US Patent 9867615 Surgical instrument with articulation lock having a detenting binary spring

A apparatus includes a shaft, an end effector, an articulation joint, and a locking feature. The end effector is pivotable from a first position to a second position. The end effector is aligned with a longitudinal axis of the shaft in the first position and angled relative to the longitudinal axis of the shaft in the second position. The articulation joint couples the shaft with the end effector and pivots the end effector from the first position to the second position. The locking feature is coupled with the articulation joint and translates from a proximal position to a distal position. The locking feature locks the articulation joint when the locking feature is in the distal position.