Single-sided crash cushion system

Abstract

A single-sided crash attenuation cushion system having an impact head and three stage energy absorption mechanism. The energy absorbing mechanism has a mandrel for deforming thin-walled tubes in a controlled collapse to absorb impact forces from a colliding vehicle. The third stage of the absorption mechanism includes an additional deformable compressible tube between the fixed-object hazard and the thin walled tubes.

1 . A single-side crash cushion system for attachment to a fixed-object hazard comprising: 
 an impact head;    an energy absorption mechanism attached to said impact head, said energy absorption mechanism further comprising: 
 a first stage energy absorber attached to said impact head;  
 a second downstream energy absorber spliced to said first stage energy absorber at a first end of said second stage energy absorber;  
 a third stage energy absorber having a first end section, a middle section, and  
   second end section, said third stage energy absorber extending downstream of said second energy absorber, said first end section of said third stage energy absorber spliced to a second end of said second stage energy absorber, said second end section of said third stage energy absorber connected to said fixed object hazard, said third stage energy absorber having an additional compressible member positioned between said fixed-object barrier and said first end section of said third stage energy absorber.    
     
     
         2 . The system of  claim 1  wherein said additional compressible member is a blockout rail.  
     
     
         3 . The system of  claim 1  wherein said second end of said third stage energy absorber is a tubular member having a first cross-sectional width at the location of said splice between said first stage energy absorber to said second stage energy absorber and tapering to a smaller cross-sectional width a the location of said connection of said second end of said third stage energy absorber to said fixed-object barrier.  
     
     
         4 . The system of  claim 1  wherein said energy absorption mechanism further comprises: 
 a first mandrel having a first tensile strength;  
 a tubular member having a second tensile strength, said first mandrel receivable within a first end of said tubular member such that upon impact forces being applied to said impact head, said first mandrel is urged through said tubular member rupturing said tubular member thereby absorbing said impact forces;  
 means for selectively controlling said rupturing along a length of said tubular member.  
 
     
     
         5 . A single-sided cushion system for attachment to a fixed-object hazard comprising: 
 an impact head;    an energy absorption mechanism attached at a first end to said impact head and at a second end to said fixed-object hazard, said energy absorbing mechanism further comprising; 
 a first mandrel having a first tensile strength;  
 a tubular member having a second tensile strength, said first mandrel receivable within a first end of said tubular member such that upon impact forces being applied to said impact head, said first mandrel is urged through said tubular member rupturing said tubular member thereby absorbing said impact forces, said first mandrel is generally rectangular and said tubular member is generally rectangular and said rupturing of said tubular member is confined to corners of said rectangular tubular member.