Frangible energy absorbing bumper mounting device

Claim 2

An impact energy absorbing assembly for a vehicle comprising an outer casing having a side wall and a pair of end plates, an elongated shaft extending slidably through the end plates, a transverse plate within the casing extending generally transversely to the shaft and mounted thereon adjacent one of the casing end plates for movement with the shaft as the shaft moves toward the other casing end plate, a shear pin on the transverse plate extending through an opening in the casing side wall, the shear pin being shearable upon the application of predetermined longitudinal force to the shaft, and a plurality of Belleville washers formed of mild steel and mounted on the shaft between the transverse plate and the other end plate of the casing, the Belleville washers being permanently and inelastically deformable as the shaft and the transverse plate slide toward the other end plate of the casing after shearing of the shear pin whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the Belleville washers.

Claim 3

An impact energy absorbing assembly for a vehicle comprising an outer casing having a pair of ends and adapted to be secured to the vehicle, en elongated shaft extending through the casing ends and slidably mounted therein for longitudinal sliding movement, frangible lock means on the shaft engaging the casing for preventing sliding movement of the shaft toward one of the casing ends, the lock means being releasable upon the application of a predetermined longitudinal force to the shaft, and a plurality of Belleville washers formed of mild steel interposed between the lock means and said one casing end, the shaft extending through the Belleville washers, the plates being permanently and inelastically deformable as the shaft slides toward the one casing end whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the plates when the lock means is released.

Claim 4

An impact energy absorbing assembly for a vehicle comprising an outer casing having a pair of ends and adapted to be secured to the vehicle, en elongated shaft extending through the casing ends and slidably mounted therein for longitudinal sliding movement, frangible lock means on the shaft engaging the casing for preventing sliding movement of the shaft toward one of the casing ends, the lock means being releasable upon the application of a predetermined longitudinal force to the shaft, and a plurality of Belleville washers formed of mild steel interposed between the lock means and said one casing end, the shaft extending through the Belleville washers, the plates being permanently and inelastically deformable as the shaft slides toward the one casing end whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the plates when the lock means is released.

Claim 5

An impact energy absorbing assembly for a vehicle comprising an outer casing having a side wall and a pair of end plates, an elongated shaft extending slidably through the casing end plates, a transverse plate within the casing extending generally transversely to the shaft and mounted thereon adjacent one of the casing end plates for movement with the shaft as the shaft moves toward the other casing end plate, a shear pin on the transverse plate extending through an opening in the casing side wall, the shear pin bearing shearable upon the application of predetermined longitudinal force to the shaft, and a plurality of parallel spaced-apart plates within the casing extending generally transversely to the casing end plates and generally parallel to the longitudinal dimension of the shaft between the transverse plate and the other end plate of the casing, and hard plastic foam filler material filling the space between the spaced-apart plates, the spaced-apart being permanently and inelastically deformable as the shaft and transverse plate slide toward the other casing end plate aftEr shearing of the shear pin and being substantially prevented from buckling by the filler material whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the plates.

Claim 6

An impact energy absorbing assembly for a vehicle comprising an outer casing having a side wall and a pair of end plates, an elongated shaft extending slidably through the casing end plates, a transverse plate within the casing extending generally transversely to the shaft and mounted thereon adjacent one of the casing end plates for movement with the shaft as the shaft moves toward the other casing end plate, a shear pin on the transverse plate extending through an opening in the casing side wall, the shear pin bearing shearable upon the application of predetermined longitudinal force to the shaft, and a plurality of parallel spaced-apart plates within the casing extending generally transversely to the casing end plates and generally parallel to the longitudinal dimension of the shaft between the transverse plate and the other end plate of the casing, and hard plastic foam filler material filling the space between the spaced-apart plates, the spaced-apart being permanently and inelastically deformable as the shaft and transverse plate slide toward the other casing end plate aftEr shearing of the shear pin and being substantially prevented from buckling by the filler material whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the plates.

Claim 7

An impact energy absorbing assembly for a vehicle comprising an outer casing having a side wall and a pair of end plates, an elongated shaft extending slidably through the casing end plates, a transverse plate within the casing extending generally transversely to the shaft and mounted thereon adjacent one of the casing end plates for movement with the shaft as the shaft moves toward the other casing end plate, a shear pin on the transverse plate extending through an opening in the casing side wall, the shear pin being shearable upon the application of predetermined longitudinal force to the shaft, and a plurality of spaced-apart metal cylinders concentrically arranged about the shaft between the transverse plate and the other end plate of the casing, and hard plastic foam filler material filling the space between the spaced-apart cylinders, the spaced-apart cylinders being permanently and inelastically deformable as the shaft and transverse plate slide toward the other casing end plate after shearing of the shear pin and being substantially prevented from buckling by the filler material whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the cylinders.

Claim 8

An impact energy absorbing assembly for a vehicle comprising an outer casing having a side wall and a pair of end plates, an elongated shaft extending slidably through the casing end plates, a transverse plate within the casing extending generally transversely to the shaft and mounted thereon adjacent one of the casing end plates for movement with the shaft as the shaft moves toward the other casing end plate, a shear pin on the transverse plate extending through an opening in the casing side wall, the shear pin being shearable upon the application of predetermined longitudinal force to the shaft, and a plurality of spaced-apart metal cylinders concentrically arranged about the shaft between the transverse plate and the other end plate of the casing, and hard plastic foam filler material filling the space between the spaced-apart cylinders, the spaced-apart cylinders being permanently and inelastically deformable as the shaft and transverse plate slide toward the other casing end plate after shearing of the shear pin and being substantially prevented from buckling by the filler material whereby the energy of impact on the shaft is absorbed by the inelastic deformation of the cylinders.