US4484479A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Gas flow metering
Assignee: Individual
•
Filing: 1978-04-05
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Granted: 1984-11-27
•
Expires: 1998-04-05
Abstract
Abstract Gas flow metering using a capacitance measurement and comprising a taut elastomeric membrane, preferably tubular in form, which expands or contracts as a function of flow rate past it to an extent determined by Bernouilli's principle. The thus changing distance between this membrane and one or more external electrodes measured by capacitance change or other means is correlatable with the instantaneous flow rate and such measurement can be made essentially without regard to entrained solids or liquids in the gas flow, phase and temperature changes (moderate) within the gas flow or mixture or changing composition therein and with rapid response and low back pressure.
Inventors
- 👤 Richard Eckhardt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:25
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/56; G01F1/05; G01F1/34; G01F1/36; G01F1/38; G01F1/383; G01L; G01L9/00; G01L9/0001; G01L9/0005
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
124 words
Flow metering instrument comprising a casing, a a tubular flow through passage in said casing, a membrane stretched taut in said flow passage and arranged to deflect in accordance with flow back pressure changes to an extent in accordance with Bernouilli's principle, means on the interior of said casing providing a signal directly responsive to the deflection of the membrane by measuring capacitance change, means defining a conductive surface on said stretched membrane, said signal providing means comprising means defining a capacitive gap between said means on the interior of said casing and the said conductive surface, whereby the said deflection of the membrane will vary the size of the capacitive gap and thereby vary an electrical signal obtainable through use of said gap.
Claim 2
Dependent Claim
124 words
Flow metering instrument comprising a casing, a a tubular flow through passage in said casing, a membrane stretched taut in said flow passage and arranged to deflect in accordance with flow back pressure changes to an extent in accordance with Bernouilli's principle, means on the interior of said casing providing a signal directly responsive to the deflection of the membrane by measuring capacitance change, means defining a conductive surface on said stretched membrane, said signal providing means comprising means defining a capacitive gap between said means on the interior of said casing and the said conductive surface, whereby the said deflection of the membrane will vary the size of the capacitive gap and thereby vary an electrical signal obtainable through use of said gap.
Claim 3
Dependent Claim
108 words
Flow metering instrument comprising a casing, a flow through passage in said casing, a tubular membrane stretched taut therein and arranged to deflect inwardly to an extent in accordance with flow back pressure changes within the tube in accordance with Bernouilli's principle, means mounted on the interior of said casing, means for establishing a capacitive gap between said means on the interior said casing and a portion of said tubular membrane therein, said portion of the tubular membrane being electrically conductive, whereby the said deflection of the membrane will vary the size of the capacitive gap and thereby vary an electrical signal obtainable through use of said gap.
Claim 4
Dependent Claim
108 words
Flow metering instrument comprising a casing, a flow through passage in said casing, a tubular membrane stretched taut therein and arranged to deflect inwardly to an extent in accordance with flow back pressure changes within the tube in accordance with Bernouilli's principle, means mounted on the interior of said casing, means for establishing a capacitive gap between said means on the interior said casing and a portion of said tubular membrane therein, said portion of the tubular membrane being electrically conductive, whereby the said deflection of the membrane will vary the size of the capacitive gap and thereby vary an electrical signal obtainable through use of said gap.
Claim 5
Dependent Claim
23 words
Flow metering instrument in accordance with claim 2 wherein a central core is provided within the tubular membrane defining a flow passage therebetween.
Claim 6
Dependent Claim
22 words
Flow metering instrument in accordance with claim 1, wherein two fixed electrodes are provided in opposing relation to said conductive membrane surface.
Claim 7
Dependent Claim
40 words
Flow metering instrument in accordance with claim 4 wherein the membrane is pretensioned so that in the absence of flow induced back pressure drop the membrane would touch said electrodes and is deflected to be spaced therefrom by such drop.
Claim 8
Dependent Claim
25 words
Flow metering instrument in accordance with any of claims 1 and 3 wherein the membrane comprises longitudinal folds to establish its expansion and contraction capability.
Claim 9
Dependent Claim
29 words
Flow metering instrument in accordance with claim 6 wherein the membrane has transverse (to membrane tensioning direction) end folds to relieve lengthwise tension as the membrane expands and contracts.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1987-11-27 | 1988-05-28 | 1988-11-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-11-27 | 1992-05-28 | 1992-11-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-11-27 | 1996-05-28 | 1996-11-27 | $7700.00 | Window Closed / Lapsed |