Patent ID: 7143926
Filing Date: 2006-12-05
Classification: A61B

Abstract:
1. The surgical instrument, comprising: an end effector responsive to a longitudinal firing motion to perform a surgical operation; a shaft connected to the end effector; a firing member slidingly received by the shaft to transfer the firing motion to the end effector between an unfired position and a fully fired position; a rack attached to the firing member; a firing mechanism operably configured to engage and distally advance the rack during a firing stroke and to disengage thereafter; a gear mechanism engaged to the rack; a handle containing the rack, firing mechanism and gear mechanism; and a retraction member mounted for rotation external to the handle and coupled for rotation to the gear mechanism; wherein the gear mechanism further comprises a ratchet gear rotating in a first direction when the rack moves distally and a second direction when the rack moves proximally, and wherein the retraction member comprises a gear retraction lever and a retraction pawl, the retraction pawl positioned to engage the ratchet gear as the gear retraction lever is actuated to turn the ratchet gear in the second direction to retract the rack and firing member.