Patent attributes
A protective impact device is provided that produces an approximately constant force during compression. The device distinguishes several structural features. First, the cross-sectional area in between two impact surfaces increases over the stroke distance when compression takes place. Second, a compressible fluid containing vessel, held in between two impact surfaces, defines an outer shape with a positive second derivative slope defined from one impact surface towards the other impact surface. Third, orifices allow the fluid to bleed out from the compressible vessel when an impact force causes compression of the protective impact device. The resulting approximately constant force scales more or less linearly with impact energy, regardless of impact velocity caused by the impact force. Applications include athletic equipment, automotive bumpers, aircraft landing gear, and any other application that would benefit from maximum energy absorption during an impact.