Patent ID: 7527253

Claim:
A variable stiffness actuator comprising: a leaf spring having a length, a longitudinal axis, a width, and a thickness, the leaf spring adapted to rotate about the longitudinal axis and sustain loads along the longitudinal axis; a first end; and a second end and wherein when the leaf spring is rotated about the longitudinal axis from at least one of the first and second ends, the bending stiffness of the actuator is changed; and a coil spring mounted concentrically around the leaf spring, the coil spring having a first coil spring end and a second coil spring end and wherein when a load is applied to at least one of the first and second coil spring ends the coil spring and the leaf spring can cooperatively deflect in a vertical plane relative to the longitudinal axis and wherein the coil spring inhibits movement of the leaf spring in a horizontal direction relative to the longitudinal axis when the load is applied to the at least one of the first and second coil spring ends.