Mechanism for dividing tissue in a hemostat-style instrument

1. An open electrosurgical forceps for sealing tissue, comprising:

first and second shaft portions pivotably associated with one another, each shaft portion having a jaw member disposed at a distal end thereof, the jaw members being movable from a first position in spaced relation relative to one another to at least one subsequent position wherein the jaw members cooperate to grasp tissue therebetween, each of the jaw members including an electrically conductive sealing surface being configured to communicate electrosurgical energy through tissue held therebetween, at least one of the jaw members including a slot formed through the sealing surface thereof;

a cutting mechanism operatively associated with the first and second jaw members, the cutting mechanism including:

a cutting element disposed within the slot of the at least one jaw member, the cutting element being movable about a pivot from a first position wherein the cutting element is retracted within the at least one jaw member and a second position in which a cutting edge of the cutting element at least partially projects from a sealing surface of the at least one jaw member, the cutting element including a biasing member at a proximal end thereof, the biasing member operably disposed within the jaw member and configured for biasing the cutting element toward the first position and pivoting the cutting element, the biasing member including a notched portion configured to facilitate pivoting the cutting element between the first and second positions, the notched portion disposed proximal relative to the pivot and extending to the cutting edge of the cutting element; and

an actuator operatively associated with the cutting element which upon movement thereof selectively advances the cutting element from the first position to the second position.

2. The open electrosurgical forceps according to claim 1 , wherein the cutting element is pivotably disposed within the slot of the jaw member.

3. The open electrosurgical forceps according to claim 1 , wherein the cutting element extends out through the jaw member and defines a camming surface.

4. The open electrosurgical forceps according to claim 3 , wherein the second shaft portion reciprocably supports the actuator, the actuator being movable from a first position spaced from the cutting element to a second position in contact with the cutting element.

5. The open electrosurgical forceps according to claim 4 , wherein upon displacement of the actuator from the first position to the second position, the actuator engages the camming surface of the cutting element and urges the cutting element from the first position to the second position.

6. The open electrosurgical forceps according to claim 1 , wherein the biasing member located at the proximal end of the cutting element is a torsion spring.

7. The open electrosurgical forceps according to claim 4 , wherein movement of the actuator pivots the cutting element between the first and second positions.

8. An open electrosurgical forceps for sealing tissue, comprising:

a pair of shaft portions pivotably coupled to one another at a first pivot, each shaft portion including a jaw member at a distal end thereof for grasping tissue therebetween, each jaw member including a sealing surface adapted to conduct electrosurgical energy through tissue grasped therebetween and one of the sealing surfaces includes a slot defined therein;

a cutting mechanism operatively coupled to at least one of the pair of shaft portions, the cutting mechanism comprising:

a cutting element pivotably coupled to at least one of the jaw members and configured to pivot within the slot, the cutting mechanism being selectively moveable about a second pivot from a first position in which the cutting element is retracted within the slot and a second position in which a cutting edge of the cutting element at least partially projects from the slot to cut tissue disposed between the jaw members;

a biasing member operably disposed on the cutting element and within the jaw member, the biasing member configured for biasing the cutting element toward the first position and pivoting the cutting element about the second pivot, the biasing member including a notched portion configured to facilitate pivoting the cutting element between the first and second positions about the second pivot, the notched portion disposed proximal relative to the second pivot and extending to the cutting edge of the cutting element; and

an actuator operatively associated with the cutting element that, upon movement thereof, selectively pivots the cutting element from the first position to the second position,

wherein the cutting element pivots with respect to the actuator.

9. The open electrosurgical forceps according to claim 8 , wherein the actuator is integrally associated with the cutting element.

10. The open electrosurgical forceps according to claim 8 , wherein the actuator is pivotably coupled to the cutting element.

11. The open electrosurgical forceps according to claim 8 , wherein the actuator is spaced a distance from a first shaft portion.

12. The open electrosurgical forceps according to claim 8 , wherein the actuator selectively activates the cutting element when moved relative to a first shaft portion.

13. The open electrosurgical forceps according to claim 8 , wherein the actuator is a drive rod.