Note: Descriptions are shown in the official language in which they were submitted.
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SIDEWALK GRADER APPARATUS AND METHOD
BACKGROUND
This invention relates generally to earth moving and
excavation equipment, and more particularly to equipment
provided to finish grade sidewalk base material including
crushed rock, in preparation for a concrete or asphalt
sidewalk overlay.
Construction equipment provided to grade a road base or
sidewalk base are well known, and have been employed in such
work for quite some time. Typically, a sidewalk base, for a
specified sidewalk site is prepared by grading the same to a
specific elevation. This is sometimes followed by base
material being brought in by truck or loader equipment which
requires additional grading.
For this purpose, blade type grading equipment is
usually employed along with a crew of construction workers
using rakes, shovels and the like to add or take away
material as needed by the operator of the finish grader.
Accordingly, this process consumes a large amount of
manpower, and is slow thereby tying-up resources that could
be used else where on the construction site.
For example, one early sidewalk grader is disclosed in
U.S. Patent No. 2,664,794 issued in 1954 showing a hopper-
like storage bin for spreading base material over a sidewalk
area, as the storage bin is pulled or dragged along the
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sidewalk base area. This design requires constant loading of
the hopper, and would also require a smooth ground in front
of the machinery which is dragged.
Another early design is U.S. Patent No. 2,825,984 issued
in 1958 which discloses a sidewalk fine grader for grading
the earth between steel edge forms laid down on grade to
provide side-forms for pouring concrete sidewalks. Like the
'984 patent, this device travels directly over the sidewalk
base and also requires a pair of spaced base rails installed
l0 to guide the machine.
In 1962 U.S. Patent 3,059,355 issued disclosing a curb
and sidewalk grading device that is pulled by a tractor or
the like between form-rails similar to the '954 device. In
addition, this invention uses an internal rotating auger-like
member disposed horizontally to grade the base material.
This design would be difficult to operate with base material
that is larger than fine granular material.
A later design is U.S. Patent 3,566,759 issued in 1971
showing a mounting arrangement for sidewalk building
equipment where a motorized, wheeled vehicle employs sensors
to sense reference points to follow a predetermined path.
This design is complicated, and requires pre-installation of
reference points.
Various other later designs, include U.S. Patent(s) No.
3,651,588 issued in 1972, No. 3,914,064 issued in 1975, and
No. 4,113,402 issued in 1978. These designs are based on
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complicated machinery that is built integrally with the
grading apparatus thereby increasing its initial cost.
More recent inventions include U.S. Patent(s) No.
6,109,825 issued in 2000, No. 6,168,348 issued in 2001, and
No. 6,322,287 issued in 2001 which show machines designed for
the placement of material, wherein each of the same vary in
complexity and consistency of intended results. In
particular, the '287 reference relies on the upper edge of a
concrete form to provide a reference point to grade the
l0 sidewalk base as the machine moves over the same.
Importantly, none of the designs noted above are
intended to employ a point of reference provided by existing,
permanent portions of road structures to finish grade a
sidewalk base. Further, none of the above designs are
intended to be used with common construction equipment that
is not required to be positioned over the sidewalk base while
advancing forward to grade the same.
Accordingly a need remains for a simple design to
precisely grade and prepare the base of a sidewalk with
reference to existing, permanent portions of an existing road
structure, while minimizing the manpower required, and while
quickly advancing the sidewalk grading process, minimizing
the number of passes over the sidewalk base to complete the
grading process.
SUMMARY
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One object of the invention is to precisely grade and
prepare the base of a sidewalk according to its exact
planned, engineered and reserved location while minimizing
the number of passes over the sidewalk base.
A second object is to decrease the amount of time a
contractor spends to prepare the base of a sidewalk according
to its engineered reserved location in relation to the
adjacent road structure.
Another object is to reduce the number of man-hours
required to prepare the base of a sidewalk according to
specification.
Yet another object is to increase the accuracy and
quality of the base of a sidewalk to meet the specifications
according to its exact planned and engineered location.
A further object is to reduce the amount of concrete
required to form a finished sidewalk.
Still another object is to reduce the time that a
subcontractor has to be on a job site.
The invention is a sidewalk grader provided for grading
sidewalk base material, including crushed rock, to a
predetermined specified grade and elevation to form the base
of a designed sidewalk. Typically, the sidewalk grader
accommodates grading activity for sidewalks that extend
adjacent to and along an existing road structure of the type
that incorporates a curb as a border.
In its construction, the sidewalk grader comprises a
tracking assembly adapted for fixable engagement with a
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vertically movable accessory extending from a piece of
construction excavation equipment. Commonly, a vertically
adjustable backfill blade extending from a compact excavator
is the ideal accessory for this purpose. The construction
equipment is generally positioned to move forward over an
existing road structure to advance the sidewalk grader in a
direction along the existing road structure, substantially
parallel thereto. Importantly, the excavation equipment so
provided is disposed and operated over an existing road
structure thereby minimizing the impact it has on the
sidewalk base. Accordingly, the tracking assembly is
configured to extend from the vertically movable accessory,
or blade, in a transverse direction to the course of
advancement, transversely across the road structure and the
curb thereof .
Additionally, the tracking assembly further comprises a
vertically adjustable tracking means disposed for engagement
with the top surface of the curb portion of the road
structure. With this configuration, the top surface of the
curb provides a point of reference for operation of the
sidewalk grader.
Importantly, a grading assembly is mounted and fixed to
the tracking assembly so that the grading assembly extends
outward, beyond the curb portion, positioned over the
location of the area reserved for the designed sidewalk and
base thereof. More Specifically, the grading assembly
comprises a frame, and a grading blade rotatingly mounted to
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the frame to permit adjustment of slope of the blade
according to the specified sidewalk design grade. In order
to lock the rotation of the grading blade, at a predetermined
position, in relation to the frame, a means for fixing the
blade rotation is provided. One common way to provide such
fixing means is to provide an adjustable link with one end
connected to the frame, and the opposing end connected to the
grading blade.
As noted above, the tracking means is vertically
adjustable. This feature is provided to enable the tracking
means to engage with the top surface of a curb, that is used
to provide a point of reference, for precise adjustment,
control, and positioning of the grading assembly, and for
maintaining the desired position of the sidewalk grader in
relation to the curb as the sidewalk grader advances along
the existing road structure. Because the top surface of the
curb is usually rough concrete, the preferred tracking means
is constructed for rolling engagement along the top surface
of the curb. However, other arrangements would be employed,
for example a flat rigid shoe could be formed to slide over
the curb.
The foregoing and other objects, features, and
advantages of this invention will become more readily
apparent from the following detailed description of a
preferred embodiment which proceeds with reference to the
accompanying drawings, wherein the preferred embodiment of
the invention is shown and described, simply by way of
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illustration of the best mode contemplated of carrying out
the invention. As will be realized, the invention is capable
of other and different embodiments, and its several details
are capable of modifications in various obvious respects, all
without departing from the invention. Accordingly, the
drawings and description are to be regarded as illustrative
in nature, and not as restrictive.
to
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of a sidewalk grader
mounted and fixed to the backfill blade of a compact
excavation machine, with the tracking assembly comprising a
tracking wheel to engage the top surface of a curb, and with
the grading assembly extending from the tracking assembly,
over the curb, and where the grading assembly is braced to
the excavator structure.
FIGS. 2A through FIG. 2C are a sequence of overhead
plan views of a sidewalk grader fixed to the backfill blade
of a compact excavator, the sequence illustrating the folding
motion of a sidewalk grader moving from a unfolded position
(FIG. 2A) to an folded position (FIG. 2C).
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FIG. 3 is a perspective view of a sidewalk grader in a
folded position, adjacent to, and in front of the backfill
blade of a compact excavator.
FIG. 4 is a partial perspective view of a sidewalk
grader in a folded position adjacent to, and in front of the
backfill blade of an excavator, wherein the grading assembly
includes a brace partially exploded to illustrate the
l0 attachment thereof to the frame of the grading assembly.
FIG. 5 is a partial rear perspective view of a
grading assembly extending from a tracking assembly, of a
sidewalk grader, with the tracking means, i.e., tracking
roller, disposed for rolling engagement with the top surface
of a curb .
FIG. 6 is a partial front perspective view of the
tracking assembly in the unfolded position fixed to the
backfill blade of a compact excavator.
FIG. 7 is a partial rear elevation view of a sidewalk
grader fixed to a backfill blade of a compact excavator,
wherein the frame of the grading assembly is braced.
FIG. 8 is a plan view illustrating a sidewalk grader
fixed to a backfill blade of a compact excavator, wherein the
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sidewalk grader is in the unfolded position, with portions
thereof extending over a curb, and where the frame of the
grading assembly is braced to the structure of the compact
excavator.
FIG. 9 is a rear elevation view of a sidewalk grader
having a dual-axis pivot joint connecting the
tracking assembly to the grading assembly, and wherein a
hydraulically actuated adjustable slope control link extends
from the tracking assembly to the frame of the grading
assembly.
FIG. 10 is a front elevation view of a sidewalk grader
fixed to one end of a backfill blade of a compact excavator,
and a hydraulically operated, vertically adjustable backfill
blade stabilizer fixed to the opposing end of the backfill
blade, the sidewalk grader having a dual-axis pivot joint
connecting the grading assembly to the tracking assembly, and
the backfill blade stabilizer having a wheel for rolling
engagement with the existing road structure.
FIG. 11 is a partial perspective view illustrating a
dual-axis pivot joint defined by a portion of the tracking
assembly, wherein the dual-axis pivot joint permits the
grading assembly to pivot upward and downward to control
grading blade slope, as well as pivot sideways to fold the
grading assembly from a first fixed unfolded position
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extending outward from the tracking assembly, to a second
folded position adjacent the blade of the excavator, wherein
a optional wedge is also illustrated to represent an
alternate embodiment where the upward pivot capability of the
joint is fixed by the wedge so that the slope control link is
not required and can therefore be eliminated.
FIG. 11A is a perspective view illustrating a hinge
insert employed to fit into a pivot joint to enable the same
to pivot up and down about a substantially horizontal axis.
FIG. 12 is a partial rear perspective view illustrating
a hydraulically operated, vertically adjustable backfill
blade stabilizer having a wheel for rolling engagement with
the existing road.
FIG. 13 is a perspective view illustrating the inside
of a cab of a compact excavator having a Topcon system five
9256 control box for controlling the hydraulically actuated
slope control link for controlling the slope of the grading
blade, and a hand-controlled "joy-stick" with thumb buttons
for electronically controlling the up & down motion of the
backfill blade, and for controlling the up & down motion of
the backfill blade stabilizer in combination with the up and
down motion of the tracking means, i.e., tracking roller.
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FIG. 14. is a perspective view of an electrically
operated hydraulic valve stack having two primary hydraulic
control lines that are redirected from the original-stock
compact excavator backfill blade hydraulic circuit, which is
now redirected to hydraulically supply three hydraulic
circuits including:
(1) a hydraulically actuated slope control link in
electronic communication with the Topcon positioning system
for control of the slope control link to maintain a specified
l0 slope to produce the specified sidewalk base grade;
(2) a hydraulically actuated circuit having three limit
controlled hydraulic actuators for moving the sidewalk grader
from a first sidewalk grading position, to a second driveway
grading position, wherein any or all of the actuators can be
disabled and removed; and
(3) a backfill blade hydraulically actuated circuit
defined by the original hydraulic actuators of the backfill
blade.
FIG. 15 is a partial perspective view looking down at
the frame of a grading assembly and the adjustable limit
control stop thereof, the frame having a limit lug being
disposed between a first limit stop bolt and a second limit
stop bolt, wherein the limit stop bolts define a range that
the grading blade can rotate in relation to the frame as the
hydraulically actuated adjustable blade link is operated
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between the first sidewalk grading position and the second
driveway grading position.
FIG. 16 is an exploded elevational view illustrating
the primary components of a sidewalk grader including an
optional extension assembly provided to extend the grading
assembly to accommodate the situation where a specified
sidewalk base is spaced-apart from the curb of a road
structure.
15
DETAILED DESCRIPTION OF PREFERRED EMBODIMENT
Referring to FIGURES 1 through 16 of the drawings,
numeral 20 generally designates a sidewalk grader. The
sidewalk grader 20 is provided for preparing and grading
sidewalk base material 22, which sometimes includes crushed
rock 24, to a predetermined specified grade and elevation to
form the base 26 of a designed sidewalk (not illustrated).
Typically, the sidewalk grader 20 accommodates grading
activity for sidewalks that extend adjacent to and along an
existing road structure 30 of the type that incorporates a
curb 32 as a border.
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More specifically, the sidewalk grader 20 comprises a
tracking assembly 34 adapted for fixable engagement with a
vertically movable accessory 36 extending from a piece of
construction excavation equipment 38. Commonly, a vertically
adjustable backfill blade 40 extending from a compact
excavator 42 is the ideal accessory 36 for this purpose. In
addition, when a compact excavator 42 is used, the bucket 43
thereof, can be very useful to either remove or add
additional sidewalk base material 22 depending on the
to condition of the site reserved for the sidewalk. In
addition, as the sidewalk grader 20 advances along the road
structure 30, the bucket 43 can be used to break-up native
hard-pan type soil, and to remove large rocks and the like.
Accordingly, the use of a bucket 43, on a compact excavator
42 can greatly increase the productivity of the grading
process.
The construction equipment 38 is generally positioned to
move forward over an existing road structure 30 to advance
the sidewalk grader 20 in a direction along the existing road
structure 30, substantially parallel thereto. This forward
movement is indicated by arrow 46. Importantly, the
excavation equipment 38 so provided is disposed and operated
over an existing road structure 30 thereby minimizing the
impact it has on the base 26. Accordingly, the tracking
assembly 34 is configured to extend from the vertically
movable accessory 36, or similarly, a backfill blade 40, in a
transverse direction to the course of advancement (indicated
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by an arrow 46), transversely across the road structure 30
and the curb 32 thereof.
In addition, the tracking assembly 34 further comprises
a vertically adjustable tracking means 48 disposed for
engagement with the top surface of the curb 32 portion of the
road structure 30. With this configuration, the top surface
50 of the curb 32 provides a point of reference for operation
of the sidewalk grader 20.
Importantly, a grading assembly 54 is mounted and fixed
to to the tracking assembly 34 so that the grading assembly 54
extends outward, beyond the curb 32, positioned over the
location of the area reserved for the designed sidewalk and
base 26 thereof. More Specifically, the grading assembly 54
comprises a frame 56, and a grading blade 58 rotatingly
mounted to the frame 56 to permit adjustment of slope of the
grading blade 58 according to the specified sidewalk design
grade. In order to lock or fix the rotation of the grading
blade 58 in relation to the frame 56, according to a
predetermined grade, a means 60 for fixing the blade rotation
is provided. One common way to provide such fixing means 60
is to provide an adjustable blade link 62 with one end
connected to the frame 56, and the opposing end connected to
the grading blade 58. It should be understood that there are
many existing mechanisms that could be employed as an
adjustable blade link 62. For example, a hydraulic cylinder
or actuator could be used, and allow the operator to control
the same from a remote location like the inside of a cab.
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Another good example would be a ratchet-type turnbuckle that
is set by hand, and maintains the setting until another hand
adjustment is completed.
As noted above, the tracking means 48 is vertically
adjustable. This feature is provided to enable the tracking
means 48 to engage with the top surface 50 of a curb 32 to
provide a relative reference, or point of reference, for
precise vertical and horizontal adjustment of the sidewalk
grader 20, to position the grading assembly 54, and for
maintaining the grading assembly in the desired position in
relation to the curb as the sidewalk grader 20 advances along
the existing road structure 30 as indicated by arrow 46.
Because the top surface 50 of the curb 32 is usually
rough concrete, the preferred tracking means 48 is
constructed for rolling engagement along the top surface 50
of the curb 32. However, other arrangements would be
employed, for example a flat rigid shoe (not illustrated)
could be adapted to slide over the curb. Additionally, a
brush 63 is attached to the tracking assembly 34, in front of
the tracking means 48 to remove any rocks or debris on the
curb 32 that might interfere with the tracking means 48
Considering now in more detail the structure of sidewalk
grader 20, in a simplified embodiment of the sidewalk grader
20, the tracking assembly 34 comprises a pivot joint 64,
disposed adjacent the backfill blade 40 to enable the
sidewalk grader 20 to fold from a first unfolded position as
illustrated in FIGS. 5 through 8, to a folded position as
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illustrated in FIGS. 3 and 4. This folding action is also
illustrated in FIGS. 2A through FIG. 2C which show a sequence
of the sidewalk grader 20 folding from an unfolded position
in 2A, to a fully folded position in 2C, in front of the
backfill blade 40 of a compact excavator 42. Also
illustrated in this sequence is an additional pivot joint 65
provided to form an additional folding point to fold the
sidewalk grader 20 for storage and transportation. As will
be discussed more fully below, pivot joint 65 can provide an
additional pivot axis for up and down movement of the grading
assembly 54 to provide greater flexibility thereof.
The pivot joint 64 includes a hinge bracket plate 66
that is welded by weld 67 to the end of backfill blade 40
(see FIG. 6). It should be noted, however that the hinge
bracket plate 66 could be welded on to any vertically
adjustable accessory of excavation construction equipment
such as a skid-steer loader (not illustrated) with similar
results.
In this way, stationary hinge sleeve 70 can be welded to
the hinge bracket plate 66 as illustrated in FIG. 6. This
arrangement facilitates a pivotal connection with- spaced-
apart rotating upper and lower hinge sleeves 68 disposed to
receive stationary hinge sleeve 70 therebetween, in axial
alignment to allow a pivot pin 72 to be placed through all
three aligned sleeves.
As illustrated in FIG. 4, the spaced-apart rotating
upper and lower hinge sleeves 68 are welded to a header
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flange plate 74 thereby permitting the header flange plate 74
to pivot. In order to firmly hold the header flange plate 74
in place when the sidewalk grader 20 is in the unfolded
position, a plurality of bolts 78 are placed through aligned
holes 79 (FIG. 3) provided in the hinge bracket plate 66 and
header flange plate 74 when the two plates are butted
together as illustrated in FIGS. 6 and 7. Likewise, a
support tube 76 is welded to the header flange plate 74,
wherein the support tube 76 extends outward to provide
support to a vertically disposed upright cylinder support 82.
Turning now to FIG. 6, the cylinder support 82 is
fabricated from solid steel for strength, and is welded
directly to the support tube 76. At the top of the cylinder
support 82 is an upper eye 84, defining a hole (not
illustrated) disposed to provide a connection point for the
upper portion of hydraulic cylinder 86. Similarly, at the
opposing end, its ram 88 is connected to a vertically movable
wheel carriage 90 having a wheel retainer 92 bolted thereto.
The wheel retainer 92 is U-shaped to rotatingly receive a
wheel 94 and its axle (not illustrated). With this
arrangement, the ram 88 can be operated to vertically adjust
the wheel carriage 90, and wheel 94 to the proper elevation
to rest on the top surface 50 of curb 32 to track the curb 32
as the sidewalk grader 20 advances along the road structure
30. Although a preferred embodiment employs a wheel 94 to
track the curb 32, any type of rolling device or track-type
roller (not illustrated) would be satisfactory. Indeed, even
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a solid metal plate (not illustrated) could be used in this
situation with somewhat less desirable results.
In addition to the above, the wheel carriage 90 includes
two spaced-apart upright stabilizer columns 98 and 100,
welded to a flange 102 of the wheel carriage 90. In this
way, the upright stabilizer columns 98 and 100 can be
slidingly received into spaced-apart stabilizer sleeves 104
and 106 which are welded to support tube 76 and welded to the
cylinder support 82 for added strength to stabilize the wheel
carriage 90 as it is adjusted up and down vertically. To
provide a lifting point, a lifting lug 101 is welded to the
upper most portion of the cylinder support 82.
As will be discussed more fully in the following, as the
sidewalk grader 20 advances along the road structure 30, the
wheel 94 should be adjustable between a first lower limit, to
raise the sidewalk grader 20, where the sidewalk grader 20
is tracking the top surface 50 of a curb 32 to grade and
prepare a sidewalk base 26, to a second upper limit, thereby
lowering the sidewalk grader 20 to enable the sidewalk grader
20 to follow the curb 32 as it drops to an area reserved for
a driveway (not illustrated), i.e., where the curb
transitions downward and fades into the driveway. At this
point, the wheel 94 would have to be raised to the upper
limit to make up for the loss of the curb 32.
In order to set these limits, a plurality of limit holes
108 are provided through the upper portion of the cylinder
support 82 to receive a limit stop pin 110 disposed to stop
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the upper movement of the wheel, and a spaced-apart limit
stop pin 112 disposed to stop the lower movement of the wheel
as the same moves over a top surface 50 of a curb 32. For
this purpose, a limit lug 114 is provided. One example of a
limit lug 114 is a bolt 116 that extends through stabilizer
column 100 as illustrated in FIG. 6.
Turning now to FIGS. 5 through 7 a grading assembly 54
is illustrated extending from the tracking assembly 34. In
one embodiment, the tracking assembly 34 further comprises an
additional pivot joint 65 to facilitate the ease of folding
the sidewalk grader 20 to the fully folded position as
illustrated in FIG. 2C. In the construction thereof, pivot
joint 65 is similar to pivot joint 64. Specifically, pivot
joint 65 includes a header flange plate 120 that is welded to
the end of support tube 76 (see FIG. 6). In this way,
stationary hinge sleeve 122 can be welded to the header
flange plate 120. This arrangement facilitates a pivotal
connection with spaced-apart rotating upper and lower hinge
sleeves 124 disposed to receive stationary hinge sleeve 122
therebetween, in axial alignment to allow a pivot pin 126 to
be placed through all three aligned sleeves.
Accordingly, spaced-apart rotating upper and lower
hinge sleeves 124 are welded to a hinge plate 128 thereby
permitting the hinge plate 128 to pivot about a substantially
vertical axis. In order to firmly hold the hinge plate 128
in place when the sidewalk grader 20 is in the unfolded
position, a plurality of bolts 130 are placed through aligned
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holes 132 (FIG. 4) provided in the header flange plate 120,
and hinge plate 128 when the two plates are butted together
as illustrated in FIGS. 5, 6 and 7. Likewise, a frame
support tube 134 is welded to the hinge plate 128, and
reinforced by plate 136. Further, the frame support tube
134 extends outward as part of the frame 56 to provide
support to the grading blade 58. As can be seen, the above
describes an embodiment comprising one type of hinged joint
construction. It should be understood, however, that many
different configurations and reinforcements could be used
with equal effectiveness.
Directing attention to FIG. 5 a rear perspective view of
one embodiment of a grading assembly 54 is illustrated.
Typically, the structure of grading assembly 54 is a modified
tractor rear-blade of the type commonly built for use in a
three-point connection set-up configuration that is found on
most farm tractors. For example, FIG. 5 shows a rear blade
manufactured by FRONTIER, model No. RB1072. As can be seen,
the frame support tube 134 was formed by removing the three-
point connection portion (not illustrated). Thus, the grader
assembly 54 comprises this modified portion. To integrate
the grader assembly 54 as a part of the sidewalk grader 20,
the frame support tube 134 is welded to hinge plate 128.
Accordingly, frame support tube 134 is positioned, i.e.,
rotated to align for pivotal connection between the hinge
plate 128 and the header flange plate 120.
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Further, the grader assembly 54 includes a frame housing
138 that, in its pre-modified form, is rotatably mounted to
frame support tube 134 for rotation about a substantially
vertical axis. However, in the present invention, the frame
housing 138 is fixed, i.e., welded to the frame support tube
134 to maintain their relative position as illustrated in
FIG. 5.
Moreover, the typical construction of a farm-type rear
blade includes a frame housing 138 configured to receive the
journal portion of a shaft (not illustrated) extending from
the blade to rotatingly support the grading blade 58.
Accordingly, for the present application, an adjustable link
62 is disposed to connect the grading blade 58 to the frame
housing 138 of the frame 56. This connection could be made
either behind the blade 58 as illustrated in FIG. 5, or in
front of the blade as illustrated in FIG. 9.
Because the "length" of adjustable link 62 is variable,
the slope of the grading blade 58 can be set to a
predetermined slope to produce the specified grade as the
sidewalk grader 20 advances along the road structure 30. It
should be noted that "turnbuckle" type links, commonly
employed as farm tractor top links, are satisfactory for use
as adjustable link 62. Similarly, "ratchet" type tractor
links, are also commonly substituted and provided as
adjustable link 62, as well as hydraulically controlled
cylinder type actuators.
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As described above the grading assembly 54 comprises
the FRONTIER RB1072 farm type rear blade as illustrated in
FIGS. 5 and 7. In some applications, however, a slightly
larger rear blade would be more suitable for the sidewalk
grader 20. One example of such a rear blade is FRONTIER
model RB1184 which is illustrated in FIGS. 9, 10 and 16. As
can be seen, in most respects, the components thereof
correspond to, and are mostly the same. Accordingly, for
simplicity, the numerals indicating the various corresponding
components are the same.
One difference in arrangement, however is that the
adjustable blade link 62 is disposed on the other side of
frame support tube 134. To facilitate this placement, eye
lug 201 is welded to the grading blade 58 to receive one end
of adjustable blade link 62, and eye support 202 is disposed
to extend from housing plate 203, to receive the other end of
the link, wherein the housing plate 203 is fixed to the frame
housing 138.
Another variation in grading blade 58, is the
modification thereof to include a directional blade
attachment 205. This attachment is provided to attach to the
end of the grading blade 58 that is disposed closest to the
curb 32. This the use and placement of the directional blade
attachment 205 is to improve, and efficiently direct the flow
of graded material from the grading blade 58.
Directing attention to FIGS. 10 and 12, a blade
stabilizer 144 is illustrated and provided as an option to
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add stability to the backfill blade 40 of a compact excavator
42. The optional blade stabilizer 144 is fixed to an end of
backfill blade 40, opposing the tracking assembly 34. In
construction, it is similar to portions of the tracking
assembly 34. For example, a bracket plate 146 is either
bolted or welded to the backfill blade 40 to receive and
maintain cylinder support 148. For this purpose, cylinder
support 148 is welded to bracket plate 146. The cylinder
support 148 includes a lifting ring 150 above, and an upper
eye 152 disposed to receive a hydraulic cylinder 154.
In addition, the ram portion 156 thereof is attached to
wheel carriage 158 for vertical movement. Such vertical
movement is provided to position a wheel 160 on the road
structure 30 to stabilize the backfill blade 40. To
facilitate attachment of the wheel 160 to the wheel carriage
158, wheel retainer 162 is provided. Similar to the tracking
assembly 34, a stabilizer sleeve 166 is fixed or welded to
cylinder support 148. In this way, stabilizer column 164 can
be slidingly received into the stabilizer sleeve 166 so that
2o the same acts as a guide for the vertical movement thereof
when the hydraulic cylinder is operated in concert with the
up and down motion of the backfill blade 40. Also provided
are a plurality of limit holes 168 disposed to receive an
upper limit pin 170, and a lower limit pin 172. These pins
are positions to define a upper and lower range of movement
of the wheel carriage 158 and accordingly the wheel 160. For
this purpose, a limit lug (FIG. 16) extends horizontally from
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the stabilizer column 164, between the limit pins 170 and
172.
Turning now to FIGS. 11 and 11A, another embodiment is
illustrated where a dual-axis pivot joint 180 is employed to
allow an up-down pivotal movement of the grading assembly 54.
Similarly, the dual-axis pivot joint 180 is a modification of
pivot joint 65. The modification is accomplished by
separating and spacing hinge plate 128 from header flange
plate 120, followed by the insertion of
l0 hinge insert 181. Hinge insert 181 comprises hinge plate 183
having spaced apart hinge sleeves 185 fixed thereto, and
hinge plate 187 having stationary hinge sleeve 189 fixed
thereto, i.e., welded. The two hinge plates 183 and 187 are
hingedly joined by axially aligning stationary hinge sleeve
189 between spaced apart hinge sleeves 185 with a hinge pin
188 disposed to hingedly join them together. As will be
discussed more fully in the following, one embodiment of the
invention comprises a grading assembly 54 that pivots up-and-
down about a substantially horizontal axis defined by pivot
pin 188.
To enable hinge insert 181 to pivotally join existing
header flange plate 120 to hinge plate 128, stationary sleeve
190 is fixed to hinge plate 183, and spaced-apart hinge
sleeves 191 are fixed to hinge plate 187 as illustrated. In
this way, alignment of stationary hinge sleeve 122 between
hinge sleeves 191, will accommodate pivot pin 126 for the
connection. Similarly, alignment of stationary sleeve 190
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CA 02503171 2005-04-18
between upper and lower hinge sleeves 124, will accommodate
pivot pin 186 for the connection of hinge plate 128 to hinge
plate 183.
In addition, a pattern of holes 193 is provided in each
hinge plate 183 and 187 so that hinge plate 187 will bolt up
to header flange plate 120, and hinge plate 183 will bolt up
to hinge plate 128. With this arrangement, the sidewalk
grader 20 can be fixed in the unfolded position yet still
permit up and down pivotal movement about pivot pit 188.
Depending on the construction of the hinge plates 183 and
187, a spacer plate 194 may be required for precise fit with
adjacent plates.
Importantly, this arrangement is provided so that a
slope control link 196 can extend from the eye lug 198
provided on cylinder support 82, of tracking assembly 34, to
the eye lug 200 of grading assembly 54 to control the slope
of the grading blade 58. In a preferred embodiment, the
slope link 196 is.a hydraulically actuated cylinder that is
electronically controlled as will be more fully discussed
below. With this configuration, the grading blade 58 can be
remotely controlled. However, if a more simplified
embodiment of the above noted arrangement is desired, a wedge
192 could be inserted in the dual-axis pivot joint 180 as
illustrated in FIG 11. A wedge 192 so inserted would fix the
up-down pivot motion of the dual-axis pivot joint 180, and
therefore eliminate the need for a slope control link 196.
CA 02503171 2005-04-18
Also with this modification of pivot joint 65, an
extension assembly 204, as illustrated in FIG 16, can
employed to extend the grading assembly 54 further from the
tracking assembly 34 to accommodate a situation where the
sidewalk is spaced some distance from the curb 32. As
illustrated, an extension assembly 204 comprises an extension
shaft 206 that is received into an extension receiver tube
208. The extension shaft 206 comprises a plurality of
extension holes 210 disposed for alignment with a stop pin
l0 212 that extends through a stop hole 214 provided through
extension receiver tube 208. As illustrated, the ends of the
extension assembly 204 are configured to mate-to the existing
hinge plates with existing hinge pins: to hinge plate 128 on
the end disposed adjacent the grading assembly 54, and to
hinge plate 183 of pivot joint 65. Accordingly, the
extension assembly 204 can be set to multiple extension
lengths.
Because the above noted extension can place the grading
assembly 54 at a distance from the tracking assembly 34, a
brace 215 can be employed to help absorb some of the forces
generated from the grading operation. FIGS. 1 and 7
illustrate such a brace 215 that includes a brace extension
216 which is received into brace socket 217 fixed to the
grading assembly 54. The brace typically extends from the
excavator to the grading assembly 54.
Turning now to FIGS. 9, 13 and 14 a slope control system
218 is illustrated. The primary components of the slope
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CA 02503171 2005-04-18
control system 218 are provided by Topcon positioning Systems
Inc. located in Pleasanton, CA. For this equipment, Topcom
supplies a "payer" software espically designed for road work.
Briefly, the positioning system, i.e., slope control system
218 includes a slope sensor 220 which is located on the frame
of the grading assembly 54. The slope sensor 220 is in
communication with a proprietary control box 222 provided by
Topcon. In the preferred invention, a " System Five 9256
Control Box" is employed. This system is a readily
l0 obtainable off-the-shelf system that is easily set-up by
technicians employed by a compact excavator dealer.
Additionally, because this system includes proprietary
information, a discussion of the internal "workings" and
circuits is beyond the scope of this specification.
In operation, this slope control system 218 is installed
to compensate for any deviation in slope of the grading blade
58 caused by bumps in the road structure 30, change in slope
of the road structure, and excavator load changes and the
like. Accordingly, the slope sensor 220 senses any change
in slope and communicates the change to the Control box 222
which then signals an electronically controlled valve stack
224 to activate the slope control link 196, i.e. slope
control link hydraulic cylinder 226, to compensate for the
change. In this way, the grading blade 58 is automatically
controlled to provide a smoothly graded base 26 for the
sidewalk.
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The electronic controlled valve stack 224 controls
hydraulic fluid supplied thereto, and is supplied by Sauer
Danfoss. Specifically, the preferred embodiment includes an
electrically actuated and controlled valve stack 224 that
includes a PVG 32-Variable controller for electronically
controlling the hydraulic valve stack 224 dedicated to the
slope control link 196, i.e., slope control hydraulic
cylinder 226. Accordingly, this type of electronic control
is well suited for interface with the slope control system
l0 218 as noted above.
Additionally, in the present invention, the
electronically controlled valve stack 224 includes at least
two other electronically controlled valves: one to control
the backfill blade 40 of the compact excavator 42, and
another valve to control the hydraulic circuit that includes
the adjustable blade link hydraulic cylinder 62, the tracking
assembly hydraulic cylinder 86 and the backfill blade
stabilizer hydraulic cylinder 154. This arrangement is the
result of reconfiguring the hydraulic hoses that operate the
backfill blade 40 on a stock compact excavator 42.
Specifically, the two hydraulic hoses that operate the
stock backfill blade 40 are rerouted to the electronically
controlled valve stack 224 for supplying the same as noted
above. Accordingly, the backfill blade 40 is now connected
to, and controlled by the aftermarket valve stack. In this
way, the operator can electronically control the valve stack
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from within the cab of the excavator to control all hydraulic
circuits that effect the sidewalk grader.
This arrangement results in the hydraulic hose routing
illustrated in FIG. 14, i.e., two hydraulic hoses from the
excavator are routed to the valve stack, and six hydraulic
hoses (three pairs of two hoses each) are routed to the
various hydraulic components as noted above.
Moreover, because the electronically controlled valve
stack 224 is electronically controlled, the supplier of the
excavator can arrange the "thumb control" in the cab, with
electrically operated button controls. For example, one pair
of buttons could control the up and down motion of the
backfill blade 40. Similarly, one pair of buttons could
control, simultaneously the up and down motion of the
backfill blade stabilizer, the tracking assembly 34, and the
grading blade slope. This arrangement would be particularly
useful when each of the same are restrained between limits
set according to whether the sidewalk grader is grading along
a constant elevation curb top surface, or whether the
sidewalk grader is grading at the intersection of a driveway
where the elevation and grade setting have to change to
accommodate the driveway.
Finally it should be noted that in an embodiment of the
invention, the frame housing 138 comprises a slope limit
assembly 232 to limit the range that a grading blade 58 can
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travel. For that purpose, the slope limit assembly 232
includes a limit base 237 adapted to threadedly receive a
left stop 234 defined as a bolt 238 with an adjusting nut
240, and a right stop 236 defined by a like bolt 242 with an
adjusting nut 244. In operation, a limit lug 246 attached to
the rotating portion of the grading blade 58 is disposed
between the left and right stops 234, 236 which thereby
define the range that the grading blade 58 can travel to a
predetermined slope to produce a specified grade of the
sidewalk base 26.
Having illustrated and described the principles of my
invention in a preferred embodiment thereof, it should be
readily apparent to those skilled in the art that the
invention can be modified in arrangement and detail without
departing from such principles. I claim all modifications
coming within the spirit and scope of the accompanying
claims.
