Patent ID: 7624902

Claim:
A surgical instrument comprising: (a) a handle assembly; (b) a body extending distally from the handle assembly, the body defining a first longitudinal axis; (c) a tool assembly pivotably supported on a distal end of the body, the tool assembly defining a second longitudinal axis, the tool assembly being pivotable from a non-articulated position in which the first longitudinal axis is aligned with the second longitudinal axis and at least one articulated position in which the second longitudinal axis is at an angle to the first longitudinal axis; and (d) an articulation mechanism including: (i) a receptacle positioned adjacent the handle assembly; (ii) a main shaft having base portion, the main shaft being rotatably supported within the receptacle; (iii) a lower clutch fixedly positioned within the receptacle, the lower clutch having a serrated portion and being positioned about the main shaft, the serrated portion including a series of shallow serrations and at least one deep serration; (iv) an upper clutch slidably positioned about the main shaft, the upper clutch being rotatably fixed to the main shaft such that rotation of the main shaft effects rotation of the upper clutch, the upper clutch including at least one projection positioned to engage the serrations of the lower clutch to releasably retain the main shaft at a rotatably fixed position; and (v) an articulation link having a proximal end operatively connected to the base portion of the main shaft and a distal end operatively connected to the tool assembly, wherein the main shaft is rotatable to move the articulation link to effect movement of the tool assembly between the non-articulated position and the at least one articulated position.