Patent ID: 9520548
Filing Date: 2016-12-13
CPC Classification: H02N

Claim Text:
1. An actuator, comprising: a threaded screw; a piezo inertia driver; and a piezo amplifier; wherein the piezo inertia driver comprises: a clamp having a first movable jaw for engagement with the threaded screw on a first side and a second jaw for engagement with the threaded screw on a second side opposite to said first side; and a first piezo stack mounted in said clamp for parallel movement of said first jaw relative to said second jaw; wherein when an alternating voltage is applied to the first piezo stack, the first piezo stack causes a parallel back-and-forth movement of the first movable jaw relative to the second jaw by expansion and contraction of the first piezo stack as a result of the applied alternating voltage; wherein the alternating voltage has a ramp up rate that is different from its ramp down rate, which causes the threaded screw to slip in the clamp more in one direction than in another direction of the back-and-forth movement, resulting in a net rotation of the threaded screw, and the rotation results in a first translation movement of the threaded screw; wherein the piezo amplifier comprises: a top wall, a bottom wall, a first and second side walls, the walls being joined by flex hinges; and a second piezo stack; wherein one end of the second piezo stack is coupled to the first side wall and the other end of the second piezo stack is coupled to the second side wall; wherein the piezo inertia driver is coupled to the top wall of the piezo amplifier such that the thread screw engaged by the clamp is offset by a distance from a plane containing the first piezo stack; wherein when a second voltage is applied to the second piezo stack, the second piezo stack causes a horizontal movement of the side walls by expansion or contraction of the second piezo stack, the horizontal movement causes a perpendicular movement of the top wall via the flex hinges, and the perpendicular movement causes a second translation movement of the threaded screw by the top wall pulling or pushing the piezo inertia driver.