Robotic arms with strap drive trains

• US 9,068,628 B2
• Filed: 05/08/2013
• Issued: 06/30/2015
• Est. Priority Date: 09/30/2004
• Status: Active Grant

• Current Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Original Assignee: Intuitive Surgical Operations, Inc. (Intuitive Surgical Holdings, LLC)
• Inventors: Solomon, Todd R., Cooper, Thomas G.
• Primary Examiner(s): Krause, Justin
• Assistant Examiner(s): PRATHER, GREGORY T
• Application Number:
  US13/890,233
• Publication Number:
  US 20130239735A1
• Time in Patent Office: 783 Days
• Field of Search: 744/900.1, 744/900.4, 744/900.5, 744/900.6, 74/892, 74/892.2, 901/15, 901/19, 901/21, 901/27, 901/28, 901/29, 606/1, 606/130, 24/68.A, 24/68.D, 24/68.R, 24/32, 254/208, 254/226, 254/242, 254/280, 254/284, 254/312, 254/325, 254/334, 254/359, 254/385, 254/390
• US Class Current: 1/1
• CPC Class Codes: A61B 2017/00845 of moving parts with respect to each other
• CPC Class Codes: A61B 2034/305 Details of wrist mechanisms at distal ends of robotic arms
• CPC Class Codes: A61B 2034/715 Cable tensioning mechanisms for removing slack
• CPC Class Codes: A61B 34/30 Surgical robots
• CPC Class Codes: A61B 34/37 Master-slave robots A61B34/35 takes precedence
• CPC Class Codes: A61B 34/71 Manipulators operated by drive cable mechanisms
• CPC Class Codes: A61B 90/361 Image-producing devices, e.g. surgical cameras
• CPC Class Codes: B25J 18/00 Arms
• CPC Class Codes: B25J 18/005 having a curved shape
• CPC Class Codes: B25J 18/007 the end effector rotating around a fixed point
• CPC Class Codes: B25J 9/1045 comprising tensioning means
• CPC Class Codes: F16H 7/20 Mountings for rollers or pulleys
• CPC Class Codes: Y10S 901/21 Flaccid drive element
• CPC Class Codes: Y10T 29/49455 Assembly
• CPC Class Codes: Y10T 29/49826 Assembling or joining
• CPC Class Codes: Y10T 74/20305 Robotic arm
• CPC Class Codes: Y10T 74/20323 including flaccid drive element

Abstract

In one embodiment of the invention, a robotic arm is provided including a linkage assembly and a strap drive train. The linkage assembly includes first, second, third, and fourth links pivotally coupled in series together at first, second, and third joints to define a parallelogram with an insertion axis. The strap drive train includes first and second sets of straps coupled to the linkage assembly. As the linkage assembly is moved about a pitch axis, the first set of straps ensures the third link maintains the same angle relative to the first link, and the first and second set of straps ensures the fourth link maintains the same angle relative to the second link.

Claims

1. A robotic arm comprising:

a linkage assembly including a plurality of links pivotally coupled in series together at one or more joints to slidingly support a tool along an insertion axis, the plurality of links including a first pulley and a second pulley;

at least one strap coupled between the first pulley and the second pulley to drive the linkage assembly; and

a strap tensioning system coupled to the at least one strap, the strap tensioning system to tension the at least one strap;

wherein the strap tensioning system includes

the first pulley having a first pocket;

the second pulley having a second pocket; and

the at least one strap including

a tab coupled to a first end of the at least one strap, the tab to hook into the first pocket of the first pulley to couple the first end of the at least one strap thereto, and

a tensioning block coupled to a second end of the at least one strap, the tensioning block to hook into the second pocket of the second pulley to couple the second end of the at least one strap thereto;

wherein the first pulley further has a first recess in a portion of its circumference joining the first pocket to receive the first end of the at least one strap, a first stop at a front of the first pocket to couple to a front side of the tab, a first side restraining protrusion extending from the first stop to retain the tab in the first pocket, and a first lip at the back of the first pocket to further retain the tab in the first pocket; and

wherein the second pulley further has a second recess in a portion of its circumference joining the second pocket to receive the second end of the at least one strap, a second stop at a front of the second pocket to couple to a front side of the tensioning block, a second side restraining protrusion extending from the second stop to retain the tensioning block in the second pocket, and a second lip at the back of the second pocket to further retain the tensioning block in the second pocket.

2. The robotic arm of claim 1, wherein the strap tensioning system further includes

a tensioning fastener to tension the at least one strap,

and wherein

the tensioning block has an opening with threads, and

the second pulley further has a cutout and an opening into the second pocket to receive the tensioning fastener and allow the tensioning fastener to mate with the threaded opening in the tensioning block.

3. The robotic arm of claim 2, wherein the strap tensioning system further includes

a screw-lock helical coil in the threaded opening of the tensioning block to keep the tensioning fastener from rotating and changing tension on the at least one strap.

4. The robotic arm of claim 2, wherein the strap tensioning system further includes

a locking fastener to keep the tensioning fastener from backing out on its own and reducing the tension on the at least one strap, and

the second pulley further has a threaded opening to receive the locking fastener and couple it against the tensioning fastener.

5. The robotic arm of claim 1, wherein

the at least one strap is formed of multiple plies of metal generating a spring force to keep the tab locked into the first pocket of the first pulley and the tensioning block locked into the second pocket of the second pulley to avoid complete collapse of the arm if the at least one strap is slackened.