Dual axle robotic end effector

1. An end effector, comprising:

a distal clevis;

an axle mounted to the distal clevis;

a first jaw holder and corresponding first jaw member rotatably mounted to the axle;

a second jaw holder and corresponding second jaw member rotatably mounted to the axle; and

a sleeve axle comprising a straight cylindrical body extending entirely between opposing first and second ends of the sleeve axle, the straight cylindrical body defining a central passageway also extending entirely between the opposing first and second ends,

wherein the axle is received within the central passageway and the sleeve axle is rotatable relative to the axle,

wherein a head is provided at the second end of the sleeve axle and exhibits a diameter larger than a diameter of remaining portions of the sleeve axle, and wherein the head is received within an end recess defined on the second jaw holder.

2. The end effector of claim 1 , wherein the sleeve axle is secured to the first jaw holder such that movement of the first jaw holder causes the sleeve axle to rotate.

3. The end effector of claim 2 , wherein the first end of the sleeve axle is welded or brazed to the first jaw holder.

4. The end effector of claim 1 , further comprising a wear-resistant substance provided at a radial interface between the sleeve axle and the second jaw holder.

5. The end effector of claim 4 , wherein the wear-resistant substance comprises a material coated on one or both of an outer radial surface of the sleeve axle and an inner radial surface of the second jaw holder.

6. The end effector of claim 1 , further comprising a wear-resistant substance provided at an axial interface between the head and the end recess.

7. The end effector of claim 1 , further comprising a wear-resistant substance provided at an interface between the axle and the sleeve axle.

8. The end effector of claim 7 , wherein the wear-resistant substance comprises a material coated on one or both of an outer radial surface of the axle and an inner radial surface of the sleeve axle.

9. The end effector of claim 1 , wherein opposing ends of the axle are received within corresponding apertures defined in the distal clevis, and wherein one or both of the opposing ends are secured to the distal clevis at the corresponding apertures and thereby prevent the axle from rotating relative to the distal clevis.

10. The end effector of claim 9 , wherein the one or both of the opposing ends are secured to the distal clevis by at least one of welding, brazing, a threaded engagement, orbital riveting an interference fit, and a shrink fit.

11. The end effector of claim 1 , wherein the first jaw holder provides a first pulley operable to receive and seat one or more first drive cables, and the second jaw holder provides a second pulley operable to receive and seat one or more second drive cables, and

wherein actuation of the one or more first drive cables and the one or more second drive cables causes the corresponding first and second jaw members to pivot relative to one another.

12. A surgical tool, comprising:

a drive housing;

an elongate shaft that extends from the drive housing;

a wrist operatively coupled to a distal end of the shaft and having a distal clevis and an axle mounted to the distal clevis;

an end effector having a first jaw holder and corresponding first jaw member rotatably mounted to the axle and a second jaw holder and corresponding second jaw member rotatably mounted to the axle; and

a sleeve axle comprising a straight cylindrical body extending entirely between opposing first and second ends of the sleeve axle, the straight cylindrical body defining a central passageway also extending entirely between the opposing first and second ends,

wherein the sleeve axle radially interposes the first and second jaw holders and the axle and is rotatable relative to the axle,

wherein a head is provided at the second end of the sleeve axle and exhibits a diameter larger than a diameter of remaining portions of the sleeve axle, and wherein the head is received within an end recess defined on the second jaw holder.

13. The surgical tool of claim 12 , wherein the axle extends through the central passageway.

14. The surgical tool of claim 12 , wherein the sleeve axle is secured to the first jaw holder such that movement of the first jaw holder causes the sleeve axle to rotate.

15. The surgical tool of claim 12 , further comprising a wear-resistant substance provided at an axial interface between the head and the end recess, wherein the wear-resistant substance comprises a low-friction material selected from the group consisting of a diamond-like carbon coating, an ultra-hard material, a lubricant, a dry film coating, and any combination thereof.

16. The surgical tool of claim 12 , further comprising a wear-resistant substance provided at a radial interface between the sleeve axle and the second jaw holder, wherein the wear-resistant substance comprises a low-friction material selected from the group consisting of a diamond-like carbon coating, an ultra-hard material, a lubricant, a dry film coating, and any combination thereof.

17. The surgical tool of claim 12 , further comprising a wear-resistant substance provided at an interface between the axle and the sleeve axle, wherein the wear-resistant substance comprises a low-friction material selected from the group consisting of a diamond-like carbon coating, an ultra-hard material, a lubricant, a dry film coating, and any combination thereof.

18. A method of operating a surgical tool, comprising:

positioning the surgical tool adjacent a patient for operation, the surgical tool including:

a drive housing;

an elongate shaft that extends from the drive housing;

a wrist operatively coupled to a distal end of the shaft and having a distal clevis and

an axle mounted to the distal clevis;

an end effector having a first jaw holder and corresponding first jaw member rotatably mounted to the axle and a second jaw holder and corresponding second jaw member rotatably mounted to the axle; and

a sleeve axle comprising a straight cylindrical body extending entirely between opposing first and second ends of the sleeve axle, the straight cylindrical body defining a central passageway also extending entirely between the opposing first and second ends, wherein the sleeve axle radially interposes the first and second jaw holders and the axle and is rotatable relative to the axle,

wherein a head is provided at the second end of the sleeve axle and exhibits a diameter larger than a diameter of remaining portions of the sleeve axle, and wherein the head is received within an end recess defined on the second jaw holder;

articulating at least one of the first and second jaw members about the axle; and

mitigating galling of the axle with the sleeve axle.