Surgical stapling instrument having a firing lockout for an unclosed anvil

A surgical instrument comprising:

• a handle portion operable to separately produce a firing motion and a closing motion;
• an implement portion responsive to the separate firing and closing motions from the handle portion, the implement portion comprising:
• an elongate channel coupled to the handle portion,
• an anvil pivotally coupled to the elongate channel and including a recess and an anvil slot,
• a firing device including a distally presented cutting edge longitudinally received between the elongate channel and the anvil, an upper member engageable to the anvil slot and a lower portion longitudinally engaging the elongate channel, the upper member residing within the anvil pocket when in an unfired position to allow the separate closing motion of the anvil, and
• an anvil lockout mechanism communicating between the anvil pocket and the anvil slot wherein the anvil lockout mechanism blocks the upper member when the anvil is not closed.

An endo-surgical instrument, comprising:

• a handle portion operable to separately produce a firing motion and a closing motion;
• an end effector sized for insertion through an endo-surgical cannula passageway;
• and
• a shaft attached between the handle portion and the end effector and operably configured to separately transfer the firing and closing motions therebetween;
• the end effector further comprising:
• an elongate channel coupled to the shaft,
• an anvil pivotally coupled to the elongate channel responsive to the closing motion to move between an open position to a closed position,
• a firing device longitudinally received between the elongate channel and the anvil and including an upper member engageable to the anvil slot during distal movement for firing, and
• an anvil lockout mechanism operably configured to preclude distal movement of the firing device in response to an anvil open condition.