Surgical fastener applying apparatus

A staple cartridge assembly receivable in a distal end portion of a cartridge receiving half-section of a surgical stapler, the staple cartridge assembly comprising:

• a safety lockout pivotably disposed along an upper surface of the cartridge assembly and movable from an unblocked orientation permitting assembly of an anvil half-section to the cartridge receiving half-section, to a locked orientation preventing assembly of the anvil half-section with the cartridge receiving half section;
• and
• a loading and lockout mechanism configured and adapted to facilitate loading of the cartridge assembly to the cartridge receiving half-section and to prevent firing of the surgical fastener applying apparatus until the cartridge assembly is properly assembled with cartridge receiving half-section, the loading and lockout mechanism including;
• a rocker pivotably mounted to the cartridge receiving half-section, the rocker having a locked-out position which prevents firing of the surgical fastener applying apparatus and a firing position which permits firing of the surgical fastener applying apparatus, defining a downwardly extending blocking surface, the rocker, when in the locked-out position, engages a cam bar and prevents displacement of the cam bar in a distal direction and, when in the firing position, disengages the cam bar and allows the cam bar to be displaced distally.