US Patent 11234700 Wrist architecture

A surgical device includes an elongated shaft, an end effector, and a wrist assembly. The wrist assembly includes a first outer link, a first inner link, and a second outer link. The first outer link is connected to the shaft and includes first gear teeth. The first inner link is pivotally coupled with the first outer link. The second outer link is pivotally coupled with the first inner link. The second outer link includes second gear teeth that interface with the first gear teeth and control orientation of the first inner link relative to the first outer link and the first outer link throughout a range of orientations of the wrist assembly.