1. Field of the Invention
The impact absorbing device is mounted between the bumper and vehicle frame to absorb crash forces. It includes an energy absorber and at least one bendable plate adjacent to but spaced vertically from the energy absorber.
2. Prior Art
Various forms of energy absorbers have been proposed for vehicles to reduce the shock of an impact on vehicle occupants and vehicle structure. Devices which have been proposed in the past have been effective to absorb impact shock when the vehicle is involved in an accident wherein the impact is directly applied to the front or rear bumpers in a head-on fashion. However, if the impact is angular, prior art devices have been generally ineffective because they are designed for direct impact only. Many automobile accidents do occur in an angular fashion as a result of the driver's swerving the vehicle in an attempt to avoid contact. Most energy absorbers are designed to compress or deform in a linear direction, either fore or aft of the vehicle. When such vehicles are struck at an angle, the sideward force results in sideward bending or tipping of the energy absorber with the end result that it cannot function as desired.
Attempts have been made in the past to overcome this problem by the provision of linkage between the energy absorber and the bumper. The object of the linkage is to translate the forces of impact in such a fashion so as to constrain energy absorber movement in the axial direction for which the absorber is designed. Examples of this approach are shown in U.S. Pat. Nos. 3,834,686, Moritz et al and 4,109,899, Takatsu. However, such arrangements have not been entirely satisfactory in that there is always a translation of forces in linkage structures which results in a non-linear application of the impact forces when such forces are at an angle to the bumper. Further, it is difficult to design linkages which are strong enough to take high-impact forces or forces at a relatively high angle such as a thirty degree crash impact.
The present invention provides a plate construction which is mounted adjacent to an energy absorber. The plate can only bend in one direction. It is oriented so that it bends in a direction perpendicular to the axis along which the energy absorber is designed to function and constrain the energy absorber to collapse along such axis with the result that the desired shock absorbing effect is obtained.