Abstract: Impact energy absorbing devices, in some embodiments, may be configured as a helmet having suspension elements employing “rate activated tethers” (RATs), a speed-sensitive flexible strapping material. The RATs are configured to suspend a helmet shell on the head of a wearer, so that impact to the helmet causes extension of the RATs. The RATs provide for: (1) steady force over long strokes, and (2) a stroke force that increases with increasing impact velocity. Standard impact testing of a helmeted headform shows that the RAT suspension decreases head accelerations by 50% relative to a standard suspension system. This decrease in head acceleration is expected to lead to a reduced likelihood of brain and head injury. Because the RATs absorb energy during tensile extension, they offer increases in energy absorption efficiency. These RAT suspensions can potentially replace or complement existing helmet pad and suspension systems in military, sports, and industrial safety-wear.

Abstract: Impact energy absorbing devices, in some embodiments, may be configured as a helmet having suspension elements employing “rate activated tethers” (RATs), a speed-sensitive flexible strapping material. The RATs are configured to suspend a helmet shell on the head of a wearer, so that impact to the helmet causes extension of the RATs. The RATs provide for: (1) steady force over long strokes, and (2) a stroke force that increases with increasing impact velocity. Standard impact testing of a helmeted headform shows that the RAT suspension decreases head accelerations by 50% relative to a standard suspension system. This decrease in head acceleration is expected to lead to a reduced likelihood of brain and head injury. Because the RATs absorb energy during tensile extension, they offer increases in energy absorption efficiency. These RAT suspensions can potentially replace or complement existing helmet pad and suspension systems in military, sports, and industrial safety-wear.