Abstract: Protective devices, such as, for example, helmets, have one or more efficient, fluid-containing shock absorbers in place of protective devices' original shock absorbing material to minimize the overall weight of the protective devices. The more efficient, fluid-containing shock absorbers yield improved impact force attenuation but occupy substantially less volume and, consequently, less weight, than the original shock absorbing material.

Abstract: Impact protection for people and goods involved in athletics, transportation, industrial, and military activities comprises a hybrid crush zone shock absorber apparatus, systems, and methods of using the same. More specifically, the present invention reduces forces transmitted to a person or item exposed to impact. Primary applications are in protective articles such as helmets and body padding, surfaces which people or goods may impact, and shock isolation packaging. In addition to reduction in transmitted impact forces, our invention provides clear, irreversible visual indication of the state of readiness of the protective gear to which it is fitted.

Abstract: A novel liquid-based system and shock absorber for reducing the forces experienced during high-energy impacts is provided. Individual shock absorbing devices can be used in parallel or in series to create a tunable network that is based on the specific energy absorption requirements for each application. Each shock absorbing device consists of a flexible, primary fluid-filled reservoir that, when impacted, ejects the liquid at high pressure through an array of orifices into a secondary flexible, low-pressure collection reservoir, where it is temporarily stored before the liquid returns to the primary reservoir where the device is ready for the next impact. Optionally, the shock absorbing device may be a single-use device, where the liquid ejects from but does not return to the reservoir.