US Patent 10413291 Surgical instrument articulation mechanism with slotted secondary constraint

A surgical instrument that comprises an elongate shaft assembly that defines a shaft axis. A surgical end effector is pivotally coupled to the elongate shaft assembly for selective pivotal travel about an articulation axis that extends transversely relative to the shaft axis. First and second articulation drivers are supported for selective longitudinal travel relative to the elongate shaft assembly. A first end effector link is movably coupled to the surgical end effector and is coupled to the first articulation driver for axial and pivotal travel relative thereto. A second end effector link is movably coupled to the surgical end effector and is coupled to the second articulation driver for axial and pivotal travel relative thereto.