Helmet structures and methods

Abstract

A helmet includes an inner layer comprising a plurality of hexagonal tubes, each hexagonal tube of the inner layer having a first end and a second end and being formed by a plurality of walls, and an outer layer comprising a plurality of hexagonal tubes, each hexagonal tube of the outer layer having a first end and a second end and being formed by a plurality of walls. A shear plane is defined between the inner layer and the outer layer. Connecting shear structures couple the inner layer to the outer layer at the shear plane, the connecting shear structures being arranged and configured to break away and permit movement of the outer layer relative to the inner layer when subject to a shear force greater than a predetermined magnitude. The thicknesses of the walls may also vary in a radial direction towards the outside of the helmet.

What is claimed is: 
     
         1 . A helmet, comprising:
 an inner layer comprising a plurality of hexagonal tubes, each hexagonal tube of the inner layer having a first end and a second end and being formed by a plurality of walls;   an outer layer comprising a plurality of hexagonal tubes, each hexagonal tube of the outer layer having a first end and a second end and being formed by a plurality of walls, the inner layer being located inside the outer layer with a shear plane defined between the inner layer and the outer layer; and   connecting shear structures coupling the inner layer to the outer layer at the shear plane, the connecting shear structures being arranged and configured to break away and permit movement of the outer layer relative to the inner layer when subject to a shear force greater than a predetermined magnitude.   
     
     
         2 . The helmet of  claim 1 , wherein connecting shear structures comprise discs located at intersections of the plurality of walls forming the inner layer and outer layer. 
     
     
         3 . The helmet of  claim 1 , wherein edges of the hexagonal tubes of the inner layer and edges of the hexagonal tubes of the outer layer adjacent to the shear plane have beads formed thereon. 
     
     
         4 . The helmet of  claim 1 , wherein the inner layer and the outer layer have approximately the same thickness. 
     
     
         5 . The helmet of  claim 4 , wherein the thickness of the inner layer tapers more quickly than the thickness of the outer layer where the inner and outer layer meet at a periphery of the helmet. 
     
     
         6 . The helmet of  claim 1 , further comprising end caps located at outer ends of the hexagonal tubes of the outer layer. 
     
     
         7 . The helmet of  claim 6 , wherein the end caps comprise hollow tubes. 
     
     
         8 . The helmet of  claim 1 , further comprising end caps located at inner ends of the hexagonal tubes of the inner layer. 
     
     
         9 . The helmet of  claim 1 , further comprising supporting columns along the hexagonal tubes of the inner and outer layers where the walls of adjacent hexagonal tubes meet. 
     
     
         10 . The helmet of  claim 1 , wherein the plurality of hexagonal tubes forming the outer layer are formed of double walls. 
     
     
         11 . The helmet of  claim 10 , wherein a total thickness of the double walls varies with distance from a user's head. 
     
     
         12 . The helmet of  claim 1 , wherein the plurality of hexagonal tubes forming the outer layer are formed of single walls. 
     
     
         13 . The helmet of  claim 1 , wherein at least some of the walls in the outer layer comprise relatively thicker portions and at least some of the walls in the inner layer comprise relatively thinner portions. 
     
     
         14 . The helmet of  claim 13 , wherein at least some of the walls in both the inner layer and the outer layer of the helmet comprise only relatively thinner portions. 
     
     
         15 . The helmet of  claim 13 , wherein the walls in both the inner layer and the outer layer of the helmet that comprise only relatively thinner portions are located at a back side of the helmet. 
     
     
         16 . A helmet, comprising:
 an energy management layer comprising a plurality of hexagonal tubes, each hexagonal tube having a first end and a second end and being formed by a plurality of walls, the first ends in use being located closer to a user's head and the second ends being located in use further from the user's head, wherein;   at least some of the walls of some of the hexagonal tubes, including a relatively thicker portion at the first ends and a relatively thinner portion at the second ends.   
     
     
         17 . The helmet of  claim 16 , wherein other walls of the hexagonal tubes include only relatively thinner portions. 
     
     
         18 . The helmet of  claim 17 , wherein the hexagonal tubes including only relatively thinner portions are located at a back side of the helmet. 
     
     
         19 . The helmet of  claim 16 , wherein the energy management layer comprises an outer layer and an inner layer separated by a slip plane. 
     
     
         20 . The helmet of  claim 19 , wherein the relatively thicker portions are located in the outer layer.