ARTICULATING KNIFE ACTUATOR FOR ELECTROSURGICAL INSTRUMENT
A knife driving assembly that can advance and retract a knife along a knife blade pathway defined by the jaws of the surgical instrument regardless of continuous rotation of the shaft and jaws. The assembly includes a housing having a shaft extending along a longitudinal axis and supporting to a pair of jaws that define a knife pathway and a lever pivotally mounted to housing and extending into the housing. A knife actuator is coupled to the lever at a first end and to a bearing sleeve at a second end. A drive shaft is secured to the bearing sleeve and extends within the shaft to move a knife along the knife pathway in response to movement of the bearing sleeve. As a result, the main shaft, and the drive shaft, may be rotated through 360 degrees with movement of lever capable of moving the knife.
1 . A surgical instrument, comprising:
a housing having a shaft extending along a longitudinal axis and supporting to a pair of jaws that define a knife pathway;
a lever pivotally mounted to and extending into the housing;
a knife actuator coupled to the lever at a first end and extending longitudinally within housing to a second end;
a bearing sleeve coupled to the second end of the knife actuator; and
a knife positioned in the knife pathway and coupled to the bearing sleeve for movement therewith in response to movement of the lever and knife actuator.
2 . The surgical instrument of claim 1 , wherein the lever includes a bearing cup mechanically coupling the lever to the knife actuator.
3 . The surgical instrument of claim 2 , wherein the second end of the knife actuator comprises a fork extending about the bearing sleeve.
4 . The surgical instrument of claim 3 , wherein the bearing sleeve includes a pair of bearing members positioned on either side of the fork of the knife actuator.
5 . The surgical instrument of claim 4 , wherein the shaft is rotatable through 360 degrees.
6 . The surgical instrument of claim 5 , wherein pivotal movement of the lever between a first position and a second position will cause the knife actuator to drive the bearing sleeve from a retracted position to an extended position.
7 . The surgical instrument of claim 6 , wherein the bearing sleeve is biased toward the first position.
8 . The surgical instrument of claim 7 , wherein the bearing cup includes a tab and an aperture formed through the tab.
9 . The surgical instrument of claim 8 , wherein the first end of the knife actuator includes a post engaged with the aperture of the tab of the bearing cup.
10 . A method of making a surgical device having a knife blade that can retract and extend within jaws that are free to continuously rotate, comprising:
providing a lever pivotally mounted to a housing and extending partially therein;
coupling the lever to a first end of a knife actuator that extends longitudinally within the housing;
coupling a second end of the knife actuator to a bearing sleeve that extends around a rotatable shaft of the surgical device; and
fixing the knife blade to the bearing sleeve so that movement of the lever from a first position to a second position advances the knife actuator distally within the housing and drives the bearing sleeve along the shaft to move the knife blade from a retracted position to an extended position within the jaws.
11 . The method of claim 10 , wherein the lever includes a bearing cup that is used to mechanically couple the lever to the knife actuator.
12 . The method of claim 11 , wherein the second end of the knife actuator is coupled to the bearing sleeve by a fork that extends about the bearing sleeve.
13 . The method of claim 12 , wherein the bearing sleeve includes a pair of bearing members positioned on either side of the fork of the knife actuator.