Abstract: Protective headgear is described having an energy-absorbing shell attached to a compressible internal liner. The shell includes an outer shell layer, a non-compressible inner shell layer, and a compressible middle layer disposed between the outer shell layer and the non-compressible inner shell layer. The compressible middle layer is made of a thermoplastic elastomer material that can compress upon impact and return substantially to an original shape of the headgear after the impact has ended. Embodiments of the thermoplastic elastomer material have low rebound resilience, a low glass transition temperature, a honeycombed structure, or combinations thereof. The compressible internal liner can also be made of thermoplastic elastomer material.

Abstract: A multilayer shell for use in the construction of protective headgear, the shell including an outer layer, an inner layer, and a middle layer disposed between the outer and inner layer which resiliently compresses in response to an impact to the outer layer. The middle layer includes a plurality of compressible members, which resiliently compress to absorb the energy of a direct impact to the outer layer and resiliently shear with respect to the inner layer in response to a tangential impact to the outer layer. Each of the of compressible members may have bellows-like construction which forms a hollow chamber and includes a small opening through which air is expelled to produce a rate-sensitive response corresponding to the force of the impact. The shell may include one or more passageways to expel air from the middle layer into the interior of the headgear during and as a result of an impact.