CLAMPING BASED LOCKOUT MECHANISM FOR RIGHT ANGLE SURGICAL STAPLER

A surgical stapler includes a body, a shaft assembly, and an end effector at a distal end of the shaft assembly. The end effector is actuatable between an open state for receiving tissue and a closed state for clamping the tissue. A closure system is operable to actuate the end effector from the open state to the closed state. A firing system is operable to actuate the end effector in the closed state to staple the clamped tissue. A firing lockout mechanism is movable between a lockout state that inhibits actuation of the firing system, and a bypass state that permits actuation of the firing system. The firing lockout mechanism is configured to maintain the lockout state until the end effector assumes the closed state, and is further configured to transition from the lockout state to the bypass state in response to the end effector assuming the closed state.