Abstract: The present invention is directed to a tool having a wrist mechanism that provides pitch and yaw rotation in such a way that the tool has no singularity in roll, pitch, and yaw. A positively positionable multi-disk wrist mechanism includes a plurality of disks or vertebrae stacked in series. Each vertebra is configured to rotate in pitch or in yaw with respect to each neighboring vertebra. Actuation cables are used to manipulate and control movement of the vertebrae. In specific embodiments, some of the cables are distal cables that extend from a proximal vertebra through one or more intermediate vertebrae to a distal vertebra, while the remaining cables are medial cables that extend from the proximal vertebra to one or more of the intermediate vertebrae. The cables are actuated by a pivoted plate cable actuator mechanism.

Abstract: Surgical tools having a two degree-of-freedom wrist, wrist articulation by linked tension members, mechanisms for transmitting torque through an angle, and minimally invasive surgical tools incorporating these features are disclosed. An elongate intermediate wrist member is pivotally coupled with a distal end of an instrument shaft so as to rotate about a first axis transverse to the shaft, and an end effector body is pivotally coupled with the intermediate member so as to rotate about a second axis that is transverse to the first axis. Linked tension members interact with attachment features to articulate the wrist. A torque-transmitting mechanism includes a coupling member, coupling pins, a drive shaft, and a driven shaft. The drive shaft is coupled with the driven shaft so as to control the relative orientations of the drive shaft, the coupling member, and the driven shaft.