A surgical stapling apparatus for progressively stapling and forming an incision in body tissue is provided. The apparatus includes a body portion and a tool assembly supported on the body portion. The apparatus further includes an input cam member slidable within the body portion, a drum member rotatably supported within the body portion, and an output cam member slidable within the body portion. The drum member is coupled to the input cam member such that linear movement of the input cam member effects rotatable movement of the drum member. The output cam member is coupled to the drum member such that rotatable movement of the drum member effects linear movement of the output cam member. Linear movement of the input cam member effects movement of an anvil in relation to a cartridge between unclamped and clamped positions.
