Remotely actuated surgical gripper with seize resistance

Patent metadata

Field	Value
Publication number	US-9918731-B2
Application number	US-201313936077-A
Country	US
Kind code	B2
Filing date	Jul 5, 2013
Priority date	Jul 6, 2012
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

A surgical end effector includes a clevis and one or more jaws pivotally coupled to the clevis. At least one jaw includes a slot. An axle assembly includes a bearing axle that rotatably supports a bearing, which may be a plain bearing. An actuator coupling is coupled to the bearing axle. The bearing engages the slot such that pushing and pulling on the actuator coupling causes one jaw to close against the other jaw. The bearing axle and the jaws may be made from materials that are prone to galling and the bearing may be made from a material that resists galling. The slot may include a lip that supports the bearings in a spaced apart relationship. The bearing axle may be less than 1.5 millimeters in diameter and each bearing may be less than 3.0 millimeters in diameter.

First claim

What is claimed is:

1. A surgical end effector comprising:
a clevis comprising two walls, each wall of the two walls having an inward-facing surface;
a jaw comprising an outward-facing surface, a slot comprising an inward-facing portion and an outward-facing portion, and a pivot hole comprising an inward-facing portion and an outward-facing portion,
the outward-facing surface of the jaw being adjacent the inward-facing surface of a first one of the two walls,
the outward-facing portion of the slot being enlarged to form a lip between the inward-facing and outward-facing portions of the slot, and
the outward-facing portion of the slot being open to the outward-facing portion of the pivot hole;

a pivot that passes through the two walls of the clevis and the pivot hole of the jaw; and
an axle assembly that includes
an actuator coupling,
a bearing axle at an end of the actuator coupling and extending from the actuator coupling through the inward-facing and outward-facing portions of the slot, and
a bearing rotatably supported by the bearing axle in the outward-facing portion of the slot, the bearing being axially constrained by the lip of the slot.

2. The surgical end effector of claim 1 wherein the bearing axle is less than 1.5 millimeters in diameter and the bearing is less than 3.0 millimeters in diameter.

3. The surgical end effector of claim 1 wherein the bearing is a plain bearing.

4. The surgical end effector of claim 1 wherein:
the bearing axle is made from a first material;
the jaw is made from a second material wherein a first threshold galling stress between the first material and the second material is less than 10 kpsi; and
the bearing is made from a third material wherein a second threshold galling stress between the first material and the third material is greater than 35 kpsi.

5. The surgical end effector of claim 4 wherein a third threshold galling stress between the second material and the third material is greater than 35 kpsi.

6. The surgical end effector of claim 1 wherein the lip supports the bearing in a spaced apart relationship to the actuator coupling.

7. The surgical end effector of claim 1 further comprising a second jaw comprising a second slot and a second bearing rotatably supported by the bearing axle in the second slot.

8. The surgical end effector of claim 7 wherein each wall of the two walls comprises a groove that receives one of two ends of the bearing axle.

9. The surgical end effector of claim 8 further comprising a third bearing and a fourth bearing that support the two ends of the bearing axle in the grooves in the two walls of the clevis.

10. The surgical end effector of claim 7 wherein the pivot further passes through a second pivot hole in the second jaw to couple the second jaw to the clevis and wherein pushing and pulling on the actuator coupling causes the jaw to rotate about the pivot in opposition to the second jaw.

11. A minimally invasive surgical instrument comprising:
an elongate shaft having a distal end, a proximal end, and a longitudinal axis extending between the distal end and the proximal end;
an end effector having a clevis coupled to the distal end of the elongate shaft, the clevis comprising two walls, each wall of the two walls having an inward-facing surface;
a jaw comprising an outward-facing surface, a slot comprising an inward-facing portion and an outward-facing portion, and a pivot hole comprising an inward-facing portion and an outward-facing portion,
the outward-facing surface of the jaw being adjacent the inward-facing surface of a first one of the two walls,
the outward-facing portion of the slot being enlarged to form a lip between the inward-facing and outward-facing portions of the slot, and
the outward-facing portion of the slot being open to the outward-facing portion of the pivot hole;

a pivot that passes through the two walls of the clevis and the pivot hole of the jaw;
an actuating link extending through the elongate shaft between the distal end and the proximal end; and
an axle assembly that includes
an actuator coupling,
a bearing axle at an end of the actuator coupling and extending from the actuator coupling through the inward-facing and outward-facing portions of the slot, and
a bearing rotatably supported by the bearing axle in the outward-facing portion of the slot, the bearing being axially constrained by the lip of the slot.

12. The surgical instrument of claim 11 wherein the bearing axle is less than 1.5 millimeters in diameter and the bearing is less than 3.0 millimeters in diameter.

13. The surgical instrument of claim 11 wherein the bearing is a plain bearing.

14. The surgical instrument of claim 11 wherein:
the bearing axle is made from a first material;
the jaw is made from a second material wherein a first threshold galling stress between the first material and the second material is less than 10 kpsi; and
the bearing is made from a third material wherein a second threshold galling stress between the first material and the third material is greater than 35 kpsi.

15. The surgical instrument of claim 14 wherein a third threshold galling stress between the second material and the third material is greater than 35 kpsi.

16. The surgical instrument of claim 11 wherein the lip supports the bearing in a spaced apart relationship to the actuator coupling.

17. The surgical instrument of claim 11 wherein each wall of the two walls comprises a groove that receives one of two ends of the bearing axle.

18. The surgical instrument of claim 17 further comprising a third bearing and a fourth bearing that support the two ends of the bearing axle in the grooves in the two walls of the clevis.

19. A minimally invasive surgical instrument comprising:
means for receiving a controller motion;
an elongate shaft coupled to the means for receiving the controller motion at a proximal end of the elongate shaft, the elongate shaft having a distal end opposite the proximal end along a longitudinal axis extending between the distal end and the proximal end;
an end effector having a clevis coupled to the distal end of the elongate shaft, the clevis comprising two walls, each wall of the two walls having an inward-facing surface;
a jaw comprising an outward-facing surface, a slot comprising an inward-facing portion and an outward-facing portion, and a pivot hole comprising an inward-facing portion and an outward-facing portion,
the outward-facing surface of the jaw being adjacent the inward-facing surface of a first one of the two walls,
the outward-facing portion of the slot being enlarged to form a lip between the inward-facing and outward-facing portions of the slot, and
the outward-facing portion of the slot being open to the outward-facing portion of the pivot hole;

a pivot that passes through the two walls of the clevis and the pivot hole of the jaw;
an actuating link extending through the elongate shaft between the distal end and the proximal end; and
an axle assembly that includes
an actuator coupling;
a bearing axle at an end of the actuator coupling and extending from the actuator coupling through the inward-facing and outward-facing portions of the slot, and
a bearing rotatably supported by the bearing axle in the outward-facing portion of the slot, the bearing being axially constrained by the lip of the slot.

20. The surgical instrument of claim 19 wherein the bearing axle is less than 1.5 millimeters in diameter and the bearing is less than 3.0 millimeters in diame

Assignees

• Intuitive Surgical Operations

Inventors

• Cooper Thomas G
• Saraliev Daniel
• Williams Mathew R
• Mcdonald Iii William A

Classifications

• A61B34/30

  Surgical robots · CPC title

• A61B2017/2939

  Details of linkages or pivot points · CPC title

• A61B2017/2936

  Pins in guiding slots · CPC title

• A61B17/3201

  Scissors (for biopsy A61B10/02) · CPC title

• A61B17/29 Primary

  Forceps for use in minimally invasive surgery · CPC title