Patent ID: 8678098

Claim:
An actuator comprising: a carrier including an axially elongated fluid conduit therein, the fluid conduit configured to receive a ball therein; and an axially elongated ball receiving element extending along the fluid conduit, wherein one of the ball and the ball receiving element is configured to produce a magnetic field, and another of the ball and the ball receiving element includes an electrically conductive material, the ball and the ball receiving element configured so that the ball is magnetically coupled to the ball receiving element so that the electrically conductive material is exposed to the magnetic field as the ball advances through the ball receiving element, and eddy currents are generated in the electrically conductive material that cause a repulsive force between the ball receiving element and the ball, the ball receiving element defining an elongated portion of the fluid conduit including a seating element disposed thereon, the elongated portion having a reduced diameter relative to adjacent portions of the fluid conduit, the reduced diameter defining a distance between the ball receiving element and the ball that results in a magnetic coupling strength sufficient to reduce a velocity of the ball as the ball advances through the ball receiving element relative to the velocity of the ball when the ball is in one of the adjacent portions.