Patent ID: 8020743

Claim:
A surgical cutting and fastening instrument comprising: a handle assembly; a generator of rotary motion supported by said handle assembly; an elongate shaft assembly operably coupled to said handle assembly and defining an elongate axis; an elongate channel coupled to said elongate shaft for selective pivotal travel about a pivot axis that is substantially transverse to said elongate axis, said elongate channel sized to operably support a staple cartridge therein; and a rotary drive system comprising: a main drive shaft assembly operably interfacing with said generator of rotary motion; a gear train in meshing engagement with said main drive shaft for receiving said rotary motion therefrom; and a flexible drive shaft in meshing engagement with said gear train, said flexible drive shaft further having a distal end non-threadably coupled to a knife supporting assembly in said elongate channel such that said flexible drive shaft can rotate relative thereto to drive said knife supporting assembly in a distal direction upon receipt of a rotary motion in a first direction from said gear drive train and wherein upon receipt of another rotary motion in a second direction from said gear drive train, said flexible drive shaft pulls said knife supporting assembly in a proximal direction.