Note: Descriptions are shown in the official language in which they were submitted.
CA 02583035 2007-03-29
GRADER BLADE EXTENSION
Field of the Invention
This invention relates to digging ditches in general and in particular to a
grader
blade and grader blade extension for use in digging curved-bottom ditches.
Background of the Invention
When a road is cut in the side of a hill or mountain, drainage ditches are
usually
required to carry away water flowing down the hill or mountain towards the
road. Such ditches
usually have a V-shaped cross-sectional configuration which tends to
concentrate water into a
small area of the ditch increasing the likelihood of erosion. With a view to
reducing or preventing
erosion, it is preferable that the bottom of drainage ditches be round so that
the flow of water is
spread over a greater area, without under-cutting the embankment.
Round bottom ditches have conventionally been cut using excavators, backhoes
or
"other mechanical digging machines having extensible or articulated booms to
the distal ends of
which are mounted buckets of known type. The machine is parked on the shoulder
of a road, the
boom and bucket is extended toward the proposed ditch area, the bucket is
dropped or forced
downwardly into the soil and curled inwardly and the boom is simultaneously
retracted. The
process is repealed two or three times. During the first pass or passes, the
soil is disrupted. The
. number of such passes required to loosen the soil is dictated by a number of
factors including the
nature or rockiness of the soil, its compaction, the angle of attack of the
edge of the bucket
engaging the soil, the available power of the machine which may be applied
downwardly on the
bucket, and so on. The last pass or passes serve to scoop and clear the
loosened soil. Completion
of the passes may be considered as a cycle. In the case of conventional square
sided buckets, with
each cycle a ditch segment the width of the bucket is completed. Conventional
square sided
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buckets are approximately five feet wide, and accordingly each cycle produces
approximately five
feet of ditch. At the usual speeds, a round bottomed ditch can be produced at
a rate of
approximately 50 lineal meters per hour.
The conventional ditch digging method described above with respect to using
excavators or backhoes suffers from the disadvantage that the quality of the
ditch relies heavily on
the skill of the operator of the excavator or backhoe. In addition, after each
cycle the machine
must be moved along the road so as to present the bucket parallel to the road
for the next adjacent
five foot segment. This results in a relatively low quantity of linear ditch
that may be produced
during a given time period and presents a danger to passing traffic on the
roadway.
Motor graders are known and have been used for creating flat surfaces. Motor
graders typically include three axles with a blade disposed between the two
rear driving axles and
the front axle. The blade may be rotatable about the three orthogonal axes of
the motor grader so
as to enable a plurality of graded surface finishes. As the motor grader
proceeds along the surface
to be graded, a layer of the surface or a portion thereof is removed by a
scraping or cutting motion
of the blade. It is known that rotation of the blade about the three axes of
the motor grader may
enable the blade to be oriented such that the more material is removed from
one side of the blade.
The removed material may also be removed to a desired side of the blade or
such that the blade is
oriented at a greater angle of attack relative to the surface.
Motor graders have not typically been used for the creation of drainage
ditches
although grader blades may be so inclined to dig a ditch with one edge. Grader
blades typically
have parallel ends with square corners. Accordingly any ditch dug with a
corner edge of a grader
blade will have a V-shaped bottom. Thus, ditches formed by a conventional
grader blade will still
suffer the same increased likelihood of erosion.
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Accordingly, what is desired is a method and apparatus for cutting a round-
bottomed drainage ditch without requiring repetitive repositioning of the
ditch digging machine,
by using the linear motion of the ditch forming machine.
Summary of the Invention
According to a first embodiment of the present invention there is disclosed an
extension for a grader blade. The grader blade extends between first and
second ends and has a
bottom edge. The extension comprises an extension body securable to one of
first or second ends
of the grader blade and has a proximate attachment edge conforming to the one
of first or second
ends of the grader blade and a distal outer edge. The extension further
includes a curved bottom
edge extending from the attachment edge to the outer edge wherein the bottom
edge is adapted and
shaped to form a curved-bottom ditch into an adj acent soil surface when the
grader blade is angled
from a horizontal orientation such that the extension is at a lowermost end of
the grader blade.
The extension may include an extension moldboard and an extension cutting edge
wherein the bottom edge is disposed at lowermost edge of the extension cutting
edge. The
extension moldboard may include a cross- section profile matching the profile
of a moldboard of
the grader blade. The extension moldboard may have a concave blade surface.
The concavity of
the extension moldboard may increase in a direction from said attachment
surface to said distal
end. The concavity of said extension moldboard may decrease in a direction
from said attachment
surface to said distal end.
The bottom edge may have an arcuate shape. The arcuate shape may include a
constant radiused arc. The arcuate shape may include an ovaloid arc. The
arcuate shape may
include an ellipsoid arc. The arcuate shape may include an parabolic arc. The
bottom edge may
further comprise a first portion collinear with the bottom edge of the grader
blade.
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The extension may further include attachment means for attaching the extension
body to one of the first or second side edges of the grader blade. The
extension may be welded to
one of the first or second side edges of the grader blade. The extension may
be bolted to one of
the first or second side edges of the grader blade.
According to a further embodiment of the present invention there is disclosed
a
grader blade. The grader blade comprises a body extending between first and
second ends and has
a bottom edge. At least one of the first or second ends has a curved portion
extending from the
bottom edge to the at least one of the first or second end, wherein the curved
portion is adapted to
cut a curved-bottom ditch into an adjacent soil surface when the grader blade
is angled from a
horizontal orientation such that the ditch digging edge is at a lowermost end
of the grader blade.
According to a further aspect of the present invention there is disclosed a
method
for digging a ditch. The method comprises providing a grader blade having a
first and second
spaced apart side edges and a bottom edge, and attaching an extension to one
of the first or second
side edges of the grader blade. The extension has a proximate attachment
surface confomiing to
the one of first or second end of the grader blade and a distal outer end and
a curved bottom edge
extending from the attachment end to the outer end. The method further
comprises orienting the
grader blade angularly from the horizontal orientation such that the bottom
edge of the extension is
at a lowermost end thereof so as to form a curved bottom ditch.
According to a further embodiment of the present invention there is disclosed
a
method-for digging a ditch. The method comprises providing a grader blade
having a first and
second spaced apart side ends and a bottom edge. At least one of the first or
second ends has a
curved portion extending from the bottom edge to the at least one of the first
or second end. The
method further comprises orienting the grader blade angularly from a
horizontal orientation such
that the curved portion is at a lowermost end thereof so as to form a curved
bottom ditch.
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Other aspects and features of the present invention will become apparent to
those
ordinarily skilled in the art upon review of the following description of
specific embodiments of
the invention in conjunction with the accompanying figures.
Brief Description of the Drawings
In drawings which illustrate embodiments of the invention,
Figure 1 is an isometric perspective view of a motor grader having a grader
blade
extension according to a first embodiment of the present invention.
Figure 2 is a perspective view of the grader blade and grader blade attachment
of
Figure 1.
Figure 3 is a cross-sectional view of the grader blade attachment taken along
the line
3-3 of Figure 2.
Figure. 4 is an exploded isometric view of the grader blade and grader blade
attachment of Figure 2.
Figure 5 is an isometric perspective view of the motor grader having a grader
blade
extension of Figure 1 forming a curved bottom ditch.
Detailed Description of Embodiments of the Invention
Referring to Figure 1, a grader blade having a grader blade attachment 40
according
to a first embodiment of the invention is shown generally at 10 as mounted on
a motor grader 8.
The motor grader has first, second and third axes 12, 14 and 16, respectively
corresponding to the
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longitudinal, transverse and yaw axes, respectively of the motor grader 8. The
grader blade 10 is
connected to the motor grader 8 such that the grader blade orientation may be
selectively and
fixedly positioned with respect to the first, second and third axes 12, 14,
and 16 of the motor
grader 8.
Turning now to Figure 2, a grader blade 10 having a grader blade attachment 40
is
illustrated. The grader blade 10 comprises an elongate member having first and
second blade
edges 28 and 34, respectively and a longitudinal blade axis 18 and a curved
blade surface 20
disposed towards the front of the grader. As illustrated in Figure 2, the
grader blade may include a
moldboard 22 and a cutting edge 24 having a bottom edge 26 adapted for
engaging a ground
surface although other types of grader blades as are conventionally known may
also be used.
The grader blade attachment 40 mounts onto a first blade edge 28 of grade
blade
10. In the illustrations, first blade edge 28 is the left hand end as viewed
by the operator of the
motor grader 8 of Figure 1, although it is understood that an attachment 40
may be made as either
a left or right hand version for mounting to corresponding left or right hand
ends of blade 10. The
illustrated version of atta.chment 40 is thus a left hand version, adapted for
mounting to the left
hand end of blade 10.
In particular, as viewed in Figures 1 to 3, attachment 40 comprises an
upwardly
curved blade extending between a substantially vertical attachment edge 42 and
an outer edge 44
and having an upwardly curved upper edge 46 and an upwardly curved lower or
ditch digging edge
48. As shown in Figures 1 to 3, the outer edge 44 is orthogonal to the
attachment edge 42
although it will be appreciated that other orientations of the outer edge 44
relative to the
attachment edge 42 will also be useful. The upwardly curved upper edge 46
adjoins the
attachment edge 42 at an upper end 50 thereof. The upwardly curved lower edge
48 adjoins the
attachment edge 42 at a lower end 52 thereof. The lower edge 48 includes a
first portion 54 that is
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CA 02583035 2007-03-29
collinear with the bottom edge 26 of the grader blade 10 so as to form a
continuation thereof when
the attachment is attached to the grader blade.
It will be appreciated that conventional grader blades 10 do not necessarily
have
vertical end edges 28 and 34 as illustrated in Figures 1 to 3, that is, end
edges 28 and 34 are not
necessarily square or orthogonal to the upper edge of the blade. In which case
it is understood that
edge 28 may be other than vertical so that, in one embodiment, attachment edge
42 may be
mounted so as to be conformal with edge 28. Similarly, for a right hand
attachment (not shown)
attachment edge 42 may be adapted to conform to edge 34 of blade 10. For ease
of discussion
herein however, it is assumed that edges 28 and 34 of blade 10 and the
corresponding attachment
edge 42 of attachments 40 are substantially vertical, it being the intention
that such references
herein include off-vertical edges and specifically any angle of inclination of
the end edges of
conventional grade blades. As illustrated in Figure 2, the outer edge 44 of
the grader blade
attachment 40 extends above the top edge 23 of the grader blade 10 by a grader
indicated generally
at 25. It will be appreciated that the extension height 25 will be selected
based upon the intended
use of the grader blade attachment as well as the depth of a rounded bottom
ditch which the grader
blade attachment is intended to form. For applications in which a deeper
rounded bottom ditch is
to be formed, an increased grader extension height 25 will be required. In
addition, for
applications in which the soil to be removed during the formation of the
rounded bottom ditch is to
be deposited to an outside surface of the rounded bottom ditch grader
extension an increased
height 25 will also be required.
Referring now to Figure 3, an exploded view of the grader blade 10 and
attachment
40 is shown. As illustrated in Figure 3, the grader blade attachment 40 may
include an attachment
moldboard 60 and an attachment cutting edge 70. The attachment cutting edge 70
may attach to a
bottom portion 62 of the attachment moldboard 60 and may include the lower
edge 48 of the
attachment 40. The attachment cutting edge 70 may be attached to the
attachment moldboard 60
by conventional means as are known in the field of grader blade construction.
It will also be
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CA 02583035 2007-03-29
appreciated that a single piece grader blade attachment 40, without separate a
moldboard and
cutting edge may also be utilized.
Referring now to Figure 4, a cross sectional view of the attachment is shown
as
taken along the line 4-4 of Figure 2. As illustrated, the attachment 40 has a
attachment blade
surface 58 disposed towards the front of the motor grader. The attachment
blade surface 58 may
have a concave profile as illustrated in Figure 4. It will be appreciated that
other profile will also
be useful, such as a flat or a convex profile, for example. The profile of the
attachment may be
formed by rotating the cross section profile illustrated in Figure 3 about a
point 59 as illustrated in
Figure 2. As illustrated in the accompanying figures, the profile remains
constant as it is rotated
about point 59 from the attachment edge 42 to the outer edge 44. It will be
appreciated, however
that the profile may also be tapered or expanded as it is rotated from the
attachment edge 42 to the
outer edge 44. The concavity or curvature of the attachment blade surface 58
may also be varied
as the profile is rotated about point 59.
As illustrated in Figures 1 to 4, the lower edge 48 of the attachment has a
rounded
curvature about point 59 as described above. However, other shapes for the
lower edge may also
be useful. The lower edge 48 may also have a parabolic shape as well as an
elliptical or any other
arcuate shape, for example. In addition, for specialized application, the
lower edge 48 may also
have other complex shaped curves or corners so as to form the required ditch
shape.
Further, reference herein to upper edge 46 as being upwardly curved or
reference
herein to outer edge 44 as being substantially linear are not intended to be
limiting, it being the
intention that such references include inclined, substantially upper edges 46
and curved outer
edges 44 respectively. The purpose of the present invention is to allow the
use of a grade blade, to
which an attachment 40 is mounted, to carve, scoop or otherwise form a curved-
bottom ditch 82.
Consequently, it is only lower edge 48 which must be curved to accomplish the
formation of a
curved-bottom ditch 82.
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It will be appreciated by those of skill in the art that the separate grader
blade and
grader blade attachment described herein may be constructed as a single
component. This may be
useful in applications where greater strength in the connection therebetween
is required or when
the combined grader blade is largely to be used for the single purpose of
digging ditches.
The attachment may be attached to the grader blade by any conventional means
as
are well known in the art. In particular, the attachment may include an
attachment plate (not
shown) extending therefrom substantially parallel to and to the rear of the
grader blade. The
attachment plate may include bolt holes through which studs secured to 'and
extending
perpendicular from a rear surface of the grader blade may be passed and
secured thereon with nuts.
Attachment with nuts or other suitable fasteners enables the attachment to be
quickly replaced if
damaged or if a different attachment having a different lower edge profile is
required. In addition,
the attachment may be stitch, butt or otherwise welded to the grader blade,
for example.
Operation
Referring to Figure 5, in operation, the grader blade 10 may be selectively
inclined
downwardly such that blade axis 18 is oriented at angle 90 relative to
horizontal plane defmed by
motor grader axes 12 and 14 whereby attachment 40 is at a lowermost portion
thereof. The motor
grader may be moved forward in the direction indicated by arrow 76 so as to
engage lower edge 48
of the attachment 40 with a road-side shoulder 80 of the ground 78. Forward
motion of the motor
grader 8 will carve, scoop or otherwise form a curved-bottom ditch 82.
The grader blade 10 may be rotated by the operator about the third axis 16 of
the
motor grader such that the material removed from the ditch 82 by the
attachment 40 moved toward
the centerline of the motor grader and deposited on the roadway. The grader
blade 10 may also be
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oriented such that the material is moved towards the outer edge 44 of the
attachment and deposited
to the far side of the ditch generally indicated at 88.
As shown in Figure 5, the road-side shoulder 80 may first have an inclined cut
86
so as to remove a portion of the shoulder material and thereby form a first
inclined surface 84 of
the ditch 82. Such a first cut may be made by a first pass of an inclined
grader blade with out an
attachment as described above. The above attachment may then be attached to
the grader blade so
as to form the curved bottom of the ditch 82. Optionally, the first pass may
be made by a first
grader while the rounded bottom may be formed by a second grader. It will be
appreciated,
however that the ditch 82 may be formed by a single pass of the motor grader
with both the
inclined surface and the rounded bottom of the ditch 82 being formed by a
grader blade with an
attachment as set out above.
As will be apparent to those skilled in the art in the light of the foregoing
disclosure, many alterations and modifications are possible in the practice of
this invention
without departing from the spirit or scope thereof. Accordingly, the scope of
the invention is to be
construed in accordance with the substance defmed by the following claims.
