US Patent 8734443 Vessel sealer and divider for large tissue structures

An endoscopic bipolar forceps includes a housing having a shaft affixed thereto, the shaft including jaw members at a distal end thereof. The shaft includes jaw members adapted to connect to a source of electrosurgical energy such that the jaw members are capable of conducting energy through tissue held therebetween to effect a tissue seal. The forceps include a drive assembly that moves the jaw members relative to one another from a first position to a second position for manipulating tissue. A movable handle is included that is rotatable about a pivot. A knife assembly is also included having a movable knife rod to operatively engage a knife blade, the knife rod having a first longitudinal section having a first predetermined shape, and a second longitudinal section having a second predetermined shape. The first predetermined shape is different than the second predetermined shape.