US Patent 7118587 Vessel sealer and divider

A electrosurgical instrument includes a housing having a shaft attached thereto which connects a pair of first and second jaw members in an opposing manner relative to one another. The jaw members are movable relative to one another from a first open position wherein the jaw members are disposed in spaced relation relative to one another to a second closed position wherein the jaw members cooperate to grasp tissue therebetween. The instrument also includes a handle assembly having a four-bar mechanical linkage which cooperates with a drive assembly to impart movement to the first and second jaw members from the first and second positions.