Medical instruments are provided having end effectors and end effector actuator apparatus which are rotatable relative to the end effectors. The instruments generally include a tube which is typically coupled to the end effectors via a clevis around which the end effectors pivot, a push rod extending...http://www.google.com.au/patents/US5293878?utm_source=gb-gplus-sharePatent US5293878 - Endoscopic surgical instruments having stepped rotatable end effectors
