Note: Descriptions are shown in the official language in which they were submitted.
USTPO Customer #: 52554
Atty Ref #: GYR-004
Cutting Tooth Splitter Apparatus and Method
Inventors: Daniel Gaudreault
BACKGROUND OF THE INVENTION
Extensive felling and mulching operations are often performed with a heavy-
duty brush
cutter mounted to the front of a self-propelled vehicle. A typical brush
cutter includes a brush
cutting head with a cylindrical support body, or drum, and a plurality of
mounting blocks welded
or fastened to the outer surface of the support body. Cutting teeth are
mounted on the front
leading face of each mounting block, typically through the use of a nut and
bolt combination.
High velocity rotation of the drum causes the cutting elements to shred wood,
debris and the like.
Mounting blocks for the cutting teeth on cutting heads are also often fixedly
mounted on
the surface of the cylindrical support head in an exposed position. An example
is shown in U.S.
Pat. No. 5,873,534. These mounting blocks, and/or the teeth fixedly mounted on
them, often hit
rocks or large trees and are damaged or even broken off. Replacement of these
mounting blocks
.. is difficult and expensive. Over relatively short periods of use, one or
more of the teeth typically
break off, while others soon become too worn for effective cutting and
mulching. Breakage of a
single tooth during operation of the cutting head can cause substantial damage
to the cutting head
and presents a considerable safety hazard to nearby workers.
Protective means may be provided in front of each mounting block to prevent
the blocks
from directly striking rocks or large trees during operation of the cutting
head. Thus the blocks
are not subjected to sudden large forces which could result in serious damage.
Examples include
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protective collars encircling the cylindrical support base. These collars
typically stop just short
of the mounting block in order to provide a clearance space, while the
opposing end of the collar
may be welded to the back face of the associated mounting block.
One such brush cutting head is described in U.S. Pat. No. 6,764,035. This
patent
discloses a brush cutting head that has a cylindrical support base and a
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, 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.
While the protective collars described in U.S. Pat. No. 6,764,035 afford the
cutting tooth
assemblies some protection, the cutting teeth remain nonetheless exposed to
violent impact with
hard objects, like stones, and thus are still vulnerable to damage during
brush cutting operations.
Another example of one such brush cutting head is described in United States
Patent
Publication No. 2010/0044487. This published patent application discloses a
brush cutter that has
a cylindrical support base and a plurality of 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
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flush with the outer surface of the base. Each mounting block has a front face
which is recessed
from the front end of the mounting block so as to define a horizontal shelf
near the bottom
surface of the mounting block. Each mounting block carries a cutting tooth on
its front or leading
face. The cutting tooth is fastened to the mounting block by a nut and bolt
combination, the bolt
being inserted through a smooth bore defined in the mounting block.
However, the design of the cutting tooth for this brush cutting head tends to
suffer from
certain disadvantages. Manufacture of the guide members projecting from the
base portions of
the cutting tooth must be precise and can be time consuming. Moreover, certain
problems have
been encountered when replacing old, broken or worn cutting teeth on the brush
cutting head. In
some cases, it has been found that the guide members projecting from the base
portions of
replacement cutting teeth do not always line up with the fittings on the
mounting block into
which they are to be received. As a result of this misalignment, some cutting
teeth could not be
properly secured to the mounting blocks, thereby causing delay, excessive
warranty claims and
requiring operators to carry on hand a greater number of replacement cutting
teeth than would
ordinarily be required.
United States Patent Application Publication No. 2007/0261763 describes a
brush cutting
head provided with differently configured collars and cutting tooth
assemblies. This brush
cutting head has a cylindrical support body with a curved outer surface and a
plurality of
penannular collars. The collars are mounted to the support body at spaced
apart locations and
extend radially from its curved outer surface. Each collar cooperates with an
adjacent collar to
define a mounting station between adjacent collars. A plurality of cutting
tooth assemblies are
carried on the outer surface of the support body. Each cutting tooth assembly
has a cutting tooth
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for placement within a mounting station, and a mounting assembly engageable
with the adjacent
collars to secure the cutting tooth in the mounting station.
By having the cutting tooth and its associated mounting assembly disposed
between
adjacent collars, two-fold protection is afforded to the cutting teeth. The
collars shield the cutting
teeth from rocks and other hard objects and reduce the stresses to which the
cutting teeth are
subjected during operations by improving the distribution of forces through
the mounting
assembly.
While the brush cutting head described in United States Patent Application
Publication
No. 2007/0261763 has proven itself successful on the field and constitutes an
improvement over
what was previously available on the market, efforts continue to be made to
lengthen the service
life of the cutting teeth and their mounting assemblies by reducing the
incidence of destructive
impact with rocks.
Additional cutting heads are described in U.S. Patent No. 7,810,531, and U.S.
Patent
Publication No. 2013/0099039; all of the aforementioned patents and
publications being
incorporated herein by reference. The cutting teeth on brush cutters are often
designed and
mounted on the mounting blocks on the cutting head to cut in a tangential
direction when the
cylindrical support head is rotated. As a result, the mounting blocks are
subject to high shear
forces. The blocks must be quite large to resist these forces and this adds
weight to the cutting
head increasing power requirements. The teeth employed are also usually quite
complicated in
construction and are quite costly to replace when broken or damaged.
Furthermore, as the cutting head rotates to cut through wood and the like,
wood chips and
debris tend to build up underneath the cutting teeth and in-between the
mounting block and
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protective collars, causing detrimental effects to both the cutting assembly
and cutting
performance. This build-up of wood debris decreases cutting efficiency of the
cutting head, thus
requiring more energy to perform the cutting process. Additionally, the
effectiveness of each cut
is decreased due to wood build-up underneath the cutting portion of the teeth.
As wood is
impacted and pushed against the cutting assembly, components of the assembly
become blunted
and worn-down over time.
In light of the foregoing, it would be advantageous to provide a cutting head,
specifically
cutting teeth, which exhibit improved wear resistance characteristics. In
particular, teeth which
do not require frequent sharpening, repair or replacement would be most
desirable. It would be
1.0 further advantageous to provide a self-cleaning cutting assembly that
cuts and cleans the teeth
concurrently or sequentially, thus preventing the build-up of debris along the
cutting head.
=
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BRIEF SUMMARY OF THE INVENTION
The present invention generally relates to a cutting tooth, more specifically
a splitter
apparatus that may be mounted on a cutting tooth, for use on a cutting head,
as well as a method
for utilizing such an apparatus.
In one aspect of the present invention, a cutting tooth is provided that
performs a two-step
cut, whereby a first bite of wood is taken, and that first bite is cut again a
second time as the teeth
are cleaned of any debris.
In another aspect of the present invention, a splitter apparatus is provided
that can be
mounted on a cutting assembly for use on a brush cutter. This splitter
apparatus is designed to be
mounted on any new or pre-existing cutting teeth.
In one embodiment, the splitter may be generally oblong shaped preferably with
a curved
or rounded bottom, two flat faces opposing one another, and a wedge-shaped top
with two sides
coming together to form a splitting edge. The splitter is preferably mounted
below the cutting
portion of the tooth such that as the tooth cuts the wood, the cut wood is
directed onto the splitter
for further cutting. The tooth is mounted to cut tangentially with respect to
the rotation of the
cutter, while the splitter cuts radially and outwardly with respect to the
rotation of the cutter. In
this manner, a cutting mechanism is provided that is capable of cutting
tangentially and radially
simultaneously. The flow of cut wood is directed out of from the cutting
assembly, thus
facilitating the removal of the cutting debris away from the tooth holder and
the cutting tooth,
and thereby cleaning the tooth of any debris and preventing wood and other
debris from getting
lodged within the cutting assembly.
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DESCRIPTION OF THE DRAWINGS
These and other features, aspects, and advantages of the present invention
will become
better understood with regard to the following description, appended claims,
and accompanying
drawings where:
Figure 1 is a perspective view of an embodiment of a cutting tooth splitter;
Figure 2 is a side view of an embodiment of a cutting tooth splitter;
Figure 3 is a front view of an embodiment of a cutting tooth splitter;
Figure 4 is an exploded view illustrating how an embodiment of a cutting tooth
splitter
may be attached to one embodiment of a cutting assembly;
Figure 5 is a perspective view of one embodiment of a cutting assembly
including a
splitter mounted to the tooth holder;
Figure 6 is a cross-sectional side view of a cutting tooth mounted in a tooth
holder,
without the addition of a splitter;
Figure 7 is a front view of a cutting tooth mounted in a tooth holder, without
the addition
of a splitter;
Figure 8 is a cross-sectional side view of an embodiment of a splitter mounted
to a tooth
holder and mounting block;
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Figure 9 is a front view of an embodiment of a splitter mounted to a cutting
tooth and
tooth holder;
Figure 10 is a side view of an embodiment of a splitter mounted to a cutting
tooth;
Figure 1 la is a cross-sectional side view of one embodiment of a cutting
tooth assembly
including the addition of a splitter;
Figure 1 lb is a cross-sectional side view of an alternative embodiment of a
cutting tooth
assembly including the addition of a splitter; and
Figure 12 is a perspective view of one embodiment of a brush cutting head
whereby the
cutting teeth include a splitter mounted thereon.
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DETAILED DESCRIPTION OF THE INVENTION
In one embodiment, the splitter 20 may be generally oblong Shaped preferably
with a
curved or rounded bottom 24, two flat faces 23 opposing one another, and a
wedge-shaped top
with two sides 26 coming together to form a splitting edge 27. Figures 1-3
illustrate a preferred
embodiment of a splitter 20 of the present invention. More specifically,
referring to Figures 1
and 3, the splitter 20 has a leading face 21 and an opposed trailing face 22;
two lateral faces 23,
spaced apart; a generally curved bottom 24; and, two splitting faces 26 (a
first and a second)
extending at an angle from a second end of each lateral face 23, coming
together to form a
cutting edge 27, also referred to herein as a splitting edge. Referring in
more detail to Figure 3,
.. the curved bottom 24 generally forms a semi-circle with the lateral faces
23 or sides extending
upward such that the lower or mounting portion of the splitter 20 is generally
U-shaped. The
upper or cutting portion of the splitter 20 comprises a first and second
splitting face 26 extending
at an angle and coming together to generally form a wedge shape, thereby
forming a cutting edge
27. A threaded bore 28 extends through the splitter from the leading face 21
to the trailing face
.. 22, generally centered therethrough. This threaded bore 28 is for receiving
a fastener 19 so that
the splitter 20 may be removabley mounted to a mounting block 30 and/or a
cutting tooth 40. It
is to be noted that the size of the splitter 20 may be scaled larger or
smaller to accommodate
different sizes of cutting assemblies and various types of brush cutters.
Figures 4, 5, 10a, and 10b illustrate examples of a cutting tooth assembly 18
and how a
splitter 20 may be mounted thereto. It is to be noted that these figures and
accompanying
descriptions are meant to provide context in which the splitter 20 may be used
and assembled on
a cutting head, and are not limiting the present invention to these particular
embodiments or
assemblies. In a general overview of the assembly, the splitter 20 is fitted
into an indention or
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chamber 31 on the front leading face of the tooth holder 30 and fastened in
place with a fastener
19. The tooth 40 is then inserted into a mounting recess 32 within the tooth
holder 30 and
centered over the head of the fastener 19, holding the tooth 40 in place. A
wedge block 50 is
then inserted behind the tooth 40, adjacent the rear end of the tooth holder
30 and secured in
place with a bolt 19 and nut 57. The mounting position of the tooth 40 and
splitter 20 relative to
one another provides a cutting assembly 18 in which a tooth cutting edge 423
cuts tangentially
with respect to the rotation of the cutting head 60, while the splitting edge
27 of the splitter 20
cuts or splits radially with respect to the rotation of the cutting head 60.
The cutting tooth assembly 18 and exemplary components are now explained in
further
detail. Figure 4 shows an exploded view of an exemplary embodiment of an
assembly 18
including a tooth holder 30, a cutting tooth 40, a wedge block 50, a splitter
20, and requisite
fasteners 19, 57. In one embodiment, the tooth holder 30 includes a chamber 31
on a front face
and a central recess 32 or cavity for receiving and mounting the cutting tooth
40. The chamber
31 has a first bore 33 extending therethough to the mounting recess 32 and a
curved or concave
bottom generally corresponding to the rounded bottom 24 of the splitter 20.
The recess 32 has a
forward mounting surface 34 for mounting the tooth 40, a bottom supporting
surface 35 defining
a second threaded bore 36, and a rear surface 37 abutting the wedge block 50
once assembled. In
a typical prior art assembly, the cutting tooth 40 is inserted and fastened
into the recess 32 of the
tooth holder 30 with a bolt 19 secured by a nut. The present invention is
designed such that the
splitter 20 may be used in place of the nut, allowing the splitter 20 to be
retro-fitted to pre-
existing cutting teeth or incorporated in the design of new assemblies. In
Figure 4, the splitter 20
may be inserted into the chamber 31 on the front of the tooth holder 30, such
that the leading
face 21 of the splitter 20 is facing outward and the trailing face 22 is
abutting the wall of the
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chamber 31 with the threaded bore 28 of the splitter 20 aligned with the first
bore 33 of the
chamber 31. The splitter 20 may then be fastened or secured within the chamber
31 through the
use of the same fastener 19 that is used to fasten the tooth 40.
The cutting tooth 40 has a base portion 41 having a first end 410 and a second
end 412,
and a cutting portion 42 mounted to the second end of the base portion. The
base portion 41 is
generally planar, having a leading face 413, an opposing trailing face 414 and
two, spaced apart,
lateral faces 415. Defined in the base portion 41 is a bore 416 that extends
between the leading
face 413 and the trailing face 414. The bore 416 is adapted to receive a
fastener 19 therethrough
to permit fastening of the cutting tooth 40 to the mounting assembly 18.
Adjacent the second end
412, the trailing face 414 of the base portion 41 flares outwardly to
partially define a wedge-
shaped abutment shoulder 417. The abutment shoulder 417 serves to reinforce
the cutting tooth
40 and enables it to better resist the high impact forces to which it may be
subjected during
operation of the brush cutting head 60. As a result, the cutting tooth 40
tends to be less
vulnerable to cracking failures along the area where the cutting portion 42
meets the base portion
.. 41.
The tooth 40 is inserted into the tooth holder 30 with the leading face 413 of
the tooth 40
facing the mounting surface 34 of the mounting recess 32, such that the bore
416 of the tooth
base portion 41 is aligned with and slid forward over the head of the bolt 19.
The leading face
413 of the tooth 40 abuts the mounting surface 34 of the recess 32, and the
head of the bolt 19 is
contained within the bore 416 of the tooth 40, preferably flush with the back
trailing surface 414
of the tooth 40 (as shown in Figures ha and 11b).
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The wedge block 50, also having a first end 51, a second end 52, a leading
face 53, a
trailing face 54, and two lateral faces 55, is inserted in the mounting recess
32 behind the tooth
40, such that the leading face 53 of the wedge block 50 abuts the trailing
face 54 of the tooth 40,
and the trailing face 54 of the wedge block 50 abuts the rear surface 37 of
the mounting recess
32, as shown in Figure 5. The body of the wedge block 50 defines a threaded
bore 56 for
fastening the wedge block 50 into the tooth holder 30, this threaded bore 56
being aligned with
the second bore 36 of the mounting recess 32. As shown in Figures 11 a and
11b, the wedge
block 50 may be secured by a fastener 19 inserted through the second end 52 of
the wedge block
50 and secured with a nut 57 located underneath the tooth holder 30 in the
generally concave
bottom surface of the tooth holder 30 which engages the outer peripheral
surface of the drum 60.
Referring specifically now to the cutting aspect of the tooth assembly 18, in
a preferred
embodiment, the splitter 20 is mounted below the cutting portion 42 of the
tooth 40 such that an
acute angle 0 is formed between the leading face 420 of the cutting portion 42
of the tooth 40
and the cutting edge 27 of the splitter 20, as shown in Figure 10. The leading
face 420 of the
cutting portion 42 of the tooth 40 is preferably angled such that as the tooth
40 cuts the wood, the
cut wood is directed toward and onto the splitter 20. As the brush cutter
rotates forward, the
tooth 40 cuts tangentially with respect to the rotation of the cutter, while
the splitter 20 cuts
radially and outwardly with respect to the rotation of the cutter. in this
manner, the cutting
mechanism of the brush cutter is designed to cut tangentially and radially
simultaneously.
Simply put, as the drum 60 rotates and the tooth 40 cuts tangentially in a
forward and downward
motion, the cutting edge 27 of the splitter 20 cuts in a radial and outward
motion. As the tooth
40 takes the first cut, the leading face 420 of the tooth 40 drives that
initial bite of wood down
onto the splitting edge 27 of the splitter 20 for further cutting. The
splitter 20 further cuts the
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wood and directs the flow of wood away from the cutting assembly 18, thus
facilitating the
removal of the cutting debris away from the tooth holder 30 and the cutting
tooth 40, thereby
cleaning the tooth 40 of any debris and preventing wood and other debris from
getting lodged
within the cutting assembly 18.
The position of the cutting edge 27 of the splitter 20 in relation to the
cutting edge 423 of
the tooth 40 is now described in greater detail with reference to Figures 8-
10. In one
embodiment, the cutting portion 42 of the tooth 40 is carried on the second
end 412 of the base
portion 41 in a generally, forwardly leaning or canted fashion, and is
integrally formed with the
base portion 41. The cutting portion 42 has a leading face 420, an opposed
trailing face 421 and
two spaced-apart lateral faces 415. The leading face 420 of the cutting
portion 42 joins the
leading face 413 of the base portion 41, while the trailing face 421 of the
cutting portion 42 joins
the trailing face 414 of the base portion 41. The leading 420 and trailing
faces 421 of the cutting
portion 42 cooperate with each other to define a tapering, wedge-like, profile
that terminates in a
cutting edge 423. The cutting edge 423 extends generally linearly between the
lateral faces 415
of the tooth 40 and is carried forwardly of the leading face 413 of the base
portion 41 such that it
tends to be the first element of cutting tooth 40 to make contact with the
brush. However, in
alternative embodiments, the cutting edge 423 could be configured differently.
For instance, the
cutting edge 423 could be configured to extend generally diagonally between
the lateral faces
415 and askew of the rotational axis. This configuration would tend to favor
one end of the
cutting edge 423 over the other contacting the brush. In a further
alternative, the cutting edge 423
could be scalloped or formed to extend in a generally, zigzagging fashion.
In one embodiment, illustrated by Figure 12, the cutting assembly 18 is
mounted on the
drum 60 such that a first cutting edge is provided on a distal portion
thereof, and a second cutting
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edge is provided between the drum and the first cutting edge. More
specifically, a first cutting
edge provided by the tooth 40 lies in a first plane, with the first cutting
edge rotating and cutting
tangentially with rotation of the support body 60. In this same embodiment, a
second cutting
edge provided by the splitter 20 lies in a second plane, positioned between
the drum 60 and the
cutting edge 423 of the tooth 40. The cutting edge 27 of the splitter 20
extends generally
linearly between the leading 21 and trailing faces 22 of the splitter 20, with
the second cutting
edge cutting radially and outwardly with rotation of the drum 60. This
addition of a second
cutting edge, arranged in this preferred manner, provides a controlled two-
step cutting process,
whereby the first cutting edge makes an initial cut of wood, while the second
cutting edge makes
.. a second cut radially to the first, thereby cutting and cleaning the tooth
40 simultaneously while
directing the debris out of and away from the cutting assembly 18.
Although the present invention has been described in considerable detail with
reference
to certain preferred versions thereof, other versions are possible. Therefore,
the spirit and scope
of the appended claims should not be limited to the description of the
preferred versions
.. contained herein. All features disclosed in this specification may be
replaced by alternative
features serving the same, equivalent or similar purpose, unless expressly
stated otherwise. Thus,
unless expressly stated otherwise, each feature disclosed is one example only
of a generic series
of equivalent or similar features.
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