Pressurized fluid actuation system for amplifying operator input force in a surgical instrument
First Claim
1. A pressurized fluid actuation system suitable for moving an endoscopic or open surgery procedure instrument component, said system comprising:
- a double-acting fluid pressure actuator defining an extension chamber and a retraction chamber separated by a piston for engaging said component;
an operating lever pivotally mounted to said piston;
a servo valve that has a valve spool and that is pivotally connected on one end to said lever, said valve being connected to a source of pressurized fluid and having first and second return ports for venting said fluid;
said actuator extension and retraction chambers being connected with said valve for each communicating with said pressurized fluid source and with one of said return ports to control flow in response to the position of said valve spool; and
said system including a feedback line communicating between said extension chamber and said valve to apply a force to said valve spool in one direction in response to pressurization of said extension chamber and including a sensing line communicating between said retraction chamber and said valve to apply a force to said valve spool in the opposite direction in response to pressurization of said retraction chamber.
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Accused Products
Abstract
A pressurized fluid actuation system as provided for a surgical instrument. The system includes a double-acting fluid pressure actuator with an extension chamber and a retraction chamber separated by a piston for engaging a component of the instrument. An operating lever is pivotally mounted to the piston. The operating lever is also pivotally connected to a servo valve that has a valve spool. The valve is connected to a source of pressurized fluid and has first and second return ports for venting the fluid. The actuator extension and retraction chambers are connected with the valve for each communicating with the pressurized fluid source and with one of the return ports in response to the position of the valve spool. The system includes a feedback line communicating between the extension chamber and the valve to apply a force to the valve spool in one direction when the extension chamber is pressurized. The system also includes a sensing line communicating between the retraction chamber and the valve to apply a force to the valve spool in the opposite direction when the retraction chamber is pressurized.
308 Citations
14 Claims
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1. A pressurized fluid actuation system suitable for moving an endoscopic or open surgery procedure instrument component, said system comprising:
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a double-acting fluid pressure actuator defining an extension chamber and a retraction chamber separated by a piston for engaging said component; an operating lever pivotally mounted to said piston; a servo valve that has a valve spool and that is pivotally connected on one end to said lever, said valve being connected to a source of pressurized fluid and having first and second return ports for venting said fluid; said actuator extension and retraction chambers being connected with said valve for each communicating with said pressurized fluid source and with one of said return ports to control flow in response to the position of said valve spool; and said system including a feedback line communicating between said extension chamber and said valve to apply a force to said valve spool in one direction in response to pressurization of said extension chamber and including a sensing line communicating between said retraction chamber and said valve to apply a force to said valve spool in the opposite direction in response to pressurization of said retraction chamber. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8)
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9. A pressurized fluid actuation system suitable for moving an endoscopic or open surgery procedure instrument component, said system comprising:
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a double-acting fluid pressure actuator having a housing defining an extension chamber and a retraction chamber separated by a piston slidably disposed in said housing for engaging said component; an operating lever pivotally mounted to said piston; a valve having a body defining a cavity and having a spool that is slidably disposed in said cavity and that is pivotally connected on one end to said lever, said valve body defining; (a) a feedback port at a first end of said valve body cavity and a sensing port at a second end of said valve body cavity, (b) an extension port and an retraction port between said feedback port and sensing port, (c) a supply port between said extension port and said retraction port for admitting pressurized fluid from a source, (d) a first return port between said feedback port and said extension port for venting said fluid, and (e) a second return port between said sensing port and said retraction port for venting said fluid; a first passage system communicating between said actuator extension chamber, said valve body feedback port, and said valve body extension port; a second passage system communicating between said actuator retraction chamber, said valve body sensing port, and said valve body retraction port; said valve spool having four longitudinally spaced-apart valve members, one of the two outer valve members being disposed between said feedback port and said first return port, the other of the two outer valve members being disposed between said sensing port and said second return port; a biasing means for pivoting said lever to urge said valve spool toward said valve cavity second end; and said middle two valve members being spaced to 1) increase flow through said extension port to said actuator extension chamber and simultaneously reduce flow through said retraction port when said spool is pulled by said lever toward said cavity first end whereby said piston is extended, 2) substantially equalize the pressures at said extension and retraction ports when said spool is restrained by said lever in a moved position whereby said piston is held in an extended position, and 3) permit differential leakage across said middle two valve members when said lever is released which results in a pressure at said retraction port that is greater than the pressure at said extension port when said lever is released and said biasing means urges said spool to an intermediate position in said cavity whereby said piston is retracted. - View Dependent Claims (10, 11, 12, 13, 14)
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Specification