Variable stiffness mechanisms

Abstract

A variable stiffness spring assembly includes first and second members made of a first material and separated by a gap along at least a portion of their lengths, and one or more layers made of a second material disposed in the gap. The variable stiffness spring assembly can be incorporated into or take the form of a limb support assembly, such as a prosthetic foot. The second material disposed between the first and second members is rate-sensitive or speed-dependent, such that the material exhibits different properties when the user of the prosthetic foot is walking at high or fast walking speeds compared to low or slow walking speeds. The prosthetic foot can exhibit high damping and energy absorption, and therefore stability, at slow speeds, and high energy return at faster speeds.

Dependencies are inferred from the claim text.