Note: Descriptions are shown in the official language in which they were submitted.
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SIDEWALK GRADER APPARATUS AND METHOD
BACKGROUND OF THE INVENTION
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 Iike 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 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 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.
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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 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 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.
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SUMMARY OF THE INVENTION
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 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
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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 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
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embodiment which proceeds with reference to the accompanying drawings, wherein
the
preferred embodiment of the invention is shown and described, simply by way of
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.
BRIEF DESCRIPTION OF THE DRAWING(S)
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).
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 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.
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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 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
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.
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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.
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
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 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.
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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.
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 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 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
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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 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. 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
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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
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 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
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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 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
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
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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 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.
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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.
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,
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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.
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 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.
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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 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 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 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
SEA 1883010v1 82227-1 15
CA 02635117 2008-04-16
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 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.
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CA 02635117 2008-04-16
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 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 control system 218 are provided by Topcon
positioning Systems Inc. located in Pleasanton, CA. For this equipment, Topcom
supplies a "paver" 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 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.
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CA 02635117 2008-04-16
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.
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
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 from within the cab of the excavator to control all hydraulic circuits
that affect 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
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CA 02635117 2008-04-16
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 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.
SEA 1883010v1 82227-1 19
