Mechanically Over-Damped Actuators Having Adjustable Stiffness

A mechanically over-damped actuator comprising:

• an input link including a plate from which outwardly extends a shaft and a pivot element;
• and
• an output link mounted to the input link, the output link including a plate having an opening through which the shaft of the input link extends, the output link further including a pivotable lever and a torsion spring that is surrounded by the lever, the lever including an arcuate U-shaped portion from which extend generally parallel first and second legs, the torsion spring including a coiled portion from which extend generally parallel first and second legs, the coiled portion of the spring being positioned within the U-shaped portion of the lever, the first leg of the spring being positioned next to an inner side of the first leg of the lever, and the second leg of the spring being positioned next to an inner side of the second leg of the lever, wherein the pivot element of the input link is positioned between the first and second legs of the lever;
• wherein when a force is applied to the output link, the plate of the output link rotates relative to the input link about the shaft and the pivot element causes the lever to pivot about a pivot axis away from an initial equilibrium position, wherein the pivoting of the lever causes the first leg of the lever to deflect the first leg of the spring,
• wherein when the force is removed from the output link, the first leg of the spring urges the lever back to its equilibrium position and the second leg of the spring interfaces with the second leg of the lever to prevent the lever from pivoting in the opposite direction away from the equilibrium position, thereby limiting overshooting.