Surgical stapling system comprising a jaw closure lockout

A circular stapling assembly, comprising:

• a frame comprising a distal end;
• a cartridge body including staple cavities;
• staples removably stored in said staple cavities;
• an anvil configured to deform said staples;
• a closure drive comprising a trocar shaft movable between a retracted position and an extended position:
• a distal connector, wherein said anvil is attachable to said distal connector;
• and
• a lock notch;
• a firing drive movable toward said distal end between an unfired position and a fired position to eject said staples from staple cavities;
• a trocar lock rotatably mounted to said frame, wherein said trocar lock is movable between an unlocked configuration and a locked configuration, and wherein said trocar lock is held in said unlocked configuration by said firing drive when said firing drive is in said unfired position;
• and
• a lock spring operably coupled with said trocar lock, wherein said lock spring is configured to bias said trocar lock into said locked configuration after said firing drive has been moved distally from said unfired position, and wherein said lock spring is configured to bias said trocar lock into said lock notch when said closure drive is returned to said extended position to re-open said anvil.

A replaceable staple cartridge for use with a circular stapling instrument, said replaceable staple cartridge comprising:

• a frame comprising a distal end;
• a cartridge body including staple cavities;
• staples removably stored in said staple cavities;
• a closure drive comprising a trocar shaft movable between an extended position and a retracted position to move an anvil between an open position and a closed position;
• a firing drive movable toward said distal end between an unfired position and a fired position to eject said staples from staple cavities once said trocar shaft is in said retracted position, wherein said closure drive is movable to said extended position to re-open the anvil after said staples have been fully deformed against the anvil;
• and
• means for preventing said trocar shaft from being returned to said retracted position after said trocar shaft has been moved into said extended position to re-open the anvil.

A replaceable staple cartridge for use with a circular stapling instrument, said replaceable staple cartridge comprising:

• a frame comprising a distal end;
• a cartridge body including staple cavities;
• staples removably stored in said staple cavities;
• an anvil configured to deform said staples;
• a closure drive comprising a trocar shaft movable between an extended position and a retracted position to move said anvil between an open position and a closed position;
• a firing drive movable toward said distal end between an unfired position and a fired position to eject said staples from staple cavities once said trocar shaft is in said retracted position, wherein said closure drive is movable to said extended position to re-open said anvil after said staples have been fully deformed against said anvil;
• and
• a spent cartridge lockout configured to prevent said trocar shaft from being returned to said retracted position after said trocar shaft has been moved into said extended position to re-open said anvil.