Replaceable surgical scissor blades for surgical instruments

Abstract

A surgical tool includes a drive housing, a shaft extending from the drive housing, wrist arranged at an end of the shaft and including a distal clevis, an axle mounted to the distal clevis, and first and second actuation pulleys rotatably mounted to the axle and rotatable about a pivot axis extending through the axle, each actuation pulley providing an actuation boss eccentric to the pivot axis, and an end effector operatively coupled to the wrist and including first and second blades pivotably coupled to the actuation bosses of the actuation pulleys. The blades are movable between open and closed positions by rotating the actuation pulleys such that the actuation boss of each actuation pulley remains proximal to a centerline of the axle, and movable to an over-centered position by rotating the actuation pulleys such that the actuation boss of each actuation pulley is located distal to the centerline.