Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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LONGITUDINAL HEAP HANDLING SYSTEM AND METHOD
FIELD
The specification generally relates to handling a longitudinal heap of earthen
material
such as mixed soil and vegetation, or gravel, for example.
BACKGROUND
Non-paved road shoulders, of paved or non-paved roads, are often adjacent to
vegetation.
As time passes, the vegetation has a tendency to spread and grow on the non-
paved road
shoulder.
To maintain non-paved road shoulders in condition, it is known to use a grader
on the
non-paved surface to remove such growths by grading off an upper layer of
earthen
material therefrom. The removed earthen material can contain mixed soil,
gravel and
vegetation. When grading the shoulder of the road, the removed earthen
material can
either be moved outwardly, by pushing it into or towards a ditch for example,
or it can be
moved inwardly and form a longitudinal heap of earthen material.
Moving the earthen material into the ditch can have the downside of
encumbering the
ditch, and after a few years, it will likely become necessary to dig the ditch
for
maintenance. There are costs related to these digging operations, which add to
those
incurred when grading the non-paved road shoulder. These costs are typically
incurred
by the municipalities.
Moving the material inwardly into a longitudinal heap of earthen material
typically
requires picking the longitudinal heap up, which is normally done by a
hydraulic shovel
which loads it into a dump truck. Although this helps preventing ditch
encumbrance, the
operation can be relatively costly.
In either case, the soil and gravel which is removed from the non-paved
surface
eventually needs to be replaced, which also translates in additional costs.
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Hence, it will be understood that there was a general need felt in the art for
reducing the
costs related to maintenance of non-paved road surfaces.
SUMMARY
In accordance with one aspect, there is provided a system for handling a
longitudinal
heap of earthen material laying on the ground, such as a longitudinal heap of
mixed soil,
gravel and vegetation material removed from a non-paved road shoulder by
grading, for
example. The system is displaceable in a longitudinal direction of the
longitudinal heap,
and comprises a conveyor with an inlet close to the ground and an outlet
positioned
higher from the ground than the inlet, and a loading head adjacent the inlet
of the
conveyor, the loading head being operable in rotation about a transversal
rotation axis to
load earthen material from the longitudinal heap onto the conveyor inlet
during
displacement of the system in the longitudinal direction.
The loading head can have a shaft transversal to a longitudinal displacement
direction of
the system, and at least two pushing plates extending substantially radially
from the
shaft. The pushing plates can be rotated via the shaft in a rotation direction
for pushing a
successive portion of the longitudinal heap onto the conveyor inlet. The
pushing plates
can be pivotally mounted to the shaft and biased in the rotation direction of
the loading
head to a predetermined radial position.
The conveyor can include a downstream section mounted to a wheeled frame, and
an
upstream section having the inlet, the upstream section being pivotally
mounted to the
wheeled frame to allow an up and down displacement of the inlet. This can
allow the
conveyor inlet to closely follow the surface of the ground, and limit the
amount of
earthen material which passes underneath it. The upstream section can
advantageously be
relatively short compared to the downstream section, so it can be less costly
to replace if
it is damaged by friction against the ground.
In some cases, the costs related to maintaining non-paved shoulders of roads
can be
reduced by separating, at least partially, a soil and gravel component of the
earthen
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material from a vegetation component, after picking up by the loading head and
conveyor. This separation can be achieved using a cylindrical sieve rotatable
along a
longitudinal axis inclined from the horizontal. The sieve can have an inlet
end vertically
higher than its outlet end, and positioned to receive material exiting the
conveyor outlet.
The soil and gravel can be returned to the road surface by exiting the
cylindrical surface
of the sieve during rotation, whereas the vegetation component can be dumped
into a
ditch, or loaded in a dump truck, for example, by conveying it from the outlet
of the
sieve.
It was found that returning the soil and gravel component to the road surface
allowed an
economy in the requirement to bring new material to the road to replace the
material
removed by grading. It was also found that dumping only the at least partially
separated
vegetation component of the earthen material in a ditch can result in
significantly less
ditch encumbrance than dumping the entire earthen material. Alternately,
loading only
the separated vegetation component into a dump truck results in reducing the
amount of
dump truck trips.
In accordance with an other aspect, there is thus provided a method of
handling earthen
material removed from a non-paved road surface by grading, the method
comprising :
forming a longitudinal heap of the earthen material;
loading the earthen material from the longitudinal heap onto a conveyor while
displacing the conveyor into the longitudinal heap;
operating the conveyor to convey the loaded material into an upper inlet end
of a
cylindrical sieve mounted for rotation along an axis inclined from the
horizontal; and
rotating the sieve to separate a soil and gravel component of the earthen
material
from a vegetation component of the earthen material, including returning
the separated soil and gravel component onto the non-paved road surface,
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and conveying the vegetation component to a lower outlet end of the
sieve.
It will be understood that separating is to be understood as meaning a
significant partial
separation : there typically remains soil and gravel mixed into the vegetation
component
and vegetation mixed into the soil and gravel component.
The loading can include rotating at least two pushing plates about a
transversal rotation
axis for pushing successive portions of the longitudinal heap from the ground
against,
and onto the conveyor inlet. The at least two pushing plates being pivotally
biased to a
radial equilibrium position to aid the pushing action.
In accordance with still another aspect, there is provided a system for
handling a
longitudinal heap of earthen material, the system comprising : a wheeled frame
body
allowing displacement of the system in a longitudinal direction of the
longitudinal heap,
a cylindrical sieve having a sieve axis inclined from the horizontal, an
outlet end, and an
inlet end at a higher vertical position than the outlet end, the cylindrical
sieve being
operable in rotation about the sieve axis to return a first portion of the
earthen material
having entered the sieve to the ground while conveying a second portion of the
earthen
material to the outlet end, a conveyor mounted to the frame body and having a
conveyor
inlet, and a conveyor outlet leading into the sieve inlet, and a loading head
positioned
adjacent the conveyor inlet and being configured and adapted to load earthen
material
from the longitudinal heap onto the conveyor inlet as the system is displaced
in the
longitudinal direction.
In the present specification, the term earthen material is used to refer to
all the relatively
high density materials which are associated with the soil or ground. It
includes soil and
or gravel, which can have some vegetation mixed thereinto, and also includes
small
rocks. However, it excludes materials consisting solely of vegetation, such as
cut hay for
example.
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DESCRIPTION OF THE FIGURES
Fig. 1 is a side elevation view of an example of a vehicle for handling a
longitudinal heap
of material, towed by a tractor;
Fig. 2 is a top plan view of the vehicle of Fig. 1;
Fig. 3 is a perspective view of the vehicle of Fig. 1, shown without the
tractor;
Fig. 4 is a perspective view, enlarged and fragmented, taken from Fig. 3;
Fig. 5 is a longitudinal cross-section view of the vehicle of Fig. 1;
Fig. 6 is an enlarged view of a portion of Fig. 5;
Fig. 7 is a perspective view, enlarged and fragmented, of a loading head of
the vehicle of
Fig. 1;
Fig. 8 is a view similar to Fig. 7 with a loading head protector removed.
DETAILED DESCRIPTION
Fig. 1 shows a vehicle 10 which carries a system 11 for handling a
longitudinal heap of
material. In this example, the vehicle 10 is a trailer 10a. The trailer l0a is
shown being
towed by a tractor 12 for displacement in a longitudinal direction 13. The
tractor 12 has a
grading blade 14 which can be used to remove a surface layer of earthen
material from a
non-paved road surface, such as a non-paved shoulder of a paved or non-paved
road, and
form a longitudinal heap with the removed earthen material. The trailer l0a
has a
wheeled frame body 16 having a trailer hitch 18 at the front. It also has a
mobile frame
portion 20 pivotally mounted to the frame body 16 at a transversal and
horizontal frame
pivot axis 22. The mobile frame portion 20 is supported on two wheels, which
are
longitudinally offset from the frame pivot axis 22.
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The system 11 includes a conveyor 24. In this example, the conveyor has two
sections, or
portions : a rear section 26 mounted to the frame body 16, and a front section
28
mounted to the mobile frame portion 20.
The system 11 includes a loading head 30 operable to load earthen material
from the
longitudinal heap onto the conveyor 24, as the trailer l0a is towed in the
longitudinal
direction 13. The conveyor 24 has an inlet 32 vertically adjacent to the
ground, and an
outlet 34 substantially higher than the inlet 32. The conveyor 24 is operable
to carry
earthen material loaded on the inlet 32 from the front section 28 of the
conveyor to the
rear section 26 of the conveyor. The rear section 26 is thus downstream from
the front
section 26 relative to the handling path of the earthen material. At the
outlet 34 of the
conveyor 24, the earthen material is fed into an inlet end 35 of a cylindrical
sieve 36,
provided at the rear of the trailer 10a. The cylindrical sieve 36 is operable
in rotation
about its axis 38, which is inclined relative to the horizontal, to separate a
soil and gravel
component of the earthen material from a vegetation component of the earthen
material.
In this example, the soil and gravel component passes through the meshed
cylindrical
surface 40 of the sieve 36 and is released onto the non-paved road surface.
The
vegetation component is carried along the sieve 36 and exits through a lower,
outlet end
42 of the sieve 36.
In this example, a secondary conveyor 44 is provided at the outlet end 42 of
the sieve 36.
The secondary conveyor 44 receives the vegetation component, and carries it to
a desired
location. The secondary conveyor 44 has an outlet 46 which is displaceable
both
vertically and laterally to allow orienting the secondary conveyor outlet 46
either towards
a ditch alongside the road, or, by raising and turning it, orienting it
towards a dump truck
bin, for example. This mobility is also visible in Fig. 2.
The trailer l0a can be displaced in the longitudinal direction of the heap by
the tractor
12. As it is displaced, the conveyor inlet 32 is moved into the longitudinal
heap, and
material thereof is loaded onto the conveyor. The handling path of the earthen
material is
thus from the loading head 30, onto the conveyor 24, and into the sieve 36.
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The loading head 30, the conveyor 24, the sieve 36, and the secondary conveyor
44 can
be operated using hydraulic power. In the illustrated example, a hydraulic
power
generator 48 is provided on the frame body 16 for this purpose. In the
figures, the
hydraulic hoses are omitted, for clarity.
The support assembly 50 of the sieve 36 can be seen more clearly in Figs. 3
and 4. The
sieve 36 is vertically supported by two rotatable shafts 52, one on each side
thereof. In
Figs. 3 and 4, only the right-hand side rotatable support shaft 52 is shown,
though it will
be understood that the support assembly 50 is substantially symmetrical, and a
similar
support shaft is provided on the other side. The support shaft 52 has a
support wheel 54,
56 on each and thereof, which receives the curved surface of the cylindrical
sieve 36.
One of the support shafts 52 is driven by a hydraulic motor (not shown),
whereas the
other is idle. The support shafts 52 are inclined relative to the horizontal
and thus give
the inclination to the axis 38 of the cylindrical sieve 36. The inlet end 35
of the
cylindrical sieve 36 receives the outlet 34 of the conveyor 24 for receiving
material
therefrom. The sieve 36 has a cylindrical sieve surface 40, and has an annular
support
plate 58 extending radially therefrom adjacent the rear end. Rear support
wheels 59 are
connected to the frame 16 at the rear of the sieve 36, and receive the
radially extending
annular support plate 58 of the sieve 36. The rear support wheels 59, by their
abutment
against the annular support plate 58, prevent the sieve 36 from sliding
longitudinally
towards the rear of the trailer 10a. The amount of inclination of the sieve 36
can vary in
different applications and the exact choice thereof is left to those skilled
in the art. In can
even be made adjustable in certain applications.
The conveyor 24 is shown in greater detail in Fig. 5. The rear section 26 is
fixed to the
frame body 16 of the trailer 10a. The front section 28 is mounted to the
mobile frame
portion 20. The conveyor inlet 32 is provided on the front section 28 of the
conveyor 24.
The inlet 32 can advantageously be adjusted to be as close as functionally
possible to the
ground, to encourage as much earthen material possible to be loaded onto the
front
section 28, rather than passing under it. In the illustrated example, the
vertical height
adjustment of the conveyor inlet 32 can be made by adjusting the height of the
wheels 21
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which support the mobile frame portion 20. Fig. 6 shows how height adjusters
60 are
used to allow fine tuning of the height of the support wheels 21. The pivoting
displacement of the mobile frame portion 20 around the frame pivot axis 22
allows
vertical displacement of the conveyor inlet 32 when the support wheels 21
encounter
bumps or holes in the road surface.
Referring to Figs 7 and 8, the loading head 30 is operable in rotation to push
earthen
material from the longitudinal heap onto the conveyor inlet 32. The loading
head 30 is
supported by pivot arms 61, 62, which are pivotally mounted to the mobile
frame
portion 20. The pivot arms 61, 62 normally rest against the mobile frame
portion 20, due
to the weight of the loading head, but the loading head 30 can be lifted, and
pivoted
about the loading head pivot axis 64. Hence, the loading head 30 can pivot
about the
loading head pivot axis 64 independently of the position of the mobile frame
portion 20
about the frame pivot axis 22.
In Fig. 7, the loading head 30 is covered by a protector 66. In Fig. 8, the
loading head
protector 66 is shown removed, in dotted lines. In this example, the loading
head 30
includes a loading head shaft 68 rotatably mounted at the far ends of the
loading head
pivot arms 61, 62. Two pushing plates 70, 71 are provided on opposite sides of
the
shaft 68, and extend in a substantially opposite radial direction therefrom.
The pushing
plates 70, 71 are operable in a rotation direction 72 (shown in Fig. 5) by
rotating the
rotary shaft 68. In this case, each pushing plate 70, 71 is pivotally mounted
to brackets
74a, 74b, 74c, themselves affixed to the rotary shaft 68. Springs 76a, 76b,
76c, 76d bias
the pushing plates 70, 71 in the rotation direction 72 of the loading head 30.
Rotary stops
78a, 78b, 78c are provided on the brackets 74a, 74b, 74c, on the opposite side
of the
pushing plate 71 than the springs 76c, 76d. A similar arrangement is provided
on the
other pushing plate 70. The stops 78a, 78b, 78c, serve to limit the pivotal
movement span
of the pushing plate 71 in the rotation direction 72. The springs 76c, 76d,
normally
maintain the pushing plate 71 in a radial equilibrium position against the
rotary stops
78a, 78b, 78c, but during operation, i.e. rotation, of the loading head 30 and
engagement
of the pushing plates 70, 71 against material in the longitudinal heap, the
springs can
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allow the pushing plates 70, 71 to pivot in the direction opposite the
rotation direction 72
to limit the amount of force exerted against the rotary shaft motor 80 by the
pushing
plates 70, 71.
Referring to Fig. 5, as the trailer l0a is moved forward along the
longitudinal heap, and
the rotation of the rotary shaft 68 continues, a portion of the longitudinal
heap is
eventually pushed onto the conveyor 24 by the pushing plates 70, 71, aided by
the
biasing action of the springs 76a, 76b, 76c, 76d.
For indicative purposes, in the example described above, the rotation speed of
the rotary
shaft 68 is of about 60 RPM. The speed of the tractor is adapted to the amount
of earthen
material, and to its density. When there is less material to handle, the speed
of the vehicle
can typically be increased. The horizontal component of the speed of the front
section 28
of the conveyor 24 is adjusted to be at least that of the displacement speed
of the system
11. The rear section 26 of the conveyor is adjusted to be at least as fast as
the front
section 28, to reduce the likelihood of material accumulation. To this end,
the front
section 28 and the rear section 26 can be drivingly linked to one another. In
this example,
the sieve has 2 inch mesh, and is rotated at a speed of about 30 to 60 RPM.
It shall be understood that the example described above and illustrated is
intended to be
exemplary only. Various alternatives, variants and equivalents can be present
in alternate
embodiments of the system. For instance, in certain applications, the
secondary conveyor
and the sieve can be entirely omitted. The material can be loaded using a
loading head
onto the conveyor, and can be carried with the conveyor directly to a dump
truck, for
example.
In the example, the longitudinal heap handling system has several components
provided
in the form of a towable trailer. It will be understood that the system can
alternately be
provided directly as part of a specialized motorized vehicle, instead of being
towed as a
trailer, and that components of the system can be shared differently between a
towing
vehicle and a trailer.
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In some applications, it can be advantageous to provide closing plates to
block off the
meshed walls of the sieve, to allow converting the trailer to a non-sieving
trailer. In such
a case, the loaded material will pass through the sieve and be carried
directly onto the
secondary conveyor by the closing plates. This can be advantageous in cases
where it is
desired to load the material into a dump truck without sieving.
The system can be used to handle longitudinal heaps of earthen materials other
than
grading residues from non-paved road surfaces. For example, the system can be
adapted
to handle a longitudinal heap of 0" to 3/4" gravel, or rocks, which can be
aligned using a
stone rake, for example.
In the example above-described, the loading head, conveyor, and sieve are
aligned in a
substantially longitudinal manner. It will be understood that alternate
embodiments can
be provided where one or more of these components would not be aligned in the
longitudinal direction.
The protector cover of the loading head is provided essentially to keep
material from
being thrown by the rotary head, and to act as a barrier to dissuade persons
from placing
their limbs in the rotation span of the rotary head. In certain applications,
the loading
head cover can be omitted.
Various alternate configurations can be used to support and rotate the sieve.
Power systems other than an auxiliary hydraulic power unit can be used to
drive one or
more of the powered components of the system.
Instead of being provided in two sections, the conveyor can be provided as a
single
section. However, it is believed that it is advantageous to provide a front
section of the
conveyor with an inlet of adjustable height, or having a height which can vary
depending
on unevenness of the ground. It can also be advantageous that the front
section of the
conveyor be made of a conveyor material having a greater resistance than the
conveyor
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material used in the rear section of the conveyor, because the conveyor inlet
can have a
tendency to friction against the ground, and thus be submitted to more wear.
In alternate embodiments, the loading head can be entirely different than the
one depicted
and illustrated. For instance, a rotary brush mounted on a transversal
rotation axis can be
used in certain applications. Alternately, a shovel member attached upstream
of the front
of the conveyor inlet can be used as a loading head. Other equivalents of
rotary loading
heads can also be used. In alternate embodiments, it may not be necessary to
use a
loading head which is pivotable independently from a front portion of a
conveyor. For
example, a simple shovel member may suffice.
It will therefore be understood that the example described above and
illustrated is
intended to be exemplary only. The scope of the invention(s) is intended to be
indicated
solely by the appended claims.
