Frame catcher adaptation for guardrail extruder terminal

Apparatus and methods for preventing penetration of vehicles by causing the guardrail extruder terminal to contact and engage the frame or chassis of vehicles in a collision. In preferred embodiments, a guardrail extruder terminal end treatment is adapted for improved operation during impacts by attachment of a frame catcher penetration guard. The frame catcher adaptation extends below the usual lower edge of the impact head of the guardrail extruder terminal design in order to contact portions of the chassis of a vehicle during an impact at the guardrail end. In several embodiments, the impact head of a guardrail extruder terminal includes a substantially rigid downwardly extending portion which presents an expanded contact area, the location of which approximates the location of a portion of the vehicle's chassis. The frame catcher devices may be retrofitted onto existing guardrail extruder terminal impact heads.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
Not Applicable. 
BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention relates to methods and apparatus for improved safety 
for end treatments on roadway guardrails. In particular, the present 
invention features an improvement upon the guardrail extruder terminal 
safety device. 
2. Description of Related Art 
Guardrails present a unique fixed object safety problem due to the raised 
ends which they sometimes present. Therefore, a number of guardrail end 
treatments have been developed which attempt to reduce the hazard 
presented by the raised ends. Guardrail end treatments seek to reduce the 
harmful effects of collisions with the ends of guardrails by absorbing, 
redirecting or cushioning impacts with the end of the rail. One popular 
end treatment is the guardrail extruder terminal, which is currently 
marketed commercially under the trade name ET-2000. The guardrail extruder 
terminal serves to attenuate impacts with the end of the guardrail and 
provides anchorage for impacts to the sides of the guardrail. In an end-on 
impact, the guardrail extruder terminal progressively flattens the beam of 
the guardrail and bends the flattened member in a curvilinear arc in a 
direction away from the colliding vehicle. Aspects of the guardrail 
extruder terminal have been described and claimed in U.S. Pat. No. 
4,928,928, entitled "Guardrail Extruder Terminal," issued to Buth et al. 
on May 29, 1990, and U.S. Pat. No. 5,078,366, also entitled "Guardrail 
Extruder Terminal," issued to Sicking et al. on Jan. 7, 1992. Both of 
these patents have been assigned to the assignee of the present invention 
and are incorporated herein by reference. The ET-2000 is available 
commercially from Trinity Industries in Dallas, Tex. The guardrail 
extruder terminal features a generally vertically-oriented, rectangular 
striking plate or impact plate which will contact and engage an impacting 
vehicle. Normally, this plate is covered with a reflective material so 
that it is visible to an approaching vehicle. 
As originally developed, the guardrail extruder terminal is constructed so 
that the lower edge of the front striking plate is located approximately 
10-12" above the ground or roadway surface. At this height, however, the 
impact head may contact and engage a smaller impacting vehicle above its 
chassis or structural frame when impacted by this side of the vehicle. As 
a result, a smaller vehicle's superstructure can sustain damage from the 
impact head. Further, there is a risk that smaller vehicles having side 
door openings which are larger than the impact head may have the door 
punched through or punched out by the head during a collision in which the 
side of the vehicle impacts the head. A smaller car may even tend to wedge 
itself beneath the impact head in some situations, thus reducing or 
eliminating the advantage provided by the impact head in preventing 
penetration. This may occur, for example, if the guardrail extruder 
terminal is mounted toward the top of a convex slope, thereby leaving the 
lower edge of the head somewhat higher than is normal or desired for the 
terminal. 
SUMMARY OF THE INVENTION 
The present invention offers methods and apparatus for preventing 
penetration of vehicles by causing the guardrail extruder terminal to 
contact and engage the frame or chassis of even smaller vehicles in a 
collision. 
In preferred embodiments of the invention, a guardrail extruder terminal 
end treatment is adapted for improved operation during impacts by 
attachment of a frame catcher penetration guard. The frame catcher 
adaptation extends below the usual lower edge of the impact head of the 
guardrail extruder terminal design in order to contact portions of the 
chassis of a vehicle during an impact at the guardrail end. In several 
embodiments, the impact head of a guardrail extruder terminal includes a 
substantially rigid downwardly extending portion which presents an 
expanded contact area, the location of which approximates the location of 
a portion of the vehicle's chassis. 
In an alternative embodiment, a frame is provided which is affixed to a 
standard impact head. The frame includes a downwardly extending portion 
which presents the expanded contact area. The frame is also designed to be 
greatly collapsible when impacted from a substantially end-on direction. 
However, when impacted from a direction other than substantially end-on, 
such as a glancing impact direction, the frame is substantially 
non-collapsible and maintains its integrity. The frame includes an outer 
housing which defines a central opening. The housing is formed of a 
unitary outer of sheet metal which surrounds the central opening. In 
another described embodiment, the impact head itself is fabricated in such 
a manner that it extends downward to within four to six inches from the 
ground. 
The frame catcher devices described may be readily retrofitted onto 
existing guardrail extruder terminal impact heads.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
The methods and apparatus of the present invention have been developed for 
and are primarily directed toward use with guardrail extruder terminal end 
treatments for guardrail installations. For the sake of clarity, like 
components among the various embodiments described are numbered alike. 
A first embodiment of the invention may be understood with reference to 
FIGS. 1-3, an exemplary guardrail extruder terminal device 10 has been 
installed onto the upstream end of a guardrail installation 12 along a 
roadway lane 11 along which vehicular traffic travels. The terms 
"upstream" and "downstream," as used herein, are references to the 
direction of expected vehicle traffic along the roadway lane 11. In FIG. 
1, traffic travels in the direction of arrow 13--from upstream to 
downstream. In accordance with this convention, components of the 
guardrail installation 12 can be referred to as being located upstream or 
downstream from other components. 
The guardrail installation 12 includes a horizontal corrugated rail 14 
mounted upon a plurality of support posts 16. A rod or cable assembly 22 
extends from an intermediate portion of the rail 14 down to and through a 
lower portion of the lead support post 16. In some embodiments, such as 
that depicted in FIGS. 9 and 10, horizontal strut 24 extends between the 
two upstream posts 16. 
The guardrail extruder device 10 features a guide 18 which is slidingly 
received upon the rail end 14 and an impact head 20 of standard size and 
dimensions. Structure and operation of the guardrail extruder device 10, 
except as described otherwise herein, is generally described in U.S. Pat. 
Nos. 4,928,928 and 5,078,366. As described in greater detail there, the 
guardrail extruder device 10 will flatten and bend the corrugated rail 
during a collision and extrude the rail away from the impacting vehicle. 
The head 20 is usually formed of iron, steel or a suitable durable alloy 
and presents a top face 26, bottom face 28 and two side faces 30 which 
diverge from the sleeve 18 and terminate at striking face 32 which is 
oriented generally vertically and faces upstream. As best seen in FIGS. 3, 
4 and 21, the upstream striking face 32 is bordered by four flanges 34. 
The striking face 32 is customarily painted or covered with reflecting 
material. With the present invention it is preferred that the guide 18 be 
longer than that used in a standard guardrail extruder device so as to 
offset any bending moment effect which might be associated with the use of 
a lower or extended contact area of the type which will be described. It 
is currently preferred that the length of the guide 18 be increased from 
two to three feet or perhaps as much as 100% in length. 
The striking face 32 presents an upper contact area "A", which approximates 
the height and width of the upstream end of the head 20. The upper contact 
area "A" is located so that it generally engages upper portions of an 
impacting smaller vehicle located above the frame or chassis. For example, 
the upper contact area "A" would be expected to contact portions of the 
door of a smaller vehicle in a side impact scenario. In a typical 
guardrail extruder terminal installation, the upper contact area "A" would 
present a height of 20.5 inches and a width of 20 inches and be located so 
that the lower edge of the contact area is approximately from 10.6-11.4 
inches above the ground 21. 
A frame catcher 36 is affixed by bolts 38 to the bottom face 28 of the head 
20. The frame catcher 36 includes an upstream-facing supplementary contact 
face 40 which is covered by an elastomeric pad 42. As may be seen in FIGS. 
2 and 4, the contact face 40 presents a lower contact area "B." The lower 
contact area "B" is disposed below the upper contact area "A." The lower 
contact area "B" is preferably the same width as the striking face 32 or 
head 20 and is located so as to engage portions of the frame or chassis of 
an impacting vehicle. It is presently preferred that the lower contact 
area "B" extend downward to within four to six inches from the ground. A 
cross brace, or longitudinal fillet, 44 supports the contact face 40. 
The frame catcher 36 is located and adapted so that its lower contact area 
"B" will engage the frame of a smaller impacting vehicle. This is 
illustrated graphically by FIG. 24, wherein an exemplary small car 100 is 
shown in juxtaposition to the guardrail installation 12 with the installed 
extruder terminal device 10. The frame catcher 36 is shown installed on 
the impact head 20. As may be seen, the impact head 20 is aligned 
generally with the door 102 of the small car 100. The frame catcher 36, 
however, is aligned generally with the chassis or frame portion 104 of the 
small car 100. The chassis or frame portion 104 is the structurally 
supporting portion of the small car 100 onto which the body of the small 
car 100 is mounted. As a structural component, the chassis or frame 
portion 104 is typically stronger and significantly more resistant to 
crushing, bending and deformation than the body of a vehicle, including 
the door 102. Due to the presence of the frame catcher 36, therefore, the 
small car 100 should not be penetrated by the impact head 20 during a side 
collision. 
Referring now to FIGS. 5-8, an alternate embodiment is illustrated. A frame 
catcher 50 is affixed to flange 34 of the head 20 by bolts 52. The frame 
catcher 50 also features an upstream-facing contact face 54. An 
elastomeric pad 56 is affixed to the contact face 54. A stop bar 58 is 
affixed to the lower side of the impact head 20. The stop bar 58 helps 
prevent rotation of the frame catcher 50 with respect to the head 20 
during an impact. The stop bar 58 may be either welded or bolted to the 
head 20. 
Referring to FIGS. 9-11, yet another alternate embodiment is shown. A frame 
catcher, generally shown as 60 in FIG. 10 is provided by an 
integrally-formed head 20' which has an extended height "D." The extended 
height "D" is created by a downwardly extending portion 62 which extends 
much further toward the ground 21 than the lower portion of the standard 
impact head 20. The overall height "D" of the head 20' generally 
corresponds to the combined heights of areas "A" and "B" described 
earlier. A conventional guardrail extruder terminal installation could be 
easily retrofitted with a frame catcher 60 by replacing a standard impact 
head with a head having an extended height "D." 
Referring to FIGS. 12-15, still another embodiment of the invention is 
depicted. In this embodiment, a standard impact head 20 is supplied with a 
frame catcher 64 which is formed of a bracket 66 having a pair of 
generally vertically oriented arms 68 which are each interconnected with 
one another at one end by a cross-piece 70. The other end of the arms 68 
are affixed to the flanges 34 of the impact head 20 by a dowel or bar 72. 
As FIGS. 13, 15 and 16 illustrate, the bracket 66 is capable of pivoting 
at the dowel or bar 72 so that it can swing outward from the striking face 
32 of the head 20. A pair of slots 74 (see FIG. 16) are cut into the lower 
flange 34 to receive and accommodate the arms 68 of the bracket 66 when 
the bracket 66 is pivoted toward the striking face 32. 
Referring now as well to FIGS. 17-21, a further exemplary frame catcher 
apparatus 80 is shown which features a collapsible frame 82 that includes 
a unitary sheet metal shell 84. The sheet metal is preferably of #10 gage 
material, however, other suitable thicknesses or gages may be used. The 
sheet metal shell 84 is bent or formed to surround a central opening 86. 
The shell 84 is then affixed to a standard guardrail extruder terminal 
impact head 20 by means of suitable connectors 87. It is presently 
preferred that the connectors 86 comprise a headless, or round-head, bolt 
and nut arrangement as the headless nature of the round head bolt presents 
a smooth appearance and reduces the number of sharp edges or protrusions. 
The shell 84 is formed so that at least a portion 88 extends downwardly 
toward the ground 21 below the lower edge of the striking face 32 of the 
impact head 20. The downwardly extending portion 88, serves as a "frame 
catcher" because it provides a contact area below the level afforded by 
the striking face 32. 
The frame 82 also includes a brace piece 90. The brace piece 90 is 
preferably formed of 1/4" steel plate or plate sections, but other 
suitable plate thicknesses and materials may be used. The brace piece 90 
is generally fashioned to be sturdier than the shell 84, which is made of 
sheet metal. The brace piece 90 is made up of a central attachment section 
92 through which connectors 94 are disposed to affix the brace piece 90 to 
the striking face 32 of the head 20. Two wing braces 96 extend laterally 
from the central attachment section 92 and are affixed at their opposite 
ends to portions of the sheet metal shell 84. The brace piece 90 provides 
some support to the frame 82 against premature collapse and, because the 
brace piece 90 is sturdier than the shell 84, it provides lateral support 
if the frame 82 is impacted upon its longitudinal side as would occur if 
there is a grazing or glancing impact of the terminal by a vehicle. 
However, if the frame 82 is impacted substantially from the end, the frame 
82 should readily collapse in a manner which will be described. 
Particularly during an impact where the side of a smaller vehicle impacts 
the end of a guardrail assembly, the frame catcher 88 will contact and 
engage the chassis portion of the vehicle. Engagement of the vehicle 
chassis results in a more effective stop of the vehicle with a minimum of 
damage to the superstructure of the vehicle. The use of a sleeve 18 having 
an extended length will offset or reduce the effect of a bending moment 
caused by an off-center impact to the downwardly extending portion 88. A 
sufficiently strong bending moment might degrade the ability of a shorter 
sleeve to move along the guardrail end in the manner intended during an 
impact. 
Upon an end impact, the frame 82 will deform so as to expand laterally 
outward forming a wide barrier to penetration of the doorway by the 
object, as depicted by FIGS. 22 and 23. Prior to impact, the frame 82 
presents an end-on impact area of reduced width or "w" in FIG. 22. A 
preferred range of reduced widths, w, is generally from approximately 2 
feet to approximately 4 feet. A particularly preferred reduced width, w, 
is approximately 21/2 feet. During an end-on collision, the frame 82 
deforms so that a second end-on impact area of greater width, w', in FIG. 
23, is provided. The width of the second expanded impact area, w' 
approaches and may exceed the width of space between the "A" and "B" door 
pillars for a vehicle. Preferably, the width of the second expanded area, 
w', is about four feet. 
If desired, the central opening 86 may be filled with a readily deformable, 
energy-absorbent material or member such as aluminum cans. Alternative 
filler materials or members include styrofoam peanuts and ultra low 
strength concrete. 
Now referring to FIGS. 22-23, operation of this apparatus is further 
illustrated. In FIG. 22, an automobile 110 is shown approaching the 
guardrail assembly 12 in the general direction indicated by arrow 112 so 
as to result in an end-on impact to the guardrail assembly 12. Further, 
the automobile 110 is oriented such that the driver's side door 114 is 
facing the guardrail assembly 12 and makes a probable point of impact with 
the guardrail assembly 12. The driver's side door 114 is framed on either 
side by door pillars 116 and 118 (commonly referred to as the "A" and "B" 
pillars). 
FIG. 23 illustrates the automobile 110 and the guardrail assembly 12 during 
the initial portion of the impact between them. As the impact develops 
further (in a manner not described in detail herein), the extruder head 
will begin to flatten and bend portions of the guardrail. Further details 
concerning this aspect of the impact are described in U.S. Pat. No. 
4,928,928, entitled "Guardrail Extruder Terminal," issued to Buth et al. 
on May 29, 1990, and U.S. Pat. No. 5,078,366, entitled "Guardrail Extruder 
Terminal," issued to Sicking et al. on Jan. 7, 1992 which have been 
incorporated herein by reference. As FIG. 23 shows, the frame 82 is 
essentially flattened so that it presents an expanded width area as 
described previously. 
Those skilled in the art will recognize that while the invention has been 
herein shown and described in what is presently believed to be the most 
practical and preferred embodiments thereof, many modifications may be 
made to the invention described while remaining within the scope of the 
claims.