US Patent 9913645 Lockout feature for movable cutting member of surgical instrument

An end effector for use with a surgical instrument includes a first jaw, a second jaw, a blade assembly, and a lockout assembly. The first jaw removably couples with a staple cartridge. The second jaw is movably coupled with the first jaw. The blade assembly translates relative to the first jaw and includes a first tab. The lockout assembly includes a resilient member that biases the blade assembly to a lockout position. The lockout assembly engages the first tab of the blade assembly in the lockout position to prevent the blade assembly from translating distally relative to the first jaw when a staple cartridge is absent from the first jaw or when a spent staple cartridge is disposed in the first jaw.