Note: Descriptions are shown in the official language in which they were submitted.
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ROADSIDE BARRIER
This is a divisional application based on application
serial no. 2,106,042 filed on September 13, 1993.
BACKGROUND OF THE INVENTION
This invention relates to roadside barriers of the type
having an elongated container configured to receive and hold
a volume of fluent material, wherein the container includes a
pair of sidewalls having sufficient rigidity to allow the
container to stand alongside a roadway and sufficient
resilience to deform upon an impact by a vehicle and to recover
their shape after at least some impacts.
U.S. Patent 4,681,302 to Thompson, assigned to the
assignee of the present invention, describes an energy
absorbing roadside barrier of the type described above. The
disclosed barrier includes a water filled plastic container
that defines an array of ridges and channels along each side.
Adjacent barriers are interconnected by overlapping mounting
elements which receive vertically oriented pins.
The water contained by the barrier provides mass while
allowing the barrier to deform in an impact. The sidewalls of
the barrier are shaped to reduce friction with the tire of an
impacting vehicle, and the plastic material from which the
barrier is formed is selected to have a low coefficient of
friction. These features combine to reduce the tendency of an
impacting vehicle to climb the barrier during the impact.
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Actual testing has shown the barrier described in the
above-identified Thompson patent to be effective in many
applications. However, the disclosed barrier does have certain
drawbacks. Since the container itself utilizes plastic
materials to define the structure of the container, such
barriers have in the past been formed of relatively expensive
plastic materials such as cross linked polyethylene. Even when
such expensive materials are used, the length of the barrier
has been limited, to 5 feet in one example. This increases the
number of barriers required for any particular application, and
the overall cost. The weight of the barrier when empty should
be kept as low as possible to facilitate use.
Accordingly, it is an object of this invention to
provide an improved energy absorbing barrier which is light in
weight, and which can be built at lower cost using less
expensive materials that allow a barrier of greater length to
be used.
SUMMARY OF THE INVENTION
According to this invention, a roadside barrier of the
type described initially above is provided with at least one
port extending between the sidewalls preferably sized to
receive a fork of a forklift, further preferably comprising two
ports located to receive the forks of a two-forked forklift.
BRIEF DESCRIPTION OF THE DRAWINGS
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Figure 1 is an isometric view of a roadside barrier
that incorporates a first presently preferred embodiment of
this invention.
Figure 2 is a side view of the barrier of Figure 1.
Figure 3 is an end view taken along line 3-3 of
Figure 2.
Figure 4 is an end view taken along line 4-4 of
Figure 2.
Figure ~ is a top view of a frame included in the
barrier of Figure 1.
Figure 6 is a side view taken along line 6-6 of
Figure 5.
Figure 7 is an end view taken along line 7-7 of
Figure 6.
Figure 8 is a cross-sectional view taken along line 8-8
of Figure 2 showing the frame of Figures 5-7 positioned within
the container of Figures 1-4.
Figure 9 is a fragmentary enlarged cross-sectional view
taken along line 9-9 of Figure 3.
Figure 10 is a cross-sectional view of a roadside
barrier that incorporates a second preferred embodiment of this
invention.
Figure 11 is a fragmentary view of a portion of a sheet
of expanded metal included in the embodiment of Figure 10.
Figure 12 is a cross-sectional view of a roadside
barrier that incorporates a third preferred embodiment of this
invention.
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Figure 13 is a top view of the internal frame included
in the embodiment of Figure 12.
DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS
Turning now to the drawings, Figures 1-4 show various
external views of an energy absorbing roadside barrier 10 which
incorporates a presently preferred embodiment of this
invention. This barrier 10 includes a container 12 which is
configured to stand on a support surface alongside a roadway
to act as a barrier to vehicles. The container is formed as
a resilient plastic shell that is molded to define a hollow
internal space which is water tight and is adapted to contain
a liquid such as water to increase the mass of the barrier 10.
The container 12 defines two sidewalls 14, a top wall
16, a bottom wall 18, and two end walls 20. Each of the
sidewalls 14 defines three parallel ridges 22 separated by
channels 24. The ridges 22 and channels 24 extend axially
along the length of the container 12. The sidewalls 14
additionally define forklift ports 34 designed to receive the
forks of a forklift to allow the barrier 10 to be transported
easily. Each of the sidewalls 14 defines a respective drain
28 to allow water to be drained from the container 12. For
example, each drain can include a gate valve that selectively
closes a 1 1/2 inch tube.
The top wall 16 defines two fill openings 26 which can
be plugged with a cap after the container 12 has been filled
with water. The top wall 16 also defines an axially extending
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recess 37 designed to receive a steel cable 27 extending
between the mounting elements 30 at each end of the container
12 to provide longitudinal reinforcement to the barrier 10.
This cable 27 is preferably provided with pin receiving
openings to receive a pin 36, in a manner similar to that
described in the above referenced U.S. Patent 4,681,302.
Each of the end walls 20 defines four mounting elements
30 that protrude outwardly as shown in Figure 2. The mounting
elements 30 each define a respective pin receiving opening 32,
and the openings;32 are aligned vertically. As best shown in
Figures 2-4, the mounting elements 30 on one end of the
container 12 are staggered with respect to the mounting
elements 30 on the other end of the container 12. With this
arrangement, multiple containers 12 identical to that shown in
Figures 1-4 can be positioned end-to-end with the mounting
elements 30 of one container 12 overlying the mounting elements
30 of another adjacent container 12. Then a pin 36 can be
positioned through the pin receiving openings 32 in order to
secure the adjacent containers 12 together to form a continuous
length of barriers.
The features of the barrier 10 described above are
conventional and similar to the corresponding features of the
above-identified Thompson u.s. Patent 4,681,302. This patent
is hereby incorporated by reference in its entirety for its
description of further features of containers suitable for use
in the barrier 10.
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According to this invention, the-barrier 10 also
includes an internal frame 38 as shown in Figures 5-7. The
frame 38 is preferably rigid and formed of elongated metal
elements such as steel angles and flat bars. Preferably, the
frame 38 is more rigid than the container 12, such that the
frame 38 strengthens and rigidifies the container 12 as
described below.
The frame 38 of this preferred embodiment includes two
spaced, parallel axial braces 40 which are interconnected by
two spaced, parallel cross braces 42 to form a rigid structure.
Two upright braces 44 are secured, as for example by welding,
to each of the axial braces 40, and as best shown in Figure 7
the upright braces 44 diverge upwardly.
As best shown in Figures 5 and 7, end braces 46 are
provided at each end of the frame 38. Each of the end braces
46 comprises a set of steel tubes 47, which in turn receive and
retain the ends of respective steel cables 49. The cables 49
are each positioned to fit around a respective one of the pin
receiving openings 32 (Figure 1). Note that the cables 49 are
offset on one end of the frame 38 with respect to the other.
In particular, one end of the frame 38 defines two cables 49
which are secured to the respective tubes 47, while the other
end of the frame 38 defines a single cable 49 which is secured
to the respective tubes 47. If desired, the frame 38 can
include diagonal braces (not shown) to provide increased
rigidity to the frame 38. Bolts may be mounted in the upright
braces 44 to secure the frame 38 to the sidewalls 14.
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Figure 8 shows a cross-sectional view of the frame 38
within the container 12. As shown in Figure 8, the axial
braces 40 are received within respective ridges 22 in the
sidewalls 14, and the upright braces 44 lie alongside the
sidewalls 14. Bolts secure the upright braces 44, and thereby
the frame 38, to the sidewalls 14. Preferably, the frame 38
is positioned with the axial braces 40 approximately 20 inches
above the bottom wall 18. At this height, the frame 38 is
positioned at or near the height of the center of gravity of
a typical passenger car.
Figure 9 shows the manner in which one of the cables
49 is positioned to surround the pin receiving opening 32. As
shown in Figure 9, the cable 49 passes between the pin
receiving opening 32 and the outer wall of the mounting element
30. With this arrangement, a pin positioned in the pin
receiving opening 32 links the frames 38 of adjacent barriers
10 together, while simultaneously linking the containers 12 of
adjacent barriers 10 together.
Simply by way of example and in order to define the
best mode of this invention, the following details of
construction are provided. It should be clearly understood,
however, that these details of construction are not intended
to limit the scope of this invention. In this embodiment the
container 12 is molded from a plastic material such as low
cost, medium density polyethylene which is not cross linked.
The material supplied by Schulman as resin 8461 has been found
suitable. The length of the container 12 is approximately 6
1/2 feet, and the overall height of the container is 32 3/4
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inches. The overall width of the container is about 21 1/2
inches. Conventional molding techniques can be used to mold
the container 12 in one piece around the frame 38. Because the
frame 38 is preferably not heated greatly in the molding
process, the frame 38 is not bonded to the container 12, and
the sidewalls 14 remain free to move relative to the frame 38.
The components of the frame 38 can be formed of a metal
such as ASTM A-36 or AISI M-1020 steel. Simply by way of
example, the axial braces 40 can be angles measuring 2 inches
by 1 1/2 inch in cross secti4n with a wall thickness of 1/8
inch. The cross braces 42, the upright braces 44 and the end
braces 46 can be angles measuring 2 inches by 2 inches in cross
section with a wall thickness of 1/8 inch. The frame 38 can
be welded together so as to be completely prefabricated before
the container 12 is molded around the frame 38.
The barrier 10 described above provides a number of
significant advantages. It is formed of relatively low cost
materials, even though it is longer in length than the prior
art energy absorbing barrier described above. For these
reasons, the barrier 10 can be constructed at an attractive
price.
Additionally, the internal frame 38 stiffens the
sidewalls 14 so that they provide more resistance to the
tendency of an impacting vehicle to move into the container 12
and to form a so called "pocket". In this way any tendency of
an impacting vehicle to snag on the container 12 is reduced.
Furthermore, the frame 38 including the upright braces 44
strengthens the upper central portion of the barrier 10 against
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torsion. Additionally, the frame 38 transfers loads from one
barrier to an adjacent barrier via the end braces 46
interlocked via the pins 36. All of this is achieved in a
light weight structure.
All of these advantages are obtained while largely
preserving the advantages of the barrier of the above-
identified Thompson patent. Because the sidewalls 14 are not
bonded to the frame 38, the sidewalls 14 can still develop the
travelling wave described in the Thompson patent to slow an
impacting vehicle.
Returning to the drawings, ~igures 10 and 11 relate to
a barrier 100 which incorporates a second preferred embodiment
of this invention and Figures 12 and 13 relate to a barrier 200
which incorporates a third preferred embodiment of this
invention.
Both of the barriers 100 and 200 include a container
12 which is identical to that discussed above in conjunction
with Figures 1 through 4. As explained above, each of the
containers 12 includes a pair of sidewalls 14, a top wall 16,
a bottom wall 18 and a pair of end walls 20. The sidewalls 12
each define an axially extending array of ridges 22 separated
by channels 24. Though not shown in Figures 10 through 13, the
end walls 20 define mounting elements identical to the mounting
elements 30 discussed above in conjunction with Figures 1
through 4.
Figure 10 is a cross section of the barrier 100 showing
an internal frame 102 which in this embodiment is a
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substantially rectangular shell comprising axial braces 104,
cross braces 106, and end braces 108.
The axial braces 104 and the cross braces 106 are
secured together as shown in Figure 1 to form a box section.
Each of the axial braces 104 is embedded in a respective
sidewall 14, the upper cross brace 106 may be embedded in the
top wall 16, and the lower cross brace 106 is embedded in an
additional wall 110 that is formed by the forklift port 34.
The end braces 108 are secured to the axial braces 104 and the
cross braces 106, and the end braces 108 are embedded in the
respective end walls 20.
The braces 104, 106, 108 are in this embodiment formed
of expanded metal which is suspended from the sidewall of the
mold and molded into the plastic container 12 during the
molding process. Figure 11 is a fragmentary view of a portion
of one of the sheets of expanded metal. As shown in Figure 11,
the expanded metal sheet defines an array of openings 112, and
each of the openings defines a larger major axis 114 and a
smaller minor axis 116. In this embodiment, the major axes 114
are oriented vertically in the axial braces 104 when the
barrier 100 is positioned alongside a roadway, and the major
axes 114 are oriented parallel to the end wall 20 in the cross
braces 106. This arrangement allows the expanded metal to
contract with the plastic container 12, as the plastic
container 12 cools during the molding process. This
arrangement also reduces the stiffness of the barrier 100
against axially oriented compression forces, which prevents the
barrier 100 from spearing an impacting vehicle.
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The internal frame 102 strengthens the barrier 100
against bending. In particular, because the axial braces 104
are embedded in the sidewalls 14 at the base of the channels
24, the axial braces 104 extend across the ridges 22, and form
box sections with the walls of the ridges 22. In this way, the
axial braces 104 substantially stiffen the ridges 22 against
bending. Furthermore, the cross braces 106 cooperate with the
axial braces 104 to form a large box section which further
stiffens the barrier 100 against bending.
The expanded metal is in part exposed to water and
should preferably be formed of galvanized steel or aluminum.
In alternative embodiments, the internal frame 102 can be
constructed of differing materials, such as composites of
elongated fibers embedded in a resin matrix. For example,
various resin impregnated fabrics can be used, or various
fabrics can be molded directly into the walls of the container
12.
Turning now to Figures 12 and 13, the barrier 200
includes an internal frame 202 that in turn includes first and
second beams 204. Each of the beams 204 comprises a pair of
spaced axial braces 206 interconnected by upper and lower cross
braces 208. The axial braces 206 and the cross braces 208 are
secured together to form a box section.
Each of the beams 204 defines an outer end 210 and an
interior end 212. The outer ends 210 define respective loops
214 which fit around the pin receiving openings of the mounting
elements of the respective end walls 20. The interior ends 212
are coupled together for sliding movement. This can be
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accomplished for example by fitting one interior end 212 inside
the other, as shown in Figure 13. One or more fasteners 216
are provided to immobilize the first and second beams 204
against relative sliding movement.
The internal frame 202 is incorporated in the barrier
200 by first suspending the internal frame 202 within a mold
and then molding container 12 around the internal frame 202.
Initially, the fasteners 216 are not installed, to allow
relative sliding movement between the beams 204. When the
container 12 cools during the molding process, it will shrink
substantially, typically by two to three inches in this
preferred embodiment. The relative sliding movement between
the interior ends 212 accommodates this contraction of the
container 12. Once the container 12 has contracted, the
fasteners 216 are installed to prevent further sliding movement
between the beams 204. Once the fasteners 216 are tightened,
the interior frame 202 substantially reduces or eliminates
stretching of the barrier 200 between the end walls 20 and
stiffens the barrier 200 against bending. Forces applied to
one of the barriers 200 are efficiently transferred to
additional barriers in the direction of travel of an impacting
vehicle in order to cause the barriers to cooperate as a unit.
The internal frame 202 can be made for example of sheet
metal such as galvanized steel which is secured together, as
for example, by riveting. The fasteners 216 can be embodied
as a wide range of alternative structures, including threaded
fasteners, rivets, welds, adhesive fasteners, as well as
various latches and ratchet mechanisms.
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The axial braces 206 of the interior frame 202 are
preferably mounted alongside and adjacent to the respective
sidewalls 14, thereby stiffening the sidewalls 14 against an
impact. It will be understood that though the braces 206, 208
have been identified as separate elements, they can, if
desired, correspond to respective parts of an extruded section.
Because the internal frame 202 is a box frame design
and generally tubular in shape, it can be formed of lightweight
materials. In this preferred embodiment, the internal frame
202 is about 6 1/2 feet in length and lightweight, i.e., less
than 30 pounds in weight. By way of example, the interior
frame 202 can be about 12 inches in height and of an
appropriate width to extend between the sidewalls 14.
It should be appreciated that a wide range of changes
and modifications can be made to the preferred embodiments
described above. For example, the configuration of the
container can be altered to suit the application, and the
container does not require the above described channels and
ridges in all cases. The internal frames can be formed with
other geometries, as long as they provide the rigidifying
function described above. In addition, materials can all be
selected as appropriate for the particular application.
It is the following claims, including all equivalents,
which are intended to define the scope of this invention.
