US Patent 9089327 Surgical instrument with multi-phase trigger bias

An apparatus comprises an end effector, an elongate shaft, and a handle assembly. The end effector is operable to grasp tissue. The elongate shaft extends between the end effector and the handle assembly. The handle assembly comprises a body portion, a trigger, and a trigger return lever. The trigger is movable relative to the body portion from a home position to an actuated position, and is thereby operable to control the end effector to selectively grasp tissue. The trigger includes a cam feature. The trigger return lever is positioned to engage the cam feature of the trigger. The trigger return lever is configured to bias the trigger toward the home position during at least part of a range of motion of the trigger from the home position to the actuated position.