Patent ID: 7494165

Claim:
A method of making a bumper system for a vehicle, comprising steps of: providing a reinforcement beam adapted for attachment to a vehicle frame; thermoforming a sheet of material to form a thermoformed energy absorber configured to be supported on a face of the reinforcement beam, the energy absorber having a base flange and a plurality of thermoformed longitudinally-elongated crush boxes that extend generally perpendicularly from the base flange in a fore/aft direction parallel a direction of expected impact; the crush boxes each having opposing side walls and orthogonally-related end walls and a side-wall-supported front wall with the crush boxes each being spaced apart from each other along the base flange; the crush boxes each defining a separate rearwardly-facing opening; the energy absorber defining a forward-facing surface and a rearward-facing surface, each being open and unobstructed in a linear direction parallel the fore/aft direction and not having undercut surfaces, the step of thermoforming including passing a portion of mold tooling in a forming direction parallel the fore/aft direction through the base flange linearly into the rearwardly-facing openings defined by the crush boxes and stretching the opposing side walls to have a thickness dimension less than a thickness of the front walls and of the base flange due to the thermoforming process; and assembling the energy absorber to the beam including abutting the thermoformed energy absorber against the beam.