Note: Descriptions are shown in the official language in which they were submitted.
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BRUSH CUTTING HEAD
FIELD OF THE INVENTION
[0001] The present invention relates to a brush cutting head for a brush
cutter.
BACKGROUND OF THE INVENTION
[0002] Vast felling and mulching operations are often performed with heavy-
duty brush
cutters. These brush cutters often have heavy-duty cutting heads removeably or
permanently fixed on self-propelled vehicles. These cutting heads typically
include a
rotatable horizontal drum or roller upon which is mounted a plurality of
cutting elements
(i.e. cutting teeth). In operation, the rotation of the drum causes the
cutting teeth to shred
wood, debris and the like.
[0003] The cutting teeth are typically fixed to the outer surface of the drum
via mounting
blocks. Different mounting block configurations presently exist. For example,
United
States Patent No. 5,873,534 describes a cutter tooth holder assembly for
mounting about the
curved surface of a rotatable cutter drum. The cutter tooth holder assembly
includes a tooth
holder for holding a cutter tooth and a mounting plate for attaching the tooth
holder to the
drum. The mounting plate has a generally concave surface for engaging the
curved surface
of the drum, and a top surface with a circumferentially extending tooth-
locking groove
formed along the entire length of the plate. The mounting plate is permanently
attached to
the drum by welding. The tooth holder has a generally square cross-section and
is
positioned in the tooth-locking groove formed within the mounting plate and
welded in
place. The tooth holder has a bore formed therein that is adapted to receive a
cylindrical
connector portion of the cutter tooth. The cutter tooth is generally polygonal
with a
plurality of cutting tips. When mounted within the tooth-locking groove one of
the cutting
tips is retained within the angled wall defining the tooth-locking groove
thereby preventing
rotational movement of the cutter tooth during operation of the brush cutter
head.
[0004] While generally functional, the foregoing cutter tooth holder assembly
tends to
suffer from several drawbacks. First, to be able to withstand the high forces
to which they
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are subjected, the assembly tends to be relatively large and heavy thereby
requiring a
substantial power draw. Second, the assembly remains unprotected from repeated
contact
with rocks or large trees. This exposure tends to make the assembly more prone
to
excessive wear and/or being damaged or broken off completely. As a result,
this type of
assembly requires costly servicing and replacement, the frequency of which
tends to
adversely impact the productivity of the brush cutter.
[0005] To address these shortcomings, certain known brush cutter heads have
been
provided with mounting block protection means. One such brush cutter head is
described in
United States Patent No. 6,764,035. This patent discloses a brush cutter that
has a
cylindrical support base and a within the station plurality of cutting tooth
mounting blocks
fastened to the outer surface of the base. The bottom surface of each mounting
block is
concavely curved to match the radius of the base thereby allowing each
mounting block to
be welded onto the base with its bottom surface flush with the outer surface
of the base.
Each mounting block carries a cutting tooth on its front face. To protect the
mounting
blocks from rocks and large trees, each mounting block is provided with a
protective collar.
Each protective collar is welded to the outer surface of the base and extends
radially
therefrom, transverse to the longitudinal axis of the base. Each collar
terminates
circumferentially a short distance from the front face of the mounting block
with which it is
associated to provide a front clearance space. The opposed end of the collar
is welded to the
back face of the associated mounting block to strengthen it.
[0006] While the mounting block described in United States Patent No.
6,764,035 is a
general improvement over the cutting tooth holder assembly of United States
Patent No.
5,873,534, its monolithic construction tends to make it relatively heavy and
thus not well-
suited for use in light-duty brush cutters where improved power utilization
and reduced
power consumption are a priority.
[0007] In light of the foregoing, it would be advantageous to have a brush
cutting head
provided with a mounting assembly that is relatively light, simply constructed
and
generally less prone to damage from impact with hard objects. Such a brush
cutting head
would tend to consume less power and be suitable for use in light-duty brush
cutters.
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SUMMARY OF THE INVENTION
100081 According to a broad aspect of an embodiment of the present invention,
there is
provided a brush cutting head. The brush cutting head includes a cylindrical
support body
that has a first end, an opposed second end and an intennediate portion
extending
therebetween. The intermediate portion has a curved surface that defines the
circular cross-
section of the cylindrical support body. A plurality of collars is mounted to
the cylindrical
support body at spaced intervals along the intermediate portion. Each collar
extends
radially from the curved surface of the cylindrical support body.
Additionally, each collar
cooperates with an adjacent collar to define a mounting station between the
adjacent
collars. The brush cutter head further includes a plurality of cutting tooth
assemblies
carried on the outer surface of the cylindrical support body. Each cutting
tooth assembly
has a cutting tooth for placement within the mounting station and a mounting
assembly
engageable with the adjacent collars to secure the cutting tooth in the
mounting station.
[0009] In an additional feature, each collar includes a circumferentially
extending
sidewall defining a substantially penannular structure. The sidewall has a
first end and a
second end spaced part from the first end thereof. The space between the first
and second
ends of the sidewall define a cutout in each collar. The cutout is sized to
receive therein a
portion of the cutting tooth assembly. In a further feature, the cutout
defined in each collar
is circumferentially spaced from the cutout defined in the adjacent collar.
Additionally,
each mounting station extends between the cutout in each collar and the
portion of the
sidewall of the adjacent collar opposite the cutout.
[0010] In still another feature, each mounting assembly includes first and
second plate
members for holding therebetween the cutting tooth and a fastener for
attaching the cutting
tooth to the first and second plate members. The first and second plate
members are each
mountable to extend between adjacent collars. The first plate member is
disposed forwardly
of the cutting tooth and the second plate member is disposed rearwardly of the
cutting tooth
when the cutting tooth is secured within the mounting station. Each cutting
tooth has a
base portion and a cutting portion supported on the base portion. Each of the
plate members
and the base portion has an aperture defined therein. The apertures defined in
the plate
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members and the base portion are alignable to permit the fastener to be
inserted
therethrough. In an additional feature, the fastener is a threaded fastener
and the aperture
defined in the first plate member is adapted to threadingly engage the
fastener to thereby
fasten the second plate member and the cutting tooth to the first plate
member.
[0011] In another feature, the mounting station is adapted to receive therein
the cutting
tooth and at least a portion of the mounting assembly.
100121 In yet another feature, the mounting station is adapted to receive
therein the
cutting tooth and the second plate.
[0013] In a further feature, the sidewall of each collar has a first face and
a second face
opposite the first face. The first face of the sidewall has defined therein at
least one rebate.
In each collar the at least one rebate is circumferentially spaced from the
cutout. The at
least one rebate in each collar is substantially aligned with the cutout in
the adjacent collar.
Additionally, the second plate member has a first end and an opposed second
end. The first
end of the second plate member is locatable within the cutout in each collar
and the second
end thereof is mountable within the at least one rebate in the adjacent
collar. Further still,
the at least one rebate includes first and second rebates. In each collar the
first rebate is
circumferentially spaced from the second rebate. One of the first and second
rebates in each
collar is substantially aligned with the cutout in the adjacent collar. The
second end of the
second plate member is locatable within one of the first and second rebates in
each collar.
Each rebate is defined by first and second circumferentially spaced radial
edges. In each
collar the first rebate is radially offset from the cutout by a first angle
measured from the
centerline of the cutout to the first edge of the first rebate and the second
rebate is radially
offset from the cutout by a second angle measured from the centerline of the
cutout to the
first edge of the second rebate.
[0014] In an additional feature, one of the first plate member and the second
plate
member is fixed between adjacent collars. In another feature, the second plate
member is
fixed within the mounting station and the first plate member is removeably
mounted
between adjacent collars. In an alternate feature, the first plate member is
fixed between the
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adjacent collars and welded to the curved surface of the support body.
Moreover, the
second plate member is releasably mountable within the mounting station.
[0015] In a further feature, the mounting station is adapted to receive
therein the first
plate member, the second plate member and the cutting tooth.
[0016] In another feature, each collar has a centreline running therethrough.
The cutout
defined in the collar is axially offset from the centreline of the collar. The
sidewall of each
collar has a first face and a second face opposite the first face. The first
face of the sidewall
has defined therein a rebate. The rebate is axially offset from the centreline
of the collar.
The cutout and the rebate are disposed on opposite sides of the centreline. In
addition, the
rebate in each collar is substantially aligned with the cutout in the adjacent
collar. The
second plate member has a first end and an opposed second end. The first end
of the second
plate member is mountable within the cutout in the collar and the second end
thereof is
locatable within the rebate in the adjacent collar.
[0017] In yet another feature, the cutout defined in each collar is a first
cutout. The
sidewall of each collar is bounded circumferentially by an outer edge and an
inner edge and
has defined therein a second cutout extending partially between the outer and
inner edges.
At the location of the second cutout the width of the sidewall as measured
between the
outer and inner edges thins to define a narrow strip of sidewall for
supporting a portion of
the mounting assembly. Additionally, the first cutout in each collar is
substantially aligned
with the second cutout in the adjacent collar. The second plate member has a
first end and
an opposed second end. The first end of the second plate member is mountable
within the
first cutout in the collar and the second end thereof is locatable within the
second cutout in
the adjacent collar. The second end of the second plate member has an abutment
flange for
abutting the narrow strip formed on the adjacent collar.
[0018] In still a further feature, the mounting station is adapted to receive
therein only the
cutting tooth.
[0019] In an additional feature, the sidewall of each collar has a pair of
first and second
apertures defined therein. The first aperture is disposed adjacent the cutout.
The second
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aperture is circumferentially staggered from the first aperture. The first and
second
apertures are each adapted to receive therein a portion of the second plate
member. The
first aperture in each collar is aligned with the second aperture in the
adjacent collar. The
second plate member has a first end and an opposed second end. The first end
of the second
plate member is mountable within the first aperture in each collar and the
second end
thereof is locatable within the second aperture in the adjacent collar. The
second plate
member is detachably mounted to adjacent collars.
[0020] In another feature, each mounting station is radially offset from the
adjacent
mounting station.
[0021] In yet another feature, the plurality of cutting tooth assemblies is
disposed along
the support body in a double helix pattern.
[0022] In an additional feature, each mounting assembly includes first and
second plate
members for holding therebetween the cutting tooth and a fastener for
attaching the cutting
tooth to the first and second plate members. The first and second plate
members are
mountable to extend between adjacent collars. When the cutting tooth is
secured within the
mounting station, the first plate member is disposed forwardly of the cutting
tooth and the
second plate member is disposed rearwardly of the cutting tooth.
[0023] In still a further feature, the brush cutting head further includes a
deflector
member disposed between the adjacent collars forwardly of the mounting
station. The
deflector member is fixed to the curved surface of the support body and to the
sidewalls of
the adjacent collars. Additionally, the deflector member is disposed forwardly
of the first
plate member. Further still, the first plate member has a leading face and an
opposed
trailing face for abutting a portion of the cutting tooth. The deflector
member is an elongate
plate having first and second ends. The first end of the deflector member is
supported on
the curved surface of the support body and the second end of the deflector
member abuts
the leading face of the first plate member. The deflector member extends
generally tangent
to the curved surface.
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[0024] In an additional feature, each mounting assembly includes a mounting
block and a
plate member for holding therebetween the cutting tooth, and a fastener for
attaching the
cutting tooth to the first and second plate members. The mounting block and
the plate
member are each mountable between adjacent collars. When the cutting tooth is
secured
within the station, the mounting block is disposed forwardly of the cutting
tooth and the
plate member is disposed rearwardly of the cutting tooth. Each cutting tooth
has a base
portion and a cutting portion supported on the base portion. Each of the
mounting block,
the plate member and the base portion has an aperture defined therein. The
apertures
defined in the mounting block, the plate member and the base portion are
alignable to
permit the fastener to be inserted therethrough. Additionally, the base
portion has a leading
face and an opposed trailing face. The leading face of the base portion abuts
the mounting
block and the trailing face of the base portion abuts the plate member when
the cutting
tooth is secured within the station.
[0025] In a further feature, the mounting block is defined by a pair of first
and second
spaced apart lateral faces, opposed top and bottom faces, a leading face and
an opposed
trailing face. The leading and trailing faces of the mounting block extend
between the top
and bottom faces thereof. When the cutting tooth is secured within the
mounting station, the
mounting block is disposed between adjacent collars with the first and second
lateral faces
abutting the sidewalls of the adjacent collars, the bottom face abutting the
curved surface of
the support body and the trailing face of the mounting block abutting the
leading face of the
base portion. In another feature, the bottom face of the mounting block has an
arcuate
profile matching the curvature of the curved surface. In still another
feature, the leading
face of the mounting block slopes downwardly from top face to the bottom face
of the
mounting block to encourage the deflection of debris away from the cutting
tooth when the
cutting tooth is secured within the mounting station. Moreover, the mounting
block is fixed
between the adjacent collars.
[0026] In still another feature, each mounting assembly further includes an
elongate
support plate spanning the adjacent collars proximate the cutout defined in
one of the
collars. The support plate has a leading portion and a trailing portion. The
leading portion
of the support plate is configured to provide an abutment face for a portion
of the cutting
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tooth. The sidewall of each collar is bounded circumferentially by an outer
edge and an
inner edge. The support plate has first and second opposed ends. The ends of
the support
plate are mounted on the outer sidewall edges of the adjacent collars.
Optionally, the ends
of the support plate may be fixed to the outer sidewall edges of the adjacent
collars.
[0027] In an additional feature, the cutting tooth includes a base portion and
a cutting
portion supported on the base portion. The base and cutting portions each have
a leading
face and a trailing face. Proximate the cutting portion, the trailing face of
the base portion
has protruding therefrom an abutment shoulder for bearing on the abutment face
defined by
the leading portion of the support plate.
[0028] In another feature, the cutting tooth and the plate member are
configured for
mating engagement with each other. One of the cutting tooth and the plate
member has a
male portion and the other of the cutting tooth and the plate member has a
female portion
configured to receive the male portion therein. The cutting tooth includes a
base portion
and a cutting portion supported on the base portion. The base portion has a
leading face for
abutting the mounting block and a trailing face for abutting the plate member.
The trailing
face of the base portion has a groove formed therein. The groove defines the
female
portion. The plate member has a leading face for abutting the trailing face of
the base
portion and a trailing face. The leading face of the plate member has formed
therein a
tongue. The tongue defining the male portion.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] The embodiments of the present invention shall be more clearly
understood with
reference to the following detailed description of the embodiments of the
invention taken in
conjunction with the accompanying drawings, in which:
[0030] FIG. 1 is a perspective view of a brush cutter according to an
embodiment of the
present invention with a housing side panel removed and a portion of the
housing top panel
cut away to better reveal components of the drive assembly of the brush
cutter;
[0031] FIG. 2a is a perspective view of the brush cutting head shown in FIG.
1;
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100321 FIG. 2b is another perspective view similar to that shown in FIG. 2a
showing the
brush cutting head rotated 180 degrees;
100331 FIG. 3 is an end view of the brush cutting head shown in FIG. 2a with a
collar
removed therefrom for the sake of clarity;
[0034] FIG. 4 is an enlarged view similar to that illustrated in FIG. 2a
showing the
encircled portion '4';
[0035] FIG. 5 is an enlarged perspective view of one end of the brush cutting
head of
FIG. 2a;
[0036] FIG. 6 is an enlarged perspective view similar to that illustrated in
FIG. 5
showing a cutting tooth and a portion of its corresponding mounting assembly
exploded;
[0037] FIG. 7 is an end elevation view similar to that illustrated in FIG. 3
with a
portion of the next adjacent collar removed for clarity;
[0038] FIG. 8 is a perspective view of one of the collars shown in FIG. 2a;
[0039] FIG. 9 is a side elevation view of the collar shown in FIG. 8;
[0040] FIG. 10 is a perspective view of one of the cutting teeth shown in FIG.
6;
[0041] FIG. 11 is a side elevation view of the cutting tooth of FIG. 10;
[0042] FIG. 12 is a top plan view of the cutting tooth of FIG. 10;
[0043] FIG. 13 is a front perspective view of the first plate shown in FIG. 5;
[0044] FIG. 14 is a front perspective view of the second plate shown in FIG.
5;
[0045] FIG. 15 is an enlarged perspective view of a brush cutting head
according to an
alternative embodiment of the present invention, showing a cutting tooth and a
portion of
its corresponding mounting assembly exploded;
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[0046] FIG. 16 is a perspective view of an alternative cutting tooth to that
shown in FIG.
10;
[0047] FIG. 17 is a top plan view of the cutting tooth of FIG. 16;
[0048] FIG. 18 is a front elevation view of the cutting tooth of FIG. 16;
[0049] FIG. 19 is a side elevation view of the cutting tooth of FIG. 16;
[0050] FIG. 20 is a perspective view of a brush cutter head according to
another
embodiment of the present invention;
[0051] FIG. 21 is an end view of the brush cutting head illustrated in FIG. 20
shown with
a collar removed therefrom for the sake of clarity;
[0052] FIG. 22 is an enlarged view similar to that illustrated in FIG. 21
showing the
encircled portion '22';
[0053] FIG. 23 is an enlarged perspective view of one end of the brush cutting
head of
FIG. 20 showing a cutting tooth and a portion of its corresponding mounting
assembly
exploded;
[0054] FIG. 24 is a perspective view of one of the collars shown in FIG. 22;
[0055] FIG. 25 is a side elevation view of the collar shown in FIG. 22;
[0056] FIG. 26 is a perspective view of one of the cutting teeth shown in FIG.
22;
[0057] FIG. 27 is a side elevation view of the cutting tooth shown in FIG. 22;
[0058] FIG. 28 is a front perspective view of the first plate shown in FIG.
22;
[0059] FIG. 29 is a rear perspective view of the second plate shown in FIG.
22;
[0060] FIG. 30 is a perspective view of one end of another brush cutting head
in
accordance with the principles of the present invention, shown with a cutting
tooth and a
portion of its corresponding mounting assembly removed for the sake of
clarity;
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[0061] FIG. 31 is another perspective view similar to that illustrated in FIG.
30
showing the cutting tooth and the portion of its corresponding mounting
assembly
exploded;
100621 FIG. 32 is a side elevation view of one of the collars shown in FIG.
31;
[0063] FIG. 33 is a perspective view of one of the cutting teeth shown in FIG.
31;
[0064] FIG. 34 is rear end view of the cutting tooth shown in FIG. 31;
[0065] FIG. 35 is a side elevation view of the cutting tooth shown in FIG. 31;
[0066] FIG. 36 is a perspective view of the second plate shown in FIG. 31;
[0067] FIG. 37 is a perspective view of a yet another brush cutter head
according to an
alternative embodiment of the present invention;
[0068] FIG. 38 is an end view of the brush cutting head shown in FIG. 37 with
a collar
removed therefrom for the sake of clarity;
[0069] FIG. 39 is an enlarged view similar to that illustrated in FIG. 38
showing the
encircled portion '39';
[0070] FIG. 40 is an enlarged perspective view of one end of the brush cutting
head
illustrated in FIG. 37 showing a cutting tooth and a portion of its
corresponding
mounting assembly exploded;
[0071] FIG. 41 is a side elevation view of one of the collars shown in FIG.
40;
[0072] FIG. 42 is a perspective view of one of the cutting teeth shown in FIG.
40;
[0073] FIG. 43 is a side elevation view of the cutting tooth shown in FIG. 42;
[0074] FIG. 44 is a front elevation view of the second plate shown in FIG. 40;
[0075] FIG. 45 is a perspective view of another brush cutter head according to
a further
alternative embodiment of the present invention;
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[0076] FIG. 46 is an end view of the brush cutting head shown in FIG. 45 with
a collar
removed therefrom for the sake of clarity;
[0077] FIG. 47 is an enlarged view similar to that illustrated in FIG. 46
showing the
encircled portion '47';
[0078] FIG. 48 is an enlarged perspective view of one end of the brush cutting
head of
FIG. 45;
100791 FIG. 49 is an enlarged perspective view taken from the opposite
direction from
that shown in FIG. 48 showing a cutting tooth and a portion of its
corresponding
mounting assembly exploded;
[0080] FIG. 50 is a side elevation view of one of the collars shown in FIG.
49;
[0081] FIG. 51 is a perspective view of one of the cutting teeth shown in FIG.
49;
[0082] FIG. 52 is a side elevation view of the cutting tooth shown in FIG. 51;
[0083) FIG. 53 is a perspective view of the mounting block shown in FIG. 49;
[0084) FIG. 54 is a perspective view of the mounting plate shown in FIG. 49;
and
[0085] FIG. 55 is a perspective view of the abutment member shown in FIG. 49.
DETAILED DESCRIPTION OF THE EMBODIMENTS OF THE INVENTION
[0086] The description which follows, and the embodiments described therein
are
provided by way of illustration of an example, or examples of particular
embodiments of
principles and aspects of the present invention. These examples are provided
for the
purposes of explanation and not of limitation, of those principles of the
invention. In the
description that follows, like parts are marked throughout the specification
and the
drawings with the same respective reference numerals.
[0087] Referring to FIGS. 1, 2a and 2b, there is shown a brush cutting head
generally
designated with reference numeral 20. Brush cutting head 20 is adapted for use
in a
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conventional brush cutter 1000. The brush cutter 1000 is of the type generally
known to
those skilled in the art such that only a very general description thereof is
required for the
purposes of this specification. The brush cutter 1000 may be of the type
attached to the
front of a vehicle, such as a loader, skid steer, or the like. It has a
housing 1002 defined by a
plurality of walls mounted to each other and arranged to define a space for
accommodating
the brush cutting head 20. More specifically, the brush cutting head 20 is
mounted
longitudinally between two spaced apart housing sidewalls 1004 and 1006 and
supported
on bearing assemblies (not shown) for rotational motion about an axis of
rotation 'A-A'. A
drive assembly 1008 which includes a motor 1010 and drive belt arrangement
1012 is
supported on sidewall 1004 and operatively connected to the brush cutting head
20 to drive
the rotation thereof. Generally speaking, the brush cutting head 20 carries
about its outer
surface a plurality of teeth adapted to cut trees, brush or the like.
[0088] Brush cutting head 20 has a hollow, elongate support body 22 that has a
first end
23, an opposed second end 24 and an intermediate portion 26 extending between
the first
and second ends 23 and 24. In this embodiment, the support body 22 is
cylindrical. This,
however, need not be the case in every application. In alternative
embodiments, the
support body may be shaped differently.
[0089] The intermediate portion 26 has a curved outer surface 28 that defines
the circular
cross-section of the support body 22. Concentrically mounted to the support
body 22 at
spaced intervals along the intermediate portion 26, is a plurality of
protective collars
designated with reference numerals 30a through to 30u (collectively, "collars
30"). As will
be explained in greater detail below, pairs of adjacent collars 30 cooperate
with each other
to define mounting sites or stations 32 for each receiving a cutting tooth
assembly 34
therein.
[0090] Referring to FIGS. 8 and 9, each collar 30 has a penannular structure
defined by a
relatively flat, circumferentially extending, sidewall 40. The sidewall 40 is
bounded
circumferentially by an outer edge 42 and inner edge 44, and has first and
second spaced
apart ends 46 and 48. The space between the ends 46 and 48 defines a cutout 50
formed in
the collar 30 that is sized to accommodate therein a portion of the cutting
tooth assembly
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34. The end 46 of sidewall 40 has a notch 52 formed about the outer edge 42 to
provide
clearance for the forward leaning portion of the cutting tooth assembly 34.
The sidewall 40
has two opposed faces 54 and 56 and a pair of first and second,
circumferentially spaced,
rebates 58 and 60 formed within the face 54 of the sidewall 40. The rebates 58
and 60
extend between the outer and inner edges 42 and 44 of the sidewa1140. The
rebates 58 and
60 are disposed substantially opposite to the cutout 50. More specifically,
the first rebate 58
is circumferentially spaced from the cutout 50 by an angle (3, (as measured
from the
centerline CL of cutout 50 to the edge 62 of rebate 58), whereas the second
rebate 60 is
circumferentially displaced from the cutout 50 by an angle (32 (as measured
from the
centerline CL of the cutout 50 to the edge 64 of rebate 60). In this
embodiment, the angle 01
is approximately 180 degrees whereas the angle R2 measures about 198 degrees.
However,
it will be appreciated that the angles (3, and (32 may be varied to suit the
particular
application. As will be explained in greater detail below, each rebate 58, 60
defines a
substantially radial slot 66 in the sidewal140 that is sized to receive a
portion of the cutting
tooth assembly 34.
[0091] While in the present embodiment each collar 30 is formed with two
rebates 58 and
60 separated by an angle representing the difference between angle 02 and 01,
this particular
configuration need not be used in every application. In alternative
embodiments, each
collar could be provided with a single rebate or conversely, the collar could
have three or
more rebates defined in the sidewall at staggered locations.
[0092] The collars 30 are radially mounted to the support body 22 with their
inner
sidewall edges 44 welded to the curved surface 28. The spacing between
adjacent collars 30
is sized to correspond generally to the width of the cutting tooth assembly 34
and tends to
minimize the chance that the cutting tooth assembly 34 will be damaged by
violent contact
with a rock or a large tree. The collars 30 are mounted with their respective
faces 54 all
oriented in the same direction.
[0093] Each collar 30 is radially offset from its adjacent collar 30 by an
angle wl (as
measured between the respective centerlines CL of the cutouts 50) such that
the cutouts 50
of adjacent collars 30 are staggered relative to each other. In the present
embodiment, the
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angle col measures about 180 degrees. In this arrangement, the cutout 50 of a
given collar
30 is substantially aligned with the rebate 58 or 60 of another adjacent
collar 30 to allow a
portion of the cutting tooth assembly 34 to extend longitudinally therebetween
in an
orientation that is substantially parallel to the axis of rotation A-A. As
shown in FIG. 5, the
cutout 50 of collar 30a and the first rebate 58 of collar 30b are
substantially aligned.
[0094] Each station 32 is defined between the cutout 50 formed in a given
collar 30 and
that portion of the sidewall 40 of the adjacent collar 30 that is disposed
opposite the cutout
50. Referring again to FIG. 5, the station 32ab (previously identified
generically as "station
32") can be seen to be defined between the cutout 50 in collar 30a and the
portion of
sidewall 40 of collar 30b located opposite the cutout 50. Each of the other
stations 32,
identified in FIGS. 2a and 2b, is similarly defined between the cutout 50 of
one collar 30
and a portion of sidewall of an adjacent collar 30. As shown in FIG. 7, each
the station 32 is
circumferentially staggered from its adjacent station by the angle c)l.
[00951 Due to this stagger and the geometry of the collars 30, every alternate
station 32 is
also radially offset from its respective reference station by an angle co2.
Taking as an
example stations 32ab and 32cd, it can be seen in FIG. 7 that station 32cd is
circumferentially staggered relative to station 32ab by an angle 0)2. In this
embodiment, the
angle c02 measures approximately 18 degrees.
[0096] In this embodiment, the staggered arrangement of the collars 30 allows
the
plurality of cutting tooth assemblies 34 to be disposed along the support body
22 in a
generally double helix pattern. In this manner, the brush cutting head 20 can
achieve cutting
across the entire length of the support body 22 when rotated about axis 'A-A'.
While this
double helix pattern is generally preferred, it will be appreciated that the
arrangement of the
cutting tooth assemblies could be laid out differently. More specifically, the
angles col and
w2 could be varied to achieve a particular distribution or arrangement of
cutting tooth
assemblies 34 on the support body 22. For instance, the cutting tooth
assemblies could be
disposed in a triple or quadruple helix arrangement.
[0097] Turning now to FIGS. 4 to 6 and 10 to 12, the cutting tooth assembly 34
is now
described in greater detail. The cutting tooth assembly 34 includes a cutting
tooth 70 and a
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mounting assembly 72 for securely fixing the cutting tooth 70 within a
respective station
32.
[0098] The cutting tooth 70 includes a plate-like, base portion 74 having a
first end 76
and a second end 78, and a cutting portion 80 mounted to the second end 78 of
the base
portion 74. Base portion 74 has a generally planar, leading face 82, an
opposing trailing
face 84 and two, spaced apart, lateral faces 86 and 88. Defined in the base
portion 74 is a
bore 90 that extends between the leading face 82 and the trailing face 84. The
bore 90 is
adapted to receive a fastener therethrough to permit fastening of the cutting
tooth 70 to the
mounting assembly 72.
[0099] As best shown in FIGS. 10, 11 and 12, the cutting portion 80 is carried
on the
second end 78 of the base portion 74 in a generally, forwardly leaning or
canted fashion.
Preferably, the cutting portion 80 is integrally formed with the base portion
74 and both are
fabricated from a plate of hardened steel. In this embodiment, the steel plate
is bent
forward to obtain the forwardly leaning cutting portion 80. Alternatively, the
cutting tooth
70 could be cast with its cutting portion 80 leaning forward relative to its
base portion 74.
It will however be appreciated that in alternative embodiments, the cutting
and base
portions could be manufactured separately and then assembled to form the
cutting tooth by
welding, fastening or the like.
[00100] The cutting portion 80 includes a leading face 100, an opposed
trailing face 102
and two spaced-apart lateral faces 104 and 106. The leading face 100 of the
cutting portion
80 joins the leading face 82 of the base portion 74 while similarly, the
trailing face 102
connects to trailing face 84 of the base portion 74. As best shown in FIG. 11,
an external
obtuse angle 01 is formed between the leading face 100 and the leading face
82. Preferably,
the angle 01 lies between about 100 degrees and about 170 degrees. Most
preferably, the
angle 01 lies between about 120 and about 150 degrees. In this embodiment, the
angle 01 is
135 degrees.
[00101] The leading and trailing faces 100 and 102 cooperate with each other
to define a
tapering, wedge-like, profile 110 that terminates in a cutting edge 112. The
cutting edge
112 is carried forwardly of the leading face 82 of the base portion 74 such
that it tends to be
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the first element of cutting tooth 70 to make contact with the brush. In the
preferred
embodiment, the cutting edge 112 extends generally linearly between the
lateral faces 104
and 106 and substantially parallel to the rotational axis A-A of the brush
cutting head 20.
However, in alternative embodiments, the cutting edge could be configured
differently. For
instance, the cutting edge could be configured to extend generally diagonally
between the
lateral faces 104 and 106, askew of the rotational axis A-A. This
configuration would tend
to favor one end of the cutting edge over the other contacting the brush. In a
further
alternative, the cutting edge could be scalloped or formed to extend in a
generally,
zigzagging fashion.
[00102] The trailing face 102 of the cutting portion 80 has an upper portion
114 and a
lower portion 116 joined to the upper portion 114. The upper portion 114
extends between
the cutting edge 112 and the lower portion 116 whereas the lower portion 116
joins the
trailing face 84 of the base portion 74 at a transition section 118. As best
shown in FIG. 10,
the upper portion 114 is bent relative to the lower portion 116 such that an
internal obtuse
angle ~1 is defined therebetween. In the present embodiment, the angle ~1
measures 150
degrees. However, the angle ~1 may vary between about 120 degrees and about
180 degrees
[00103] The trailing face 102 has a plurality of knuckle-like protuberances in
the nature of
ridges 120 formed thereon. The ridges 120 are generally evenly spaced and
extend
generally transverse of the cutting edge 112 between the upper and lower
portions 114 and
116 of the trailing face 102. Defined between each pair of adjacent ridges 120
is a channel
or groove 122 which when viewed from the side (as shown in FIG. 11) is
generally curved.
The alternate arrangement of ridges 120 and channels 122 define corrugations
124 on the
trailing face 102. These corrugations serve to direct rocks, wood chips and
other debris
away from the cutting edge 80 thereby minimizing dispersion of the debris over
the cutting
area.
1001041 In this embodiment, the grooves 122 are machine ground into the
trailing face 102
during fabrication. However, it should be appreciated that in alternative
embodiments, the
cutting portion 80 could be cast or forged in such a way that grooves and
ridges are formed.
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[00105] When the cutting tooth 70 is mounted within station 32, the cutting
edge 112
extends beyond the outer edge 42 of the collar sidewall 40 to facilitate the
cutting action of
the tooth. In operation, the cutting edge 112 of each cutting tooth 70 comes
into contact
with the brush. Debris is created as a result of the cutting action of the
cutting tooth 70. As
the debris passes over the cutting edge 112, it abrades the surface of the
cutting edge 112
thereby sharpening the cutting tooth 70. This sharpening action tends to
maintain or
enhance the cutting efficiency of the cutting tooth and tends to reduce the
need for
mechanical sharpening. Thereafter the debris travels along the channels 122 to
be carried
away from cutting edge 112.
[00106] While in this embodiment, the corrugations 124 have a generally
crenellated
profile when view in cross-section, it will be appreciated that this need not
be the case in all
applications. In alternative embodiments, the corrugations could be configured
differently.
For instance, the corrugations could have a generally arcuate or zigzag
profile when viewed
in cross-section. Other profiles may also be employed to similar advantage.
[00107] While it is preferred that the brush cutting head 20 be used with
cutting teeth 70, it
will be appreciated that other types of teeth could also be used to similar
advantage. More
specifically, it may be advantageous to change the cutting tooth to adapt to
the nature of the
materials likely to be encountered during cutting operations. For instance,
where the terrain
to be cleared is rocky, the cutting tooth 70 described above could be replaced
with a
hammer-type tooth which tends to be better suited to resisting frequent
impacts with rocks
and the like. With reference to FIGS. 16 to 19, there is shown an alternate
cutting tooth
designated generally with reference numeral 230.
[00108] The cutting tooth 230 includes a base portion 232 having a first end
234 and a
second end 236, and a cutting portion 238 carried on the second end 236 of the
base portion
232. The base portion 232 has a generally planar leading face 240, an opposing
trailing
face 242 and two spaced apart lateral faces 244 and 246. Defined in the base
portion 232 is
a bore 248 that extends between the leading face 240 and the trailing face
242. The bore
248 is adapted to receive a fastener therethrough to permit fastening of the
cutting tooth
230 to the mounting assembly 72.
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[00109] As best shown in FIG. 19, the cutting portion 238 is generally T-
shaped with a
side profile that is not unlike that of the head of a hammer. The cutting
portion 238 has a
leading flange 250 and an opposed trailing flange 252. A generally arcuate
face 254, spaced
away from the base portion 232, extends between the leading and trailing
flanges 250 and
252 and further defines the contour of the cutting tooth. The leading flange
250 has a
proximal end 256 joined to the corresponding end of the trailing flange 252
and a distal end
258. The distal end 258 has formed therein a plurality of wedge-shaped
projections 260. In
the present embodiment, the cutting portion 238 has three wedge-shaped
projections 260 - a
central projection 260a flanked by a pair of side projections 260b and 260c.
While three
projections are preferred, the cutting portion 238 may be configured with an
alternate
number of projections. When viewed in plan as shown in FIG. 17, the
projections 260a,
260b and 260c impart a zigzag profile to the leading flange 252.
[00110] The central wedge-shaped projection 260a includes a first lateral face
262 and a
second lateral face 264 that meet at a cutting edge 266. Similarly, each of
the side
projections 260b, 260c also have first and second lateral faces 268 and 270
that meet at a
cutting edge 272. The first lateral faces 268 of the projections 260b and 260c
are defined by
the sides of the leading flange 250. In contrast to the cutting edge 112 of
cutting tooth 70,
when the cutting tooth 230 is operatively connected to the support body 22,
the cutting edge
266 extends substantially transverse to the rotational axis A-A of the brush
cutting head.
Adjacent the base portion 232, the lateral faces 262 and 264 of the projection
260a and the
lateral faces 268 and 270 of the projections 260b and 260c are truncated so as
to define
generally triangular impact faces 274 and 276, respectively, with which the
brush or other
material will make first contact during operation of the brush cutter.
[00111] In this embodiment, the cutting tooth 230 is of unitary construction
and cast from
hardened steel.
[00112] The mounting assembly 72 is now described in greater detail with
reference to
FIGS. 4, 6, 13 and 14. The mounting assembly 72 includes a first plate 130
disposed
forwardly of the cutting tooth 70, a second plate 132 disposed rearwardly of
the cutting
tooth 70 and a fastener in the nature of a bolt 134. In this embodiment, the
first plate 130 is
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fixed to the support body 22. As explained below, when mounted within the
station 32, the
cutting tooth 70 is fixedly retained between the first and second plates 130
and 132 by bolt
134. A deflector member 138 is further provided to reinforce the first plate
130 and to
deflect debris away from the first plate thereby protecting it from direct
impact with rocks.
[00113] As shown in FIG. 13, the first plate 130 has a rectangular shape
defined by a pair
of opposed, relatively short, sides 140 and 142 and a pair of opposed,
relatively long, sides
144 and 146 that extend between the short sides 140 and 142. In the present
embodiment,
the first plate 130 is mounted upright on the support body 22 with its long
side 146 welded
to the curved surface 28 and its short sides 140 and 142 welded to the opposed
faces of
adjacent collars. The first plate 130 further includes a leading face 152 and
an opposed,
trailing face 150 for abutting the cutting tooth base portion 74 (shown in
FIG. 4) and a
centrally threaded aperture 154 defined therein. The aperture 154 extends
between the
leading and trailing 152 and 150 and is adapted to receive the bolt 134
therethrough.
1001141 The deflector member 138 is a rectangular plate with first and second
longitudinal
ends 156 and 158. The deflector member 138 is mounted generally tangent to the
curved
surface 28 with its beveled second end 158 abutting the leading face 152 of
the first plate
130 adjacent the side 44. The deflector member 138 is securely fixed to the
support body
22, the adjacent collars 32 and the leading face 152 of the first plate 130 by
welding.
[00115] While in this embodiment, the first plate 130 and the deflector member
138 are
separate components it should be appreciated that they need not be in every
application. In
alternative embodiments, the first plate 130 and the deflector member 138 may
be
integrally formed.
[00116] As best shown in FIGS. 5, the first plate 130 and the deflector member
138 of
mounting assembly 72 are mounted between a pair of adjacent collars 30 with
the trailing
face 150 of the first plate 130 disposed flush with the end 46 of the sidewall
40 so as to
allow unobstructed access to the cutout 50 during tooling.
[00117] Referring to FIG. 14, the second plate 132 is generally similar to the
first plate
130 in that it is also rectangular and is defined by a pair of opposed,
relatively short, sides
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170 and 172 and a pair of opposed, relatively long, sides 174 and 176 that
extend between
the short sides 170 and 172. The second plate 132 further includes a leading
face 178 for
abutting the cutting tooth base portion 74 (as shown in FIG. 4), an opposed
trailing face 180
and an aperture 182 defined therein. The aperture 182 extends between the
leading and
trailing faces 178 and 180 and is adapted to receive the bolt 134
therethrough.
[00118) Preferably, the plates 130 and 132 and the deflector member 138 are
made of
hardened steel. However, other materials exhibiting similar wear resistance
and strength
characteristics may be used in the fabrication of the mounting assembly
components.
1001191 As will be appreciated by a person skilled in the art, the mounting
assembly 72
and is of generally simple construction. In contrast to known mounting
assemblies, the
uncomplicated design of the mounting assembly 72 tends to make it relatively
simple and
inexpensive to manufacture, easy to mount and easy to replace. Moreover, given
its
configuration and location between adjacent collars 30, the mounting assembly
72 tends to
be less prone to damage from contact with rocks and trees.
[00120] Referring to FIGS. 5 and 6, the attachment of the cutting tooth 70 to
the brush
cutting head 20 is now described in greater detail in the context of station
32ab. The cutting
tooth base portion 74 is urged against the first plate 130 such that its
leading face 82 abuts
the trailing face 150 of the first plate 130 and its bore 90 is aligned with
the threaded
aperture 154. The lateral face 88 of the base portion 74 abuts the face 54 of
collar 30b while
the opposed face 86 extends beyond face 54 of collar 30a and through the
cutout 50 to lie
flush with face 52 of collar 30a. In this position, the cutting portion 80 of
the cutting tooth
also extends beyond face 54 of collar 30a to lie flush with the face 52
thereof to thereby
provide a continuous cutting line running along the entire length of the
support body 22
during rotation of the brush cutter head 20.
[00121] Thereafter the short side 172 of second plate 132 is introduced into
slot 66 defined
by the first rebate 58 formed in collar 30b. With short side 172 fully
received within slot
66, the opposed side 170 of second plate 132 projects through the cutout 50 to
lie flush with
face 52 of collar 30a in similar fashion to the side 88 of base portion 74.
Thus disposed, the
second plate 132 abuts the trailing face 84 of the cutting tooth base portion
74 and its
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aperture 182 is aligned with bore 90 and threaded aperture 154. The bolt 134
is then
inserted through the aligned apertures 182, 90 and 154 and threadingly engages
the
threading of aperture 154. The bolt 134 is then tightened to ensure the
cutting tooth 70 is
held fast within the station 32ab.
[00122] In the event the cutting tooth 70 is damaged or worn, it may be easily
replaced by
releasing the cutting tooth 70 from the station 32ab. To do so, the bolt 134
is unfastened to
permit the first and second plates 130 and 132 to be detached from the cutting
tooth. The
cutting tooth may then be removed from the station. If the cutting tooth 70 is
lodged within
the station 32ab, a mallet or similar tool may be used to facilitate removal
thereof by
striking the lateral face 88 of the cutting tooth 70 so as to urge the cutting
tooth 70 to move
towards the cutout 50 formed in the collar 30.
[00123] With the appropriate modifications, the foregoing description may also
apply to
the mounting of cutting tooth 230 within a station 32.
[00124] It will thus be understood that, the cutting tooth 70 is retained not
only by the
plates 130 and 132 but also by collar 30a. The first plate 130 cooperates with
the rebate 58
defined in collar 30b and the sidewall ends 46 and 48 of collar 30a snugly
hold the cutting
tooth 70 and the second plate 132 within the cutout 50. Advantageously the
collars 30 serve
a dual purpose in the brush cutting head 20. On one hand, the collars 30
cooperate with the
mounting assembly 72 to securely fasten the cutting teeth and on the other,
the collars 30
protect the cutting teeth 70 from damage. The collars offer two-fold
protection to the
cutting teeth by shielding the cutting teeth from rocks and other hard objects
and by
reducing the stresses to which the cutting teeth are subjected during
operations by
improving the distribution of forces through the mounting assembly. Use of the
collars 30
in this manner tends to obviate the need for relatively heavy mounting blocks
thereby
making it possible to manufacture brush cutting heads that tend to be
relatively lightweight
and have modest energy requirements. As a result, the brush cutting head 20
tends to be
suitable for use in a relatively lightweight brush cutter.
[00125] In the present embodiment, the first plate 130 is fixed to the curved
surface 28 of
the support body 22 and welded to the opposed faces of the adjacent collars 30
whereas the
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second plate is releasably attached to the cutting tooth 70 and adjacent
collars 30. This need
not be the case in every application. In a different embodiment, the first
plate could be
releasably detachable from the collars and the second plate could be fixed to
the support
body. Such an embodiment is illustrated in FIG. 15 wherein a brush cutting
head designated
generally with reference numeral 188, is shown to have an alternate mounting
assembly
190.
[00126] Mounting assembly 190 is generally similar to mounting assembly 72 in
that it has
a first plate 192 disposed forwardly of the cutting tooth 70, a second plate
194 disposed
rearwardly of the cutting tooth 70, a fastener in the nature of a bolt 196 and
a deflector
member 200. Each of these components is similar in both construction and
configuration to
their respective counterpart elements 130, 132 134 and 138 in mounting
assembly 72. In
particular, the second plate 194 resembles second plate 132 in that it is
rectangular and is
defined by a pair of opposed, relatively short, sides 202 and 204 and a pair
of opposed,
relatively long, sides 206 and 208 that extend between the short sides 202 and
204.
Moreover, the second plate 194 has a leading face 210 for abutting the cutting
tooth base
portion 74 (as shown in FIG. 4), an opposed trailing face 212 and an aperture
214 defined
therein. The aperture 214 extends between the leading and trailing faces 210
and 212 and is
adapted to receive the bolt 196 therethrough.
[00127] However, the mounting assembly 190 differs from mounting assembly 72
in that
the first plate 192 is not permanently attached to any of the support member
22, collars 32
and deflector member 200. Instead, it is the second plate 194 that is fixedly
mounted to the
collars 32 and the support member 22. During fabrication of the brush cutting
head 188,
the second plate 194 is welded to the curved surface 28 along its long side
208. The second
plate 194 is also welded to the adjacent collars 30 at two locations - first
along its short side
204 to permanently fix it within the one of the rebates 58 and 60 and
secondly, along the
point of contact between the trailing face 208 and the sidewall end 46.
[00128] The deflector member 200 is mounted to the support body 22 and to the
adjacent
collars 32 in much the same manner as described above in the context of
deflector member
138, except that the deflector member 200 is not welded to the first plate
192.
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[00129] To attach the cutting tooth 70 to the brush cutting head 188, the
first plate 192 is
placed on the curved surface 28 in an upright position with its leading face
abutting the
deflector member 200 and its short sides abutting the opposed collars. The
cutting tooth
base portion 74 is then placed between the first plate 192 and the second
plate 194 such that
its trailing face 84 abuts the leading face 210 of the second plate 194.
Thereafter, the bolt
196 is inserted into the aligned apertures of the first plate 192, the cutting
tooth 70 and the
second plate 194 and tightly fastened.
[00130] Other modifications may be made without departing from the principles
of the
present invention. For instance, it may be possible to alter the configuration
of the
protective collars. In contrast to brush cutting head 20 wherein only the
second plate and
the cutting tooth 70 fit within cutout 50, in an alternative embodiment, the
collars could be
fabricated with larger cutouts so as to accommodate both mounting plates and
the cutting
tooth mounted therebetween. One such embodiment is shown in FIGS. 20 to 29,
wherein
an alternate brush cutting head is designated generally with reference numeral
300.
[00131] Brush cutting head 300 is generally similar to brush cutting head 20
in that it
employs the same support body 22. However, as is described in greater detail
below, in this
embodiment, different collars and cutting tooth assemblies are used. The brush
cutting
head 300 has a plurality of protective collars 302 concentrically mounted to
the support
body at spaced intervals along the intermediate portion 26 of the support body
22. Adjacent
collars 302 cooperate with each other to define mounting sites or stations 304
for each
receiving a cutting tooth assembly 306 therein.
[00132] Referring to FIGS. 24 and 25, each collar 302 is generally similar to
collar 30 in
that it has a penannular structure defined by a relatively flat,
circumferentially extending,
sidewall 310. The sidewall 310 is bounded circumferentially by an outer edge
312 and
inner edge 314, and has first and second spaced apart ends 316 and 318. The
space between
the ends 316 and 318 defines a cutout 320 formed in the collar 302. The cutout
320 is
axially offset from the centreline CL of the collar 302. The sidewall 310
further includes
two opposed faces 324 and 326 and a single rebate 328 formed within the face
324 of the
sidewall 310. The rebate 328 extends between the outer and inner edges 312 and
314. The
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rebate 328 is also axially offset from the centerline CL opposite the cutout
320. As best
shown in FIG. 25, the cutout 320 and the rebate 328 are disposed on opposite
sides of the
centreline CL and extend substantially parallel to each other. While in the
present
embodiment each collar 302 is formed with only a single rebate 328, it will be
appreciated
that in alternative embodiments, each collar could be provided with two or
more rebates
defined in the sidewall.
[00133] In like fashion to collars 30, the collars 302 are radially mounted to
the support
body 22 with their inner sidewall edges 314 welded to the curved surface 28.
The spacing
between adjacent collars 302 is sized to correspond generally to the width of
the cutting
tooth assembly 306. Moreover, the collars 302 are mounted with their
respective faces 324
all oriented in the same direction.
[00134] Each collar 302 is radially offset from its adjacent collar 302 such
that the cutouts
320 of adjacent collars 302 are staggered relative to each other. In this
arrangement, the
cutout 320 of a given collar 302 is substantially aligned with the rebate 328
of another,
adjacent collar 302 to allow a portion of the cutting tooth assembly 306 to
extend
longitudinally therebetween in an orientation that is substantially parallel
to the axis of
rotation A-A. As shown in FIG. 23, the cutout 320 of collar 302a and the
rebate 328 of
collar 302b are substantially aligned.
[00135] Each station 304 is defined between the cutout 320 formed in a given
collar 302
and that portion of the sidewall 310 of the adjacent collar 302 that is
disposed opposite the
cutout 320. Referring again to FIG. 23, the station 304ab (previously
identified generically
as "station 304") can be seen to be defined between the cutout 320 in collar
302a and the
portion of sidewall 310 of collar 302b located opposite the cutout 320. Each
of the other
stations 304, identified in FIG. 23 is similarly defined between the cutout
320 of one collar
302 and a portion of sidewall 310 of an adjacent collar 302. As best shown in
FIGS. 20 and
23, each station 304 is circumferentially staggered from its adjacent station.
1001361 As in the brush cutting head 20, in this embodiment, the staggered
arrangement of
the collars 302 allows the plurality of cutting tooth assemblies 306 to be
disposed along the
support body 22 in a generally double helix pattern thereby permitting cutting
across the
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entire length of the support body 22 when the brush cutting head 300 is
rotated about axis
'A-A'. It will however be appreciated that the cutting tooth assemblies 306
could be
disposed differently along the support body 22.
[00137] Turning now to FIGS. 21, 22 and 26 to 29, the cutting tooth assembly
306 is now
described in greater detail. The cutting tooth assembly 306 includes a cutting
tooth 330 and
a mounting assembly 332 for securely fixing the cutting tooth 330 within a
respective
station 304. The cutting tooth 330 is generally similar to cutting tooth 70 in
that it has a
plate-like, base portion 334 having a first end 336 and a second end 338, and
a cutting
portion 340 mounted to the second end 338 of the base portion 334. Whereas in
cutting
tooth 70, the cutting portion 80 and the base portion 74 are of a
substantially similar size, in
this embodiment the cutting portion 340 is relatively smaller than the base
portion 334.
[00138] The base portion 334 has a generally planar, leading face 342, an
opposing trailing
face 344 and two, spaced apart, lateral faces 346 and 348. Defined in the base
portion 334
is a bore 350 that extends between the leading face 342 and the trailing face
344. The bore
350 is adapted to receive a fastener therethrough to permit fastening of the
cutting tooth
330 to the mounting assembly 332. The base portion 334 however differs from
base portion
74 in two respects. First, the base portion 334 is relatively longer than the
base portion 74.
Second, adjacent its second end 338, the base portion 334 has an abutment
flange or
shoulder 352 which projects from the trailing face 344. The abutment flange
352 reinforces
the cutting tooth 330 and enables it to better resist the high impact forces
to which it may be
subjected during operation of the brush cutting head 300. As a result, the
cutting tooth 330
tends to be less vulnerable to cracking failures along the area where the
cutting portion 340
meets the base portion 334. As will be explained in greater detail below, when
the cutting
tooth 330 is mounted within the station 304, the abutment flange 352 will rest
on a portion
of the mounting assembly 332.
[00139] As in the cutting tooth 70, the cutting portion 340 is carried on the
second end 338
of the base portion 334 in a generally, forwardly leaning or canted fashion,
and is integrally
formed with the base portion 334. However, in this embodiment the cutting
tooth 330 is
fabricated by forging and machining.
CA 02546294 2006-05-11
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[00140] But for its relatively smaller size, the cutting portion 340 resembles
the cutting
portion 80 in that it also has a leading face 360, an opposed trailing face
362 and two
spaced-apart lateral faces 364 and 366. The leading face 360 of the cutting
portion 340
joins the leading face 342 of the base portion 334 while the trailing face 362
connects to the
abutment flange 352 of the base portion 334. As best shown in FIG. 27, an
external obtuse
angle 02 is formed between the leading face 360 and the leading face 342. In
this
embodiment, the angle 02 is 138 degrees.
[00141] In like fashion to leading and trailing faces 100 and 102 in cutting
tooth 70, the
leading and trailing faces 360 and 362 cooperate with each other to define a
tapering,
wedge-like, profile 370 that terminates in a cutting edge 372. The cutting
edge 372 is
carried forwardly of the leading face 342 of the base portion 334 such that it
tends to be the
first element of cutting tooth 330 to make contact with the brush. The cutting
edge 372
extends generally linearly between the lateral faces 364 and 366 and
substantially parallel
to the rotational axis A-A of the brush cutting head 300. When the cutting
tooth 330 is
mounted within the station 304, the cutting edge 372 extends beyond the outer
edge 312 of
the collar sidewa11310 to facilitate the cutting action of the tooth.
[001421 Returning to FIG. 27, the trailing face 362 of the cutting portion 330
has an upper
portion 374 and a lower portion 376 joined to the upper portion 374. The upper
portion 374
extends between the cutting edge 372 and the lower portion 376 whereas the
lower portion
376 joins the abutment flange 352 at a transition section 378. As best shown
in FIG. 27, the
upper portion 374 is bent relative to the lower portion 376 such that an
internal obtuse angle
~2 is defined therebetween. In the present embodiment, the angle k measures
161 degrees.
The trailing face 362 is configured with corrugations 380 that are similar to
the
corrugations 124 formed on cutting tooth 70 such that no further description
is required.
[00143] The mounting assembly 332 is now described in greater detail with
reference to
FIGS. 21, 22 and 23. The mounting assembly 332 is generally similar to
mounting
assembly 72 in that it includes a first plate 390 disposed forwardly of the
cutting tooth 330,
a second plate 392 disposed rearwardly of the cutting tooth 330 and a fastener
in the nature
of a bolt 394. However, in this embodiment the second plate 392 is welded to
the support
CA 02546294 2006-05-11
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body 22. As explained below, when mounted within the station 304, the cutting
tooth 330 is
fixedly retained between the first and second plates 390 and 392 by bolt 394.
Also
provided, is a deflector member 396 not unlike the deflector member 138 shown
in FIG. 4.
[00144] As shown in FIG. 28, the first plate 390 has a rectangular shape
defined by a pair
of opposed, relatively long, lateral sides 400 and 402 and a pair of opposed,
relatively short,
sides 404 and 406 that extend between the long sides 400 and 402. In the
present
embodiment, the first plate 390 is mounted upright on the support body 22 with
its short
side 406 abutting the curved surface 28. The first plate 390 further includes
a leading face
412 and an opposed, trailing face 410 for abutment against the cutting tooth
base portion
334 and a centrally threaded aperture 414 defined therein. The aperture 414
extends
between the leading and trailing faces 412 and 410 and is adapted to receive
the bolt 394
therethrough.
[00145] The deflector member 396 is a rectangular plate with first and second
longitudinal
ends 426 and 428. The deflector member 396 is mounted generally tangent to the
curved
surface 28 with its beveled second end 428 abutting the leading face 412 of
the first plate
390 adjacent the short side 404. The deflector member 396 is securely fixed to
the support
body 22 and the adjacent collars 302 by welding.
[00146] Referring to FIG. 29, the second plate 392 is also generally
rectangular and is
defined by a pair of opposed, relatively long, lateral sides 430 and 432 and a
pair of
opposed, relatively short sides 434 and 436 that extend between the long sides
430 and 432.
The second plate 392 further includes a leading face 438 for abutting the
cutting tooth base
portion 334, an opposed trailing face 440 and an aperture 442 defined therein.
The aperture
442 extends between the leading and trailing faces 438 and 440 and is adapted
to receive
the bolt 394 therethrough. The corner along which the short side 436 would
meet the
leading face 438 is truncated so as to define an arcuate face 444. The face
444 is radiused to
match the arcuate profile of the curved surface 28. This tends to facilitate
fixing the second
plate 392 to the support body 22.
[00147] During fabrication of the brush cutting head 300, the second plate 392
is welded
to the curved surface 28 along its arcuate face 444. The second plate 392 is
also welded to
CA 02546294 2006-05-11
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the adjacent collars 302 at two locations - first along its long side 432 to
permanently fix it
within the rebate 328 and secondly, along the point of contact between the
trailing face 440
and the sidewall end 318. When fixed in this position, the opposing long side
430 of the
second plate projects through the cutout 320 to lie flush with the face 326 of
collar 302.
[00148] Referring to FIG. 23, the attachment of the cutting tooth 330 to the
brush cutting
head 300 is now described in greater detail in the context of station 304ab.
The first plate
390 is placed on the curved surface 28 in an upright position with its leading
face abutting
the deflector member 396 and its long side 402 abutting the sidewall of collar
302b. The
other long side 404 of the first plate 390 extends beyond face 324 of collar
302a and
through the cutout 320 to lie flush with face 326 of collar 302a. The cutting
tooth base
portion 334 is then placed between the first plate 390 and the second plate
392 such that its
trailing face 344 abuts the leading face 438 of the second plate 392 and its
abutment flange
352 rests on the short side 434 of the second plate 392. Thereafter, the bolt
394 is inserted
into the aligned apertures of the first plate 390, the cutting tooth 330 and
the second plate
392 and tightly fastened.
[00149] In contrast to station 32ab in brush cutting head 20 which receives
therein only the
cutting tooth 70 and the second plate 132, the station 304ab accommodates both
plates 390
and 392 and the cutting tooth 330.
[00150] Moreover, while cutting tooth 330 has been described in connection
with brush
cutting head 300, it will be appreciated that with appropriate modifications,
this type of
cutting tooth could be also be successfully employed in other brush cutting
heads fabricated
in accordance with the principles of the present invention.
[00151] In each of the brush cutting heads 20, 188 and 300, the protective
collars were
formed with one cutout and at least one rebate. However, the protective
collars could be
configured differently. For instance, it may be possible to replace one or
more of the
rebates in the protective collars with an additional cutout. One such
embodiment is shown
in FIGS. 30 to 35 wherein an alternative brush cutting head is designated
generally with
reference numera1460.
CA 02546294 2006-05-11
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[00152] Brush cutting head 460 uses the same support body 22 as a brush
cutting head 20
and similarly includes a plurality of protective collars 462 concentrically
mounted to the
support body at spaced intervals along the intermediate portion 26 of the
support body 22.
As in the other previously described embodiments, the adjacent collars 462
cooperate with
each other to define mounting sites or stations 464 for each receiving a
cutting tooth
assembly 466 therein.
[00153] Referring to FIG. 32, each collar 462 has a penannular structure
defined by a
relatively flat, circumferentially extending, sidewall 470. The sidewall 470
is bounded
circumferentially by an outer edge 472 and inner edge 474, and has first and
second spaced
apart ends 476 and 478 and two opposed faces 480 and 482. The end 476 of
sidewall 470
has a notch 484 formed about the outer edge 472 to provide clearance for the
forward
leaning portion of the cutting tooth assembly 466. The space between the ends
476 and 478
defines a first cutout 490 formed in the collar 462. Disposed substantially
opposite to the
first cutout 490, is a second, partial cutout 492 defined within the sidewall
470 and
extending between the outer and inner edges 472 and 474 thereof. The second
cutout 492
is radially offset from the first cutout 490 by an angle 03 (as measured from
the centerline
of the first cutout 490 to the centerline of the second cutout 492). In this
embodiment, the
angle (33 is approximately 180 degrees. However, it will be appreciated that
the angle (33
may be varied to suit a particular application. At the location of the second
cutout 492, the
width of the sidewall 470 (as measured between the outer edge 472 and the
inner edge 474)
thins to a narrow strip 496. As will be explained in greater detail below, the
narrow strip
496 supports a portion of the cutting tooth assembly 466.
[00154] In like fashion to collars 30, the collars 462 are radially mounted to
the support
body 22 with their inner sidewall edges 474 welded to the curved surface 28.
The spacing
between adjacent collars 462 is sized to correspond generally to the width of
the cutting
tooth assembly 466.
[00155] Each collar 462 is radially offset from its adjacent collar 462 such
that the first
cutouts 490 of adjacent collars 462 are staggered relative to each other. In
this arrangement,
the first cutout 490 of a given collar 462 is substantially aligned with the
second cutout 492
CA 02546294 2006-05-11
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of another, adjacent collar 462 to allow a portion of the cutting tooth
assembly 466 to
extend longitudinally therebetween in an orientation that is substantially
parallel to the axis
of rotation A-A.
[00156] In this embodiment, each station 464 is defined between the first
cutout 490
formed in a given collar 462 and that portion of the sidewal1470 of the
adjacent collar 462
that is disposed opposite the cutout 462. Referring to FIG. 30, the station
462ab
(previously identified generically as "station 462") can be seen to be defined
between the
first cutout 490 in collar 462a and the portion of sidewall 470 of collar 462b
located
opposite the first cutout 490. Each of the other stations 464, identified in
FIG. 30 is
similarly defined between the first cutout 490 of one collar 462 and a portion
of sidewall
470 of an adjacent collar 462. As best shown in FIGS. 30 and 31, each station
464 is
circumferentially staggered from its adjacent station.
[00157] As in the brush cutting head 20, in this embodiment, the staggered
arrangement of
the collars 462 allows the plurality of cutting tooth assemblies 466 to be
disposed along the
support body 22 in a generally double helix pattern thereby permitting cutting
across the
entire length of the support body 22 when the brush cutting head 460 is
rotated about axis
'A-A'. It will however be appreciated that the cutting tooth assemblies 466
could be
disposed differently along the support body 22.
[00158] Turning now to FIGS. 31 and 33 to 36, the cutting tooth assembly 466
is now
described in greater detail. The cutting tooth assembly 466 includes a cutting
tooth 500 and
a mounting assembly 502 for securely fixing the cutting tooth 500 within a
respective
station 464. The cutting tooth 500 is generally similar to cutting tooth 70 in
that it has a
base portion 504 having a first end 506 and a second end 508, and a cutting
portion 510
mounted to the second end 508 of the base portion 504.
[00159] The base portion 504 has a generally planar, leading face 512, an
opposing trailing
face 514 and two, spaced apart, lateral faces 516 and 518. Defined in the base
portion 504
is a bore 520 that extends between the leading face 512 and the trailing face
514. The bore
520 is adapted to receive a fastener therethrough to permit fastening of the
cutting tooth
500 to the mounting assembly 502.
CA 02546294 2006-05-11
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[00160] As in the cutting tooth 70, the cutting portion 510 is carried on the
second end 508
of the base portion 504 in a generally, forwardly leaning or canted fashion,
and is integrally
formed with the base portion 504. The cutting portion 510 resembles the
cutting portion 80
in that it also has a leading face 522, an opposed trailing face 524 and two
spaced-apart
lateral faces 526 and 528. The leading face 522 of the cutting portion 510
joins the leading
face 512 of the base portion 504 while the trailing face 524 connects to the
trailing face 514
of the base portion 504. As best shown in FIG. 35, an external obtuse angle 03
is formed
between the leading face 512 and the leading face 522. In this embodiment, the
angle 03 is
135 degrees.
[00161] In like fashion to leading and trailing faces 100 and 102 in cutting
tooth 70, the
leading and trailing faces 522 and 524 cooperate with each other to define a
tapering,
wedge-like, profile 530 that terminates in a cutting edge 532. The cutting
edge 532 is
carried forwardly of the leading face 512 of the base portion 504 such that it
tends to be the
first element of cutting tooth 500 to make contact with the brush. The cutting
edge 532
extends generally linearly between the lateral faces 526 and 528 and
substantially parallel
to the rotational axis A-A of the brush cutting head 470.
[00162] However, the cutting portion 510 differs from the cutting portion 80
in that it is
relatively wider than the base portion 504. That is, the width W, of the
cutting portion 510
(as measured between its lateral faces 526 and 528) is greater than the width
W2 of the base
portion 504 (as measured between its lateral faces 516 and 518). As a result,
in the
transition section 534 where the cutting portion 510 meets the base portion
504, the lateral
face 526 projects beyond the lateral face 516 thereby defining an abutment
member or
shoulder 536. When the cutting tooth 500 is mounted within the station 474,
the abutment
shoulder 536 abuts the outer edge 472 of the collar sidewall 470 and the
lateral face 526
lies flush with the face 482 of the collar sidewall 470.
[00163] Returning to FIG. 35, the trailing face 524 of the cutting portion 510
has an upper
portion 540 and a lower portion 542 joined to the upper portion 540. The upper
portion 540
extends between the cutting edge 532 and the lower portion 542, whereas the
lower portion
542 joins the base portion 504 at the transition section 534. The upper
portion 540 is bent
CA 02546294 2006-05-11
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relative to the lower portion 542 such that an internal obtuse angle ~3 is
defined
therebetween. In the present embodiment, the angle ~3 measures 150 degrees.
The trailing
face 522 is configured with corrugations 544 that are similar to the
corrugations 124 formed
on cutting tooth 70 such that no further description is required.
[00164] Referring to FIGS. 30, 31 and 35, the mounting assembly 502 is
generally similar
to mounting assembly 72 in that it includes a first plate 550 disposed
forwardly of the
cutting tooth 500, a second plate 552 disposed rearwardly of the cutting tooth
500 and a
fastener in the nature of a bolt 554. However, in this embodiment the second
plate 552 is
welded to the support body 22 and to the collars 462. As explained below, when
mounted
within the station 464, the cutting tooth 500 is fixedly retained between the
first and second
plates 550 and 552 by bolt 554. Also provided, is a deflector member 556. The
first plate
550 and the deflector member 556 are similar in both construction and
configuration to
their counterpart components 130 and 138. However, in this embodiment the
first plate 550
is not permanently attached to the support member 22, adjacent collars 462 or
deflector
member 556. The deflector member 556 is mounted to the support body 22 and to
the
adjacent collars 462 in much the same manner as described above in the context
of
deflector member 138, except that the deflector member 556 is not welded to
the first plate
550.
[00165] Referring to FIG. 36, the second plate 552 is generally rectangular
and is defined
by a pair of opposed, relatively short, sides 562 and 564 and a pair of
opposed, relatively
long sides 566 and 568 that extend between the short sides 562 and 564. A
notch 570 is cut
out of the corner formed by the short side 564 and the long side 568. The
notch 570 defines
an abutment flange 572 that rests on the narrow strip 496 of the collar 462
when cutting
tooth 500 is mounted within the station 464. The second plate 552 further
includes a
leading face 574 for abutting the cutting tooth base portion 504, an opposed
trailing face
576 and an aperture 578 defined therein. The aperture 578 extends between the
leading and
trailing faces 574 and 576 and is adapted to receive the bolt 554
therethrough.
[00166] During fabrication of the brush cutting head 460, the second plate 552
is
positioned within the second cutout 492 with the abutment flange 572 abutting
the narrow
CA 02546294 2006-05-11
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strip 496 and the top portion of the short side 5641ying flush with the face
482 of the collar
462. The second plate 552 is welded in place within the second cutout 492 and
along the
point of contact between the trailing face 570 and the sidewall end 478.
Additionally, the
second plate 552 is welded onto the curved surface 28 along its long side 568.
When fixed
in this position, the short side 562 of the second plate 552 projects through
the first cutout
490 to lie flush with the face 480 of collar 462.
[00167] Referring now to FIG. 31, the attachment of the cutting tooth 500 to
the brush
cutting head 460 is now described in greater detail in the context of station
464ab. The first
plate 550 is placed on the curved surface 28 in an upright position with its
leading face
abutting the deflector member 556 and its short sides abutting the sidewalls
of collars 462a
and 462b. The cutting tooth base portion 504 is then placed between the first
plate 550 and
the second plate 552 such that its trailing face 512 abuts the leading face
574 of the second
plate 552. The lateral face 516 of the base portion 504 is urged to abut the
sidewall of collar
462b with the abutment shoulder 536 resting on the outer edge 472 of sidewall
470. In this
position, the opposed lateral face 518 extends through the first cutout 490
beyond face 482
to lie flush with face 480 of collar 462a. Thereafter, the bolt 554 is
inserted into the aligned
apertures of the first plate 550, the cutting tooth 500 and the second plate
552 and tightly
fastened.
[00168] In like fashion to station 32ab in brush cutting head 20, the station
464ab is
configured to receive the cutting tooth 500 and the second plate 552.
[00169] It should be appreciated that, with appropriate modifications, cutting
tooth 500
could be used in other brush cutting heads fabricated in accordance with the
principles of
the present invention.
[00170] As previously described, the brush cutting head 460 does not employ
rebates.
Instead, its collars 462 are provided with two cutouts - one full cutout 490
and a partial
cutout 492. The full cutout 490 receives therein a portion of the cutting
tooth 500 and one
end of the second plate 552 whereas the partial cutout 492 accommodates the
opposite end
of the second plate 552. In another embodiment, the protective collars may be
modified
further still by doing away with a partial cutout such as cutout 492 in favour
of apertures
CA 02546294 2006-05-11
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defined in the collar sidewall. Moreover, in such an embodiment, the full
cutout may be
sized to receive therein the cutting tooth only.
[00171] With reference to FIGS. 37 to 44, there is shown an alternative brush
cutting head
designated generally with reference numeral 600. Brush cutting head 600 is
generally
similar to brush cutting head 20 in that it employs the same support body 22.
However, as
is described in greater detail below, in this embodiment, different collars
and cutting tooth
assemblies are used. The brush cutting head 600 has a plurality of protective
collars 602
concentrically mounted to the support body 22 at spaced intervals along the
intermediate
portion 26 of the support body 22. Adjacent collars 602 cooperate with each
other to define
mounting sites or stations 604 for each receiving a cutting tooth assembly 606
therein.
[00172] Referring to FIG. 41, each collar 602 is generally similar to collar
30 in that it has
a substantially penannular structure defined by a relatively flat,
circumferentially extending,
sidewall 610. The sidewall 610 is bounded circumferentially by an outer edge
612 and
inner edge 614, and has first and second spaced apart ends 616 and 618. The
space between
the ends 616 and 618 defines a cutout 620 formed in the collar 602. The cutout
620 is
disposed slightly off centre of the centreline CL of the collar 602.
[00173] The sidewall 610 further includes two opposed faces 624 and 626 and a
pair of
first and second, circumferentially spaced, apertures 628 and 630 defined in
the sidewall
610 and extending between the faces 624 and 626. The apertures 628 and 630 are
generally
rectangular with their shape being defined by a pair of relatively short,
opposed edges 632
and a pair of relatively long, opposed edges 634. The apertures 628 and 630
are disposed
about the sidewa11610 with their long edges 634 axially offset from the
centerline CL of the
collar 602. More specifically, the apertures 628 and 630 are disposed on
opposite sides of
the centreline CL and extend substantially parallel to each other. As shown in
FIG. 41, the
first aperture 628 is circumferentially spaced from the centreline CL by an
angle (34 (as
measured from the centerline CL to the geometric centre of the rectangular
aperture 628).
The second aperture 630 is circumferentially displaced from the centreline CL
by an angle
(35 (as measured from the centerline CL to the geometric centre of the
rectangular aperture
630). In this embodiment, both angles R4 and 05 measure about 13 degrees such
that the
CA 02546294 2006-05-11
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second aperture 630 is circumferentially staggered from the first aperture by
about 180
degrees. It should however be appreciated that the angles (34 and (35 may be
varied to suit
the particular application.
[00174] On opposite sides of the centreline CL of the collar 602 and adjacent
the sidewall
ends 616 and 618, the outer edge 612 has been trimmed back (by laser cutting)
at a first
location 636 to define a first, substantially planar edge 640. Thus trimmed,
the outer edge
612 also defines a relatively small shoulder 642 a short distance away from
the second
sidewall end 618. Adjacent the shoulder 642, a first notch 644 is formed in
the sidewall
610. There is also defined a second notch 646 at the first sidewall end 616.
The second
notch 646 provides clearance for the forward leaning portion of the cutting
tooth assembly
606. In the vicinity of second aperture 630 at a second location 647, the
outer edge 612 has
also been ground to modify its originally arcuate profile to one that includes
a second,
truncated edge 648.
[00175] In like fashion to collars 30, the collars 602 are radially mounted to
the support
body 22 with the inner edge 614 of the sidewall 610 welded to the curved
surface 28. The
spacing between adjacent collars 602 is sized to correspond generally to the
width of the
cutting tooth assembly 606.
[00176] Each collar 602 is radially offset from its adjacent collar 602 such
that the cutouts
620 of adjacent collars are staggered relative to each other. The first and
second apertures
628 and 630 of adjacent collars 602 are also staggered relative to each other
to allow
alignment of the first aperture 628 of a given collar 602 with the second
aperture 630 of
another, adjacent collar 602. With reference to FIG. 40, it can be seen that
the first aperture
628 of collar 602a is aligned with the second aperture 630 of collar 602b. The
alignment of
these apertures in adjacent collars 602 permits a portion of the cutting tooth
assembly 606
to be mounted longitudinally therebetween in an orientation that is
substantially parallel to
the axis of rotation A-A.
[00177] In this embodiment, each station 604 is defined between the cutout 620
formed in
a given collar 602 and that portion of the sidewall 610 of the adjacent collar
602 that is
disposed opposite the cutout 620. Referring to FIG. 40, the station 604ab
(previously
CA 02546294 2006-05-11
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identified generically as "station 604") can be seen to be defined between the
cutout 620 in
collar 602a and the portion of sidewall 610 of collar 602b located opposite
the first cutout
620. Each of the other stations 604, identified in FIG. 37 is similarly
defined between the
cutout 620 of one collar 602 and a portion of sidewall 610 of an adjacent
collar 602. As
best shown in FIGS. 37 and 40, each station 604 is circumferentially staggered
from its
adjacent station.
[00178] As in the brush cutting head 20, in this embodiment, the staggered
arrangement of
the collars 602 allows the plurality of cutting tooth assemblies 606 to be
disposed along the
support body 22 in a generally double helix pattern thereby permitting cutting
across the
entire length of the support body 22 when the brush cutting head 600 is
rotated about axis
'A-A'. It will however be appreciated that the cutting tooth assemblies 606
could be
disposed differently along the support body 22.
[00179] Turning now to FIGS. 38, 39, 42 and 43, the cutting tooth assembly 606
is now
described in greater detail. The cutting tooth assembly 606 includes a cutting
tooth 650 and
a mounting assembly 652 for securely fixing the cutting tooth 650 within a
respective
station 604. The cutting tooth 650 is generally similar to cutting tooth 70 in
that it has a
base portion 654 having a first end 656 and a second end 658, and a cutting
portion 660
mounted to the second end 658 of the base portion 654. However, whereas in
cutting tooth
70, the cutting portion 80 and the base portion 74 are of a substantially
similar size, in this
embodiment, the cutting portion 660 is relatively larger than the base portion
654.
[00180] The base portion 654 has a generally planar, leading face 662, an
opposing trailing
face 664 and two, spaced apart, lateral faces 666 and 668. Defined in the base
portion 654
is a bore 670 that extends between the leading face 662 and the trailing face
664. The bore
670 is adapted to receive a fastener therethrough to permit fastening of the
cutting tooth
650 to the mounting assembly 652. The base portion 654 however differs from
base portion
74 in two respects. First, the base portion 654 is relatively shorter than the
base portion 74.
Second, adjacent its second end 658, the base portion 654 has an abutment
flange or
shoulder 672 which projects from the trailing face 664. While generally
similar to abutment
flange 352 of cutting tooth 330, the abutment flange 672 is relatively larger
and more
CA 02546294 2006-05-11
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prominent in cutting tooth 650. These differences notwithstanding the abutment
flange 672
serves a similar purpose to that of abutment flange 352 - it reinforces the
cutting tooth 650
and enables it to better resist the high impact forces to which it may be
subjected during
operation of the brush cutting head 650. As a result, the cutting tooth 650
tends to be less
vulnerable to cracking failures along the area where the cutting portion 660
meets the base
portion 654. As will be explained in greater detail below, when the cutting
tooth 650 is
mounted within the station 604, the abutment flange 672 will rest on a portion
of the
mounting assembly 652.
[00181] As in the cutting tooth 70, the cutting portion 660 is carried on the
second end 658
of the base portion 654 in a generally, forwardly leaning or canted fashion,
and is integrally
formed with the base portion 654. However, in like fashion to cutting tooth
330, the cutting
tooth 650 is fabricated by forging and machining.
[00182] But for its relatively larger size, the cutting portion 660 resembles
the cutting
portion 80 in that it also has a leading face 680, an opposed trailing face
682 and two
spaced-apart lateral faces 684 and 686. The leading face 680 of the cutting
portion 660
joins the leading face 662 of the base portion 654 while the trailing face 682
connects to the
abutment flange 672 of the base portion 654. As best shown in FIG. 43, an
external obtuse
angle 04 is formed between the leading face 680 and the leading face 682. In
this
embodiment, the angle 04 is 120 degrees.
[00183] In like fashion to leading and trailing faces 100 and 102 in cutting
tooth 70, the
leading and trailing faces 680 and 682 cooperate with each other to define a
tapering,
wedge-like, profile 690 that terminates in a cutting edge 692. The cutting
edge 692 is
carried forwardly of the leading face 662 of the base portion 654 such that it
tends to be the
first element of cutting tooth 650 to make contact with the brush. The cutting
edge 692
extends generally linearly between the lateral faces 684 and 686 and
substantially parallel
to the rotational axis A-A of the brush cutting head 600. When the cutting
tooth 650 is
mounted within the station 604, the cutting edge 692 extends beyond the first
and second
edges 640 and 648 of the sidewall 610 (of adjacent collars 602) to facilitate
the cutting
action of the tooth. The reduced profile of the sidewa11610 at the edges 640
and 648 tends
CA 02546294 2006-05-11
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to facilitate evacuation of the cutting debris away from the station 604 and
the cutting tooth
650.
[00184] Returning to FIG. 43, the trailing face 682 of the cutting portion 660
has an upper
portion 694, a lower portion 696 and an intermediate portion 698 connecting
the upper
portion 694 to the lower portion 696. The upper portion 694 extends between
the cutting
edge 692 and the upper margin of the intermediate portion 698, whereas the
lower portion
376 extends from the lower margin of the intermediate portion 698 and
terminates at the
abutment flange 672 - the lower portion 696 partially defining the abutment
flange 672.
The upper portion 694 is bent relative to the intermediate portion 698 such
that an internal
obtuse angle ~4 is defined therebetween. In the present embodiment, the angle
~4 measures
about 155 degrees. Corrugations 700 not unlike corrugations 124 of cutting
tooth 70 are
formed in the upper and intermediate portions 694 and 698 of the cutting
portion trailing
face 682.
[00185] Referring to FIGS. 38, 39, 40 and 44, the mounting assembly 652 is
generally
similar to mounting assembly 72 in that it includes a first, generally
rectangular, plate 710
disposed forwardly of the cutting tooth 650, a second plate 712 disposed
rearwardly of the
cutting tooth 650, a fastener in the nature of a bolt 714 and a deflector
member 716. The
first plate 710 and the deflector member 716 are similar in both construction
and
configuration to their counterpart components 130 and 138. However, in this
embodiment,
the first plate 710 is not permanently attached to any of the support member
22, the
adjacent collars 602 or the deflector member 716. The deflector member 716 is
mounted to
the support body 22 and to the adjacent collars 602 in much the same manner as
described
above in the context of deflector member 138, except that deflector member 716
is not
welded to the first plate 710.
[00186] The mounting assembly 652 differs from the mounting assembly 72 in
that it
further includes an additional component, namely, a support plate 718 for
placement
between adjacent collars 602. During fabrication of the brush cutting head
600, the support
plate 718 is mounted between adjacent collars 602 with its ends welded to the
collar
sidewalls 610. The support plate 718 provides a surface upon which the
abutment flange
CA 02546294 2006-05-11
-40-
672 of the cutting tooth 650. As will be explained in greater detail below,
when mounted
within the station 604, the cutting tooth 650 is supported by plate 718 and
fixedly retained
between the first plate 710 and the second plate 712 by bolt 714.
[00187] Referring to FIG. 44, the second plate 712 is generally rectangular
and is defined
by a pair of opposed, relatively short, sides 720 and 722 and a pair of
opposed, relatively
long sides 724 and 726 that extend between the short sides 720 and 722.
Moreover, the
second plate 712 has a leading face 728, an opposed trailing face 730 and an
aperture 732
defined therein between the leading and trailing faces 728 and 730. The
aperture 732 is
adapted to receive the bolt 714 therethrough. The second plate 712 further
includes a first
longitudinal end 734 located adjacent short side 720 and a second longitudinal
end 736
located adjacent short side 722.
[00188] Referring now to FIG. 40, the attachment of the cutting tooth 650 to
the brush
cutting head 600 is now described in greater detail in the context of station
604ab. The first
plate 710 is placed on the curved surface 28 in an upright position with its
leading face
abutting the deflector member 716 and its short sides abutting the sidewalls
of collars 602a
and 602b. The second plate 712 is then mounted between adjacent collars 602.
The first
longitudinal end 734 of the second plate 712 is inserted into the aperture 628
formed in
collar 602a while the second longitudinal end 736 thereof is received within
the aperture
630 defined in the adjacent collar 602b. Subsequently, the cutting tooth base
portion 654 is
placed between the first plate 710 and the second plate 712 with its leading
face 662
abutting the trailing face of the first plate 710. In this position, the
abutment shoulder 672
of the base portion 654 abuts the top face of the support plate 718.
Thereafter, the bolt 714
is inserted into the aligned apertures of the first plate 710, the cutting
tooth 650 and the
second plate 712 and tightly fastened.
[00189] In contrast to previous embodiments, wherein the stations held the
cutting tooth
and one or more plates, in this embodiment, the station 604ab receives only
the cutting
tooth 650.
[00190] While cutting tooth 650 has been described in connection with brush
cutting head
600, it will be appreciated that with appropriate modifications, this type of
cutting tooth
CA 02546294 2006-05-11
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could be also be successfully employed in other brush cutting heads fabricated
in
accordance with the principles of the present invention.
[00191] Further modifications may be brought to the protective collars and the
cutting
tooth assemblies. For instance, in a further alternative embodiment, the
protective collars
could be configured with a single full cutout but without apertures defined in
the collar
sidewall. FIGS. 45 to 55 show such an embodiment wherein a brush cutting head
is
designated generally with reference numeral 750. Brush cutting head 750 is
generally
similar to brush cutting head 20 in that it employs the same support body 22.
However, as
is described in greater detail below, in this embodiment, different collars
and cutting tooth
assemblies are used. The brush cutting head 750 has a plurality of protective
collars 752
concentrically mounted to the support body 22 at spaced intervals along the
intermediate
portion 26 of the support body 22. Adjacent collars 752 cooperate with each
other to define
mounting sites or stations 754 for each receiving a cutting tooth assembly 756
therein.
[00192] Referring to FIG. 50, each collar 752 is generally similar to collar
30 in that it has
a substantially penannular structure defined by a relatively flat,
circumferentially extending,
sidewall 760. The sidewall 760 is bounded circumferentially by an outer edge
762 and
inner edge 764, and has first and second spaced apart ends 766 and 768. The
space between
the ends 766 and 768 defines a cutout 780 formed in the collar 752. The cutout
780 is
disposed slightly off centre of the centreline CL of the collar 752.
[00193] On opposite sides of the centreline CL of the collar 752 and adjacent
the sidewall
ends 766 and 768, the outer edge 762 has been trimmed back (by laser cutting)
at a first
location 782 to define a first substantially planar edge 784. A short distance
away from the
second sidewall end 768, the edge 784 terminates at a relatively small
shoulder 786 defined
in the outer edge 762. The outer edge 762 has also been trimmed at a second
location 788
opposite the first location 782, to define a second substantially planar edge
790. The edge
790 also terminates at a shoulder 787 of a size similar to that of shoulder
786. The second
location 788 is circumferentially spaced from the first location 782 by an
angle (36 (as
measured from the midpoint of the first edge 784 to the midpoint of the second
edge 790).
In this embodiment, the angle (36 measures about 180 degrees.
CA 02546294 2006-05-11
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[00194] Adjacent each of the first and second locations 782 and 788, the inner
edge 764 of
the sidewall 760 has a generally channel-shaped rebate 792, 794 (as the case
may be)
defined therein. The rebates 792 and 794 provide access to the space between
adjacent
collars 754 thereby facilitating the welding of a portion of the cutting tooth
assembly 606 to
the collar sidewalls 760. The first rebate 792 is circumferentially spaced
from the second
rebate 794 by an angle (37 (as measured from the midpoint of the first rebate
792 to the
midpoint of the second rebate 794). In this embodiment, the angle (37 measures
about 180
degrees. In alternative embodiments, the angles [i6 and (37 could be varied to
suit the
particular application.
[00195] In like fashion to collars 30, the collars 752 are radially mounted to
the support
body 22 with their inner sidewall edges 764 welded to the curved surface 28.
The spacing
between adjacent collars 752 is sized to correspond generally to the width of
the cutting
tooth assembly 756.
[00196] Each collar 752 is radially offset from its adjacent collar 752 such
that the cutouts
780 of adjacent collars are staggered relative to each other. In this
embodiment, each
station 754 is defined between the cutout 780 formed in a given collar 752 and
that portion
of the sidewall 760 of the adjacent collar 752 that is disposed opposite the
cutout 780.
Referring to FIG. 49, the station 754ab (previously identified generically as
"station 754")
can be seen to be defined between the cutout 780 in collar 752a and the
portion of sidewall
760 of collar 752b located opposite the first cutout 780. Each of the other
stations 754,
identified in FIG. 45 is similarly defined between the cutout 780 of one
collar 752 and a
portion of sidewall 760 of an adjacent collar 752. As best shown in FIGS. 45
and 49, each
station 754 is circumferentially staggered from its adjacent station.
[00197] As in the brush cutting head 20, in this embodiment, the staggered
arrangement of
the collars 752 allows the plurality of cutting tooth assemblies 756 to be
disposed along the
support body 22 in a generally double helix pattern thereby permitting cutting
across the
entire length of the support body 22 when the brush cutting head 750 is
rotated about axis
'A-A'. It will however be appreciated that the cutting tooth assemblies 756
could be
disposed differently along the support body 22.
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[00198] Turning now to FIGS. 46, 47 and 51 to 55, the cutting tooth assembly
756 is now
described in greater detail. The cutting tooth assembly 756 includes a cutting
tooth 800 and
a mounting assembly 802 for securely fixing the cutting tooth 800 within a
respective
station 754. The cutting tooth 800 is generally similar to cutting tooth 70 in
that it has a
base portion 804 having a first end 806 and a second end 808, and a cutting
portion 810
mounted to the second end 808 of the base portion 804.
[00199] The base portion 804 has a generally planar, leading face 812, an
opposing trailing
face 814 and two, spaced apart, lateral faces 816 and 818. Defined in the base
portion 804
is a bore 820 that extends between the leading face 812 and the trailing face
814. The bore
820 is adapted to receive a fastener therethrough to permit fastening of the
cutting tooth
800 to the mounting assembly 802. The base portion 804 however differs from
base portion
74 in two respects. First, the base portion 804 has, adjacent its first end
806, a V-shaped
groove 824 defined in its trailing face 814. The groove 824 extends between
the lateral
faces 816 and 818 of the base portion 804 and is adapted for mating engagement
with a
portion of the mounting assembly 802. Second, adjacent the second end 808, the
trailing
face 814 of the base portion 804 flares outwardly to partially define a wedge-
shaped
abutment shoulder 822. While generally similar to abutment flange 672 of
cutting tooth
650, the abutment shoulder 822 is relatively smaller and less prominent in the
cutting tooth
800. The abutment shoulder 822 serves a similar purpose to that of abutment
flange 672 - it
reinforces the cutting tooth 800 and enables it to better resist the high
impact forces to
which it may be subjected during operation of the brush cutting head 750. As a
result, the
cutting tooth 750 tends to be less vulnerable to cracking failures along the
area where the
cutting portion 810 meets the base portion 804. As will be explained in
greater detail
below, when the cutting tooth 800 is mounted within the station 754, the
abutment shoulder
822 will rest on a portion of the mounting assembly 802.
[00200] As in the cutting tooth 70, the cutting portion 810 is carried on the
second end 808
of the base portion 804 in a generally, forwardly leaning or canted fashion,
and is integrally
formed with the base portion 804. However, in like fashion to cutting tooth
650, the cutting
tooth 800 is fabricated by forging and machining.
CA 02546294 2006-05-11
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[00201] The cutting portion 810 resembles the cutting portion 80 in that it
also has a
leading face 830, an opposed trailing face 832 and two spaced-apart lateral
faces 834 and
836. The leading face 830 of the cutting portion 810 joins the leading face
812 of the base
portion 804 while the trailing face 832 joins the trailing face 814 to define
the abutment
shoulder 822 of the base portion 804. As best shown in FIG. 52, an external
obtuse angle
05 is formed between the leading face 830 and the leading face 812. In this
embodiment,
the angle 05 measures 120 degrees.
[00202] In like fashion to leading and trailing faces 100 and 102 in cutting
tooth 70, the
leading and trailing faces 830 and 832 cooperate with each other to define a
tapering,
wedge-like, profile 840 that terminates in a cutting edge 842. The cutting
edge 842 is
carried forwardly of the leading face 812 of the base portion 804 such that it
tends to be the
first element of cutting tooth 800 to make contact with the brush. The cutting
edge 842
extends generally linearly between the lateral faces 834 and 836 and
substantially parallel
to the rotational axis A-A of the brush cutting head 750. When the cutting
tooth 800 is
mounted within the station 754, the cutting edge 842 extends beyond the first
and second
edges 784 and 790 of the sidewall 760 (of adjacent collars 752) to facilitate
the cutting
action of the tooth. The reduced profile of the sidewall 760 at the edges 784
and 790 tends
to facilitate evacuation of the cutting debris away from the station 754 and
the cutting tooth
800.
[00203] Returning to FIG. 52, the trailing face 832 of the cutting portion 810
has an upper
portion 844 and a lower portion 846 joined to the upper portion 844. The upper
portion 844
extends between the cutting edge 842 and the lower portion 846. The lower
portion 846
partially defines the abutment shoulder 822. The upper portion 844 is bent
relative to the
lower portion 846 such that an internal obtuse angle ~5 is defined
therebetween. In the
present embodiment, the angle ~5 measures 155 degrees. The cutting portion
trailing face
832 is configured with corrugations 848 that are similar to the corrugations
124 formed on
cutting tooth 70 such that no further description is required.
[00204] Referring to FIGS. 45 to 48, the mounting assembly 802 includes a
mounting
block 850 disposed forwardly of the cutting tooth 750, a plate 852 disposed
rearwardly of
CA 02546294 2006-05-11
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the cutting tooth 750, a fastener in the nature of a nut 854 and bolt 856, and
a support plate
858 for placement on the substantially planar edges 784 and 790 of adjacent
collars 752. In
contrast to the mounting assembly 72 which has a deflector member 138 and
first and
second plates 130 and 132 between which the cutting tooth 70 is mounted, in
mounting
assembly 802, the first plate and deflector member are combined into a single
component -
mounting block 850.
[00205] Referring to FIG. 53, the mounting block 850 is defined by a top face
860, a
bottom face 862 disposed opposite the top face 860, leading and trailing faces
864 and 866
which extend between the top and bottom faces 860 and 862 and a pair of spaced
apart
lateral faces 868, 870. The bottom face 862 is generally arcuate - its radius
of curvature
matching that of the curved surface 28 to thereby facilitate welding of the
mounting block
850 to the support body 22. The trailing face 866 extends generally upwardly
from the
bottom face 862 to join the top face 860. As compared to the bottom face 862,
the top face
860 is relatively short. The leading face 864 extends away from the top face
860 at a
downward angle toward the bottom face 862. A narrow band 872 joins the leading
face
864 to the bottom face 862. The leading face 864, the narrow band 872 and the
bottom face
862 cooperate with each other to impart to the mounting block 850 a generally
tapering
(wedge-like) profile. It will be appreciated that the configuration of the
mounting block
850 with its sloped leading face 864 tends to encourage the deflection of
debris away from
the cutting tooth 750 much in the same way as deflection member 138 of
mounting
assembly 72.
[00206] Formed centrally in the leading face 864 and extending partially into
the top face
860, is a relatively large rebate 874. The rebate 874 defines a generally
curved bottom wall
876 and a leading wall 878 that is generally parallel to and spaced apart from
the trailing
face 866. The rebate 874 communicates with a bore 880 that extends between the
trailing
face 866 and the leading wall 876. The rebate 874 and the bore 880 are sized
to
accommodate the bolt 856 extending therethrough.
[00207] With reference to FIG. 54, the plate 852 is now described in greater
detail. The
plate 852 is generally rectangular and is defined by a pair of opposed,
relatively short, sides
CA 02546294 2006-05-11
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890 and 892 and a pair of opposed, relatively long sides 894 and 896 that
extend between
the short sides 890 and 892. Moreover, the second plate 852 has a leading face
898, an
opposed trailing face 900 and an aperture 902 defined therein between the
leading and
trailing faces 898 and 900. The aperture 902 is adapted to receive the bolt
856 therethrough.
Disposed between the aperture 902 and the long side 896 is a V-shaped tongue
904 that ext
longitudinally between the short sides 890 and 892. The tongue 904 is
configured for
mating engagement with groove 824 formed in the cutting tooth base portion
804.
1002081 Referring now to FIG. 55, there is shown the support plate 858.
Support plate 858
is generally C-shaped when viewed in top plan. It has a back portion 910 and a
pair of
spaced apart arms 912 and 914 joined to the back portion 910 and extending
away
therefrom. The support plate 858 further includes a top face 916, an opposed
bottom face
918 and a leading face 920 spanning the back portion 910. The leading face 920
extends
downwardly from the top face 916 toward the bottom face 918. A narrow band 922
joins
the leading face 920 to the bottom face 918. The leading face 920, the narrow
band 922 and
the bottom face 918 cooperate with each other to impart to the support plate
858 a generally
tapering (wedge-like) profile.
[00209] As best shown in FIG. 49, during fabrication of the brush cutting head
750, the
mounting block 850 and the support plate 858 are fixed to adjacent collars
752a and 752b
(as the case may be). More specifically, the mounting block 850 is positioned
between
adjacent collars 752a and 752b with its bottom face 862 abutting the curved
surface 28 of
the support body 22 and its trailing face 864 disposed flush with the sidewall
end 766 of
collar 752a so as to allow unobstructed access to the cutout 780 during
tooling. The
mounting block 850 is then welded to the adjacent collars 752 about the first
and second
rebates 792 and 794. The support plate 858 is mounted to span the space
between adjacent
collars 752a and 752b. The first arm 912 of the plate 858 is supported on the
first
substantially planar edge 784, while the second arm 914 rests on the second
substantially
planar edge 790. At their terminal extremities the arms 912 and 914 abut the
shoulders 786
and 787 defined on the outer edges of the collars 752a and 752b. Thus
disposed, the support
plate 858 is welded in place.
CA 02546294 2006-05-11
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[00210] Referring now to FIGS. 48 and 49, the attachment of the cutting tooth
800 to the
brush cutting head 750 is now described in greater detail in the context of
station 754b. The
cutting tooth base portion 804 is placed between the mounting block 850 and
the support
plate 858 with its leading face 812 abutting the trailing face 866 of the
mounting block 850
and its abutment shoulder 822 bearing on the leading face 920 of the support
plate 858. The
plate 852 is then placed between the collars 752a and 752b with its long edge
896 abutting
the curved surface 28 and its opposed long edge 894 abutting the bottom of the
support
plate 858. The tongue 904 formed on the trailing face 898 of the plate 852 is
urged to mate
with the groove 824 defined in the cutting tooth base portion 804. This
arrangement tends
to prevent the cutting tooth 750 from moving within the station 754 and also
tends to
minimize shear forces in the bolt 856 during use. Thereafter, the bolt 856 is
inserted into
the aligned apertures of the mounting block 850, the cutting tooth 800 and the
plate 852 and
securely fastened with the nut 854. The space between the arms 912 and 914
facilitates the
use of a tool to tighten or loosen (as the case may be) the nut 854. In like
fashion to station
604ab of brush cutting head 600, the station 754ab receives only the cutting
tooth 750.
[00211] While in this embodiment, the second plate 852 has tongue 904 and the
cutting
tooth 750 has groove 824 formed therein. It will be appreciated that in an
alternative
embodiment, the tongue could be provided on the trailing face of the cutting
tooth whereas
the groove could be defined in the second plate. In other embodiments,
different male and
female mating elements could be used to similar advantage. Alternatively, the
cutting tooth
and second plate could be configured without mating elements at all.
[00212] While cutting tooth 750 has been described in connection with the
embodiment
shown in FIGS. 45 to 55, it will be appreciated that with appropriate
modifications, this
type of cutting tooth could be also be successfully used in alternative brush
cutting heads.
[00213] Although the foregoing description and accompanying drawings relate to
specific
preferred embodiments of the present invention as presently contemplated by
the inventor,
it will be understood that various changes, modifications and adaptations, may
be made
without departing from the spirit of the invention.
