Patent ID: 7617916

Claim:
A longitudinally-crushable energy-absorbing frame rail tip constructed to mate with a vehicle frame and adapted to support a transverse bumper reinforcement beam on the vehicle frame, comprising: an elongated polygonal tube defining a longitudinal direction and having at least four walls and corners joining the four walls, the tube having a larger first end constructed to mate with a vehicle frame rail and a smaller second end, at least two of the walls including one or more longitudinally elongated channel-shaped tapered ribs starting at the smaller second end and extending toward the larger first end, the ribs extending at least half of a length of the tube and becoming shallower the closer that the ribs are to the larger first end, the channel-shaped tapered ribs undesirably strengthening the at least two walls, but the walls including crush initiators so that the ribs do not provide undesired strength to the tube during a longitudinal impact parallel the longitudinal direction.