US Patent 7771425 Vessel sealer and divider having a variable jaw clamping mechanism

An endoscopic bipolar forceps includes a housing and a shaft, the shaft having an end effector assembly at its distal end, which includes two jaw members for grasping tissue therebetween. Each jaw member is adapted to connect to an electrosurgical energy source, enabling them to affect a tissue seal to tissue held therebetween. A drive assembly is included within the housing for moving the jaw members and it includes first and second gear-like cam members. A movable handle is also included, such that movement of the handle rotates the first gear-like cam member into cooperation with the second gear-like cam member to actuate the drive assembly to move the jaw members relative to each other.