Articulation device

Abstract

A moving member 2 is rotatably and slidably arranged in a holder 11 having a spherical inner surface 11a. An inertia body 5 is connected to the moving member 2 via a supporting member 4. At a location opposite the inertia body 5, an arm 3 extends so that it is directed outwardly via an opening of the holder. A piezo electric actuator 63 is arranged between the rotating member 2 and the supporting member 4. An elongation of the actuator causes a relative swing movement between the inertia body 5 and moving member to occur in one direction such that a reaction force in the moving member 2 due to the inertia of the inertia body 5 exceeds the frictional force between the moving member 4 and the holder 11, which allows the moving member 4 to be displaced with respect to the holder 11. A contraction of the actuator causes a relative movement between the inertia body 5 and moving member to occur in the opposite direction such that a reaction force in the moving member 2 does not exceed the frictional force, which allows the inertia body to follow with the actuator 63. A reception of the elongation and the contraction allows a movement of the moving member to occur so that it exceeds the limit of the bonding movement of the actuator.