A surgical instrument including a drive mechanism configured to advance a staple driver and/or cutting member at a first rate and retract the staple driver and/or cutting member at a different rate. In at least one embodiment, the rate at which the driver and cutting member is advanced and/or retracted...http://www.google.se/patents/US20110121051?utm_source=gb-gplus-sharePatent US20110121051 - SHAFT BASED ROTARY DRIVE SYSTEM FOR SURGICAL INSTRUMENTS
