U.S. patent application number 09/865888 was filed with the patent office on 2002-11-28 for mounting arrangement for a cutting tooth for a trencher chain.
Invention is credited to Hoelting, Keith A., Kenkel, Brian, Reeves, James V., Robillard, Jerome.
Application Number | 20020174574 09/865888 |
Document ID | / |
Family ID | 25346461 |
Filed Date | 2002-11-28 |
United States Patent
Application |
20020174574 |
Kind Code |
A1 |
Robillard, Jerome ; et
al. |
November 28, 2002 |
Mounting arrangement for a cutting tooth for a trencher chain
Abstract
The present disclosure relates to a mounting arrangement for a
cutting tooth for a trencher chain. The tooth includes a base
portion aligned along a first plane. The base portion includes
structure for allowing the cutting tooth to be connected to the
trencher chain. The tooth also includes a distal portion that is
generally obliquely aligned with respect to the first plane. A
curved transition is located between the distal portion and the
base portion. The curved transition curves away from the first
plane and at least partially forms a cupped portion that is
effective in the trenching operation. The base portion also
includes a recess into which the mounting hardware can fit, to
protect the mounting hardware from wear.
Inventors: |
Robillard, Jerome; (Pella,
IA) ; Kenkel, Brian; (Montezuma, IA) ;
Hoelting, Keith A.; (Allerton, IA) ; Reeves, James
V.; (Leighton, IA) |
Correspondence
Address: |
HENDERSON & STURM LLP
1213 MIDLAND BUILDING
206 SIXTH AVENUE
DES MOINES
IA
50309-4076
US
|
Family ID: |
25346461 |
Appl. No.: |
09/865888 |
Filed: |
May 25, 2001 |
Current U.S.
Class: |
37/465 |
Current CPC
Class: |
E02F 3/143 20130101;
E02F 3/142 20130101; E02F 9/2866 20130101 |
Class at
Publication: |
37/465 |
International
Class: |
E02F 009/28 |
Claims
We claim:
1. A cutting tooth for a trencher chain, the cutting tooth
comprising: a base portion comprising a first mounting side defined
by a plane and a second side opposite the first side defining the
thickness of the base portion with a hole that passes between the
first and second sides; the base portion having a void that is
aligned with the hole and extends from the second side to between
the first and second sides such that the void defines a
fastener-engaging surface;
2. The cutting tooth of claim 1, wherein the fastener engaging
surface is parallel to the first mounting side and the void is a
counterbore.
3. The cutting tooth of claim 1 wherein the fastener engaging
surface is parallel to the first mounting surface and the void is a
closed slot.
4. The cutting tooth of claim 1 wherein the fastener engaging
surface is parallel to the first mounting surface and the void is
an open slot.
5. The cutting tooth of claim 1, wherein the fastener engaging
surface is conical with an axis perpendicular to the first mounting
side and the void is a countersink.
6. A trenching chain for a trencher, the chain comprising: a base
chain assembly comprising rollers, rivets, side plates and side
mounting plates; mounting bolts and nuts; and, cutting teeth
comprising a base portion configured for mounting to the base chain
assembly and a cutting portion for engagement with soils wherein
the base portion includes a hole to receive the mounting bolt and a
cooperating void wherein the head of the mounting bolt or the nut
fits into the void.
7. The trencher chain of claim 6 wherein the bolt is a standard hex
headed bolt and the nut is a standard hex nut
8. The trencher chain of claim 7 wherein the bolt and nut are Grade
8.
9. A cutting tooth for a trencher chain, said cutting tooth
comprising: a cutting portion; a base portion having an inside
surface adapted to abut a base chain assembly, said base portion
also having an outside surface; a hole disposed along an axis
extending from said inside surface to said outside surface for
receiving an elongated portion of a fastener; and a void disposed
in the outside surface of said base portion around said axis for
receiving an enlarged portion on one end of said fastener whereby
the enlarged portion of the fastener will be protected from wear.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to excavation
machines. Specifically, the present invention relates to a mounting
arrangement for cutting teeth for use with trencher chains.
BACKGROUND OF THE INVENTION
[0002] Trenchers are conventionally used to dig lengths of trenches
for laying underground pipe and cable. Most trenchers include a
tractor unit equipped with an elongated boom. The boom is typically
movable between a raised, generally horizontal position, and a
lowered, substantially vertical position. The boom typically
includes a cutting chain that is entrained about the boom. The
chain generally includes exterior teeth or cutters for engaging the
soil. Trenchers also commonly include a conveyer assembly for
transporting the soil this is excavated by the chain.
[0003] There are various types of cutting teeth or attachments that
are commonly bolted to a trencher digging chain. Exemplary cutters
are disclosed in U.S. Pat. No. 3,022,588 to Brown and U.S. Pat. No
6,154,987 to Rumer et al. Looking at the mounting arrangements
disclosed in these two references: the '588 reference discloses a
cup cutter having a leading edge and a cupped portion for scooping
loose material from a trench. The cup cutters are mounted on headed
projections that extend from the side plates of the chain wherein
the cutters have keyhole shaped openings that engage with the
projections for securing the cutters to the chain. This design does
not require the projections to be removed from the chain to repair
the cutters. However, this design does not hold the cutters
securely, the components are relatively delicate, and relatively
expensive to manufacture. The '987 reference discloses cutting
teeth that are designed for cutting very compacted soils, gravel or
rock and are mounted onto the digger chain by a more robust
standard nut and bolt combination.
[0004] Cutters, such as the cutters disclosed in the '588 and '987
patents, work effectively in a variety of digging conditions. The
cup cutters disclosed in the '588 patent work well in relatively
soft soils while the cutters disclosed in the '987 patent are
intended for conditions wherein very abrasive materials are being
trenched, including solid rock and loose rock conditions. In the
harder digging conditions the cutters are subjected to higher loads
and need to be mounted in a robust fashion. In those same
conditions the cutters wear quickly and as a result the digging
chain assembly needs frequent maintenance. The more robust mounting
arrangement, as disclosed in the '987 patent, subjects the mounting
bolts to potential wear. This wear on the mounting hardware
typically results in difficulties engaging a tool with the mounting
hardware and as a result the chain assembly becomes difficult, time
consuming and expensive to repair. Cutters used in the more
demanding applications are typically mounted as shown in the '987
patent and operators are confronted with the difficulty of properly
maintaining them due to the wear of the mounting hardware.
[0005] In these more demanding conditions the loads on the
components of the chain assemblies increase and the structural
integrity of those components becomes more critical. As a result
the specific shapes and the material selected for the components
becomes critical. During development and testing of this invention
many different combinations of both shapes and materials were
tested. A satisfactory combination has been identified, as set
forth in the description that follows.
SUMMARY OF THE INVENTION
[0006] One aspect of the present invention relates to a cutting
tooth for a trencher chain. A cutting tooth includes a base portion
aligned along a first plane. The base portion includes means for
allowing the cutting tooth to be connected to the trencher chain.
The cutting tooth further includes a pocket that cooperates with
the mounting means, the pocket being located opposite from the
first plane.
[0007] Another aspect of the present invention relates to a
trenching or digging chain assembly for use with a trencher. The
chain assembly includes a plurality of sidebars aligned along a
longitudinal centerline. The trencher chain also includes a
plurality of rollers substantially permanently interconnecting the
sidebars. The rollers are aligned along a lateral dimension that is
transverse with respect to the longitudinal centerline. The chain
further includes a plurality side mounting plates, these side
mounting plates being substantially permanently interconnected with
the rollers and sidebars. The chain further includes a plurality of
cutting teeth that are fixedly mounted to the side mounting plates
such that they can be removed for service. The cutting teeth
include a physical feature that provides the mounting hardware with
protection from wear that results from contact with the soils being
excavated, yet does not interfere with installation tools required
to secure the mounting hardware.
[0008] A variety of advantages of the invention will be set forth
in part in the description that follows, and in part will be
apparent from the description, or may be learned by practicing the
invention. It is to be understood that both the foregoing general
description and the following detailed description are exemplary
and explanatory only and are not restrictive of the invention as
claimed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate several aspects
of the invention and together with the description, serve to
explain the principles of the invention. A brief description of the
drawings is as follows:
[0010] FIG. 1 shows a side view of a trencher;
[0011] FIG. 2 shows a schematic diagram of the components of the
trencher of FIG. 1;
[0012] FIG. 3 shows a perspective view of a prior art trencher
chain assembly;
[0013] FIG. 4 shows a cross-section of the prior art chain assembly
taken along line 4-4 of FIG. 3 with a cutting tooth mounted in a
first position;
[0014] FIG. 5 shows a cross-section of the prior art chain assembly
taken along line 5-5 of FIG. 3 with a cutting tooth mounted in a
second position;
[0015] FIG. 6 shows a cross-section of the prior art chain assembly
taken along line 6-6 of FIG. 3 with a cutting tooth mounted in a
second position;
[0016] FIG. 7 shows a perspective view of trencher chain assembly
using the principles of the present invention;
[0017] FIG. 8 shows a cross-section of a chain assembly taken along
line 8-8 of FIG. 7 with a cutting tooth mounted in a first
position;
[0018] FIG. 9 shows a cross-section of a chain assembly taken along
line 9-9 of FIG. 7 with a cutting tooth mounted in a second
position;
[0019] FIG. 10 shows a cross-section of a chain assembly taken
along line 10-10 of FIG. 7 with a cutting tooth mounted in a third
position;
[0020] FIG. 11 shows a perspective view of a cutting tooth with the
principles of the invention;
[0021] FIG. 12 shows a perspective view of an alternative
embodiment of a trencher chain assembly with the principles of the
invention;
[0022] FIG. 13 shows a side elevational view of an alternate
embodiment of the cutting tooth; and
[0023] FIG. 14 shows a side elevational view of an alternate
embodiment of the cutting tooth
[0024] FIG. 15 shows a perspective view of an alternate embodiment
of the trencher chain assembly with cup cutters installed
[0025] FIG. 16 shows a perspective view of a detailed drawing of
the cup cutter with the principles of the invention;
[0026] FIG. 17. shows a perspective view of a detailed drawing of
an alternate cutter with the principles of the invention.
DETAILED DESCRIPTION
[0027] Reference will now be made in detail to the prior art and to
exemplary aspects of the present invention that are illustrated in
the accompanying drawings. Wherever possible, the same reference
numbers will be used throughout the drawings to refer to the same
or like parts.
Prior Art
[0028] FIGS. 1 and 2 show an exemplary trencher 15. The trencher 15
includes an engine 17 coupled to a right track drive 18 and a left
track drive 20, which together form a tractor portion 22 of the
trencher 15. A boom 24 is pivotally coupled to the tractor portion
22. A digger chain 26 is mounted on the boom 24. The chain 26 is
driven around the boom 24 by a chain drive mechanism 23 powered by
the engine 17. The boom 24 is pivotally movable between a
substantially horizontal transport configuration 25, and a
substantially vertical trenching configuration 27.
[0029] When maneuvering the trencher 15 around the work site, the
boom 24 is maintained in the transport configuration 25 such that
the chain 26 generally remains above the ground. To excavate a
trench, the boom 24 is lowered toward the trenching configuration
27 and the chain 26 is driven around the boom 24. When the chain 26
contacts the ground, cutting teeth of the chain 26 penetrate the
ground and begin to excavate a trench. Once the boom 24 reaches the
trenching configuration 27, the tracks 18 and 20 are engaged
causing the tractor 22 to creep forward. The chain 26 digs the
trench and removes loose geologic material from the trench as the
tractor 22 creeps forward.
[0030] The trencher 15 is being disclosed exclusively for the
purpose of illustrating an exemplary environment in which the
various aspects of the present invention can be applied. It will be
appreciated that the variety of trenchers are known in the art, and
that the various aspects of the present invention can be applied or
used in association with any type of trenching device.
[0031] FIGS. 3-6 Illustrate a digging chain assembly 70 constructed
in accordance with the prior art. The chain assembly 70 includes a
base chain sub assembly that includes a plurality of rollers 74,
side bars 72, side mounting plates 76, and rivets 78. The majority
of these components are semi-permanently interconnected: the rivets
78 are typically upset or swaged such that the outer diameter of
the portion extending through or beyond the side mounting plates 76
is bigger than the hole in the side mounting plates 76. In this
manner the rivets 78 are effectively connected to the side mounting
plates 76. Each chain assembly typically includes one connector
link that includes one side bar 76, 2 rivets that are
semi-permanently connected to the side bar including cross holes
for pass-through retainers or grooves for a snap ring or snap
connector. This connector link is removable from the assembly and
is used to form a continuous chain assembly that is wrapped around
the desired sprockets. It is installed into the holes through the
sidebars, and through the rollers on each end of the chain, and
then a side mounting plate 76 is installed on the rivets and pass
through retainers or a snap connector installed onto the rivets,
after the chain sub assembly is properly installed onto the
sprockets.
[0032] This base chain sub assembly is repairable, but is not
typically to be repaired in the field. Due to the mounting
arrangement of the rivets 78 they do not substantially extend
beyond the plane of the outside surface of the side mounting plates
76 and are typically not subjected to wear as the other components,
as will now be explained. For the purpose of this invention this
sub assembly, with the exception of the connector link, is
considered to be permanently assembled.
[0033] The chain assembly as seen in FIG. 3 also includes tube
spacers 82, mounting bolts 80, nuts 96, washers 94 and cutting
teeth 84, 86, 88, 90, and 92. FIG. 3 shows a section of the chain
assembly 70 with the components assembled and the teeth arranged in
one of many possible patterns. The pattern includes both externally
mounted cutting teeth 88 and 90 as shown in FIGS. 5 and 6 and
internally mounted cutting teeth 86 as seen in FIG. 4. Long tube
spacers 82L are used for the externally mounted cutting teeth and
short spacer tubes 82S are used with internally mounted cutting
teeth. The teeth, which can be designed with many different shapes
and characteristics, can be arranged in a wide variety of patterns
to provide unique cutting characteristics as required by the type
of soil being trenched, or the width of the desired trench. The
cutting teeth include a base portion with a first flat mounting
surface 98 and a second flat mounting surface 100 opposite the
first, and a hole through which the mounting bolts 80 can pass. The
head of the mounting bolt 80 cooperates with the second mounting
surface 100 of the cutting tooth. In these figures there is shown
an optional washer 94 mounted between the head of the mounting bolt
80 and the second mounting surface 100 of the base portion of the
cutting tooth. As shown in FIG. 4 the shape of the cutting tooth is
typically curved away from the first mounting surface 98. The type
of cutting tooth or pattern in which they are installed on the base
chain assembly, is not a part of this invention, the invention
being applicable in all the possible configurations as will be
understood by one skilled in this technology.
[0034] FIGS. 4, 5, and 6 illustrate the prior art assembly and the
interaction of various cross-sections of the chain assembly. Plane
1, on both the left and right sides is defined by the outer most
surface of the side mounting plates 76. Anything that is located
between Planes 1L and 1R will be substantially protected from
excessive wear by the side mounting plates 76.
[0035] Plane 2, on both the left and right sides, is defined by the
second mounting surface 100 of the base portion of the externally
mounted cutting teeth 88, or 90. In this manner the second mounting
surface 100 of the cutting teeth serves as a wear surface when the
cutting teeth are externally mounted. It is found, in actual use,
that anything that is located between Planes 2L and 2R will be
substantially protected from excessive wear by these surfaces of
the cutting teeth. For instance nut 96 in FIG. 5 or FIG. 6 will be
substantially protected and they typically do not experience
excessive wear.
[0036] Plane 3, on both the left and right sides, is defined by the
plane passing through the outer-most surface of the head of bolt
80. The head of bolt 80 is the only material in that plane. The
result is that the head of bolt 80 in that position experiences
excessive wear. When the bolt head wears significantly it becomes
impossible to get a wrench to properly engage with the bolt head,
and it becomes impossible to disassemble the chain assembly with
standard, non-destructive tools.
Best Modes
[0037] FIGS. 7-10 illustrate a digging chain assembly 70
constructed in accordance with the current invention. The chain
assembly 70 includes a base chain sub assembly that is considered
to be permanently assembled as described previously as related to
the prior art shown in FIGS. 1-6. The remaining components of the
chain assembly are also similar to those described in the prior art
FIGS. 1-6 with the following exceptions.
[0038] The cutting teeth have been modified to include a void 102
that is formed by removal of a portion of the second mounting
surface 100. This void 102 is designed such that it is defined by a
fastener engaging surface 104 of the base portion of the cutting
tooth that is between the second mounting surface 100 and the first
mounting surface 98. It is also defined by a surface of variable
shape, a side 106, also part of the base portion of the cutting
tooth. This shape is designed to minimize the amount of material
removed from the base portion of the cutting tooth, and the
resultant stress level seen in the tooth upon loading in actual
use.
[0039] As a result of the addition of this void 102, the head of
the mounting bolts 80 is substantially located between Plane 2L and
Plane 2R, as described in relation to prior art FIGS. 4-6. These
results in the heads of bolts 80 being protected from excessive
wear by the second mounting surface 100 of the base portion of the
cutting teeth.
[0040] FIG. 7 illustrates the complete assembly. Due to the loading
conditions on the cutting teeth, the selection of fasteners as well
as the shape of the void are important details. The FIG. 7 and FIG.
11 illustrate a preferred embodiment of the invention wherein the
fastener is a standard hex-headed bolt 80 and hex nut 96. The void
102 is a counterbore wherein the diameter of the counterbore is
sufficient to allow a standard socket that fits on the head of the
bolt 80 or the cooperating hex nut 96 to be inserted for full
engagement.
[0041] The choice of a standard hex-headed bolt 80 is made to
assure availability of a wide selection of bolt lengths and
materials. As can be seen by comparing FIG. 8 with FIG. 9 the bolt
80 needs to be of different lengths to accommodate externally
mounted or internally mounted cutting teeth. In addition it is
possible to mount a cutting tooth on both sides of the base chain.
This is not illustrated, but it is clear that this arrangement
would require a slightly longer bolt.
[0042] The selection of the counterbore 102 of tooth 188 as
illustrated in FIG. 11 is made to minimize manufacturing cost, to
maximize strength, and maximize flexibility. This type of
configuration, including a hole 101and a counterbore or void 102,
can typically be manufactured in one process with a specialized
drilling tool, minimizing cost. This design can also be used in
either single internal or external mounts as illustrated in FIGS.
8-10. It can also be used in a double external mount not
illustrated, wherein the head of the bolt 80 will be within the
void 102 on one side and the cooperating nut 96 will be within the
void 102 on the opposite side.
[0043] FIG. 12 illustrates an alternate embodiment of the assembly
wherein the bolt 80 has been changed from a standard hex headed
bolt to a countersunk head bolt 80 with the mating void 102 in the
cutting tooth base being correspondingly changed to a countersink.
This figure also illustrates dual mounts, an assembly designed with
cutting teeth specifically designed as dual mount teeth with
alternating counterbored voids for engagement with a nut 96 and
countersunk voids 102 for engagement with the countersunk head of
the bolt 80. The cutting teeth used for single external mount
applications will have exclusively countersunk voids 102 for
engagement with the countersunk head of the bolt 80.
[0044] FIGS. 13 and 14 Illustrate alternate embodiments wherein the
voids in teeth 288 and 388 are a closed slot 202 and an open slot
302. The slot 202 surrounds hole 201. Both of these embodiments can
be designed such that the width of the slot 202, 302 is equal to
the width across flats of the bolt head selected. This results in
the slot 202, 302 acting to hold the bolt from rotating, and
installation requires simple insertion of the bolt into the slot
202, 302 with subsequent tightening of the nut 96 against the side
mounting plate on the opposite side. This type of configuration is
typically more difficult and more costly to manufacture than the
embodiment of FIGS. 7-11.
[0045] FIG. 15 illustrates a digging chain assembly 70 constructed
in accordance with the present invention with cup cutters 170. FIG.
16 Illustrates a cup cutter constructed in accordance with the
present invention. FIG. 17 illustrates another type of cutter 180,
known as a rotary cutter, constructed in accordance with the
present invention.
[0046] The nut 96 and bolt 80 is the preferred type of fastener for
the present invention but other fasteners may be substituted for
these nut and bolt fasteners.
[0047] With regard to the foregoing description, it is to be
understood that changes may be made in detail, especially in
matters of the construction materials employed and the size, shape
and arrangement of the parts with departing from the scope of the
present invention. It is intended that the specification and the
depicted aspects be considered exemplary only, with a true scope
and spirit of the invention being indicated by the broad meaning of
the following claims.
* * * * *