Impact absorbing structures for athletic helmet
A garment worn by a wearer has an impact absorbing material comprising arrays of various hexagonal or other deformable polygonal-shaped structures positioned between an exterior surface and an interior surface. When force is applied to the exterior surface, the structures of the impact absorbing materials deform (e.g., buckle) in a desired manner, reducing the force received by the interior surface.
1. A helmet comprising:
a shell having a curved surface; and
an impact absorbing layer flexible to conform to the curved surface of the shell, the impact absorbing layer comprising a face sheet and a plurality of individual polygonal impact absorbing elements interconnected by the face sheet, the individual polygonal impact absorbing elements being spaced apart and configured to buckle in response to an axial compressive force, the buckling being a lateral deflection, wherein:
the face sheet is flexible at locations between the individual polygonal impact absorbing elements;
a first polygonal impact absorbing element of the plurality of individual polygonal impact absorbing elements comprises only a first plurality of filaments and a first plurality of lateral walls, each filament of the first plurality of filaments comprising a solid column, each of the first plurality of lateral walls extending between two adjacent filaments of the first plurality of filaments of the first polygonal impact absorbing element; and
a second polygonal impact absorbing element of the plurality of individual polygonal impact absorbing elements comprises only a second plurality of filaments and a second plurality of lateral walls, each filament of the second plurality of filaments comprising a solid column and each of the second plurality of lateral walls extending between two adjacent filaments of the second plurality of filaments.
2. The helmet of claim 1 , wherein each lateral wall in the first plurality of lateral walls is planar.
3. The helmet of claim 1 , wherein the individual polygonal impact absorbing elements are square elements.
4. The helmet of claim 1 , wherein a thickness of the first plurality of lateral walls is less than a diameter of the first plurality of filaments.
5. The helmet of claim 1 , further comprising a second shell having a second curved surface, wherein the impact absorbing layer is disposed between the curved surface and the second curved surface.
6. The helmet of claim 1 , wherein the curved surface comprises a hemispherical interior of the shell.
7. The helmet of claim 1 , wherein each individual polygonal impact absorbing element is tapered.
8. The helmet of claim 1 , wherein a first cross-section of the plurality of individual polygonal impact absorbing elements at a base of the plurality of individual polygonal impact absorbing elements adjacent to the shell is different from a second cross-section at a top of the plurality of individual polygonal impact absorbing elements.
9. The helmet of claim 1 , wherein
each filament of the first plurality of filaments is connected to two lateral walls of the first plurality of lateral walls; and
each filament of the second plurality of filaments is connected to two lateral walls of the second plurality of lateral walls.
10. The helmet of claim 1 , further comprising a foam layer adjacent to the impact absorbing layer.
11. The helmet of claim 1 , wherein the plurality of individual polygonal impact absorbing elements comprise hexagonal elements.
12. A helmet comprising:
an inner shell having a curved outer surface;
an outer shell having a curved inner surface; and
an interface layer disposed between the curved inner surface and the curved outer surface, the interface layer comprising an array of a plurality of individual polygonal elements interconnected by a face sheet flexible at locations between the individual polygonal impact absorbing elements and having one end secured to one of the inner shell and the outer shell, wherein the array is flexible to conform to the curved outer surface or the curved inner surface of the one of the inner shell and the outer shell, the plurality of individual polygonal elements being spaced apart, wherein the plurality of individual polygonal elements comprises:
a first polygonal impact absorbing element comprising only a first plurality of filaments and a first plurality of lateral walls, each filament of the first plurality of filaments comprising a solid column, each of the first plurality of lateral walls extending between two adjacent filaments of the first plurality of filaments of the first polygonal impact absorbing element, at least one of the first plurality of filaments configured to buckle in response to an axial compressive force, the buckling being a lateral deflection; and
a second polygonal impact absorbing element comprising only a second plurality of filaments and a second plurality of lateral walls, each filament of the second plurality of filaments comprising a solid column and each of the second plurality of lateral walls extending between two adjacent filaments of the second plurality of filaments.
13. The helmet of claim 12 , wherein the face sheet comprises perforations.
14. The helmet of claim 12 , wherein:
the outer shell is more flexible than the inner shell such that an impact force locally deforms the outer shell; and
deformation of the outer shell causes an opposite end of the plurality of individual polygonal elements of a localized section of the plurality of individual polygonal elements to contact the other one of the inner shell and the outer shell to transmit the impact force to the localized section of the plurality of individual polygonal elements.
15. A helmet comprising:
a shell having a curved surface;
an impact absorbing layer configured to conform to the curved surface of the shell, the impact absorbing layer comprising a first polygonal impact absorbing element and a second polygonal impact absorbing element spaced apart from the first polygonal impact absorbing element, at least one of the first polygonal impact absorbing element and the second polygonal impact absorbing element being configured to buckle in response to an axial compressive force, the buckling being a lateral deflection, wherein:
the first polygonal impact absorbing element comprises only a first plurality of filaments and a first plurality of lateral walls, each filament of the first plurality of filaments comprising a solid column, each of the first plurality of lateral walls extending between two adjacent filaments of the first plurality of filaments of the first polygonal impact absorbing element; and
the second polygonal impact absorbing element comprises only a second plurality of filaments and a second plurality of lateral walls, each filament of the second plurality of filaments comprising a solid column and each of the second plurality of lateral walls extending between two adjacent filaments of the second plurality of filaments.
16. The helmet of claim 15 , wherein the first polygonal impact absorbing element comprises a square element.
17. The helmet of claim 15 , wherein the first polygonal impact absorbing element comprises a hexagonal element.
18. The helmet of claim 15 , further comprising a face sheet, wherein the first polygonal impact absorbing element and the second polygonal impact absorbing element are interconnected by the face sheet and the face sheet is flexible at a location between the first polygonal impact absorbing element and the second polygonal impact absorbing element.
19. The helmet of claim 15 , further comprising a foam layer adjacent to the impact absorbing layer.
20. The helmet of claim 19 , wherein the foam layer is disposed between the impact absorbing layer and a wearer to improve comfort.