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US 7,837,674 B2Granted
Compact counter balance for robotic surgical systems
AssigneeIntuitive Surgical Operations, Inc.
InventorThomas G. Cooper
Life of this patent
Estimating the term…
Abstract
In one embodiment of the invention, an apparatus is provided including a linkage and a balancing mechanism coupled to the linkage around a pivotal joint. The linkage couples to a support structure at a first end and support a weight applied to a second end. The balancing mechanism counter balances the weight applied to the second end of the linkage. As the linkage is deformed to vertically adjust the height of the weight with a different moment arm length, the balancing mechanism varies a cable path length to modify the compression of a spring and a tension in a cable to adjust the amount of counter balance force applied to the linkage.
Claims33
A set-up arm to support a robotic arm, the set-up arm comprising:
- a first set-up joint to couple to a support structure;
- a second set-up joint spaced apart from the first set-up joint, the second set-up joint to couple to a robotic arm to provide support thereto;
- a counter balancing link pivotally coupled to the first set-up joint at a first pivot point and to the second set-up joint at a second pivot point, the counter balancing link to balance out the force of load at the second set-up joint, the counter balancing link including a hollow housing having a cylindrical cavity with a first opening at a first end;
- a spring in the cylindrical cavity having a first end coupled to the hollow housing, the spring to provide a spring force to balance out the force of load at the second set-up joint;
- a plurality of pulleys including a first pulley rotatably coupled to the first set-up joint at the first pivot point between the counter balancing link and the first set-up joint, and one of a pair of pulleys rotatably coupled to the first setup joint and another one of the pair of pulleys rotatably coupled to the hollow housing;
- at least one cable under tension coupled to the setup arm and wrapped over the plurality of pulleys to couple to a second end of the spring;
- and
- wherein a linear distance between the pair of pulleys varies to change a cable path length in response to the pivoting of the counter balancing link with respect to the first set-up joint to modify the spring force and the tension in the at least one cable under tension to counter balance changes in moment and mechanical advantage.
5 more elements
A set-up arm to support a robotic arm, the set-up arm comprising:
- a first set-up joint to couple to a support structure, the first set-up joint having a first pulley rotatably coupled thereto;
- a second set-up joint spaced apart from the first set-up joint, the second set-up joint to couple to a robotic arm to provide support thereto;
- a counter balancing link pivotally coupled to the first set-up joint at a first pivot point and to the second set-up joint at a second pivot point, the counter balancing link to balance out the force of load at the second set-up joint, the counter balancing link including
- a hollow housing having a cylindrical cavity with a first opening at a first end
- a second pulley rotatably coupled to the hollow housing,
- a first compression spring in the cylindrical cavity having a first end coupled to the housing, the first compression spring under compression to balance out the force of load at the second set-up joint;
- and
- a third pulley having a center point at the first pivot point between the counter balancing link and the first set-up joint, wherein center point positions of the first, second, and third pulleys are corners of a triangle, wherein the triangle formed by the center point positions of the first, second and third pulleys is adjustable in response to pivoting of the counter balancing link with respect to the first set-up joint to modify the tension in the at least one cable under tension;
- at least one cable under tension wrapped over the second pulley into the cylindrical cavity and coupled to a second end of the first compression spring, the at least one cable under tension further wrapped over the first and third pulleys and coupled to the set-up arm;
- and wherein
- a sum of the wrap angles of the at least one cable under tension wrapped around the first, second and third pulleys is substantially constant in response to the pivoting of the counter balancing link with respect to the first set-up joint;
- and
- a linear distance between the first pulley and the second pulley varies in response to the pivoting of the counter balancing link with respect to the first set-up joint to modify the tension in the at least one cable under tension to balance out changes in moment and mechanical advantage at the pivot point between the counter balancing link and the first set-up joint due to the pivoting of the counter balancing link and the load at the second set-up joint.
10 more elements
A set-up arm to support a robotic arm, the set-up arm comprising:
- a first set-up joint to couple to a support structure, the first set-up joint having a first pulley rotatably coupled thereto;
- a second set-up joint spaced apart from the first set-up joint, the second set-up joint to couple to a robotic arm to provide support thereto;
- a counter balancing link pivotally coupled to the first set-up joint at a first pivot point and to the second set-up joint at a second pivot point, the counter balancing link to balance out the force of load at the second set-up joint, the counter balancing link including
- a hollow housing having a cylindrical cavity with a first opening at a first end,
- a second pulley rotatably coupled to the hollow housing,
- a first compression spring in the cylindrical cavity having a first end coupled to the housing, the first compression spring under compression to balance out the force of load at the second set-up joint;
- and
- a third pulley having a center point at the first pivot point between the counter balancing link and the first set-up joint, wherein center point positions of the first, second, and third pulleys are corners of a triangle;
- at least one cable under tension wrapped over the second pulley into the cylindrical cavity and coupled to a second end of the first compression spring, the at least one cable under tension further wrapped over the first and third pulleys and coupled to the set-up arm;
- and wherein
- each of the first, second, and third pulleys have a substantially similar diameter,
- a first linear distance between the first pulley and the second pulley to vary in response to a pivoting of the counter balancing link at the first pivot point with the first set-up joint;
- a second linear distance between the first pulley and the third pulley to remain constant in response to the pivoting of the counter balancing link at the first pivot point with the first set-up joint;
- and
- a third linear distance between the second pulley and the third pulley to remain constant in response to the pivoting of the counter balancing link at the first pivot point with the first set-up joint.
12 more elements
A set-up arm to support a robotic arm, the set-up arm comprising:
- a first set-up joint to couple to a support structure, the first set-up joint having a first pulley rotatably coupled thereto;
- a second set-up joint spaced apart from the first set-up joint, the second set-up joint to couple to a robotic arm to provide support thereto;
- a counter balancing link pivotally coupled to the first set-up joint at a first pivot point and to the second set-up joint at a second pivot point, the counter balancing link to balance out the force of load at the second set-up joint, the counter balancing link including
- a hollow housing having a cylindrical cavity with a first opening at a first end
- a plug coupled into the first opening to close the cylindrical cavity at the first end to increase stiffness of the counter balancing link,
- a second pulley rotatable coupled to the hollow housing,
- a first compression spring in the cylindrical cavity having a first end coupled to the housing, the first compression spring under compression to balance out the force of load at the second set-up joint;
- and
- a third pulley having a center point at the first pivot point between the counter balancing link and the first set-up joint, wherein center point positions of the first, second, and third pulleys are corners of a triangle;
- and
- at least one cable under tension wrapped over the second pulley into the cylindrical cavity and coupled to a second end of the first compression spring, the at least one cable under tension further wrapped over the first and third pulleys and coupled to the set-up arm.
8 more elements
Dependencies are inferred from the claim text.