U.S. patent application number 11/427459 was filed with the patent office on 2006-10-26 for impact absorbing barrier.
Invention is credited to Bret A. Conway, Tim Lee Williams.
Application Number | 20060239774 11/427459 |
Document ID | / |
Family ID | 35599595 |
Filed Date | 2006-10-26 |
United States Patent
Application |
20060239774 |
Kind Code |
A1 |
Williams; Tim Lee ; et
al. |
October 26, 2006 |
IMPACT ABSORBING BARRIER
Abstract
A deformable panel member is provided for absorbing the energy
of a moving object impacting the panel member. The panel member is
adapted to be connected to a rigid member and has a front wall, a
rear wall and two side walls extending between and interconnecting
the front and rear walls. A support member in panel member extends
between and interconnects at least two of the walls. The side walls
are adapted to be angled relative to the rigid member in a
direction of movement of the object when the panel member is
mounted to the rigid member. An impact on the panel member will
tend to deform the panel member toward the rigid member in the
direction of movement of the object. This deformation allows the
panel member to absorb the energy of the object for decelerating
and redirecting the object subsequent to impact. An energy
absorbing barrier is also provided comprising a plurality of the
panel members mounted at spaced intervals along the rigid member.
The panel members are positioned in adjacent relation for allowing
relative independent movement of the panel members upon impact.
Impact of a panel member will transmit the force of the impact to
adjacent panel members which are similarly deformed for
successively absorbing energy and redirecting the object subsequent
to impact at an angle relative to the rigid member less than the
angle of impact.
Inventors: |
Williams; Tim Lee; (Mt.
Ulla, NC) ; Conway; Bret A.; (Denver, CO) |
Correspondence
Address: |
MOORE & VAN ALLEN PLLC
P.O. BOX 13706
Research Triangle Park
NC
27709
US
|
Family ID: |
35599595 |
Appl. No.: |
11/427459 |
Filed: |
June 29, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11187371 |
Jul 22, 2005 |
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11427459 |
Jun 29, 2006 |
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10390291 |
Mar 17, 2003 |
6921228 |
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11187371 |
Jul 22, 2005 |
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09713362 |
Nov 15, 2000 |
6533495 |
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10390291 |
Mar 17, 2003 |
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Current U.S.
Class: |
404/6 ;
404/10 |
Current CPC
Class: |
E01F 15/145 20130101;
E01F 15/0492 20130101; E01F 15/0453 20130101 |
Class at
Publication: |
404/006 ;
404/010 |
International
Class: |
E01F 15/00 20060101
E01F015/00 |
Claims
1. An apparatus adapted to be mounted to a rigid member for
absorbing the energy of a moving object impacting the apparatus,
the energy absorbing apparatus comprising: a panel member formed of
a deformable material, the panel member having a front wall, a rear
wall and first and second side walls extending between and
interconnecting the front and rear walls, the side walls adapted to
be angled relative to the rigid member in a direction of travel of
the moving object when the panel member is mounted to the rigid
member such that an impact on the panel member by the moving object
will tend to deform the panel member toward the wall and in the
direction of movement of the object along the rigid member to
absorb the energy of and decelerate the object and redirect the
object subsequent to impact at a low angle relative to the rigid
member; and wherein the front, rear and side walls define a cavity
and the panel member further comprises a support member disposed in
the cavity and extending between and interconnecting at least two
of the front, rear, and side walls for providing support to the
panel member.
2. An energy absorbing apparatus as recited in claim 1, wherein the
deformable material of the panel member is also resilient so that
the panel member returns to its original shape after impact by the
moving object.
3. An energy absorbing apparatus as recited in claim 1, wherein the
deformable material of the panel member has a durometer of 70A.
4. An energy absorbing apparatus as recited in claim 1, wherein the
deformable material of the panel member has a Young's modulus of
5000 lb.sub.f/in.
5. An energy absorbing apparatus as recited in claim 1, wherein the
deformable material of the panel member is urethane.
6. An energy absorbing apparatus as recited in claim 1, wherein the
angle of the side walls relative to the rigid member is from about
25 degrees to about 60 degrees.
7. An energy absorbing apparatus as recited in claim 1, wherein the
support member comprises first and second inner walls extending
between and interconnecting the ends of the front wall and rear
wall of the panel member.
8. An energy absorbing apparatus as recited in claim 1, wherein
support member define voids in the panel member cavity, and further
comprising compressible members occupying the voids.
9. An apparatus to be mounted to a rigid member for absorbing the
energy of a moving object impacting the apparatus, the energy
absorbing apparatus comprising: a panel member formed of a
deformable material, the panel member having a front wall, a rear
wall and first and second side walls extending between and
interconnecting the front and rear walls, the side walls adapted to
be angled relative to the rigid member in a direction of travel of
the moving object when the panel member is mounted to the rigid
member such that impact of the panel member by the moving object
will tend to deform the panel member toward the wall in the
direction of movement of the object along the rigid member to
absorb the energy of and decelerate the object and redirect the
object subsequent to impact at a low angle relative to the rigid
member; wherein the front, rear and side walls define a cavity and
the panel member further comprises a support member disposed in the
cavity and extending between and interconnecting at least two of
the front, rear, and side walls for providing support to the panel
member; and means for mounting the panel member to the rigid
member.
10. An energy absorbing apparatus as recited in claim 9, wherein
the deformable material of the panel member is also resilient so
that the panel member returns to its original shape after impact by
the moving object.
11. An energy absorbing apparatus as recited in claim 9, wherein
the deformable material of the panel member has a durometer of
70A.
12. An energy absorbing apparatus as recited in claim 9, wherein
the deformable material of the panel member has a Young's modulus
of 5000 lb.sub.f/in.
13. An energy absorbing apparatus as recited in claim 9, wherein
the deformable material of the panel member is urethane.
14. An energy absorbing apparatus as recited in claim 9, wherein
the angle of the side walls relative to the rigid member is from
about 25 degrees to about 60 degrees.
15. An energy absorbing apparatus as recited in claim 9, wherein
the support member comprises first and second inner walls extending
between and interconnecting the ends of the front wall and rear
wall of the panel member.
16. An energy absorbing apparatus as recited in claim 9, wherein
the support member define voids in the panel member cavity, and
further comprising compressible members occupying the voids.
17. An energy absorbing apparatus as recited in claim 9, wherein
the panel member has a plurality of longitudinal ridges formed on
the outer surface of the rear wall and the mounting means comprises
a mounting bracket having a front surface and a back surface, the
mounting bracket adapted to be attached to the rigid member so that
the rear surface abuts the rigid member, the front surface of the
bracket having a plurality of longitudinal channels for receiving
the correspondingly-shaped ridges on the panel for coupling the
panel member to the bracket.
18. A barrier for absorbing the energy of a moving object impacting
the barrier, the energy absorbing barrier comprising: an elongated
rigid member; a plurality of panel members, each panel member
formed of a deformable material and having a front wall, a rear
wall, and first and second side walls extending between and
interconnecting the front and rear walls, the side walls adapted to
be angled relative to the rigid member in a direction of travel of
the moving object when the panel member is mounted to the rigid
member, wherein the front, rear and side walls define a cavity and
further comprising a support member disposed in the cavity and
extending between and interconnecting at least two of the front,
rear, and side walls for providing support to the panel member; and
means for mounting the plurality of panel members to the rigid
member at spaced intervals extending longitudinally along the rigid
member so that at least a portion of the back wall of each panel
member directly or indirectly abuts the rigid member and the panel
members are positioned in adjacent relation for allowing relative
independent movement of adjacent panel members upon impact by the
moving object, wherein the impact of a panel member by the moving
object will tend to deform the panel member toward the wall and in
the direction of movement of the object along the rigid member for
absorbing the energy and retarding movement of the object and for
transmitting the force of the impact to adjacent panel members such
that the adjacent panel members are similarly deformed for
successively absorbing energy and redirecting the object subsequent
to impact at an angle relative to the rigid member less than the
angle of impact.
19. An energy absorbing barrier as recited in claim 18, wherein the
rigid member comprises a perimeter wall of an automobile
racetrack.
20. An energy absorbing barrier as recited in claim 18, wherein the
rigid member comprises a guardrail adapted to be positioned
adjacent a roadway.
21. An energy absorbing barrier as recited in claim 18, wherein the
deformable material of the panel member is also resilient so that
the panel member returns to its original shape after impact by the
moving object.
22. An energy absorbing barrier as recited in claim 18, wherein the
deformable material of the panel member has a durometer of 70A.
23. An energy absorbing barrier as recited in claim 18, wherein the
deformable material of the panel member has a Young's modulus of
5000 lb.sub.f/in.
24. An energy absorbing barrier as recited in claim 18, wherein the
deformable material of the panel member is urethane.
25. An energy absorbing barrier as recited in claim 18, wherein the
front wall of the panel member presents an outer surface which is
generally smooth and uniform.
26. An energy absorbing barrier as recited in claim 18, wherein the
angle of the side walls relative to the rigid member is from about
25 degrees to about 60 degrees.
27. An energy absorbing barrier as recited in claim 18, wherein the
support member comprises first and second inner walls extending
between and interconnecting the ends of the front wall and rear
wall of the panel member.
28. An energy absorbing barrier as recited in claim 18, wherein the
support member defines voids in the panel member cavity, and
further comprising compressible members occupying the voids.
29. An energy absorbing barrier as recited in claim 18, wherein the
panel member has a plurality of longitudinal ridges formed on the
outer surface of the rear wall and the mounting means comprises a
mounting bracket having a front surface and a back surface, the
mounting bracket adapted to be attached to the rigid member so that
the rear surface abuts the rigid member, the front surface of the
bracket having a plurality of longitudinal channels for receiving
the correspondingly-shaped ridges on the panel for coupling the
panel member to the bracket.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation application of U.S.
patent application Ser. No. 11/187,371, filed Jul. 22, 2005, which
is a divisional application of U.S. patent application Ser. No.
10/390,291, filed Mar. 17, 2003, now U.S. Pat. No. 6,921,228, which
is a continuation application of U.S. patent application Ser. No.
09/713,362, filed Nov. 15, 2000, now U.S. Pat. No. 6,533,495, the
entire contents of all of which are incorporated herein by
reference.
BACKGROUND
[0002] The present invention relates generally to a barrier for
absorbing the energy of impact of a moving object and, more
particularly, to an impact energy absorbing barrier for
decelerating and redirecting a moving object, such as a vehicle,
upon impact with the barrier.
[0003] Almost all automobile racetracks have a perimeter wall
adjacent the track. Racetracks also typically have walls protecting
areas of the infield, especially along pit road. The walls are
designed primarily for the purpose of protecting spectators and
other persons near the track. However, the walls present a danger
to the drivers in the event of a wreck. For example, when a race
car impacts against the wall, even at a shallow angle, the car is
suddenly decelerated resulting in significant damage to the car and
potentially serious and sometimes fatal injury to the driver. In
addition, cars impacting the wall tend to rebound back into traffic
on the racetrack where the cars may be struck by other race cars
traveling at high speeds.
[0004] Similarly, barriers flank roadways or serve as a median
barrier between adjacent roadways. The barriers are generally in
the form of permanent installations, such as heavy concrete
barriers or metal guardrails. Of course, damage to impacting
vehicles and potential injury to occupants of the vehicles is
substantial at high speed due to rapid deceleration and sharp
redirection of the vehicles by the barriers. Some guardrails have
been designed to yield under impact and produce a reduced
resistance to advancement of the vehicle in a selected direction.
However, repair and replacement of guardrails as a result of impact
damage is expensive and time consuming.
[0005] For the foregoing reasons, there is a need for an impact
absorbing barrier which absorbs the impact forces of a moving
object, such as a vehicle, colliding with the barrier for
decelerating the object. The impact absorbing barrier should be
effective for use as a wall on a vehicle racetrack, or as a barrier
installed on a roadway. Ideally, the new impact absorbing barrier
will absorb and dissipate the energy of the impacting vehicle while
also redirecting the vehicle along the barrier to prevent the
rebound of the vehicle into traffic. The new barrier should suffer
little or no damage due to impact, but in the event of damage be
easy to install and repair. The barrier should also be of minimal
depth to prevent loss of roadway or track surface area.
SUMMARY
[0006] Therefore, an object of the present invention is to provide
an impact absorbing barrier which upon impact by a moving object,
such as a vehicle, absorbs the impact energy for decelerating the
vehicle.
[0007] Another object of the present invention is to provide an
impact absorbing barrier which also redirects the vehicle at a low
relative angle with the barrier.
[0008] A further object of the present invention is to provide an
impact absorbing barrier which may be installed or replaced quickly
and easily.
[0009] A still further object of the present invention is to
provide an impact absorbing barrier which requires a small
effective for minimizing loss of roadway or track surface area.
[0010] According to the present invention, there is provided an
apparatus adapted to be mounted to a rigid member for absorbing the
energy of a moving object impacting the apparatus. The energy
absorbing apparatus comprises a panel member formed of a deformable
material. The panel member has a front wall, a rear wall and two
side walls extending between and interconnecting the front and rear
walls. The side walls are adapted to be angled relative to the
rigid member in a direction of travel of the moving object when the
panel member is mounted to the rigid member such that an impact on
the panel member by the moving object will tend to deform the panel
member toward the wall in the direction of movement of the object
along the rigid member. This deformation allows the panel member to
absorb the energy of the object for decelerating and redirecting
the object subsequent to impact at a low angle relative to the
rigid member. A support member is disposed in the cavity defined by
the walls of the panel member and extends between and interconnects
at least two of the walls for providing support to the panel
member.
[0011] Also according to the present invention, an apparatus is
provided to be mounted to a rigid member for absorbing the energy
of a moving object impacting the apparatus. The energy absorbing
apparatus comprises the above-described panel member and support
member and means for mounting the panel member to the rigid member.
In one embodiment, the mounting means comprises a mounting bracket
having a front surface and a back surface and is adapted to be
attached to the rigid member so that the rear surface abuts the
rigid member. The front surface of the bracket has a plurality of
longitudinal channels for receiving correspondingly-shaped ridges
on the outer surface of the rear wall of the panel member for
coupling the panel member to the bracket.
[0012] Further according to the present invention, a barrier is
provided for absorbing the energy of a moving object impacting the
barrier. The energy absorbing barrier comprises an elongated rigid
member and a plurality of the above-described panel members,
including support structure. Means are provided for mounting the
panel members to the rigid member at spaced intervals extending
longitudinally along the rigid member so that at least a portion of
the rear wall of each of the panel members directly or indirectly
abuts the rigid member and the panel members are positioned in
adjacent relation for allowing relative independent movement of
adjacent panel members upon impact. Impact of a panel member by the
moving object will tend to deform the panel member toward the wall
and in the direction of movement of the object along the rigid
member for absorbing the energy and retarding movement of the
object and for transmitting the force of the impact to adjacent
panel members such that the adjacent panel members are similarly
deformed for successively absorbing energy and redirecting the
object subsequent to impact at an angle relative to the rigid
member less than the angle of impact.
[0013] A feature of the deformable material of the panel member is
the physical characteristics which allow then panel member to
withstand the impact while absorbing the energy of the moving
object, including a durometer of 70A and a Young's modulus of 5000
lb.sub.f/in. These properties may be found in rubbers such as
urethane and the like. The material may also be resilient so that
the panel member returns to its original shape after impact by the
moving object. The front wall of the panel member features an outer
surface which is generally smooth and uniform. In one embodiment,
compressible members fill the voids defined voids defined by the
support member in the panel member cavity.
[0014] The energy absorbing panel member and barrier of the present
invention is useful as a perimeter wall of an automobile racetrack
or on a guardrail positioned adjacent a roadway. The barrier
absorbs and dissipates the energy of a collision of a moving
vehicle with a fixed surface while deflecting the vehicle safely
along the fixed surface for reducing the potential injury to the
driver of the vehicle and damage to the protected surface and the
vehicle. Moreover, the barrier is designed to minimize installation
time and maintenance. The mounting assembly has a minimal number of
attachments which allows substantial portions of the barrier
assembly to be removed and replaced quickly on the barrier in the
event of damage. The impact absorbing barrier of the present
invention provides an alternative to rigid perimeter walls on
racetracks lined or other areas including inner walls, pits and
other spectator participant areas.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the present invention
reference should now be had to the embodiments shown in the
accompanying drawings and described below. In the drawings:
[0016] FIG. 1 is a perspective view of an impact absorbing barrier
according to the present invention adjacent a racetrack or
roadway;
[0017] FIG. 2 is an exploded perspective view of an energy
absorbing structure of the barrier as shown in FIG. 1;
[0018] FIG. 3 is a top plan view of an energy absorbing structure
shown in FIG. 2 mounted on a rigid member;
[0019] FIG. 4 is a top plan view of another embodiment of an energy
absorbing structure according to the present invention;
[0020] FIG. 5 is a top plan view of a barrier shown in FIG. 1;
and
[0021] FIG. 6 is a barrier wall as shown in FIG. 1 being impacted
by a moving vehicle.
DESCRIPTION
[0022] Certain terminology is used herein for convenience only. It
is not to be taken as a limitation on the invention. For example,
words such as "upper", "lower", "left", "right", "horizontal",
"vertical", "upward", and "downward" merely describe the
configurations shown in the Figures. Indeed, the components of the
invention may be oriented in any direction in the terminology.
Therefore, the present invention should be understood as
encompassing such variations unless specified otherwise.
[0023] The term "wall" is used broadly herein to cover
longitudinally extending fixed obstacles such as walls of various
heights, as well as bridge piers, medians, guardrails and the
like.
[0024] Referring now to FIG. 1 there is shown a portion of an
automobile racetrack or a roadway adjacent to which is mounted a
barrier wall assembly constructed in accordance with the present
invention and generally designated at 20. The barrier wall assembly
20 includes a plurality of energy absorbing structures 30 mounted
to a rigid wall 32 such as, for example, the perimeter wall of the
racetrack or a guard rail along the roadway 34. As will be
described below, the energy absorbing structures 30 are deformable
under impact by a moving vehicle for decelerating and redirecting
the vehicle striking the barrier wall assembly 20.
[0025] An exploded view of an energy absorbing structure 30 is
shown in FIG. 2. The energy absorbing structure 30 generally
comprises a panel member 40 and a mounting assembly 42. The panel
member 40 is trapezoidal, including a base wall 44, two side
support walls 46, 47 which extend at an angle from the ends of the
base wall 44, and a front wall 48 having an outer surface exposed
to the roadway 34. The walls 44, 46, 47, 48 of the panel member 40
define a cavity 50. Support members 52, 53 span the cavity 50 from
the ends of the base wall 44 to the ends of the front wall 48. The
support members 52, 53 partition the cavity 50, in this case
defining triangular voids using an "X" shape. It is understood that
the support members may partition the cavity 50 in numerous ways
thus defining voids of various shapes (See for example FIG. 4). The
void space formed in the panel member 40 allows the panel member to
deform upon impact for absorbing the kinetic energy of the
impacting object. The voids may also be filled with compressible
material such as open cell foam or the like for further energy
absorbing potential.
[0026] The dimensions of the panel member 40 will be governed by
the material of the panel member 40, racetrack or roadway 34
conditions and use, and the desired energy absorbing capacity of
the barrier wall 20. For example, a panel member for use on a
retaining wall adjacent stock car racetrack has the following
characteristics: TABLE-US-00001 Durometer (shore hardness) 70 A
Young's Modulus (100% elongation) 5000 lb.sub.f/in.sup.2 Poisson's
Ratio .3300 Shear Modulus 1880 lb.sub.f/in.sup.2 Mass Density
0.0041 lb.sub.m/in.sup.3 Thermal Coefficient of Expansion 0.00025
in/in/.degree. F. Allowable Stress 8500 lb.sub.f/in.sup.2 Max.
Yield Stress 8000 lb.sub.f/in.sup.2 Thermal Conductivity 0.00792
btu/sec * in * .degree. F. Specific Heat 0.229846 btu/lb.sub.m *
.degree. F.
[0027] Preferably, the panel member 40 having these characteristics
is made from rubber, and more preferably from urethane. The
urethane panel member 40 may be extruded as one piece. The
one-piece construction is stronger than a multi-piece component and
simplifies installation and repair. Each wall 44, 46, 47, 48 of the
panel member 40 formed from urethane for the stock racetrack
application has a thickness of about 0.5 inches. Preferably, the
panel members 40 accommodate as little space as possible beyond the
face of the wall 32. A representative depth of the panel member 40
from the racetrack wall is about 12 inches and the front wall 48 is
about 8 inches wide. The height of the panel member 40 may vary
with the application and the position of the panel member 40 on the
wall or other rigid member 32. The height and position of the panel
members 40 is selected to provide an impacting vehicle of an
average size with the least tendency for ramping or overturning. In
the proper position, the panel members 40 provide vertical support
to an impacting vehicle so there is no tendency for the vehicle to
roll upon impacting the wall. This can be accomplished by raising
the height of the center of the mass of the panel members 40. For
example, an average passenger vehicle usually has a center of
gravity of about 15 to about 25 inches above the ground which then
determines the height of the panel members 40 to prevent ramping
and rolling.
[0028] It is understood that suitable materials other than urethane
may be used for the panel member 40, as long as the preferred
physical characteristics are achieved. Such materials may include
every kind of raw rubber, including vulcanized rubber, mixed
rubber, and rubber mixed with other materials such as reinforcing
particle rubber with carbon black as the reinforcing particle,
reinforcing short fiber rubber, reinforcing long fiber rubber,
cellular rubber and latex. Other materials that may be used include
high molecular weight, high density polyethylene, synthetic plastic
materials, resin impregnated materials, composites and the
like.
[0029] The mounting assembly 42 comprises a substantially flat
rectangular bracket 54 preferably formed of extruded aluminum. One
side of the bracket 54 defines a plurality of longitudinal channels
57 which are nearly cylindrical in cross-section. The bracket 54
may be secured directly to the wall 32, as for example with
threaded fasteners such as six or eight lag bolts (not shown). With
simple fasteners for mounting the bracket 54, it is possible to
easily replace a bracket damaged during impact with a new bracket
54.
[0030] The outer surface of the base wall 44 has integral,
longitudinal ridges 60. The ridges 60 also present a nearly
cylindrical cross-section and are sized to correspond to the
channels 57 in the bracket 54. Accordingly, the panel member 40 may
be slid into the bracket 54 (FIG. 3) for coupling the panel member
40 to the mounting assembly 42. Other means of coupling the panel
member 40 to the bracket 54 and wall 32 are possible. The goal of
the coupling is to maximize the surface area of the panel member
contacting the rigid member 32, directly or indirectly through the
bracket 54, for distributing the impact force over the greatest
possible area. However, the panel member 40 connection means should
not tend to interfere with the energy absorbing capacity of the
panel member 40 and the smooth redirection of an impacting vehicle
along the length of the barrier assembly 20.
[0031] In constructing the barrier wall 20, a plurality of brackets
54 of the mounting assembly 42 are attached to the wall 32 such
that the channels 57 in the brackets 54 extend generally
vertically. The brackets 54 are arranged in side-by-side spaced
relation along the wall 32. As described above, the panel members
40 are then slid into the brackets 54 with the longitudinal ridges
60 received in the slots 57 in the brackets 54. The panel members
40 are thus suspended in place above the level of the roadway 34
adjacent to the wall 32. As seen in FIGS. 1 and 5, the brackets 54
are positioned so that when the panel members 40 are installed, the
outer surface of the front wall 48 of the panel members 40 present
a smooth surface and are substantially parallel, to the direction
of traffic flow on the adjacent roadway 34. In addition, a space is
left between the adjacent edges of the front walls 48 of succeeding
panel members 40. This configuration prevents the front walls 48
from contacting one another and prevents snagging on impacting
vehicles.
[0032] Another embodiment of the panel member 40 according to the
present invention is shown in FIG. 4. In this embodiment, the
energy absorbing structure 30 includes tubular partitions 62 within
the cavity 50 defined by the walls of the panel member 40. The
tubular partitions 62 thus form the support structure in the panel
member 40. The partitions 62 define one or more hollow cylinders
extending vertically in the cavity. The panel member 40 of this
embodiment may also be extruded as one piece. Alternatively,
resilient tubular components 62 may be mounted individually in the
cavity 50 and attached to the inner surface of the walls 44, 46,
47, 48 of the panel member by any suitable means such as adhesive,
straps, bolts and the like. The tubular partitions 62 may also be
extruded as one piece separate from the panel member 40 and only
one of the tubes needs to be secured to the panel member for
support. When attached by bolts, this arrangement preferably does
not present any obstruction to be struck by an impacting vehicle.
The wall thickness and size of the voids are selected based on the
application. In a stock car racetrack application, the panel member
material should have the same physical characteristics as listed
above.
[0033] Referring to FIG. 1, vehicles that travel along the roadway
34 move in the direction of the arrow "A" which is therefore
generally oriented in the anticipated direction of impact of a
moving vehicle against the wall 34. When mounted on the wall or
rigid member 32, the side walls 46, 47 of the panel member 40 form
an angle with the wall. Preferably, the angle is about 25 degrees
to about 60 degrees with the wall 32. At angles below about 25
degrees, the panel member 40 will not deform forwardly in the
direction of travel of the moving object as efficiently as when a
greater angle is used. Wall 46, 47 angles above 60 degrees result
in a pulling effect on the panel member 40 upon impact, and
straining on the mounting assembly, rather than flexure as a result
of deformation of the panel member 40. The side support wall 46 of
the first panel member 40 is angled in the direction of traffic.
This configuration prevents impacting vehicles from snagging a
forward end of the impact absorbing barrier wall 20.
[0034] Referring to FIG. 6, the outer surface of the front wall 48
of an impacted panel member 40 receives the initial impact force
from a moving vehicle. As the vehicle impacts the panel member 40,
the panel member bends generally inwardly and forwardly, in the
direction of travel of the vehicle, towards the wall 32. The energy
absorbing structure 30 is thus generally elastically deformed
thereby dissipating the kinetic energy and decelerating the moving
vehicle. As the panel member 40 absorbs the impact and continues to
bend inwardly and forwardly toward the wall 32, the panel member
will contact the next adjacent panel member 40 which, in turn,
deforms to further absorb the impact energy of the vehicle. The
panel members 40 assume the general configuration shown in FIG. 6.
The impact force is thus transferred to each successive panel
member 40 in the direction of travel of the vehicle as the impact
event continues. The impact energy is thus effectively distributed
between at least two panel members 40 at any point in time. The
more panel members 40 involved in the impact event, the more energy
absorbing capability. Since the panel members 40 are arranged to
not contact one another prior to impact, each panel member 40 moves
independently towards the wall 32 prior to contacting the adjoining
panel member thus enabling the panel members to work together with
subsequent panels so that the overall deceleration of the vehicle
is achieved. In the racetrack example described above, the panel
members 40 are capable of moving inward and forward to a depth of
about 4 inches, or about two thirds of the initial depth of the
panel member 40.
[0035] Because the operation of the panel members 40 allows each
panel member to articulate with respect to each other, collapsing
inwardly with a component of movement in the direction of travel of
the impacting vehicle, the barrier wall 20 tends to redirect the
impacting vehicle at a low angle of deflection relative to the
direction of the impact, generally along the length of the barrier
wall 20. The low coefficient of friction of the panel member
surface enables the car to slide from panel member 40 to panel
member further reducing any rebounding effect. This encourages the
impacting vehicle to be gradually and smoothly redirected along the
length of the barrier wall 20 and not returned to oncoming traffic.
This reduces risk of further collision with other vehicles.
[0036] Thus, several details of the construction of the disclosed
invention operate severally and jointly to absorb the impact energy
of a moving vehicle and to properly deflect the vehicle from the
barrier wall 20 at a very low angle. The barrier wall 20 redirects
the vehicle sufficiently slowly thus preventing the vehicle from
bouncing back into oncoming traffic adjacent the wall while
minimizing damage to the vehicle and injury to the occupants.
Ultimately, the vehicle is brought to rest clear of the racetrack
or roadway 34.
[0037] The energy absorbing structures 30 are preferably
self-restoring. When the impact event is over and the vehicle is
moved away from a portion of the barrier wall 20, the resilient
material of the panel member 40 allows the panel members 40 to move
outwardly and return to their original configuration. Moreover, the
energy absorbing structures 30 are not damaged in a typical impact.
Even if one or more structures 30 are damaged, a panel member 40 or
mounting assembly 42 can be quickly and easily replaced by simply
removing the panel member from the slots 57 and replacing it with a
new panel member.
[0038] The barrier wall assembly 20 described herein has been
modeled to withstand a head on impact of a stock car vehicle
weighing 3400 pounds at 188 mph. Under these conditions, 31,560
pounds of impulse force at impact will act on the driver. Assuming
a driver weight of 180 pounds, the driver will experience 8.56 G's
of force. The impulse force on the driver of a car impacting the
barrier wall 20 of the present invention acting is 23,140 pounds. A
27% reduction over 0.0001 seconds. The driver will thus experience
a force of 6.25 G's. The rate of reduction in velocity versus the
contact velocity determines the force the driver will experience.
The barrier wall 20 of the present invention reduces this rate by
absorbing energy quickly.
[0039] The new barrier of the present invention has many
advantages, including the ability to absorb and dissipate the
energy of a collision of a moving vehicle with a fixed surface
while deflecting the vehicle safely away from the fixed surface for
reducing the potential injury to the driver of the vehicle and
damage to the protected surface and the vehicle. Moreover, the
barrier is designed to minimize installation time and maintenance.
The mounting assembly has a minimal number of attachments which
allows substantial portions of the barrier assembly to be removed
and replaced quickly on the barrier in the event of damage. The
impact absorbing barrier of the present invention provides an
alternative to rigid perimeter walls on racetracks lined or other
areas including inner walls, pits and other spectator participant
areas. The barrier also is useful on roadways in place of
guardrails or in median strips.
[0040] Although the present invention has been shown and described
in considerable detail with respect to only a few exemplary
embodiments thereof, it should be understood by those skilled in
the art that we do not intend to limit the invention to the
embodiments since various modifications, omissions and additions
may be made to the disclosed embodiments without materially
departing from the novel teachings and advantages of the invention,
particularly in light of the foregoing teachings. For example, the
panel member and barrier may be used under any circumstance where
the energy of a moving member must be absorbed upon impact with the
panel member or barrier. Accordingly, we intend to cover all such
modifications, omission, additions and equivalents as may be
included within the spirit and scope of the invention as defined by
the following claims. In the claims, means-plus-function clauses
are intended to cover the structures described herein as performing
the recited function and not only structural equivalents but also
equivalent structures. Thus, although a nail and a screw may not be
structural equivalents in that a nail employs a cylindrical surface
to secure wooden parts together, whereas a screw employs a helical
surface, in the environment of fastening wooden parts, a nail and a
crew may be equivalent structures.
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