Abstract: An impact attenuation liner assembly is provided for use in an outer shell of a protective helmet. The liner assembly includes an impact cap formed from a resilient, heat-resistant material, such as expanded polypropylene. The impact cap defines a head receiving cavity and includes a plurality of passageways extending therethrough. A suspension system is also provided and comprises a plurality of straps disposed within the head receiving cavity. The straps have end portions, each of which extends through a different one of the passageways in the impact cap. Ribs are located on the exterior surface of the impact cap for securing the end portions to the impact cap. Tape extending about a peripheral portion of the exterior surface of the cap is also provided for securing the ribs in recesses formed in the exterior surface of the cap.

Abstract: An improved impact barrier structure for fire helmets and the like including a hard outer shell with a relatively thick inner liner in which a layer of flaccid material is interposed between the outer shell and inner liner in intimate heat conducting relation to the outer shell. The layer of flaccid material provides a heat sink for the outer shell to prolong the mechanical characteristics of the outer shell when it is exposed to high temperature sources of radiant or convection heating as in fire fighting operations.