Patent ID: 8308040

Claim:
A surgical instrument, comprising: a shaft, comprising: a housing; a first guide slot in said housing; and a drive bar movable between a first position and a second position, wherein said first guide slot is configured to receive at least a portion of said drive bar; an end effector pivotably coupled to said shaft about a pivot joint, wherein said end effector is rotatable about said pivot joint, and wherein said end effector comprises a staple cartridge attachment portion configured to receive a staple cartridge; and a guide member configured to move relative to said shaft and said end effector, said guide member comprising: a second guide slot configured to receive at least a portion of said drive bar; an end portion configured to be contacted by said end effector; and a datum portion; wherein said drive bar further comprises: a shaft portion; a drive portion configured to be operably engaged with a cutting member and move the cutting member within said end effector when said drive bar is moved between said first position and said second position; and a stop configured to be engaged with said datum portion of said guide member to limit the movement of said drive bar relative to said end effector.