Note: Descriptions are shown in the official language in which they were submitted.
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DRIVE SYSTEM FOR TRANSFERRING ROADWAY BARRIER SYSTEMS
Field of the invention
The present invention relates generally to vehicles
adapted to transfer roadway barrier systems and more
specifically, the present invention relates to a barrier
drive system for such vehicle which is adapted to facilitate
the transfer of barrier systems.
Background of the invention
Roadway barrier systems have become more and more
popular in the present day and age of increased traffic. They
are often used to increase road safety on construction sites,
and allow traffic to better utilise road-space.
One of the existing barrier systems comprises a series
of heavy, interconnected concrete blocks, hinged together to
form a continuous chain. The concrete blocks are designed to
be solid and strong enough to withstand impact by a car and
preventing the car from crossing over the barrier which could
result in a head on collision with oncoming traffic. Such
barrier systems are designed to be moved by a mobile transfer
and transport vehicle that moves the barrier system from a
first position on the roadway to a laterally displaced second
position. The cross-sectional shapes of the concrete blocks
are designed with a T-shaped upper portion that can be
engaged and lifted by such vehicles in order to effect the
movement of the barriers from a first position to a second
position.
A common use for roadway barrier systems is to block off
one or more lanes of traffic on or around construction sites.
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The barrier system thereby protects the workers from
surrounding traffic while they are performing construction on
or around the roadway. Roadway construction is often
performed at night-time when traffic is minimal. During day
time, the barrier system may be positioned out of the traffic
way along the roadside and at a predetermined hour is
transferred onto the roadway to block one or two lanes to
provide the necessary room for the construction crew to
perform their task. In the early morning hours of the next
day, the barrier system is moved back onto the roadside and
the lanes of traffic are re-opened. The transfer vehicle
enables to perform the displacement of the barrier system
quickly and efficiently such that a minimal amount of
construction time is used to set up the barriers.
Another common use for roadway barrier systems is to
divide lanes of oncoming traffic on city arteries in order to
adjust the number of lanes going in each direction during
times of peak traffic. For example, a barrier system may be
used to divide a five-lane highway entering a city into three
lanes entering the city and two lanes exiting the city during
a morning rush hour when the majority of traffic is entering
the city. In the evening, when the majority of traffic is
exiting the city, the barrier system may be moved so that
there are three lanes exiting the city and only two lanes
entering the city. Therefore, the movable barrier system
allows traffic to use the road-space more efficiently. Again
the transfer of the barrier system by the transfer vehicle
must be perform quickly and efficiently to minimise the
amount of time of displacement.
U.S. Patent 4,500,225 and U.S. Patent 4,653,954 both
describe barrier-transferring vehicles adapted to move
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barrier systems from a first position to a laterally
displaced second position. U.S. Patent 4,500,225 describes a
vehicle comprising a conveyor system having a plurality of
guide and support wheels formi.ng an elongated S-shaped track
underneath the vehicle. The guide and support wheels engage
the T-shaped top section of the modules of the barrier system
at one end of the track, gently lift the barrier sections
which are moved through the conveyor system, and deposit the
barrier sections back on the road on the opposite side of the
vehicle. It should be noted that the movement of the vehicle
itself provides the necessary force to lift and move the
barrier sections through the track and effect the
repositioning of the barrier system.
A common problem that arises in barrier moving vehicles
such as the ones described above lies in the fact that in
curved sections of roadway, repositioning of the barrier
system requires an elongation or a retraction of the barrier
system which is proportionate to the radius of the curved
section of the roadway. In practice, the barrier modules
tend to stack up towards one of the ends of the barrier
system when the barrier system is moved towards a smaller
radius and the chain of barrier modules may jammed in front
of the barrier moving vehicle causing long delay. On the
other hand, when the barrier system is moved to a larger
radius, the barrier system tends to stretch and the tension
between each barrier module may become such as to stop the
transfer vehicle in its path or deflect the transfer vehicle
from its course. Even installed in a rectilinear
configuration, tension or compression build up between the
barrier modules may occur which impedes or stop the barrier
moving vehicle.
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U.S. Patent 5,253,951 discloses the use of a barrier
drive system that is capable of either pulling or retarding
the movement of the barrier sections within the elongated S-
shaped track of the transfer vehicle such as to regulate the
forces between the barrier modules as they pass through the
conveyor track. This drive system comprises a pair of large
motorized wheels and tires which frictionally engage the
lower portion of barrier modules and either apply a pulling
force or a retarding force to the barrier modules. However,
this drive system is bulky and applies frictional forces at a
position distant from the position where the barrier modules
are supported thereby creating some tensions at the hinges of
each barrier modules.
U.S. Patent 4,653,954 describes a transfer vehicle for
moving barriers that comprises a series of trolley wheels
that picks up a barrier section under the T-shaped top
portion of the barrier so that the barrier rides up onto a
first guide drum platform. On the vehicle are fore and aft
guide drums, and the barrier chain passes around the first
guide drum and then back around the second guide drum in an
S-shaped path before being lowered onto a second set of
trolley wheels on the opposite side of the vehicle that
deposits the barriers back on the road. The guide drums are
movable longitudinally of the transfer vehicle to vary the
length of barrier carried aboard the vehicles such that any
additional sections required on the larger arc of the larger
radius of a curve may be made up by moving the guide drums
closer together and any excess sections when depositing along
a smaller radius of a curve are absorbed by separating the
guide drums thus retaining them on the transfer vehicle.
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This transfer system is very bulky and requires that a
substantial length of the barrier chain be supported and
handled within the transfer vehicle itself. The vehicle
comprises large moving drums supporting the weight of up to
nine barrier sections each actuated by large hydraulic
cylinders.
Therefore, there exists a need in the industry for a
barrier drive system for a transfer vehicle which is simple
and compact and which facilitates the transfer of a barrier
chain from a first position on a supporting surface to a
second position on the roadway.
Object and Statement of the invention
It is an object of the present invention to provide a
barrier driving system for a barrier-transfer vehicle that is
compact and able to regulate the forces between barrier
sections of a barrier system through its transfer path.
In a second embodiment it is a still further object of
the present invention to provide a barrier drive system for a
barrier-transfer vehicle that is capable of pivoting between
two separate barrier moving paths.
As embodied and broadly described herein, the present
invention provides a barrier transfer vehicle adapted to
transfer a plurality of pivotally connected barrier
sections from a first side of the vehicle to a second
side of the vehicle, said barrier transfer vehicle
comprising:
- a frame;
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- at least one conveyor tract mounted on said frame;
said at least one conveyor tract including a
plurality of aligned guide wheels for engaging,
supporting and guiding the barrier sections;
wherein a section of said at least one conveyor
tract comprises drive wheels adapted to guide,
support and either pull or retard the movement of
the barrier sections through said at least one
conveyor tract, said drive wheels aligned with said
guide wheels.
As embodied and broadly described herein, the present
invention provides a barrier drive system for use in a
vehicle adapted to transfer a plurality of pivotally
connected barrier sections from a first side of the vehicle
to a second side of the vehicle. The barrier drive system
comprises a support frame, at least one actuating means, and
drive wheels pivotally mounted to the support frame. The
drive wheels are adapted to guide and support the barrier
sections. The actuating means is adapted to apply a force to
the drive wheels so that the drive wheels frictionally engage
the surface of the barrier sections. At least one motor is
provided for driving the drive wheels so that the drive
wheels either pull or retard the movement of the barrier
sections through the barrier drive system.
Other objects and features of the invention will become
apparent by reference to the following description and the
drawings.
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Brief description of the drawings
Figure 1 is a partial top plan view of a barrier-transfer
vehicle incorporating a barrier drive system
according to one embodiment of the invention;
Figure 2 is a front elevational view of a conveyor track of
the barrier-transfer vehicle of Figure 1 which is
defined by a plurality of pairs of guide and support
wheels;
Figure 3 is an enlarged perspective view illustrating the
barrier drive system shown in Figure 1 engaging a
section of a roadway barrier system;
Figure 4 is a side elevational view of the barrier drive
system of Figure 3;
Figure 5 is a front elevational view of the barrier drive
system of Figure 3;
Figure 6 is a cross sectional view of the barrier drive
system taken at line 6-6 of Figure 5; and
Figure 7 is a top plan view of the barrier drive system of
Figure 3 as well as a portion of tracks from the
barrier-transfer vehicle of Figure 1; the barrier
driving system being shown in full line aligned to a
first conveyor track and schematically in dotted
lines aligned to a second conveyor track.
In the drawings, preferred embodiments of the invention are
illustrated by way of examples. It is to be expressly
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understood that the description and drawings are only for the
purpose of illustration and are an aid for understanding.
They are not intended to be a definition of the limits of the
invention.
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Detailed description of the preferred embodiment
Figure 1 shows a preferred embodiment of a barrier-
transfer vehicle 10 incorporating a central barrier drive
system 20. Barrier-transfer vehicle 10 is adapted to move a
chain of barrier sections 30 from a first position to a
laterally displaced second position. It comprises a
structural frame 12, an operator cabin 52 located at the
front of Barrier-transfer vehicle 10, a right to left
conveyor track 16, a left to right conveyor track 14 and a
central barrier drive system 20 positioned at the
intersection of conveyor tracks 14 and 16. Barrier-transfer
vehicle 10 is supported on the ground and steered by a front
wheel tandem 54, a rear wheel tandem 56 and two central
wheels on each side of structural frame 12. Front and rear
wheel tandems 54 and 56 are positioned in between the front
and rear portions of conveyor tracks 14 and 16 to minimize
the overall width of Barrier-transfer vehicle 10. The dual
conveyor tracks 14 and 16 allow barrier-transfer vehicle 10
to laterally displace barrier sections 30 from left side of
the road to right side of the road or from right to left.
The dual conveyor tracks 14 and 16 enable barrier-transfer
vehicle 10 to move barrier system 31 from one side of the
road to the other, regardless of which side of the roadway
barrier system 31 is installed. Barrier-transfer vehicle 10
is adapted to move barriers at a speed of approximately 8-
9km/hr.
It should be appreciated that although Figure 1 shows
barrier transfer vehicle 10 as having a single cab area 52,
it is within the scope of the invention for barrier transfer
vehicle 10 to have two cab areas, one at the front of the
vehicle and one at the back of the vehicle. Alternatively
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barrier-transfer vehicle 10 may have no cab areas and simply
be a trailer that can be attached to a truck or other moving
vehicle.
The barrier system 31. comprises a series of closely
spaced, free-standing barrier sections 30 that are
interconnected by hinge-like connectors 35 to form a
continuous chain of barriers sections 30. The hinge-like
connectors 35 are designed to enable barrier sections 30 to
pivot in relation to each other such that barrier system may
easily negotiate the bends of conveyor tracks 14 and 16. The
hinge-like connectors 35 preferably comprise a pair of hinge
plates secured to each end of the barrier sections and a
hinge pin. Each hinge plate comprises an aperture for
insertion of the hinge pin. Barrier sections 30 are
connected together by aligning their respective hinge plates
and inserting the pin inserted into the aligned apertures of
the hinge plates. The pin fits loosely into the aperture
such that there is play between each barrier section 30 so
that they may be placed on the ground closer together, or
farther apart than they were initially picked up.
As best shown in Figure 2, the cross-sectional shape of
barrier section 30 comprises a wide base 32, a central body
33 and a T-shaped upper section 34. Base 32 provides a wide
surface area for barrier section 30 to rest upon. Base 32
not only makes barrier section 30 more stable, but it also
helps to re-direct car wheels back into their appropriate
lane if a car should drive into a barrier section 30. T-
shaped upper section 34 enables barrier-transfer vehicle 10
to engage, and move barrier section 30. As seen in Figure 2,
conveyor tracks 14 and 16 comprise a series of pairs
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inclined guide wheels 22 that engage the shoulders of T-
shaped upper portion 34 and
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guide and support barrier sections 30 trough one of the track
14 or 16.
Referring back to Figure 1, in operation, barrier-
transfer vehicle 10 moves forward as depicted by arrow A, and
barrier sections 30 are engaged and picked up at the front
end of conveyor track 16. Once barrier sections 30 have
entered conveyor track 16, they bend around curved section 18
and travel diagonally across track 16 until they reach the
center of the diagonal section of track 16 at which point is
located barrier drive system 20. After passing through
barrier drive system 20, barrier sections 30 continue along
the diagonal section of track 16 until they bend around
curved section 19. Curved section 19 puts barrier sections 30
back in alignment with the direction of the road. The
forward movement of barrier-transfer vehicle 10 causes
barrier sections 30 to roll through conveyor tracks 14 or 16
along guiding wheels 22 and displaces the chain of barrier
sections 30 from one side of barrier-transfer vehicle 10 to
the other side of barrier-transfer vehicle 10.
The front portions of each conveyor track 14 or 16 are
inclined upwardly and act as ramps that pick up barrier
sections 30, carry them upwards towards central drive system
20 where barrier sections 30 are completely off the ground.
The rear portions of each conveyor track 14 or 16 are
inclined downwardly and carry barrier sections 30 back down
onto the road. Barrier sections 30 enter either of conveyor
tracks 14 or 16 at ground level and as conveyor tracks 14 and
16 ramp upwards, barrier sections 30 are carried upwards off
the ground. Once barrier sections 30 reach the center of the
diagonal section of either of track 14 or 16, barrier
sections 30 are transported through barrier drive system 20
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which is the highest point in the ramp, after which, conveyor
tracks 14 and 16 begin to ramp downwardly so that at the end
of the track, barrier sections 30 are placed gently back on
the road.
It is common for barrier system 31 to pile up or stretch
and jam in various situations such as, but not limited to,
curved portions of roadways, hills or due to improper
installation of the barrier system 31, operator's error or a
combination of these situations. To prevent such
occurrences, a barrier drive system 20 is provided at the
center of conveyor tracks 14 and 16, to help pull through or
retard the movement of barrier sections 30. Central barrier
drive system 20 is rotatably mounted beneath the structural
frame 12 of barrier-transfer vehicle 10, at the intersection
of conveyor tracks 14 and 16 such that it can be positioned
into alignment with either one of tracks 14 or 16. Once
oriented, barrier drive system 20 is an integral part of the
conveyor track that is in operation and guides barrier
sections 30 through barrier-transfer vehicle 10.
Referring now to Figures 3 and 4, the barrier drive
system 20 comprises a support frame 24 underneath which, is
pivotally mounted a pair of brackets 25 and 27 each carrying
a series of three drive wheels 26 driven by two hydraulic
motors 28 mounted atop each bracket 25 and 27. Support frame
24 is pivotally mounted to structural frame 12 through a
large bearing 29 and through clamping devices (not shown).
Support frame 24 may be suitably mounted to structural frame
12 in any other fashion adapted to provide rotational
movement to barrier drive system 20. Each brackets 25 and 27
are pivotally mounted on support frame 24 by a pair of pivots
42 located at opposite ends of each bracket 25 and 27. Each
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bracket 25 and 27 is actuated by a pair of hydraulic pistons
36 pivotally attached at one end via pin 43 to a branch 44
of support frame 24, and at the other end pivotally attached
via pin 43 to brackets 25 and 27. Hydraulic pistons 36 are
used to pivot drive wheels 26 into frictional engagement
with the T-shaped portions 34 of barrier sections 30. In
operation, barrier drive system 20 is aligned with either
one of conveyor tracks 14 or 16 and drive wheels 26 acts as
guiding wheels as well as driving wheels.
Figure 5 shows a front view of barrier drive system 20
engaging a barrier section 30. In operation, drive wheels 26
are brought into frictional engagement with barrier sections
30 by actuating hydraulic cylinders 36 to pivot brackets 25
and 27 downwardly. Hydraulic pistons 36 are used to generate
a force between drive wheels 26 and the surface of barrier
sections 30 in order ensure that there is enough frictional
engagement between drive wheels 26 and the surface of
barrier sections 30 to pull or retard the movement of the
barrier sections 30 through barrier drive system 20.
Without this frictional engagement, drive wheels 26 would
simply spin when motor 28 was activated, and drive wheels 26
would not be able to control the movement of barrier
sections 30. Extension and retraction of hydraulic pistons
36 is selectively controlled by the operator by using
standard controls within cab 52. The initial distance
between each set of drive wheels 26 is adjustable either
mechanically or hydraulically to account for wear of the
drive wheels and to receive barriers of different sizes.
Drive wheels 26 are composed of an elastomeric material that
exhibits flexibility and frictional qualities that enables
them to securely engage barrier sections 30.
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As shown in Figure 6, a standard reversible motor 28 is
mounted to the support bracket 27 and, has its output shaft
connected to drive wheels 26 by a series of gears 56 in order
to supply drive wheels 26 with rotational motion in the same
direction. Motor 28 is connected to a standard control
system accessible to the operator. The control system
provides three possible function modes. In the first mode,
when barrier system 31 is moved from a larger radius to a
smaller radius, motor 28 causes drive wheels 26 to retard
barrier sections 30 into barrier drive system 20 so that they
do not stack up within conveyor tracks 14 or 16. In this
mode, motor 28 and conseqtzently the rotational motion
supplied to drive wheels 26 is controlled by the operator.
Therefore, the operator is in control of the speed at which
barrier sections 30 move through drive system 20 relative to
the speed of barrier transfer vehicle 10. In the second mode,
when barrier system 31 is moved from a smaller radius to a
larger radius, motor 28 causes drive wheels 26 to pull
barrier sections 30 through drive system 20 so that they do
not come under excessive tension. In this mode the operator
is able to control the rotational motion supplied to drive
wheels 26 and therefore is able to control the speed at which
barrier sections 30 are moved through tracks 14 and 16.
Finally, the last mode is the neutral mode, when barrier
system 31 is located in a substantially straight line and the
movement of barrier-transfer vehicle 10 is enough to cause
barrier sections 30 to move smoothly through conveyor tracks
14 or 16. In this mode, motor 28 does not supply any
rotational motion to drive wheels 26, barrier drive system 20
is not operational and drive wheels 26 serve only to guide
barrier sections 30. Tension or compression build up between
barrier sections 30 may still occur when barrier system 31 is
in a substantially straight line configuration and the
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operator may elect to activate barrier drive system 20 and
retard or pull barrier system 31 through conveyor track 14
or 16.
As can be seen by referring back to Figure 5, both
sides of barrier drive system 20 have a motor 28. Although
only one motor on each side is shown in the drawings, it
should be expressly understood that it is within the scope
of the invention to have a single motor run all six drive
wheels 26, or alternatively to have a motor for each
individual drive wheel 26.
As described above, and as shown more specifically in
Figure 7, barrier drive system 20 is pivotable about bearing
29 to be aligned with either conveyor track 14 or 16 in
order to complete the path of whichever track is being used.
Barrier drive system 20 is positioned at the intersection of
tracks 14 and 16, which are separated by an angle of about
30 degrees. Depending upon which track is in use, drive
system 20 may be pivoted between the two. The frame 24
comprises a rotation member, which can take any suitable
form such as a ring gear driven by a small hydraulic motor.
A variety of rotational system may be used to effect
rotational motion to barrier drive system 20 without
departing from the spirit and scope of the invention.
Barrier drive system 20 is pivotally mounted such as to
service two different paths of barrier transferal.
The above description of preferred embodiments should
not be interpreted in a limiting manner since other
variations, modifications and refinements are possible
within the spirit and scope of the present invention. The
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the invention is defined in the appended claims and their
equivalents.
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