Patent attributes
A surgical stapling and severing instrument particularly suited to endoscopic procedures incorporates a handle that produces separate closing and firing motions to actuate an end effector. In particular, the handle produces multiple firing strokes in order to reduce the required amount of force required to fire (i.e., staple and sever) the end effector. A linked transmission reduces the required handle longitudinal length, yet achieves a rigid, strong configuration when straightened for firing. A traction biased firing mechanism avoids binding in driving this straightened linked rack. The instrument further has a manually actuatable retraction system that does not require the use of additional springs or other mechanisms to generate retraction forces which must be overcome when generating the forces necessary to fire the device. In various embodiments, the retraction system provides a visual indication to the surgeon as to how far firing has progressed.
