Patent ID: 8147489

Claim:
A disposable open electrosurgical forceps for sealing tissue, comprising: a pair of first and second shaft members, each shaft member having a jaw member disposed at a distal end thereof, the jaw members being movable from an open position in spaced relation relative to one another to at least one subsequent closed position wherein the jaw members cooperate to grasp tissue therebetween; each of the jaw members including an electrically conductive sealing plate for communicating electrosurgical energy through tissue held therebetween; at least one of the jaw members including a curved knife channel defined along a length thereof, the curved knife channel being dimensioned to reciprocate a flexible blade therealong; at least one of the shafts including a longitudinal channel disposed therein; a cutting mechanism operatively connected to one of the shaft members, the cutting mechanism being configured to selectively advance the flexible blade from a first position wherein the flexible blade is disposed proximal to tissue held between the jaw members to at least one subsequent position wherein the flexible blade is disposed distal to tissue held between the jaw members, the cutting mechanism including a trigger in slidable communication with the longitudinal channel which cooperates with a rack and pinion system to advance the flexible blade from the first to second positions through tissue held therebetween; and a lockout mechanism including: a recess defined at a proximal end of the longitudinal channel; a positive stop defined at a distal edge of the recess; wherein the positive stop is configured to engage a distal end of the cutting mechanism to prevent distal advancement of the flexible blade when the jaw members are in an open position and to allow distal advancement of the flexible blade when the jaw members are in a subsequent closed position.