An end effector (212) for use with a surgical instrument includes a first jaw (216), a second jaw (218), and a closure ring (233). The second jaw is pivotable relative to the first jaw. The second jaw has a proximal end with a first ramped surface (224) and a second ramped surface (226) distal of the first ramped surface. The closure ring is coupled with the second jaw to engage the first and second ramped surfaces of the second jaw. The closure ring translates from a proximal position to a distal position to engage the first ramped surface of the second jaw and then the second ramped surface of the second jaw. The camming engagement of the closure ring with the first and second ramped surfaces of the second jaw pivots the second jaw toward the first jaw. The closure ring may also provide camming engagement to pivot the second jaw away from the first jaw.
