US Patent 7871122 Crash box for a vehicle

A crash box consists of two U-profiles (18, 19) of sheet metal, the webs of which (21, 23 and 20, 22) overlap and are joined such that the crash box obtains a closed profile. The two joined sides (21, 23 and 20, 22) of the crash box have a number of transverse dents (26-33) with intermediate side areas (34-40) along their lengths. One web, or both webs, in one pair or in each pair of joined webs (21, 23 and 20, 22) has notches (50-54) in its edge in some of the dents (26-33) or in the intermediate areas (34-40), or both of these, as initiators of deformation.