SURGICAL INSTRUMENT AND METHOD

摘要

This invention relates generally to surgical instruments, and is especially suitable for incorporation in various instruments, particularly staplers, used in endoscopic procedures as well as in open surgery procedures. In a broad aspect of the invention, a control mechanism is provided for use in an articulating surgical instrument having a reciprocable articulating driver member engaged with a pivoting portion that is pivotable between first and second positions in response to linear movement of the articulation driver member. The control mechanism moves the articulation driver member between extended and retracted positions, with increased mechanical advantage at one of the extended and retracted positions. The control mechanism comprises a frame integral with the instrument containing the articulation driver member. A tooth is provided on the articulation driver member. A helical gear, having a decreasing pitch ov er at least a portion of its length, is engaged with the tooth and mounted for rotation in the frame.