Patent ID: 7367772

Claim:
A robotic mechanism, comprising: a support base, an end effector and a biasing member having opposed ends and attached at one of said opposed ends to the support base and attached at the other of said opposed ends to the end effector; three cables each connected at a first end thereof to said end effector and said at least three cables having second ends being attached to an associated positioning mechanism for moving the second ends of said three cables to position said end effector in a selected position in space, a length of each of said three cables between said end effector and said associated positioning mechanism being fixed, said biasing member applying force on the end effector with respect to the support base for maintaining tension in said three cables; and said biasing member is pivotally attached to said end effector with a first revolute joint and is pivotally connected to said support base with a second revolute joint, the first and second revolute joints having axis of rotation with are parallel, and wherein said positioning mechanism includes three rigid link arms each having first and second ends with the first end of each support arm being pivotally attached to said support base in such a way that the rigid link arms pivot in planes parallel to each other, and wherein the first ends of each cable is attached to the end effector and the second ends of each cable is attached to the second ends of an associated rigid link arm, and wherein said positioning mechanism includes an actuator attached to each rigid link arm for pivotally moving each rigid link arm for moving said cables thereby moving the end effector.