Patent Publication Number: US-2022220681-A1

Title: Transitions for joining crash impact attenuator systems to fixed structures

Description:
This application claims the benefit under 35 U.S.C. 119(e) of the filing date of U.S. Provisional Application Ser. No. 63/135,413, entitled Transitions for Joining Crash Impact Attenuator Systems to Fixed Structures, filed on Jan. 8, 2021, which application is expressly incorporated herein by reference, in its entirety. 
    
    
     BACKGROUND OF THE INVENTION 
     The present invention relates generally to crash impact attenuators, and more particularly to motor vehicle and highway barrier crash impact attenuators comprising fixed systems protecting leading edges of abutments and other fixed roadside hazards. Most particularly, this invention is concerned with transition hardware for joining the crash impact attenuators to the abutments and other fixed roadway hazards. 
     Vehicular accidents on the highway are a major worldwide problem and are undoubtedly one of the largest causes of economic and human loss and suffering inflicted on the developed world today. In an effort to alleviate, in particular, the human toll of these tragic accidents, guardrails, crash cushions, truck-mounted crash attenuators, crash barrels, and the like have been developed to attenuate the impact of the vehicle with a rigid immovable obstacle, such as a bridge abutment. 
     A crash attenuator of the type described must absorb the vehicle impact energy without exceeding limits on the vehicle deceleration. In addition, it must accommodate both heavy and light weight vehicles. The lightest vehicle will set the limit on the maximum force produced by the attenuator and the heavy vehicle—which will experience a lower deceleration, and thus will determine the total impact deformation required. When impacted head-on, crash attenuators/cushions are designed to absorb energy and to gradually slow the vehicle to a controlled stop. The force cannot exceed the light vehicle limit and therefore the initial force and deceleration is low, limiting the energy absorption. Increasing crash resistance as the vehicle “rides down” from its impact speed to zero is a vitally important feature of a crash attenuator system which meets rigid governmental safety standards. When impacted obliquely on its side, crash cushions are designed to redirect the vehicle back toward the roadway and to prevent severe impact with the rigid point hazard. Typical crash cushions incorporate side rails/panels, intermediate diaphragms, a track to anchor and guide the intermediate diaphragms, and energy absorbers. As crash safety standards have evolved to higher and higher requirements in order to better protect vehicle occupants from injury, it has become clear that new generation crash impact attenuators, or crash cushions, are required to perform this function and meet these high standards in innovative, inexpensive, and very simple, but effective, manners. 
     An important element of an effective crash attenuation system is the transition, or structural connection, between the crash attenuator and the rigid structure behind it, and which it is designed to protect. The present invention is directed to a unique and improve transition structure for securing a crash attenuator to a fixed structure. 
     SUMMARY OF THE INVENTION 
     The present invention provides an improved crash attenuation system, particularly with respect to a significantly improved transition system for securing a crash attenuator to a fixed structure which it is positioned to protect, such as a concrete barrier known in the industry as a “Jersey Barrier”. 
     More particularly, in one aspect of the invention, there is provided a transition system adapted for securing a roadside safety system to a fixed structure, wherein the transition system comprises a plate having a forward end and a rearward end, as well as a front face and a rear face. The transition system further includes a transition mount adapted to secure a rearward end of the roadside safety system to the forward end of the plate, the plate comprising a flat surface which is configured to be conformed to a corresponding surface on the fixed structure. 
     In exemplary embodiments, the system includes a plurality of apertures disposed through the front and rear faces of the plate at its rearward end, the plurality of apertures being adapted to receive mechanical fasteners for securing the plate to the corresponding surface on the fixed structure. 
     Advantageously, the plate includes a taper from a location partially along a length of the plate and extending at an angle rearwardly to the rearward end of the plate. This location, in the illustrated embodiment, is about midway along a distance between the forward end of the plate and the rearward end of the plate. 
     The plate comprises a first width at its forward end and a second width at its rearward end, the second width being smaller than the first width. The width of the plate narrows gradually from the first width at the location partially along the length of the plate to the second width at the rearward end of the plate because of the taper. In the illustrated embodiment, the corresponding surface on the fixed structure is also flat, so that the plate flat surface is adapted to lie in a flush manner on the corresponding flat surface on the fixed structure. 
     The second width at the rearward end of the plate is adapted to correspond in size to a width of the corresponding flat surface on the fixed structure. The taper angle is adapted to the length of the transition plate and to a size of the corresponding flat surface on the fixed structure. The size of the corresponding flat surface on the fixed structure is one or more of its length, width, or area. 
     The transition mount is secured to the forward end of the plate by either mechanical fasteners or by one or more welds. 
     In another aspect of the invention, a transition system is provided which is adapted for securing a roadside safety system to a fixed structure, wherein the transition system comprises a plate having a forward end and extending along a length to a rearward end, as well as a front face and a rear face. The system further comprises a transition mount adapted to secure a rearward end of the roadside safety system to the forward end of the plate. A plurality of reinforcement ribs are disposed in spaced relation to one another on the rear face of the plate. 
     Each one of the plurality of reinforcement ribs is disposed along the length of the plate, and each of the plurality of reinforcement ribs has its own length. The lengths of at least two of the plurality of reinforcement ribs are different from one another, permitting the ribs to be customized to the length and configuration of the plate, particularly taking the taper of the plate into account. Advantageously, each of the plurality of reinforcement ribs is comprised of a C-channel construction. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is an isometric view of an exemplary embodiment of a crash attenuator and transition structure constructed in accordance with the principles of the present invention, taken from a forward perspective, looking rearward; 
         FIG. 2  is an isometric view similar to  FIG. 1 , taken from a rearward perspective, looking forward; 
         FIG. 3  is an isometric view of an exemplary embodiment of the transition structure of the present invention; 
         FIG. 4  is a plan view of the transition structure of  FIG. 3 ; 
         FIG. 5  is a top view of the transition structure of  FIGS. 3 and 4 ; and 
         FIG. 6  is a plan view of the rear or back face of the transition structure of  FIGS. 3-5 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now more particularly to the drawings, there is shown in  FIGS. 1 and 2  a vehicular crash attenuator  10 , which is secured to a fixed abutment or structure  20  by means of a transition plate  30 . The transition plate  30  is shown in greater detail in  FIGS. 3-6 . 
     The vehicular crash attenuator  10  may be of any known type in the industry, typically constructed with a nosepiece  12  at a front end thereof, designed to absorb the first impact from an errant vehicle, and a plurality of compressible sections or stages  14  ( FIG. 2 ). The illustrated example is the DELTA CRASH CUSHION® system, sold by the applicant for the present application, TrafFix Devices, Inc., of San Clemente, Calif., and herein expressly incorporated by reference, but other available crash attenuation systems, available from competitors in the roadside safety marketplace, may also be used. 
     The transition plate  30  is constructed to be conformed to or compatible with the surface of the fixed structure to which it is to be attached, so that the plate lies in a flush manner on that surface when attached. Thus, in the illustrated embodiment, the transition place  30  is substantially flat in configuration, as opposed to prior art transition plates which are typically of a thrie-beam construction. The term “substantially flat” means that it is designed to be flat, and is manufactured to that design, within certain reasonable tolerances. Henceforth, and throughout the claims, the term “flat” will be used, but it is to be understood to mean “substantially flat” to allow for the tolerances typical in all manufacturing operations. The transition plate, as shown, is designed with a taper and shape to mimic the concrete barrier, in this case a barrier commonly identified in the industry as a “Jersey Barrier” to which it is adapted to be attached. However, the type of fixed structure is not important to the invention—any such structure or object having an available flat surface to which the rearward end of the plate can be attached is potentially usable with the inventive transition system. 
     More particularly, the plate  30  includes a taper  32  from a location  34  partially (about midway) along a length of the plate  30  and extending rearwardly to a rearward end  36  of the plate  30 . Thus, the plate  30  comprises a first width at its forward end, and a second smaller width at its rearward end  36 , the width of the plate narrowing gradually from the first width to the second smaller width along the taper  32 . 
     Bolt holes  40  are disposed in the rearward end  36  of the plate  30  for securing the plate  30  to the fixed structure  20 , extending through a front face  41   a  of the plate and a rear face  41   b  of the plate. Note that the taper  32  may be adapted to narrow the plate  30  so that at its rearward end  36 , it is sized so that its width corresponds to the width of an available flat surface  42  on the fixed structure  20 , and the rearward end  36  of the plate  30  may thus be readily secured to the available flat surface  42  using bolts disposed through the bolt holes  40 . Thus, the angle of the taper is adaptable to the length of the transition plate and the size (length, width, and/or area) of the available flat surface  42  on the structure  20 , so that no matter the type of structure to which the transition is to be secured, that securement should be easily attained. 
     Transition mount  44  is adapted to secure the rearward end of the crash attenuator  10  to the transition plate  30 . Fastening of the transition mount  44  may be attained by using mechanical fasteners, but may also be by welding. 
     Shims  46 , illustrated as being of wood, may be inserted between the plate  30  and the fixed structure  20  in locations where there is a gap between the plate  30  and the structure  20 , to fixedly secure the plate to the structure between the transition mount  44  and the fasteners at the rearward end  36  of the plate. 
     A plurality of ribs  48  may be advantageously secured to the rear face  41   b  of the transition plate  30  ( FIG. 6 ) to reinforce the plate. As illustrated, the plurality of ribs are of differing lengths, extending along the length of the plate and spaced vertically from one another, in order to be adapted to the configuration and taper of the plate. Although the structural ribs  48  may be formed of most any known shape, such as commonly available box tubes, they are advantageously formed using a C-channel structure, with the open side of the C-channel facing the rear plate face  41   b . This arrangement is advantageous because it avoids a double thickness of material, thus maximizing cost effectiveness without reducing the strength of the plate. 
     In one exemplary embodiment, for illustrative purposes only, the plate  30  is 3/16 inch plate, with a galvanized finish. The rearward end (second) width is 15.3 in., and the front end (first) width is 24.0 inches. 
     The innovative transition plate of the present invention has been found to result in successful crash testing under current federal MASH standards. In particular, it has been found to minimize snagging, minimize vehicle floor board deformation, and to maximize re-direction of the impacting vehicle.