US Patent 9844379 Surgical stapling instrument having a clearanced opening

A stapling assembly comprising a first jaw and a second jaw, wherein the first jaw is rotatable relative to the second jaw. The stapling assembly comprises a detachable cartridge portion comprising a plurality of staples and an anvil configured to deform the staples. The stapling assembly comprises a staple firing member comprising a first cam configured to engage the first jaw and a second cam configured to engage the second jaw when the staple firing member is advanced from an initial position, and wherein the first jaw comprises a clearanced opening configured to receive the first cam when the staple firing member is in the initial position such that the first cam is not engaged with the first jaw when the staple firing member is in the initial position.