 78 also defines a bore 104 (FIG. 5) extending
through the length of the sleeve 78.
[0024] Referring to FIG. 5, the bit 74 includes a cutting end 106
and a shank 110. The shank 110 is positioned within the bore 104 of
the sleeve 78, and the shank 110 defines a shank axis or bit axis
112. In some embodiments, an end of the shank 110 protrudes from
the end of the sleeve 78 and includes a slot 114. The slot 114
receives a retaining mechanism (e.g., by a cotter pin or hairpin
clip--not shown) for securing the bit 74 against axial movement
relative to the sleeve 78. Unless otherwise specified, the term
"axial" refers to a direction extending parallel to the bit axis
112 and the term "radial" refers to a direction extending
perpendicularly to the bit axis 112.
[0025] The bit 74 also includes a shoulder 118 positioned between
the cutting end 106 and the shank 110. The shoulder 118 is
positioned adjacent the forward surface 98 of the sleeve flange 96.
In the illustrated embodiment, the shoulder 118 abuts or contacts
at least a portion of the forward surface 98. A portion of the bit
74 extending between the shoulder 118 and the cutting end 106 has
an outer surface 120 defining a bit profile. In the illustrated
embodiment, the bit profile has a frustoconical shape. In other
embodiments, the bit profile may have other shapes, such as a
curved shape that tapers in a non-linear manner between the cutting
end 106 and the shoulder 118.
[0026] In the illustrated embodiment, the bit 74 includes a bit
body 122 and an insert 124 is positioned in an opening (not shown)
on the cutting end 106 of the bit body 122. The insert 124 forms
the cutting tip 126. The insert 124 includes an outer surface 128
extending from the tip 126 toward the cutting end 106, and the
outer surface 128 defines an insert profile. In the illustrated
embodiment, the insert profile has a frustoconical shape; in other
embodiments, the insert profile may have another shape. In one
embodiment, the insert 124 is made from tungsten carbide. In other
embodiments, the insert 124 is made from another material, and/or
may be made from multiple materials. In other embodiments, the bit
74 may be formed without an insert, such that the cutting end 106
of the bit body 122 is formed as a cutting tip.
[0027] As shown in FIGS. 6 and 7, when the bit 74 is positioned
within the sleeve 78, the bit profile of the bit 74 is generally
continuous with the sleeve profile. Although a gap may exist at the
mating interface between the bit 74 and the sleeve 78 (i.e.,
between the shoulder 118 and the forward surface 98), the overall
profile of the combination of the bit 74 and the sleeve 78 is
virtually continuous. Stated another way, the portion of the outer
surface 120 adjacent the shoulder 118 has a profile that
corresponds to the profile of a portion of the outer surface 102 of
the sleeve flange 96 adjacent the forward surface 98. The contour
of the outer surface 120 of the shoulder 118 is aligned with the
contour of the outer surface 102 of the flange 96 at least in the
area of the interface between the two components. Stated yet
another way, the contour of the outer surface 120 of the shoulder
118 generally follows the same path as the contour of the outer
surface 102 of the flange 96 near the interface between the two
components. Stated still another way, an imaginary line 130 (FIG.
7) extends parallel to the outer surface 102 of the flange 96 and
extends beyond the forward surface 98 of the flange 96. The
imaginary line 130 is aligned with and parallel to the outer
surface 120 of the bit 74 adjacent the shoulder 118.
[0028] Referring to FIG. 7, in the illustrated embodiment, the
shoulder 118 includes an edge 134 defining a perimeter. A first
inclined surface 138 extends along the perimeter adjacent the edge
134. The first bevel or first inclined surface 138 forms a first
angle 142 relative to a plane 144 oriented perpendicular to the bit
axis 112 (FIG. 5). In addition, the forward surface 98 of the
flange 96 includes a second bevel or second inclined surface 146
extending along the perimeter of the forward surface 98. The second
inclined surface 146 forms a second angle 150 relative to the plane
144. In the illustrated embodiment, the first angle 142 and the
second angle 150 are approximately equal. Also, in some
embodiments, similar bevel surfaces may be provided on the rear
surface 100 of the flange 96 and the forward surface 90 of the
block 82.
[0029] In some embodiments, the first angle 142 is between
approximately 5 degrees and approximately 22.5 degrees. In some
embodiments, the first angle 142 is between approximately 10
degrees and approximately 22.5 degrees. In some embodiments, the
first angle 142 is approximately 15 degrees. In some embodiments,
the second angle 150 is between approximately 5 degrees and
approximately 22.5 degrees. In some embodiments, the second angle
150 is between approximately 10 degrees and approximately 22.5
degrees. In some embodiments, the second angle 150 is approximately
15 degrees.
[0030] The inclined surfaces 138, 146 provide a space for an
operator to insert an edge of a prying tool in order to apply force
and extract the bit 74 from the sleeve 78. The first angle 142 and
the second angle 150 form a combined wedge angle. In some
embodiments, the combined wedge angle is between approximately 10
degrees and approximately 45 degrees. In some embodiments, the
combined wedge angle is between approximately 20 degrees and
approximately 45 degrees. In some embodiments, the combined wedge
angle is approximately 30 degrees.
[0031] In the embodiment of FIGS. 3-5, the bit 74 and the sleeve 78
have a generally continuous profile. In addition, the outer edge of
the forward surface 90 of the block 82 is radially adjacent the
outer edge of the rear surface 100 of the flange 96. As a result,
the profile of the outer surface 92 of the block 82 adjacent the
forward surface 90 is generally continuous with the profile of the
outer surface 102 of the flange 96 adjacent the rear surface 100,
even though the block profile and the sleeve profile do not have
the same shape. In a similar manner, the insert 124 may be formed
with an outer surface 128 forms a profile that is continuous with
the bit profile adjacent the cutting end 106 of the bit body
122.
[0032] The cutting bit assembly 72 has a continuous or smooth
profile between the individual components, reducing and/or
eliminating corners, hard edges, or other sizable discontinuities.
The streamlined profile of the cutting bit assembly 72 reduces
sharp contact, rubbing, scrubbing, scraping, crushing, and material
carrying that occurs in conventional bit assemblies. As a result,
the cutting bit assembly 72 can engage the material to be cut more
efficiently, reducing the amount of airborne dust and fines caused
by cutting the material and also improving power consumption
required by cutter head drive motors.
[0033] FIGS. 8 and 9 illustrate a cutting bit assembly 472
according to another embodiment. The cutting bit assembly is
similar to the cutting bit assembly 72 described above with respect
to FIGS. 3-7, and similar features are identified with similar
reference numbers, plus 400. For the sake of brevity, only
differences between the cutting bit assembly 472 and the cutting
bit assembly 72 are described.
[0034] The cutting bit assembly 472 includes a bit 474, a sleeve
478, a holder block 482, and an insert 524. The bit 474 includes an
outer surface 520 extending between the cutting end 506 and the
shoulder 518. The outer surface 520 includes a first portion 520a
having a first profile and a second portion 520b having a second
profile. The insert 524 includes an outer surface 528 having a
profile that is generally continuous with the profile of the first
portion 520a. The sleeve flange 496 includes an outer surface 502
having a profile that is generally continuous with the second
portion 520b.
[0035] In addition, a forward portion of the block 482 includes an
outer surface 492 having a profile that is generally continuous
with the profile of the flange outer surface 502, and also
corresponds to the profile of the flange outer surface 502. A
portion of the outer surface 492 adjacent the forward surface 490
defines a profile that corresponds to the profile of the portion of
the outer surface 502 of the flange 496 adjacent the rear surface
500. The contour of the outer surface 492 of the block 482 is
aligned with the contour of the outer surface 502 of the flange 496
at least in the area of the interface between the two components.
Stated yet another way, the contour of the outer surface 492 of the
block 482 generally follows the same path as the contour of the
outer surface 502 of the flange 496 near the interface between the
two components. Although a gap may exist at the mating interface
between the block 482 and the sleeve 478 (i.e., between the block
forward surface 490 and the rear surface 500 of the flange 476),
the overall profile of the combination of the block 482 and the
sleeve 478 is virtually continuous. The block 482 further includes
a lateral opening 550 (FIG. 8) extending transversely through the
block 482 to provide access to a rear end of the bit 474.
[0036] In addition, the contour of the outer surface 492 of the
block 482 also generally follows the same path as the contour of at
least the second portion 520b of the outer surface 520 of the bit
474. In the illustrated embodiment, the portion of the outer
surface 492 adjacent the forward surface 490 of the block 482 has a
frustoconical shape; in other embodiments, the portion of the outer
surface 492 may have another shape. In the illustrated embodiment,
the frustoconical shape of the portion of the outer surface 492 is
the same shape as the frustoconical shape of the second portion
520b of the bit 474. The block profile corresponds to and is
aligned with the bit profile.
[0037] In some embodiments, the cutting bit assembly may be formed
without a sleeve such that the bit is secured directly to the
block. In such a configuration, a portion of the outer surface of
the bit may define a bit profile and a portion of the outer surface
of the block may define a block profile that corresponds to the bit
profile.
[0038] Although aspects of the cutting bit assembly 72 have been
described in the context of a mining machine, it is understood that
the cutting bit assembly 72 could be incorporated into other types
of machines having earth-engaging attachments, including other
types of mining machines, construction machines, and road milling
machines.
[0039] Although aspects have been described in detail with
reference to certain preferred embodiments, variations and
modifications exist within the scope and spirit of one or more
independent aspects as described.
* * * * *