Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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MATERIAL MANAGEMENT SYSTEM AND METHOD FOR CONTINUOUS COLD
IN-PLACE RECYCLING OF PAVEMENT
TECHNICAL FIELD
The invention relates to systems for cold in-place recycling of pavement, and
more
specifically to material management system for continuous cold in-place
recycling of
pavement. The invention also relates to a method for performing cold in-place
recycling of pavement and to a method for manufacturing a material feeder for
a
material management system.
BACKGROUND
Roads are usually coated or paved with a coating material such as asphalt to
enable
them to sustain traffic and to improve their durability.
To pave a road, one may use a road-paving technique called "Cold In-Place
Recycling" (CIR), in which the damaged pavement on a paved surface is recycled
and mixed with new material before being used to repave the road.
Usually, this technique is performed by a crusher vehicle, also known as an
asphalt
milling machine or a cold planer, which "crushes" (i.e. breaks up) the
existing
pavement. The crusher vehicle may comprise a conveyor which evacuates the
crushed pavement material forwardly or rearwardly, typically towards a dump
truck,
which keeps the material until needed by a paver vehicle. A paver vehicle is a
vehicle which uses the used crushed pavement material and/or new pavement
material to repave the road.
The crushing and the paving may be performed in separate operations, or the
crushed pavement material may directly be dumped in or in front of the paver
vehicle. Unfortunately, the rate at which pavement material is crushed and
dispensed to the paver vehicle may not exactly match the quantity of pavement
material needed to repave the road.
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Furthermore, when the paver vehicle requires more crushed pavement material to
repave the road, it may be necessary to resupply the paver vehicle using a
dump
truck containing crushed pavement material. In this case, the operator may
need to
stop the paver vehicle until resupplying is completed, which is time consuming
and
generally undesirable.
Alternatively, a "buggy" may be used to resupply the paver vehicle with
crushed
pavement material. The buggy goes back and forth between the paver vehicle and
the crusher vehicle located further in front of the paver vehicle, or another
external
source of crushed pavement material. Once again, the operator may need to stop
the paver vehicle until resupplying is completed, which is time consuming and
generally undesirable.
There is therefore a need for a system and a method which would overcome at
least
one of the drawbacks identified above.
Features of the invention will be apparent from review of the disclosure,
drawings
and description below.
BRIEF SUMMARY
According to one aspect, there is provided a material management system for
continuous cold in-place recycling of pavement, the system comprising: a
crusher
vehicle for crushing pavement material on a paved ground surface, the crusher
vehicle comprising a first conveyor extending rearwardly from the crusher
vehicle for
continuously evacuating crushed pavement material rearwardly from the crusher
vehicle; a paver vehicle located rearwardly of the crusher vehicle for
repaving the
ground surface using the crushed pavement material; and a material feeder
located
between the crusher vehicle and the paver vehicle for supplying the paver
vehicle
with the crushed pavement material from the crusher vehicle, the material
feeder
comprising a container for receiving and temporarily storing the crushed
pavement
material, the container having an open top container end and a closed bottom
container end, the container further having a front container end located near
the
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first conveyor and a rear container end in communication with the paver
vehicle, and
a second conveyor extending between the front container end and the rear
container
end for continuously moving crushed pavement material rearwardly from the
front
end towards the rear end in order to enable the paver vehicle to repave the
ground
surface the crushed pavement material.
In one embodiment, the crusher vehicle extends between a front end and a rear
end;
further wherein the first conveyor comprises a first conveyor end connected to
the
rear end of the crusher vehicle and a second conveyor end located rearwardly
and
upwardly relative to the first conveyor end.
In one embodiment, the second conveyor end is located above the open top
container end, near the front container end to enable crushed pavement
material to
fall from the first conveyor into the container through the open top container
end.
In one embodiment, the second conveyor end is located rearwardly of the front
container end when the front container end is near the crusher vehicle.
In one embodiment, the material feeder comprises a live bottom truck including
a
trailer mounted on wheels for receiving the container and a mover vehicle
mounted
on powered wheels and coupled to the trailer for displacing the live bottom
truck.
In one embodiment, the live bottom truck comprises a controller secured to the
mover vehicle forwardly of the container, the controller being operatively
connected
to the second conveyor to enable adjusting a conveying speed of the second
conveyor.
In one embodiment, the controller is sized and shaped to fit under the first
conveyor
while remaining spaced from the first conveyor.
In one embodiment, the first conveyor extends upwardly and rearwardly from the
crusher vehicle, the first conveyor thereby defining a first conveyor angle
relative to
the paved ground surface.
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In one embodiment, the material feeder further comprises a guard plate
extending
above the controller, the guard plate being angled relative to the paved
ground
surface at the same angle as the first conveyor angle.
In one embodiment, the controller is operatively connected to the powered
wheels of
the mover vehicle.
In one embodiment, the live bottom truck further comprises a steering system
operatively connected to at least one of the wheels of the trailer and the
powered
wheels of the mover vehicle, the controller being operatively connected to the
steering system to enable an operator to steer the live bottom truck using the
controller.
In one embodiment, the second conveyor comprises: a plurality of axles
rotatably
mounted to the container, near the closed bottom container end, the plurality
of
axles extending transversely relative to the container, each axle having a
first axle
end, a second axle end and a pair of sprockets, each sprocket being secured to
one
of the first and second axle ends; spaced-apart left and right chains, each
chain
engaging the sprocket secured at a corresponding one of the first and second
axle
ends of each one of the plurality of axles; a plurality of transverse members
extending between the left and right chains, the plurality of transverse
members
being spaced from each other to form a support structure; and a belt received
on the
support structure.
According to another aspect, there is also provided a method for performing
cold in-
place recycling of pavement comprising: providing a crusher vehicle comprising
a
first conveyor extending rearwardly from the crusher vehicle; providing a
material
feeder comprising a container having an open top container end and a closed
bottom container end, the container further having a front container end and a
rear
container end, and a second conveyor extending between the front container end
and the rear container end; locating the front container end near the first
conveyor;
locating a paver vehicle near the rear container end such that the rear
container end
is in communication with the paver vehicle; crushing pavement material on a
ground
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surface using the crusher vehicle; continuously moving crushed pavement
material
from the crusher vehicle into the container using the first conveyor;
continuously
moving crushed pavement material from the container to the paver vehicle using
the
second conveyor; repaving the ground surface with the paver vehicle using the
crushed pavement material supplied to the paver vehicle.
In one embodiment, the method further comprises adjusting a debit of crushed
pavement material supplied to the paver vehicle according to a forward travel
speed
of the paver vehicle.
In one embodiment, adjusting the debit of crushed material comprises adjusting
a
conveying speed of the second conveyor.
In one embodiment, the method further comprises, after crushing pavement
material
on the ground surface, mixing the crushed pavement material with a binder
material.
According to yet another aspect, there is also provided a method for
manufacturing
the material feeder of the material management system, the method comprising:
providing a live bottom truck comprising a container and a cab located
forwardly of
the container; removing the cab from the live bottom truck; securing a
controller to
the live bottom truck forwardly of the container to thereby form the material
feeder,
the controller being sized and shaped to fit under the first conveyor when the
front
container end is near the crusher vehicle; operatively connecting the
controller to the
second conveyor to enable controlling a conveying speed of the second
conveyor.
In one embodiment, the method further comprises operatively connecting the
controller to powered wheels of the live bottom truck.
BRIEF DESCRIPTION OF THE DRAWINGS
In order that the invention may be readily understood, embodiments of the
invention
are illustrated by way of example in the accompanying drawings.
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FIG. 1 is a side elevation view of a material management system for continuous
cold
in-place recycling of pavement, in accordance with one embodiment.
FIG. 2 is a longitudinal cross-section view of the material management system
shown in FIG. 1.
FIG. 3 is an enlarged side elevation view of the material management system
shown
in FIG. 1, to better show the controller of the material feeder.
FIG. 4 is an enlarged perspective view, partially cut away, of a feeder
conveyor for
the material management system shown in FIG. 1.
Further details of the invention and its advantages will be apparent from the
detailed
description included below.
DETAILED DESCRIPTION
In the following description of the embodiments, references to the
accompanying
drawings are by way of illustration of an example by which the invention may
be
practiced. It will be understood that other embodiments may be made without
departing from the scope of the invention disclosed.
With reference to FIG. 1, there is provided a material management system 100,
which allows continuous cold in-place recycling of pavement covering a paved
ground surface, such as a road 150. A certain amount of pavement is first
removed
from the road 150, and then may be processed before being reapplied on the
road to
form a new paved surface. Alternatively, instead of a road, the paved ground
surface
may comprise any other paved surface such as a paved surface of a parking lot
or
the like.
In the illustrated embodiment, the system 100 comprises a crusher vehicle 102,
a
paver vehicle 104 located rearwardly of the crusher vehicle 102 and a material
feeder 106 located between the crusher vehicle 102 and the paver vehicle 104.
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It will be understood that the terms "rearwardly" and "forwardly", as used
herein, are
relative to a forward travel direction, indicated by reference arrow F, of the
paver
vehicle 104, the crusher vehicle 102 and the material feeder 106
During a paving operation, the paver vehicle 104, the crusher vehicle 102 and
the
material feeder 106 move in the forward travel direction F, while remaining
substantially close to each other. The crusher vehicle 102 crushes pavement on
the
road 150 and evacuates or moves the crushed pavement rearwardly towards the
material feeder 106. The material feeder 106 supplies the paver vehicle 104
with
crushed pavement material from the crusher vehicle 102, and the paver vehicle
104
repaves the road 150 using the crushed pavement material.
Since the crushed pavement material is first removed from the road before
being
reapplied in a subsequent operation, the system requires little, if any,
crushed
pavement material to be provided by an external source such as a supply truck.
This
advantageously enables the system to operate continuously, i.e. without
stopping,
over relatively great distances, because it does not have to stop in order to
be
resupplied.
Furthermore, the material feeder 106 acts as a buffer between the crusher
vehicle
102 and the paver vehicle 104. The material feeder 106 may be used to
temporarily
store the crushed pavement material and to provide a desired amount of the
crushed
pavement material to the paver vehicle 104, as required by the paving
operation
performed on that location of the road 150. For instance, if more pavement
material
is removed from the road than is needed to repave the road, the material
feeder 106
will accumulate a reserve of crushed pavement material. If more pavement
material
is needed to repave the road than is currently removed from the road, then the
material feeder 106 will draw on its reserve to still provide to the paver
vehicle 104
the desired amount of crushed pavement material to repave the location of the
road
150 over which the paver vehicle 104 is travelling at that moment.
In the illustrated embodiment, the material feeder 106 is located rearward of
the
crusher vehicle 102, and the paver vehicle 104 is located rearward of the
material
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feeder 106 such that the crusher vehicle 102, the material feeder 106 and the
paver
vehicle 104 form a single file during a paving operation. Still in this
embodiment, the
crusher vehicle 102, the material feeder 106 and the paver vehicle 104 each
have a
width which is substantially similar to the width of a single lane of the
road. This
configuration advantageously enables the system 100 to occupy only a single
lane
of the road, thereby preventing the system 100 from blocking traffic in two or
more
lanes during a paving operation.
In one embodiment, a binder material may further be mixed with the crushed
pavement material before the crushed pavement material is applied to the road,
in
order to bind together the crushed pavement material and thereby form a new
paved
surface. The binder material may comprise emulsified bitumen, foamed bitumen
or
any other binder material deemed appropriate by the skilled addressee.
Now referring to FIGS. 1 and 2, the crusher vehicle 102 extends between a
front end
108 and a rear end 110 and comprises a frame 112 mounted on continuous tracks
114. It will be appreciated that instead of the continuous tracks 114, the
frame 112 of
the crusher vehicle 102 may alternatively be mounted on wheels or on any other
type of support means which would enable the crusher vehicle 102 to move
forward.
The crusher vehicle 102 further comprises a cab 116 mounted on the frame 112
between the front end 108 and the rear end 110 to receive an operator of the
crusher vehicle 102 and a crushing drum or cutter drum 118 extending
downwardly
from the frame 112 so as to be able to contact the road 150. The cutter drum
118 is
configured to crush the pavement material on the road 150 when the cutter drum
118 contacts the road 150 during a paving operation.
In the present embodiment, the cutter drum 118 comprises a plurality of
projections
or teeth, not shown, and is operatively coupled to a drum actuator, also not
shown,
which rotates the cutter drum 118 and provides sufficient force to enable the
plurality
of teeth to crush the pavement material on the road 150. It will be
appreciated that
the cutter drum 118 may alternatively be configured according to other
configurations known to the skilled addressee.
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In the illustrated embodiment, the crusher vehicle 102 further comprises a
first
conveyor, or evacuation conveyor 120, which extends rearwardly from the
crusher
vehicle 102 for evacuating the crushed pavement material rearwardly from the
crusher vehicle 102. Specifically, the evacuation conveyor 120 comprises a
first
conveyor end 122 connected to the rear end 110 of the crusher vehicle 102 and
a
second conveyor end 124 located rearwardly and upwardly relative to the first
conveyor end 122. Still in this embodiment, the crusher vehicle 102 further
comprises an intermediate conveyor 126 having a first lower end 128 located
near
the cutter drum 118 and a second upper end, not shown, located near the first
conveyor end 122 of the evacuation conveyor 120 for conveying the crushed
pavement from the cutter drum 118 to the evacuation conveyor 120. The
intermediate conveyor 126 may comprise a belt conveyor, an endless screw
conveyor or other types of conveyors known to the skilled addressee.
The evacuation conveyor 120 is generally sized and shaped to allow its second
conveyor end 124 to be positioned above a desired evacuation location, which,
in
the present case, is the material feeder 106, as will become apparent below.
The
first conveyor end 122 of the evacuation conveyor 120 may be hingeably
connected
to the rear end 110 of the crusher vehicle 102 to allow the second conveyor
end 124
of the evacuation conveyor 120 to be selectively raised and lowered, for
instance to
facilitate storage of the crusher vehicle 102 and/or to facilitate
displacement of the
crusher vehicle 102 at relatively high speeds from one site to another. In
operation,
the evacuation conveyor 120 is maintained at a first conveyor angle 81
relative to the
road 150, such that the second conveyor end 124 of the evacuation conveyor 120
is
located above its first conveyor end 122.
Furthermore, the evacuation conveyor 120 is operatively connected to a
conveyor
actuator, not shown, for actuation of the evacuation conveyor 120. The
intermediate
conveyor 126 may further be operatively connected to this conveyor actuator,
or
may alternatively be connected to a different actuator.
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In one embodiment, the crusher vehicle 102 further comprises an engine, not
shown, operatively coupled to its continuous tracks 114, and may therefore be
independently moved. In this embodiment, the cutter drum 118, the evacuation
conveyor 120 and the intermediate conveyor 126 may further be operatively
connected to the engine, which is selected to provide sufficient power to
operate
these elements.
During operation of the crusher vehicle 102, pavement material on the road is
crushed using the cutter drum 118. The crushed pavement material is then
conveyed upwardly and rearwardly from the road and the cutter drum 118 towards
the first conveyor end 122 of the evacuation conveyor 120 via the intermediate
conveyor 126. The crushed pavement material is then conveyed via the
evacuation
conveyor 120 towards the second conveyor end 124 of the evacuation conveyor
120, to be thereby evacuated rearwardly from the crusher vehicle 102.
In the present embodiment, the evacuation conveyor 120 comprises a belt
conveyor.
However, it will be appreciated that other evacuation means may alternatively
be
used to transfer the crushed pavement material from the crusher vehicle 102 to
the
material feeder 106.
Still in the illustrated embodiment, the crusher vehicle 102 comprises a cold
milling
machine such as one of the WseriesTM cold milling machines manufactured by
Wirtgen GmbH (Winhagen, Germany). It will be appreciated that another type of
crusher vehicles may alternatively be used instead.
In one embodiment, the crusher vehicle 102 further comprises a binder
reservoir, not
shown, containing binder material for mixing with the crushed pavement
material.
The mixing of the binder material with the crushed pavement material may be
performed as the crushed pavement material is conveyed from the cutter drum
118
to the evacuation conveyor 120, for instance when the crushed pavement
material is
conveyed by the intermediate conveyor 126. In this embodiment, the crushed
pavement material is therefore substantially coated with binder material when
it is
transferred from the crusher vehicle 102 to the material feeder 106. In an
alternative
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embodiment, the crusher vehicle 102 does not comprise a binder reservoir. In
this
case, the binder material may be provided from an external source, such as
another
vehicle located near the crusher vehicle 102, or the crushed pavement material
may
be transferred uncoated, i.e. without being coated with binder material, into
the
material feeder 106.
Now referring to FIGS. 1 and 2, the paver vehicle 104 comprises a frame 130
mounted on continuous tracks 131. The paver vehicle 104 has a front end 132
located substantially adjacent the material feeder 106 and a rear end 134. The
paver
vehicle 104 further comprises an inlet hopper 136 to receive crushed pavement
material from the material feeder 106, and material processing means, shown
generally at 138, in communication with the inlet hopper 136 for processing
the
crushed pavement material using processes known to the skilled addressee and
applying the processed crushed pavement material on the road 150 to form a new
paved surface.
In the illustrated embodiment, the inlet hopper 136 is located at the front
end 132 of
the paver vehicle 104, near the material feeder 106, to facilitate the
transfer of
crushed pavement material from the material feeder 106 to the paver vehicle
104.
In one embodiment, the binder material is not provided in the crusher vehicle
102,
but is instead provided by the material processing means 138 of the paver
vehicle
104. In this embodiment, the crushed pavement material is therefore evacuated
uncoated from the crusher vehicle 102 and is temporarily stored uncoated in
the
material feeder 106, before being transferred towards the paver vehicle 104 to
be
received still uncoated in the inlet hopper 136. The crushed pavement material
then
enters the material processing means 138 to be coated with binder material and
processed for application on the road 150.
In the illustrated embodiment, the paver vehicle 104 comprises a standard
paver
vehicle, such as a Vision 5200-2 manufactured by Joseph Vogele AG
(Ludwigshafen, Germany). Alternatively, the paver vehicle 104 may instead
comprise any paver vehicle known to the skilled addressee and deemed
appropriate
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for use in the present system. In yet another embodiment, the paver vehicle
104
instead comprises a custom paver vehicle built for use in the present system.
Now turning to FIGS. 1 and 2, the material feeder 106 comprises a container
140
which is generally elongated in the direction F of forward travel of the
material feeder
106. The container 140 comprises an open top container end 200 and a closed
bottom container end 202 for receiving and temporarily storing the crushed
pavement material. More specifically, the container 140 comprises a front
container
end 204 which is adapted to be located near the second conveyor end 124 of the
evacuation conveyor 130 and a rear container end 206 which may be placed in
communication with the paver vehicle 104, and more specifically with the inlet
hopper 136 of the paver vehicle 104, during a paving operation. The material
feeder
106 further comprises a second conveyor, or feeding conveyor 208, which
extends
generally longitudinally relative to the container 140 at or near the closed
bottom
container end 202 for moving a desired amount of crushed pavement material
rearwardly, from the front container end 204 to the rear container end 206,
towards
the paver vehicle 104 during a paving operation.
In the illustrated embodiment, the feeding conveyor 208 extends generally
horizontally, as shown in FIG. 2. Alternatively, the feeding conveyor 208 may
instead
be angled relative to the closed bottom container end 202.
Still in the illustrated embodiment, the feeding conveyor 208 comprises a belt
conveyor. Alternatively, the feeding conveyor 208 may instead comprise any
other
type of conveyor deemed to be suitable by the skilled addressee.
Still in the illustrated embodiment, the material feeder 106 comprises an
existing
vehicle known in the art as a live bottom truck 210, which has been modified
to be
used specifically in the system 100. A live bottom truck is usually used to
facilitate
dumping of the content of its container rearwardly using a conveyor located at
the
bottom of the container. The conveyor is usually activated to move the content
of the
container rearwardly until the container is substantially empty, and the
conveyor is
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then deactivated. Live bottom trucks are therefore not usually operated
continuously
over a relatively long period of time.
In one embodiment, the live bottom truck 210 comprises an ABS RCseriesTM or BC-
seriesTM live bottom trailer manufactured by ABS Remorques Inc. (Asbestos,
Canada). Alternatively, the live bottom truck 210 may instead comprise any
live
bottom truck known to the skilled addressee and deemed appropriate for use in
the
present system. In yet another embodiment, the material feeder 106 instead
comprises a custom material feeder built for use in the present system.
In the illustrated embodiment, the live bottom truck 210 comprises a trailer
212
mounted on wheels 214 for receiving the container 140 and a mover vehicle 216
mounted on powered wheels 217 and coupled to the trailer 212 for displacing
the
live bottom truck 210. The live bottom truck 210 may further comprise a brake
system, such as a hydraulic brake system, not shown but widely known in the
art,
operatively connected to the wheels 214.
A live bottom truck of the prior art typically further comprises a cab mounted
on the
mover vehicle near the front end of the container for housing an operator of
the live
bottom truck. However, in the present embodiment, the cab of the live bottom
truck
210 has been removed and replaced with a controller 218 secured to the live
bottom
truck 210 on the mover vehicle 216, forwardly of the container 140. The
controller
218 is used to control various elements of the material feeder 106. This
configuration
advantageously prevents the cab from possibly interfering with the evacuation
conveyor 120 and thereby preventing the evacuation conveyor 120 from extending
over the container 140 of the material feeder 106, as will become apparent
below.
Furthermore, if the cab were not removed, it would be located below the
evacuation
conveyor 120. The operator of the material feeder 106 would therefore have to
be
located inside the cab during the paving operation. Since crushed pavement
material
is conveyed on the evacuation conveyor 120 and may fall off from the
evacuation
conveyor 120, the present configuration provides a relatively high level of
safety for
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the operator by obviating the need for the operator of the material feeder 106
to
stand or sit below the evacuation conveyor 120.
In one embodiment, the controller 218 comprises an engine 300 operatively
coupled
to the powered wheels 217 of the mover vehicle 216. This configuration
advantageously provides sufficient power to displace the live bottom truck 210
containing crushed pavement material, which may significantly increase the
weight
of the live bottom truck 210 as one skilled in the art will appreciate. This
configuration also enables the material feeder 106 to be moved independently.
This
advantageously obviates the need to use another vehicle to tow or push the
material
feeder 106 to the desired site or into a storage area, for instance.
Alternatively, the material feeder 106 may not comprise an engine and may
instead
be pushed by the paver vehicle 104.
The controller 218 may further be operatively connected to a steering system,
not
shown, of the live bottom truck 210 to enable the operator to steer the live
bottom
truck 210 using the controller 218. This advantageously enables the system 100
to
be used for paving curved portions of the road 150. It will be appreciated
that the
steering system may be operatively connected to the wheels 214 of the trailer
212 or
to the powered wheels 217 of the mover vehicle 216.
In one embodiment, the steering system comprises an existing steering system
of
the live bottom truck 210, but alternatively, the steering system may comprise
any
other steering system known to the skilled addressee operatively connected to
the
wheels.
In one embodiment, the controller 218 further comprises a hydraulic drive
system
containing hydraulic fluid, which may be operatively coupled to the hydraulic
brake
system of the live bottom truck 210 to power and control the hydraulic brake
system.
The hydraulic drive system may further be operatively coupled to the feeding
conveyor 208 to enable the feeding conveyor 208 to be actuated by the
hydraulic
drive system.
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To enable a desired amount of crushed pavement material to be transferred to
the
paver vehicle 104, a conveying speed of the feeding conveyor 208 may be
adjusted.
More specifically, the feeding conveyor 208 may be operatively connected to a
conveyor speed controller, not shown, for controlling the conveying speed of
the
feeding conveyor 208.
The skilled addressee will understand that when the system 100 is used
continuously over a certain distance, for instance to repave a certain portion
of the
road 150, and during a certain time, the desired amount of crushed pavement
material may instead be expressed as a debit of crushed material.
In one embodiment, the conveyor speed controller comprises a flow valve which
is
operatively coupled to the hydraulic drive system. By manually adjusting the
flow of
hydraulic fluid in the hydraulic drive system using the conveyor speed
controller, the
operator may adjust the speed of the feeding conveyor 208, as a person skilled
in
the art will appreciate.
Alternatively, the conveyor speed controller may instead comprise electronic
control
means which are operated by the operator to adjust the speed of the feeding
conveyor 208.
In yet another embodiment, the conveyor speed controller may instead comprise
automated control means to automatically control the speed of the feeding
conveyor
208 according to the amount of crushed pavement material desired for the
paving
operation. For instance, the automated control means may be configured to
adjust
the speed of the feeding conveyor 208 according to the speed of forward travel
of
the paver vehicle 104. Alternatively, the automated control means may be
configured according to a preprogrammed sequence which corresponds to a
desired
configuration of a portion of the road 150 to be paved. For instance, the
speed of the
feeding conveyor 208 may be increased when the paver vehicle 104 is paving a
predetermined portion of the road 150 in order to deliver a greater amount of
crushed pavement material to the paver vehicle 104. This would enable the
paver
vehicle 104 to form a thicker paved surface on this predetermined portion of
the road
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150. Similarly, the speed of the feeding conveyor 208 may be decreased when
the
paver vehicle 104 is paving the predetermined portion of the road 150 in order
to
deliver a lesser amount of crushed pavement material to the paver vehicle 104.
This
would enable the paver vehicle 104 to form a thinner paved surface on this
predetermined portion of the road 150.
It will also be appreciated that the thickness of the road surface may be
controlled by
varying the forward travel speed of the paver vehicle 104. For instance, in
one
embodiment, the forward travel speed of the paver vehicle 104 and of the
material
feeder 106 may be adjusted within a range extending between about 4 m/min. to
about 7 m/min. It will be appreciated that a lower forward travel speed will
generally
create a thicker road surface, while a greater forward travel speed will
generally
create a thinner road surface.
Furthermore, the controller 218 is sized and shaped to fit under the
evacuation
conveyor 120 while remaining spaced from the evacuation conveyor 120, i.e.
without
interfering with the evacuation conveyor 120. In the embodiment shown in FIGS.
1
and 2, the elements of the controller 218 are selected and positioned on the
live
bottom truck 210 such that the controller 218 is low enough to fit under the
evacuation conveyor 120 without interference with the evacuation conveyor 120,
while still enabling the second conveyor end 124 of the evacuation conveyor
120 to
be positioned above the front container end 204.
In the present embodiment, a guard plate 220 further extends above the
controller
218. The guard plate 220 may be used to prevent damage to the controller 218
which may be caused by crushed pavement material falling from the evacuation
conveyor 120. In one embodiment, the guard plate 220 has a surface area which
is
sufficient to cover the controller 218 when the guard plate 220 is installed
over the
controller 218.
Furthermore, in the illustrated embodiment, the guard plate 220 is angled
relative to
the road 150 at the same angle el as the evacuation conveyor 120 to be able to
fit
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Our ref.: 288682.4
under the evacuation conveyor 120 even when the material feeder 106 is
substantially close to the crusher vehicle 102.
Alternatively, the controller 218 may be positioned elsewhere on the material
feeder
106.
In the illustrated embodiment, the controller 218 is further configured to be
readily
accessible to an operator standing next to the material feeder 106. More
specifically,
the controller 218 comprises a control panel 302 which faces laterally
relative to the
live bottom truck 210. This configuration enables the operator to control the
material
feeder 106 while standing beside the controller 218 and walking alongside the
live
bottom truck 210 as the material feeder 106 travels forward.
Alternatively, the controller 218 may instead be configured to be readily
accessible
to an operator of the paver vehicle 104, which is located rearwardly of the
material
feeder. In this configuration, the operator of the paver vehicle 104, who is
located on
the paver vehicle 104, may thereby visually assess the level of crushed
pavement
material in the inlet hopper 136 and adjust the speed of the feeding conveyor
208 to
prevent the inlet hopper 136 from becoming empty or from overflowing.
In yet another embodiment, the controller 218 may instead be configured such
that
some elements of the controller 218 are accessible by a first operator
standing
beside the live bottom truck 210 while other elements of the controller 218
are
accessible by a second operator located on the paver vehicle 104 and operating
the
paver vehicle 104.
In the illustrated embodiment, a rear end 222 of the feeding conveyor 208 is
located
above and overlaps the inlet hopper 136 of the paver vehicle 102, such that
the
crushed pavement material may fall into the inlet hopper 136 by gravity.
In one embodiment, the paver vehicle 104 may further be secured to the
material
feeder 106 to ensure that the rear end 222 of the feeding conveyor 208 is
always
located above the inlet hopper 136 of the paver vehicle 104 during a paving
operation, as both the paver vehicle 104 and the material feeder 106 are
travelling
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Our ref.: 288682.4
forward. In this configuration, the paver vehicle 104 and the material feeder
106
would travel at the same forward travel speed during the paving operation.
A person skilled in the art will appreciate that other means for transferring
the
crushed pavement material from the feeding conveyor 208 to the inlet hopper
136 of
the paver vehicle 104 may alternatively be used.
The paver vehicle 104 may further be removably secured to the material feeder
106
such that the paver vehicle 104 may be detached from the material feeder 106
when
the system 100 is not performing a paving operation. This would advantageously
facilitate displacing the paver vehicle 104 and the material feeder 106 from
one site
to another and storing the paver vehicle 104 and the material feeder 106
between
paving operations.
In one embodiment, the material feeder 106 is not secured to the crusher
vehicle
102. Instead, the material feeder 106 is spaced from the crusher vehicle by a
given
distance. This given distance may be adjustable during a paving operation to
enable
the material feeder 106 and the crusher vehicle 102 to travel forward at
different
forward travel speeds. For instance, on a portion of the road 150, it may be
desirable
to remove a relatively thin pavement surface and repave this portion of the
road 150
with a relatively thick pavement surface. In this case, the crusher vehicle
102 may
travel at a faster forward travel speed than the paver vehicle 104 and the
material
feeder 106.
As a skilled person will appreciate from FIGS. 1 and 2, the given distance
between
the crusher vehicle 102 and the material feeder 106 may be adjusted such that
the
second conveyor end 124 of the evacuation conveyor 120 is located within a
certain
horizontal range R over the container 140. This certain horizontal range R
extends
rearwardly from the front container end 204 towards the rear container end
206. The
certain horizontal range R is delimited by a rear limit position 224 and a
front limit
position 226. The rear limit position 224 is defined by the location of the
second end
214 of the evacuation conveyor 120 when the crusher vehicle 102 is
substantially
adjacent the material feeder 106 or even contacts the material feeder 106. The
front
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Our ref.: 288682.4
limit position 226 is defined by the location of the second end 214 of the
evacuation
conveyor 120 when the second end 214 of the evacuation conveyor 120 is
substantially vertically aligned with the front container end 204. In this
embodiment,
the second end 214 of the evacuation conveyor 120 remains aligned vertically
with
the open top container end 200 to enable the crushed pavement material to be
transferred by gravity from the evacuation conveyor 120 into the container
140.
A person skilled in the art will appreciate that the crushed pavement material
may be
evacuated rearwardly by the evacuation conveyor 120 with a certain horizontal
rearward speed if the speed of the evacuation conveyor 120 is relatively high.
This
may cause the crushed pavement material to be transferred from the second end
214 of the evacuation conveyor 120 into the container 140 along an arcuate
trajectory, as shown in FIG. 2. Accordingly, in one embodiment, the second end
214
of the evacuation conveyor 120 may be located slightly frontwardly of the
front
container end 204 and still enable the crushed pavement material to be
transferred
by gravity into the open top container end 200.
In an alternative embodiment, the horizontal location of the second end 214 of
the
evacuation conveyor 120 may not be confined within the certain range R
described
above. For instance, the evacuation conveyor 120 may be extendable such that
the
second end 214 of the evacuation conveyor 120 is located rearwardly beyond the
rear limit position 224. Alternatively, the crushed pavement material may be
transferred from the evacuation conveyor 120 into the container 140 using any
other
means deemed suitable by the skilled addressee, in which case the second end
214
of the evacuation conveyor 120 need not be necessarily vertically aligned with
the
open top container end 200.
Now referring to FIGS. 2 and 4, the feeding conveyor 208 extends generally
longitudinally relative to the container 140 and comprises a plurality of
axles 402
which are rotatably mounted to the container 140, near the closed bottom
container
end 202, and which extend transversely relative to the container 140. Each
axle 402
has a first axle end 404, a second axle end, not shown, and a pair of
sprockets 406,
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Our ref.: 288682.4
each sprocket being secured to one of the first and second axle ends 404. The
sprockets 408 engage spaced-apart left chain 400 and right chain, not shown,
and
drive the left and right chains 400 at substantially the same speed.
A plurality of transverse members 408 further extend between the chains 400
and
are spaced from each other to form a support structure for receiving a belt
410. In
this configuration, little or no tension is applied on the belt 410 itself
during operation,
because the tension is instead applied on the chains 400. This advantageously
prevents the belt 410 from being damaged or even breaking under tension,
especially when enough crushed pavement material is deposited on the belt 410
to
substantially impede movement of the feeding conveyor 208. This is also very
advantageous when the belt 410 is used in a substantially continuous manner
over a
certain time, which may impose to the belt 410 more fatigue than it was
designed
for.
Alternatively, instead of a belt conveyor, the feeding conveyor 208 may
comprise
any other type of conveyors deemed suitable by the skilled addressee.
With reference to FIGS. 1 to 4, a method for performing cold in-place
recycling of
pavement will now be described, in accordance with one embodiment.
The paver vehicle 104, the material feeder 106 and the crusher vehicle 102 are
first
provided and positioned on the road 150 to be repaved. The material feeder 106
is
positioned rearwardly of the crusher vehicle 102 and the paver vehicle 104 is
positioned rearwardly of the material feeder 106, as described above. More
specifically, the front container end 204 is located below the second conveyor
end
124 of the evacuation conveyor 130, and the rear container end 206 is located
near
the paver vehicle 104 such that it is in communication with the paver vehicle
104.
The evacuation conveyor 120 is further angled at the angle el and the crusher
vehicle 102 is spaced from the material feeder 106 by a given distance such
that the
second end 214 of the evacuation conveyor 120 is positioned above the open top
container end 200 of the material feeder 106.
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The cutter drum 118 of the crusher vehicle 102 is then powered to crush
pavement
on the road 150. The crushed pavement material is transferred from the road
150 to
the evacuation conveyor 120 via the intermediate conveyor 126, and is
continuously
moved or evacuated rearwardly by the evacuation conveyor 120.
In one embodiment, the crushed pavement material is mixed with a binder
material
before being evacuated rearwardly, as explained above.
The crushed pavement material then falls by gravity from the second end 214 of
the
evacuation conveyor 120 into the container 140 and onto the feeding conveyor
208.
Once in the container 140, the crushed pavement material may accumulate
depending on the conveying speed of the feeding conveyor 208, as one skilled
in the
art will appreciate. The crushed pavement material in the container 140
therefore
acts as a buffer, as explained above.
The crushed pavement material is continuously moved rearwardly by the feeding
conveyor 208 to the paver vehicle 104.
In one embodiment, the debit of crushed pavement material may be adjusted
according to the forward travel speed of the paver vehicle 104. More
specifically, the
debit of crushed pavement material may be adjusted by adjusting the conveying
speed of the feeding conveyor 208 according to the desired debit of crushed
pavement material to be transferred to the paver vehicle 104, as explained
above.
The crushed pavement material is then continuously conveyed or moved
rearwardly
at the desired debit and falls into the inlet hopper 136 of the paver vehicle
104. The
crushed pavement material may then be processed by the material processing
means and applied on the road 150 to thereby repave the road 150.
A person skilled in the art will appreciate that the system 100 described
above may
alternatively be configured according to one of various other configurations.
For
instance, instead of using an existing live bottom truck, the material feeder
106 may
instead be entirely manufactured from scratch.
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Our ref.: 288682.4
In an alternative embodiment, the material feeder 106 does not comprise a live
bottom truck, or any other vehicle. Instead, the container 140 is directly
secured to
the front end of the paver vehicle 104. In this embodiment, the engine of the
paver
vehicle 104 may be selected according to the extra weight of the container 140
and
of the crushed pavement material which may be received in the container 140.
Although the above description relates to a specific preferred embodiment as
presently contemplated by the inventor, it will be understood that the
invention in its
broad aspect includes mechanical and functional equivalents of the elements
described herein.
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