Surgical stapling apparatus

A tool assembly comprising:

• an anvil defining a stop;
• a cartridge assembly including an actuation sled having a first mechanical interface;
• a drive member having a working end, the drive member including a second mechanical interface and being movable from a first position aligned with the stop to a second position misaligned with the stop, the first mechanical interface positioned to engage the second mechanical interface to retain the drive member in the second position;
• and
• a biasing member positioned to urge the drive member towards the first position, wherein the first mechanical interface on the actuation sled is a protuberance having a slanted configuration that extends proximally and the second mechanical interface on the drive member is wall defining a recess having a configuration that complements the slanted configuration of the protuberance.

A reload assembly comprising:

• a shaft portion;
• and
• a tool assembly pivotably supported on the shaft portion, the tool assembly including a cartridge assembly, an anvil, a drive member, and a biasing member, the anvil defining a stop, the drive member having a working end and being movable from a first position aligned with the stop to a second position misaligned with the stop, the biasing member positioned to urge the drive member towards the first position;
• wherein the cartridge assembly of the tool assembly includes an actuation sled having a first mechanical interface and the drive member of the tool assembly includes a second mechanical interface, the first mechanical interface positioned to engage the second mechanical interface to retain the drive member in the second position.