US Patent 11937892 Variable jaw closure of a robotic surgical system

A surgical instrument includes a drive housing, a spline, a carriage, an elongate shaft assembly, an end effector, and an activating mechanism. The at least one spline includes a drive gear rotatable with the spline. The elongate shaft assembly extends from the carriage. The activating mechanism includes a barrel cam extending along a rotational axis and having a first cam profile radially extending about the rotational axis. The barrel cam is operatively coupled to the drive gear such that rotation of the drive gear is configured to actuate the activating mechanism to move at least a portion of the end effector. The first cam profile defines a plurality of slopes relative to the rotational axis such that the first cam profile is configured to drive movement of the end effector or the elongate shaft assembly at different rates according to the plurality of slopes.