Abstract: Shock absorbers for integration into protective structures generally take the form of hollow, fluid-filled, compressible cells. In various embodiments, the cell enclosure includes one or more orifices, or vents, through which a fluid (such as air or water) can escape from the inner chamber formed by the enclosure.

Abstract: An impact-absorbing protective structure comprises one or more compressible cells. Each cell is in the form of a thin-walled plastic enclosure defining an inner, fluid-filled chamber with at least one small orifice through which fluid resistively flows. Each cell includes an initially resistive mechanism that resists collapse during an initial phase of an impact and that then yields to allow the remainder of the impact to be managed by the venting of fluid through the orifice. The initially resistive mechanism may be implemented by providing the cell with semi-vertical side walls of an appropriate thickness or by combining a resiliently collapsible ring with the cell. After the initially resistive mechanism yields to the impact, the remainder of the impact is managed by the fluid venting through the orifice. The cell properties can be readily engineered to optimize the impact-absorbing response of the cell to a wide range of impact energies.

Abstract: Shock absorbers for integration into protective structures generally take the form of hollow, fluid-filled, compressible cells. In various embodiments, the cell enclosure includes one or more orifices, or vents, through which a fluid (such as air or water) can escape from the inner chamber formed by the enclosure.

Abstract: Shock absorbers for integration into protective structures generally take the form of hollow, fluid-filled, compressible cells. In various embodiments, the cell enclosure includes one or more orifices, or vents, through which a fluid (such as air or water) can escape from the inner chamber formed by the enclosure.

Abstract: Magnetic repulsive forces can be exploited for impact absorption in protective body gear such as, e.g., helmets.

Abstract: A protective structure for protecting a body from impact includes an inner layer of relatively flexible material, and which has a plurality of spaced-apart openings extending between opposite faces thereof and a corresponding plurality of protective units. Each protective unit includes a thin-wall, collapsible, fluid-tight enclosure with a volume of fluid filling the enclosure and at least one orifice in an enclosure wall that resistively vents fluid from the enclosure at a selected rate in response to an impact on the structure. The plurality of protective units are received in the plurality of openings so that corresponding first segments of the enclosures projecting form one face of the first layer together form a middle layer. Cooperating surfaces on the inner layer and each protective unit retain each protective unit in the corresponding opening in the inner layer. A method of making the protective units is also disclosed.

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.