A staple instrument is provided. The staple instrument includes a staple holder, a rotational drive shaft, and a linkage operatively coupled to the staple holder. The linkage is configured to expand the staple holder via an expansion motion imparted thereon. A converter coupling intermediate the rotational drive shaft and the linkage converts rotational motion of the rotational drive shaft into expansion of the staple holder. The staple instrument also includes a housing that supports the linkage, converter coupling, and rotational drive shaft. The rotational drive shaft has a stop surface that engages a corresponding surface formed in the housing to inhibit proximal translation of the rotational drive shaft relative to the housing.