#$%^&*AU2010235864B220140717.pdf#####SURGICAL INSTRUMENT Abstract A surgical instrument (10) comprising a handle assembly (12), a body (14), a tool assembly (17) and an articulation assembly (420) is disclosed. The articulation 5 mechanism (420) includes a receptacle (436), and a main shaft (432). A lower clutch (430) is fixedly positioned within the receptacle (436) and has a serrated portion (444) including a plurality of serrations (448). An upper clutch (428) includes at least one projection (440) positioned to engage the serrations (448) of the lower clutch (430) to releasably retain the main shaft (432) at a rotatably fixed position. An angle between a 1o first pair of adjacent serrations (450) is defined as a first angle (al), an angle between a second pair of adjacent serrations (450) is defined as a second angle (a2), and an angle between a third pair of adjacent serrations (450) is defined as a third angle (a3). The first angle (al), the second angle (a2), and the third angle (a3) are each different from one another.2/49 Q co 0 00 CON N CV N1 Nl NVN3/49 C NC c'co N t % N i CO % CVii/7 NV30/49 tN
