US Patent 7001382 Electrosurgical coagulating and cutting instrument

An electrosurgical coagulating and cutting instrument employing pairs of clamping arms having wrist portions proximal to closing ramps and jaws and configured to close at their wrists first, then their distal tips and lastly, their heels. The instrument includes mechanisms for preventing the advancement of a cutting blade when the jaws are not closed. An actuator for closing the jaws includes an actuator handle and a drive head having teeth formed therein and a pawl mounted in the handle for engaging the teeth, these latter structures forming a ratcheting mechanism. Said mechanism is controllably releaseable.