US Patent 10278702 Stapling system comprising a firing bar and a lockout

A stapling system is disclosed. The stapling system comprises an anvil, a channel, a firing bar, a replaceable staple cartridge, and a locking member. The anvil comprises an anvil ledge. The channel comprises a channel ledge. The firing bar comprises a first projection configured to engage the anvil ledge and a second projection configured to engage the channel ledge. The replaceable staple cartridge comprises staples, a vertical slot configured to receive the firing bar during a staple firing stroke, and a sled movable between a proximal unfired position and a distal fired position. The locking member is movable vertically and spring-biased into a locked configuration which inhibits the firing bar from being advanced through the staple firing stroke. The sled comprises a proximally-extending portion configured to overcome the spring bias of the locking member if the sled is in its proximal unfired position.