US Patent 8931682 Robotically-controlled shaft based rotary drive systems for surgical instruments

A surgical instrument including an end effector that has a selectively reciprocatable implement movably supported therein. The implement is selectively advanceable in a distal direction upon application of a rotary actuation motion thereto and retractable in a proximal direction upon application of a rotary retraction motion thereto. An elongate shaft assembly is coupled to the end effector and is configured to transmit the rotary actuation motion and rotary retraction motion to the reciprocatable implement from a robotic system that is configured to generate the rotary actuation motion and said rotary retraction motion.