Impact absorption structure
The present invention includes an article of manufacture with a layer with a plurality of corrugations to form an energy absorbing structure, where each corrugation has a floor and two walls connecting the floor to the base layer and the length of each corrugation is longer than the widest width of the corrugation. The present invention also includes an energy absorbing structure with a multi-layer energy absorber having a layer with a plurality of surface features and a second layer with a second plurality of surface features wherein the surface features of one layer are nested within the surface features of the other layer such that the base layers are adjacent to each other. The present invention also includes a single step method of manufacturing the energy absorbers including forming a two layer material in a single step. Further, the present invention includes a method of absorbing impact energy that involves generating heat through friction between surface features on a pair of base layers.
1. An energy absorber structure comprising, a first layer having a first plurality of surface features and a second layer with a second plurality of surface features wherein the surface features of one layer are nested within the surface features of the other layer and the cross-sectional shape of the first layer surface features are different than the surface features of the second layer, wherein the cross-sectional shape of one layer is negative draft and the other layer is positive draft, and further wherein the cross-sectional shape is selected from the group consisting of square waveform, positive draft, negative draft, sinusoidal waveform, open loop shape, closed loop shape or combinations thereof.
2. The energy absorber structure of claim 1 , wherein at the first layer, second layer surface or both have friction raising attributes selected from the group consisting of protrusions, valleys, micro textures, nano textures, coating, abrasive or combinations thereof thereon.
3. The energy absorber structure of claim 1 , wherein the cross-sectional shape of one layer is negative draft and the other layer is square draft.
4. An energy absorber structure comprising, a first layer having a first plurality of surface features and a second layer with a second plurality of surface features wherein the surface features of one layer are nested within the surface features of the other layer and the cross-sectional shape of the first layer surface features are different than the surface features of the second layer, further wherein the first and second layer are a plastic selected from a group consisting of polypropylene, polystyrene, impact modified thermoplastic polyolefin, high impact polystyrene, nylon, polycarbonate, polyester, polyurethane, and co-polymers thereof.
5. The energy absorber structure of claim 4 , wherein the first and second layer are different plastic compositions.
6. The energy absorber structure of claim 5 , wherein the first and second layer are attached by mechanical fastners, adhesives, welds, friction or combination thereof.
7. The energy absorber structure of claim 6 , wherein the first and second layer are attached by welds.
8. The energy absorber structure of claim 7 , wherein the welds are spot welds.
9. An energy absorber structure comprising, a first layer having a first plurality of surface features and a second layer with a second plurality of of surface features wherein the surface features of one layer are nested within the surface features of the other layer and the first layer, second layer or both have friction raising attributes selected from the group consisting of protrusions, valleys, micro textures, nano textures, coating, abrasive and combinations thereof thereon.
10. The energy absorber structure of claim 9 , wherein both the first and second layer have friction raising attributes.
11. The energy absorber structure of claim 9 , where the friction raising attributes are selected from the group consisting of protrusions valleys, micro textures, nano textures, and combinations thereof thereon.