Open vessel sealing instrument with pivot assembly

Abstract

An open electrosurgical forceps includes a pair of first and second shaft members each having a jaw member disposed at its distal end. The jaw members are movable about a pivot assembly from an open position in spaced relation relative to one another to a closed position wherein the jaw members cooperate to grasp tissue. Each of the jaw members includes an electrically conductive sealing surface for communicating electrosurgical energy through grasped tissue. One or both of the jaw members includes a knife channel defined along its length. The pivot assembly includes a knife slot and is configured to prevent reciprocation of a cutting mechanism when the jaw members are disposed in the open position and to permit reciprocation of the cutting mechanism when the jaw members are disposed in the closed position. An actuator selectively advances the cutting mechanism from a first position to at least one subsequent position.

What is claimed is: 
     
       1. An open electrosurgical forceps, comprising:
 a pair of first and second shaft members each having a jaw member disposed at a distal end thereof, the jaw members movable about a pivot assembly from an open position in spaced relation relative to one another to a closed position wherein the jaw members cooperate to grasp tissue therebetween, the pivot assembly including:
 a pair of insulative shoulders having a first end defining a cap and a second end operably coupled to opposing sides of an insulative hub having a knife slot defined therein, wherein one of the jaw members is configured to rotate about one of the insulative shoulders, 
 the pivot assembly configured to prevent reciprocation of a cutting mechanism when the jaw members are disposed in the open position and to permit reciprocation of the cutting mechanism therethrough when the jaw members are disposed in the closed position. 
 
 
     
     
       2. An open electrosurgical forceps according to  claim 1 , further comprising a knife channel defined along a length of at least one of the jaw members. 
     
     
       3. An open electrosurgical forceps according to  claim 1 , further comprising an actuator operatively connected to one of the shaft members configured to selectively advance the cutting mechanism from a first position wherein the cutting mechanism is disposed proximal to tissue grasped between the jaw members to at least one subsequent position wherein the cutting mechanism is disposed through the pivot assembly and into tissue grasped between the jaw members. 
     
     
       4. An open electrosurgical forceps according to  claim 2 , wherein the knife slot of the insulative hub of the is configured to align with the knife channel when the jaw members are disposed in the closed position to permit advancement of the cutting mechanism and to misalign with the knife channel when the jaw members are disposed in the open position and prevent advancement of the cutting mechanism. 
     
     
       5. An open electrosurgical forceps according to  claim 1 , wherein each of the opposing sides of the insulative hub includes a first recess defined therein configured to receive a first end of a pivot pin and a second recess substantially surrounding the first recess and configured to receive at least a portion of one of the insulative shoulders therein, the insulative shoulders configured to receive a second end of the pivot pin to operably couple the insulative shoulders to the insulative hub. 
     
     
       6. An open electrosurgical forceps according to  claim 1 , wherein the cutting mechanism includes a generally hour-glass-shaped flexible blade having a notch disposed generally midway therealong which facilitates distal translation of the cutting mechanism. 
     
     
       7. An open electrosurgical forceps, comprising:
 a first shaft member having a first jaw member disposed at a distal end thereof and a second shaft member having a second jaw member disposed at a distal end thereof;   a pivot assembly including a blade slot defined longitudinally therethrough and at least one cap configured to secure the pivot assembly to at least one of the first or second shaft members such that the jaw members are movable relative to each other about the pivot assembly between an open position and a closed position, the pivot assembly including:
 a hub; and 
 a pair of shoulders having a first portion defining the at least one cap and a second portion operably coupled to opposing sides of the hub; 
   a knife channel extending at least partially through the first and second jaw members; and   a cutting mechanism including a knife blade configured to be advanced distally through the blade slot and the knife channel when the jaw members are disposed in the closed position to cut tissue disposed between the jaw members, the blade slot configured to prevent advancement of the knife blade when the jaw members are disposed in the open position.   
     
     
       8. The open electrosurgical forceps according to claim 7, wherein at least one of the first or second shaft members is configured to rotate about the pair of shoulders. 
     
     
       9. The open electrosurgical forceps according to claim 7, further comprising an actuator operatively coupled to one of the shaft members and configured to selectively advance the knife blade distally through the blade slot and the knife channel to cut tissue disposed between the jaw members. 
     
     
       10. The open electrosurgical forceps according to claim 7, wherein the blade slot is configured to align with the knife channel when the jaw members are disposed in the closed position to permit translation of the knife blade through the blade slot and the knife channel to cut tissue disposed between the jaw members. 
     
     
       11. The open electrosurgical forceps according to claim 7, wherein at least one of the pair of shoulders is insulative. 
     
     
       12. An open electrosurgical forceps, comprising:
 a pair of first and second shaft members each having a jaw member disposed at a distal end thereof, the jaw members movable about a pivot assembly between an open position wherein the jaw members are disposed in spaced relation relative to one another and a closed position wherein the jaw members cooperate to grasp tissue therebetween, the pivot assembly including:
 a hub having a knife slot defined therethrough configured to receive a cutting mechanism therethrough; and 
 a pair of shoulders having a first end coupled to opposing sides of the hub and a second end defining a cap, the pivot assembly configured to prevent reciprocation of the cutting mechanism through the knife slot when the jaw members are disposed in the open position and to permit reciprocation of the cutting mechanism through the knife slot when the jaw members are disposed in the closed position. 
   
     
     
       13. The open electrosurgical forceps according to claim 12, further comprising a knife channel defined along at least one of the jaw members. 
     
     
       14. The open electrosurgical forceps according to claim 12, further comprising an actuator operatively coupled to one of the first or second shaft members and configured to selectively move the cutting mechanism between a first position wherein the cutting mechanism is disposed proximal to the pivot assembly and at least one subsequent position wherein the cutting mechanism is disposed through the knife slot. 
     
     
       15. The open electrosurgical forceps according to claim 13, wherein the knife slot is configured to align with the knife channel when the jaw members are disposed in the closed position and to misalign with the knife channel when the jaw members are disposed in the open position. 
     
     
       16. The open electrosurgical forceps according to claim 12, wherein each of the opposing sides of the hub includes a first recess defined therein and a second recess at least partially surrounding the first recess, the second recess configured to receive at least a portion of one of the pair of shoulders therein. 
     
     
       17. The open electrosurgical forceps according to claim 12, wherein the cutting mechanism includes a generally hourglass-shaped flexible blade. 
     
     
       18. The open electrosurgical forceps according to claim 12, wherein at least one of the pair of shoulders is insulative. 
     
     
       19. The open electrosurgical forceps according to claim 12, wherein the hub is insulative.