Patent ID: 7367771

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; and three pairs of cables, said biasing member applying force on the end effector with respect to the support base for maintaining tension in said three pairs of cables, wherein said positioning mechanism includes three winches with a winch associated with each pair of cables for independently retracting or deploying each of said three pairs of cables to position said end effector in a selected position in space, each winch being attached to said support base, each winch including a drum with said second ends of said three pairs of cables being wrapped around the drum in the associated winch, each winch including a motor connected to said drum for rotating said drum for winding and unwinding the pair of cables attached thereto, each pair of cables having the first ends of the two cables attached to the end effector and the second ends of the two cables being attached to its associated winch in such a way that two cables of each pair of cables are parallel to each other and define a parallelogram so that during movement of the end effector the orientation of the end effector remains fixed so that the robotic mechanism has three degrees of freedom.