Piezo-resistive position indicator
AssigneeAlliedSignal Inc.
InventorsRonald J. Louis, Reza Oboodi
Life of this patent
Estimating the term…
Abstract
According to principles of the present invention, a sensor beam provides a linear or non-linear continuous signal to a computer that translates the signal into a valve position reading. In an illustrative embodiment of the invention, a sensor beam incorporating piezo-resistive components forming a Wheatstone bridge abuts a cam mounted on a butterfly valve spindle. Valve movement causes rotation of the cam that, in turn, imparts a bending moment to the sensor beam. This bending moment strains the piezo-resistive components, thereby altering the resistance of the Wheatstone bridge. The computer measures the resistance change using an output signal transmitted by the sensor beam and calculates valve position based thereon.
Claims40
A position sensing apparatus operable to sense the position of a movable member operably coupled with an actuating member, the apparatus comprising:
- a voltage supply;
- and
- a sensor comprising a plurality of piezo-resistive elements coated with, and affixed to a metal substrate by, a ceramic and having a first portion, said sensor electrically communicating with said voltage supply, said sensor operably disposed with the actuating member, said first portion displaceable by the actuating member, said sensor producing at least one output signal corresponding and proportional to displacement of said first portion by said actuating member.
A valve position sensing apparatus operable to sense the position of a valve member operably coupled with an actuating member, the apparatus comprising:
- a direct current voltage supply;
- a sensor comprising a piezo-resistive Wheatstone bridge and having a first portion, said sensor electrically communicating with said voltage supply, said sensor operably disposed with the actuating member, said first portion displaceable by the actuating member, said sensor producing at least one output signal corresponding and proportional to displacement of said first portion by the actuating member;
- and
- a computer electrically communicating with said sensor, said computer receiving said at least one output signal from said sensor, said computer converting said at least one output signal into a value representative of a position of the valve member.
A method of determining the position of a movable valve member operably coupled with an actuating surface, the method comprising the steps of:
- operably disposing a sensor having a first portion with the actuating surface, whereby movement of the actuating surface displaces said first portion;
- providing a predetermined input voltage to said sensor;
- and
- measuring an output voltage from said sensor, said output voltage being proportional to the amount said first portion is displaced by the actuating surface.
A valve for regulating the flow of a fluid comprising:
- a valve member movable between an open and a closed position, said open position permitting downstream flow of the fluid, said closed position preventing downstream flow of the fluid;
- a movable actuating member operably coupled with said valve member, said actuating member moving in a manner corresponding and proportional to movement of said valve member;
- a sensor having a first portion operably coupled with said actuating member, said first portion displaceable by said actuating member, said sensor producing at least one output signal corresponding and proportional to displacement of said first portion by said actuating member;
- and
- a voltage supply electrically communicating with said sensor.
A valve for regulating the flow of a fluid comprising:
- a disk movable between an open and a closed position, said open position permitting downstream flow of the fluid, said closed position preventing downstream flow of the fluid;
- a movable cam operably coupled with said disk, said cam moving in a manner corresponding and proportional to movement of said disk;
- a sensor comprising a piezo-resistive Wheatstone bridge and having a first portion operably coupled with said cam, said first portion displaceable by said cam, said sensor producing at least one output signal corresponding and proportional to displacement of said first portion by said cam;
- a direct current voltage supply electrically communicating with said sensor;
- and
- a computer electrically communicating with said sensor, said computer receiving said at least one output signal from said sensor, said computer converting said at least one output signal into a value representative of a position of said disk.
A valve position sensing device for sensing the position of a valve operably coupled to an actuating member, comprising:
- a flexible beam having a first portion fixedly mounted and a second portion displaceable by the actuating member;
- a piezo-resistive sensing element disposed on said flexible beam and having an electrical resistance that varies in proportion to a displacement of the second portion of said flexible beam by the actuating member,
- wherein the displacement of the second portion of said flexible beam by the actuating member is proportional to the position of the valve.
A device for sensing the position of a flexduct valve, comprising:
- a flexible beam having a first portion fixedly mounted and a second portion displaceable by the flexduct valve;
- a piezo-resistive sensing element disposed on said flexible beam and having an electrical resistance that varies in proportion to a displacement of said flexible beam by the flexduct valve,
- wherein the displacement of the second portion of said flexible beam by the flexduct valve is proportional to the position of the flexduct valve.
A valve for regulating the fluid flow to an accessory, comprising:
- a flexduct having a fixedly mounted first end and a second end operably coupled to a driver element for displacing the second end, and including (i) an inlet port proximate the first end (ii) an outlet port proximate the second end and (iii) an internal flowpath providing fluid communication between the inlet and outlet ports;
- a flexible beam having a first portion fixedly mounted proximate the first end of said flexduct and a second portion in contact with, and displaceable by, the second end of said flexduct;
- and
- a piezo-resistive sensing element disposed on said flexible beam and having an electrical resistance that varies in proportion to a displacement of the second portion of said flexible beam by the second end of said flexduct,
- wherein the displacement of the second end of said flexduct by the driver element regulates the fluid flow to the accessory, and the displacement of the second portion of said flexible beam is proportional a position of the second end of said flexduct.
Dependencies are inferred from the claim text.