Four-degree-of-freedom parallel manipulator for producing Schönflies motions

A manipulating device for imparting a four-degree-of-freedom motion to an end-effector, the four-degree-of-freedom motion being composed of three independent translations and one rotation about a first axis of fixed orientation, the manipulating device comprising:

• a parallel array of at least two legs attached to the end-effector;
• each leg including an actuator unit serially coupled to a passive unit;
• each actuator and passive units including a turntable adapted to experience a rotation about a second axis parallel to the first axis;
• each actuator and passive units also including a swing member having a first end attached to the turntable and being adapted to experience a tilt motion so that a second end of the swing member is translated along a perimeter of an imaginary circle lying in a plane parallel to the second axis;
• and
• each actuator unit being provided with actuating means to provide the rotation of the turntable thereof and the tilt motion of the swing member thereof such as to produce an actuator motion, the actuator motion of each actuator unit causing a passive motion of the passive unit coupled thereto, the passive motion of the passive unit being composed of the rotation of the turntable thereof and the tilt motion of the swing member thereof, such that a combination of the actuator motion with the passive motion produces a leg motion for the corresponding leg;
• whereby a combination of the leg motions imparts the four-degree-of-freedom motion to the end-effector.