Hard Hat with Impact Protection Materials

Abstract

A hard hat including an outer shell, a linear impact absorbing material, and a rotational impact absorbing material is constructed of materials designed to provide protection to a wearer in extreme environmental conditions and under impact. In one embodiment, the rotational impact absorbing material is formed from a strain rate sensitive material in which the rigidity of the material increases under an impact.

What is claimed is: 
     
         1 . A protective work helmet, comprising:
 an outer shell, the outer shell comprising:
 an exterior surface; 
 an interior surface defining a cavity sized to receive a head of a user; 
 a crown portion configured to cover part of the head of the user, wherein a bottom segment of the crown portion defines a lower circumference extending along the exterior surface of the outer shell; 
 a brim extending radially outward from a portion of the lower circumference; and 
 a front mounting ridge configured to couple an accessory to the protective work helmet; and 
   an impact absorbing insert comprising:
 a linear impact absorbing material positioned within the outer shell; and 
 a rotational impact absorbing material positioned within the outer shell; 
   wherein the impact absorbing insert is configured to provide a peak rotational acceleration under a Virginia Tech Test Method less than 5500 radians/second 2 , and wherein the peak rotational acceleration under the Virginia Tech Test Method is greater than 4000 radians/second 2 .   
     
     
         2 . A protective work helmet, comprising:
 an outer shell, the outer shell comprising:
 an exterior surface; 
 an interior surface defining a cavity sized to receive a head of a user; 
 a crown portion configured to cover part of the head of the user, wherein a bottom segment of the crown portion defines a lower circumference extending along the exterior surface of the outer shell; 
 a brim extending radially outward from a portion of the lower circumference; and 
 a front mounting ridge configured to couple an accessory to the protective work helmet; and 
   an impact absorbing insert comprising:
 a linear impact absorbing material positioned within the outer shell; 
 a rotational impact absorbing material positioned within the outer shell; 
   wherein the impact absorbing insert is configured to provide a rotational acceleration under a Virginia Tech Test Method between 4000 radians/second 2  and 5500 radians/second 2  and wherein the impact absorbing insert is configured to provide a peak linear acceleration under the Virginia Tech Test Method less than 145 meters/second 2 .