Firing coupled closure and joint reaction

1 . A surgical tool, comprising:

an elongate shaft;

an end effector arranged at a distal end of the elongate shaft and including opposing first and second jaws;

an articulation joint interposing the end effector and the elongate shaft; and

a firing redirect assembly including:

a firing carrier;

a reaction pulley disposed distally from the firing carrier;

a firing cable coupled to a distal end of the firing carrier and wrapping around the reaction pulley and extending proximally past the firing carrier within the elongate shaft;

a redirect differential disposed distally from the reaction pulley and proximally from the articulation joint;

a reaction cable coupled to and extending between a distal end of the reaction pulley and a proximal end of the redirect differential; and

one or more redirect tubes coupled to and extending between a distal end of the redirect differential and a proximal end of the end effector,

wherein a firing load on the firing cable in a proximal direction causes the firing carrier to translate distally and causes the reaction pulley, the reaction cable, the redirect differential, and the one or more redirect tubes to translate proximally.

2 . The surgical tool of claim 1 , further comprising:

an upper and lower push rod extending distally from the firing carrier; and

an upper and lower push coil coupled to and extending distally from the upper and lower push rods, respectively,

wherein the one or more redirect tubes comprise an upper and lower redirect tube,

wherein the upper and lower push coils extend distally through upper and lower portions of the redirect differential into the upper and lower redirect tubes, respectively, and

wherein distal ends of the upper and lower push coils are coupled to an upper and lower portion of a knife body, respectively.

3 . The surgical tool of claim 2 , wherein the firing load on the firing cable in the proximal direction causes the firing carrier, the upper and lower push rods, the upper and lower push coils, and the knife body to translate distally.

4 . The surgical tool of claim 2 , wherein the redirect differential comprises:

an upper gear rack;

a lower gear rack; and

a pinion gear in meshing engagement with the upper gear rack and the lower gear rack, such that when one of the upper gear rack or lower gear rack moves in one axial direction, the other of the upper gear rack or lower gear rack axially moves in an opposite direction.

5 . The surgical tool of claim 4 , wherein the upper gear rack accommodates the upper push coil and the lower gear rack accommodates the lower push coil, wherein during articulation, the pinion gear rotates causing the upper gear rack and lower gear rack to translate in opposite directions, thereby compensating for a change in path lengths of the upper push coil and lower push coil, respectively.

6 . The surgical tool of claim 1 , wherein the end effector includes a closure system at a proximal end thereof to provide additional closure forces to the opposing first and second jaws, and wherein the one or more redirect tubes are coupled to the closure system.

7 . The surgical tool of claim 6 , wherein when the firing load on the firing cable increases, the redirect differential applies increased force on the one or more redirect tubes, which causes the closure system to induce additional rotation of one of the opposing first and second jaws, thereby providing the additional closure forces to the opposing first and second jaws.

8 . The surgical tool of claim 6 , wherein the closure system comprises:

a ramp carriage coupled to a distal end of the one or more redirect tubes, the ramp carriage including a ramp opening; and

a closure cam including a pivot, the pivot of the closure cam being disposed within the ramp opening,

wherein an upper portion of the closure cam abuts a proximal end of one of the opposing first and second jaws.

9 . The surgical tool of claim 8 , wherein moving the one or more redirect tubes in the proximal direction causes the ramp carriage to move proximally, which causes the pivot of the closure cam to translate upward in the ramp opening and the upper portion of the closure cam to force the proximal end of the one of the opposing first and second jaws upward, thereby providing the additional closure forces.

10 . The surgical tool of claim 1 , wherein when the firing load on the firing cable increases, the redirect differential applies increased force on the one or more redirect tubes, which causes the articulation joint to compress and thereby stabilize the articulation joint.

11 . A firing redirect assembly for a surgical tool, the firing redirect assembly comprising:

a firing carrier;

a reaction pulley disposed distally from the firing carrier;

a firing cable coupled to a distal end of the firing carrier and wrapping around the reaction pulley and extending proximally past the firing carrier; and

a reaction cable coupled to and extending between a distal end of the reaction pulley and a proximal end of an end effector of the surgical tool, the end effector including a cartridge jaw and an anvil jaw pivotably connected to the cartridge jaw at a pivot,

wherein a firing load on the firing cable in a proximal direction causes the firing carrier to translate distally and causes the reaction pulley and the reaction cable to translate proximally, and

wherein when the firing load on the firing cable increases, a firing coupled load is applied to the reaction pulley, and wherein the reaction cable transmits the firing coupled load through an articulation joint and causes the articulation joint to compress and thereby stabilize the articulation joint.

12 . The firing redirect assembly of claim 11 , wherein the reaction cable extends through a central lumen of an articulation joint of the end effector, and wherein a distal end of the reaction cable is coupled to a proximal bottom portion of the anvil jaw.

13 . The firing redirect assembly of claim 12 , wherein when the firing load on the firing cable increases, a firing coupled load is applied to the reaction pulley, and wherein the reaction cable transmits the firing coupled load through the articulation joint and causes additional rotation of the anvil jaw about the pivot to provide an additional closure force to the anvil jaw.

14 . The firing redirect assembly of claim 11 , wherein the reaction cable extends through a central lumen of an articulation joint, and wherein a distal end of the reaction cable is coupled to a sliding cam wedge disposed under a proximal bottom portion of the anvil jaw.

15 . The firing redirect assembly of claim 14 , wherein when the firing load on the firing cable increases, a firing coupled load is applied to the reaction pulley, and wherein the reaction cable transmits the firing coupled load through the articulation joint and causes the sliding cam wedge to slide proximally which causes additional rotation of the anvil jaw about the pivot to provide an additional closure force to the anvil jaw.

16 . A method of operating a surgical tool, the method comprising:

applying a firing force to a firing cable;

coupling the firing force to a firing redirect assembly;

transmitting the coupled firing force through an articulation joint by the firing redirect assembly;

providing an additional closure force to the anvil jaw of the end effector using the coupled firing force; and

stabilizing the articulation joint using the coupled firing force.

17 . The method of claim 16 , wherein the firing redirect assembly comprises:

a firing carrier;

a reaction pulley disposed distally from the firing carrier;

a firing cable coupled to a distal end of the firing carrier and wrapping around the reaction pulley and extending proximally past the firing carrier; and

a reaction cable coupled to and extending between a distal end of the reaction pulley and a proximal end of an end effector of the surgical tool, the end effector including a cartridge jaw and an anvil jaw pivotably connected to the cartridge jaw at a pivot.

18 . The method of claim 17 , wherein a distal end of the reaction cable is coupled to a proximal bottom portion of the anvil jaw, and wherein providing the additional closure force to the anvil jaw comprises:

transmitting the coupled firing force through the articulation joint by the reaction cable to the proximal bottom portion of the anvil jaw; and

rotating the anvil jaw about the pivot using the coupled firing force.

19 . The method of claim 17 , wherein a distal end of the reaction cable is coupled to a sliding cam wedge disposed under a proximal bottom portion of the anvil jaw, and wherein providing the additional closure force to the anvil jaw comprises:

transmitting the coupled firing force through the articulation joint by the reaction cable to the sliding cam wedge;

sliding the sliding cam wedge proximally using the coupled firing force; and

rotating the anvil jaw about the pivot via interaction of the proximal bottom portion of the anvil jaw with the sliding cam wedge.

20 . The method of claim 17 , wherein stabilizing the articulation joint using the coupled firing force comprises:

transmitting the coupled firing force through the articulation joint by the reaction cable to the proximal end of the end effector; and

compressing the articulation joint using the coupled firing force.