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US3645137A Expired / Lapsed US ⏱️ 0.0 years remaining

Quartz pressure sensor

Assignee: Bendix Corp
•
Filing: 1970-04-16
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Granted: 1972-02-29
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Expires: 1990-04-16
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Abstract

Abstract A pair of identical quartz elements each having a end wall and a sidewall are disposed in an opening through an outer quartz member so that the end walls are opposed and spaced from each other. A portion of the sidewalls of each element are secured to the outer member to define an inner space between the elements and the outer member. Capacitor plates are formed on the opposed surfaces of the end walls to form a capacitor. Each plate has a conductor connected thereto which extends through a seal in the sidewall. The outer member has an opening extending to the inner space and a capillary tube is attached to the opening. The space and a portion of the capillary tube are filled with a liquid having a known dielectric constant. A first pressure is applied to the opposing surfaces of the end walls through the capillary tube and a second pressure is applied to the other surface of each end wall so that the end walls flex in response to the pressures and the capacitance between the plates corresponds to the difference between the first and second pressures.

Inventors

  • 👤 Edward J Hazen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 18:11
CPC Classifications
G; G01; G01L; G01L13/00; G01L13/02; G01L13/025; G01L9/00; G01L9/0001; G01L9/0005; G01L9/0041; G01L9/0072; G01L9/0075

Claims Analysis

Total Claims: 19
Claim 1
Independent Claim 95 words
A device for measuring pressure, comprising: an outer quartz member having an opening therethrough; a pair of quartz elements each having an end wall and a sidewall and disposed in said opening of the outer member with the end walls spaced from and opposing one another and with at least a portion of the sidewalls heat sealed to the outer member; means for subjecting the end walls to the pressure to be measured to flex the end walls; and means for measuring flexure of the end walls and providing an output corresponding to the pressure.
Claim 2
Independent Claim 95 words
A device for measuring pressure, comprising: an outer quartz member having an opening therethrough; a pair of quartz elements each having an end wall and a sidewall and disposed in said opening of the outer member with the end walls spaced from and opposing one another and with at least a portion of the sidewalls heat sealed to the outer member; means for subjecting the end walls to the pressure to be measured to flex the end walls; and means for measuring flexure of the end walls and providing an output corresponding to the pressure.
Claim 3
Dependent Claim 21 words
A device as described in claim 1 wherein the sidewall of each element is cylindrical and the end wall is circular.
Claim 4
Independent Claim 124 words
A device for measuring pressure, comprising: an outer member having an opening therethrough; a pair of elements each having an end wall and a sidewall and disposed in said opening of the outer member with the end walls spaced from and opposing one another and with at least a portion of the sidewalls secured to the outer member; means for subjecting the end walls to the pressure to be measured to flex the end walls; capacitOr plates formed on opposing surfaces of the end walls to form a capacitor providing an output for measuring flexure of the end walls and corresponding to the pressure; seals formed in the sidewall of each element; and conductors connected to the capacitor plates and extending through the seals.
Claim 5
Independent Claim 124 words
A device for measuring pressure, comprising: an outer member having an opening therethrough; a pair of elements each having an end wall and a sidewall and disposed in said opening of the outer member with the end walls spaced from and opposing one another and with at least a portion of the sidewalls secured to the outer member; means for subjecting the end walls to the pressure to be measured to flex the end walls; capacitOr plates formed on opposing surfaces of the end walls to form a capacitor providing an output for measuring flexure of the end walls and corresponding to the pressure; seals formed in the sidewall of each element; and conductors connected to the capacitor plates and extending through the seals.
Claim 6
Dependent Claim 31 words
A device as described in claim 3, wherein each seal comprises a tube formed on the sidewall and having an opening therethrough for passing the conductor, said opening being heat sealed.
Claim 7
Dependent Claim 17 words
A device as described in claim 3, wherein the capacitor plates comprise a coating of conductive material.
Claim 8
Independent Claim 220 words
A device for measuring pressure comprising: an outer member having an opening therethrough; a pair of elements each having an end wall and a sidewall and disposed in said opening of the outer member with the end walls spaced from and opposing one another and with at least a portion of the sidewalls secured to the outer member; means for subjecting the opposing surfaces of the end walls to a first pressure including an outwardly extending tube formed on the outer member and having an opening extending therethrough to a space between the opposed surfaces of the end walls, a capillary tube having a first end connected to the outwardly extending tube and the first pressure being applied to a second end of the capillary tube; and a liquid having a stable dielectric constant contained in the space between the elements and in a portion of the capillary tube so that the first pressure is exerted on the opposing surfaces of the end walls through the liquid and the liquid is retained within the device by a meniscus formed in the capillary tube; means for subjecting the other surface of each end wall to a second pressure; and means for measuring flexure of the end walls and providing an output corresponding to the difference between the first and second pressures.
Claim 9
Independent Claim 220 words
A device for measuring pressure comprising: an outer member having an opening therethrough; a pair of elements each having an end wall and a sidewall and disposed in said opening of the outer member with the end walls spaced from and opposing one another and with at least a portion of the sidewalls secured to the outer member; means for subjecting the opposing surfaces of the end walls to a first pressure including an outwardly extending tube formed on the outer member and having an opening extending therethrough to a space between the opposed surfaces of the end walls, a capillary tube having a first end connected to the outwardly extending tube and the first pressure being applied to a second end of the capillary tube; and a liquid having a stable dielectric constant contained in the space between the elements and in a portion of the capillary tube so that the first pressure is exerted on the opposing surfaces of the end walls through the liquid and the liquid is retained within the device by a meniscus formed in the capillary tube; means for subjecting the other surface of each end wall to a second pressure; and means for measuring flexure of the end walls and providing an output corresponding to the difference between the first and second pressures.
Claim 10
Dependent Claim 27 words
A device as described in claim 6, wherein the elements have side walls having a height substantially equal to one half the width of the end walls.
Claim 11
Dependent Claim 34 words
A device as described in claim 6, wherein the side walls are secured to the outer member at a distance from the end walls equal to one half the width of the end walls.
Claim 12
Independent Claim 192 words
A device for sensing the difference between a first and a second pressure, comprising: a hollow member having at least one flexible wall and an opening to the interior thereof; a capillary tube connected to said opening for applying the first pressure to the interior of the member so that the first pressure is applied to an inner surface of the flexible wall; means for applying the second pressure to an outer surface of the flexible wall so that the wall flexes an amount corresponding to the difference between the first and second pressures; capacitor means having plates mounted within the hollow member for providing an output corresponding to the flexure of the flexible wall which also corresponds to the difference between the first and second pressures; and a liquid having a stable dielectric constant contained within the hollow member and a portion of the tube to maintain a constant dielectric between the plates of the capacitor, the capillary tube being arranged to retain the liquid in the device and providing for expansion and contraction of the liquid and changes in volume of the hollow member caused by flexures of the wall.
Claim 13
Independent Claim 192 words
A device for sensing the difference between a first and a second pressure, comprising: a hollow member having at least one flexible wall and an opening to the interior thereof; a capillary tube connected to said opening for applying the first pressure to the interior of the member so that the first pressure is applied to an inner surface of the flexible wall; means for applying the second pressure to an outer surface of the flexible wall so that the wall flexes an amount corresponding to the difference between the first and second pressures; capacitor means having plates mounted within the hollow member for providing an output corresponding to the flexure of the flexible wall which also corresponds to the difference between the first and second pressures; and a liquid having a stable dielectric constant contained within the hollow member and a portion of the tube to maintain a constant dielectric between the plates of the capacitor, the capillary tube being arranged to retain the liquid in the device and providing for expansion and contraction of the liquid and changes in volume of the hollow member caused by flexures of the wall.
Claim 14
Dependent Claim 28 words
A device as described in claim 9, wherein two opposing walls are flexible and the capacitor means provides an output corresponding to the flexure of the opposing walls.
Claim 15
Dependent Claim 30 words
A device as described in claim 10, wherein the capacitor means comprises coatings of conductive material on the interior surface of each flexible wall, said coatings forming two capacitor plates.
Claim 16
Dependent Claim 15 words
A device as described in claim 10, wherein the hollow member is made of quartz.
Claim 17
Dependent Claim 15 words
A device as described in claim 9, wherein the hollow member is made of quartz.
Claim 18
Independent Claim 232 words
A device for sensing a differential pressure, Comprising: a pair of elements each having a flexible bottom wall and a sidewall; an outer member having an opening therethrough containing the elements positioned with their bottom walls opposed and spaced from each other, a portion of each side wall is secured to the outer member around the perimeter thereof to define an inner space between the elements and the outer member; a pair of capacitor plates formed on the opposed surfaces of the bottom walls forming a capacitor having a capacitance corresponding to the distance between the bottom walls; an outwardly extending tube formed on the outer member and having an opening extending therethrough to the inner space; a capillary tube connected to said opening for applying a first pressure to the inner space and to the opposed surfaces of the bottom walls; means for applying a second pressure to the other surfaces of the bottom walls so that the bottom walls flex in response to the pressures and the capacitance corresponds to the difference between the first and second pressures; and a liquid having a stable dielectric constant contained in the inner space and in a portion of the capillary tube for maintaining a constant dielectric between the capacitor plates, the capillary tube retains the liquid within the device and provides for changes in volume of the liquid and the inner space.
Claim 19
Independent Claim 232 words
A device for sensing a differential pressure, Comprising: a pair of elements each having a flexible bottom wall and a sidewall; an outer member having an opening therethrough containing the elements positioned with their bottom walls opposed and spaced from each other, a portion of each side wall is secured to the outer member around the perimeter thereof to define an inner space between the elements and the outer member; a pair of capacitor plates formed on the opposed surfaces of the bottom walls forming a capacitor having a capacitance corresponding to the distance between the bottom walls; an outwardly extending tube formed on the outer member and having an opening extending therethrough to the inner space; a capillary tube connected to said opening for applying a first pressure to the inner space and to the opposed surfaces of the bottom walls; means for applying a second pressure to the other surfaces of the bottom walls so that the bottom walls flex in response to the pressures and the capacitance corresponds to the difference between the first and second pressures; and a liquid having a stable dielectric constant contained in the inner space and in a portion of the capillary tube for maintaining a constant dielectric between the capacitor plates, the capillary tube retains the liquid within the device and provides for changes in volume of the liquid and the inner space.

References Cited (Backward Citations)

US2482440A Cited
US2808545A Cited
US3405559A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1975-02-28 1975-08-30 1976-02-29 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1979-02-28 1979-08-30 1980-02-29 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1983-02-28 1983-08-30 1984-02-29 $7700.00 Window Closed / Lapsed

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