US4065969A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low impedance, high current pressure transducer
Assignee: Individual
•
Filing: 1976-05-04
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Granted: 1978-01-03
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Expires: 1996-05-04
Abstract
Abstract An apparatus is provided for determining the internal pressure of a fluid conduit in line with which the apparatus is inserted. Fluids transported through the conduit are caused to pass through a thin-walled inner tubular member which expands and contracts in response to increases and decreases in fluid pressure. Surrounding the thin-walled conduit is a layer of piezo-conductive material which is in turn surrounded by a snugly fitting, relatively inelastic outer tube. Pressure inside the thin-walled inner conduit causes the piezo-conductive material to be compressed between the thin-walled conduit and the outer inelastic tube thereby producing a change in the conductance of the piezo-conductive material. A conductance analog of pressure is thereby produced between electrodes attached to the thin-walled inner conduit and the inelastic outer tube. The device may be rendered in very high current, low conductance forms for use in direct modulation of high current circuits.
Inventors
- 👤 Kendall L. Dinwiddie
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 04:31
CPC Classifications
G; G01; G01L; G01L9/00; G01L9/0001
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
68 words
A device for producing a response proportional to pressure within a fluid-transporting conduit comprising: a conductive inner tubular member having an inlet and an outlet adapted at the inlet and outlet to connect to the fluid transporting conduit; a coating of piezo-conductive material applied to the exterior surface of the inner tubular member; and a conductive outer tubular member closely fitting and contacting the coating of piezo-conductive material.
Claim 2
Independent Claim
68 words
A device for producing a response proportional to pressure within a fluid-transporting conduit comprising: a conductive inner tubular member having an inlet and an outlet adapted at the inlet and outlet to connect to the fluid transporting conduit; a coating of piezo-conductive material applied to the exterior surface of the inner tubular member; and a conductive outer tubular member closely fitting and contacting the coating of piezo-conductive material.
Claim 3
Dependent Claim
11 words
The device of claim 1 wherein the piezo-conductive coating is Aquadag.
Claim 4
Dependent Claim
12 words
The device of claim 1 wherein the piezo-conductive coating is PITEL PR.
Claim 5
Dependent Claim
18 words
The device of claim 1 wherein the inner and outer tubular members are uniform and regular in cross-section.
Claim 6
Dependent Claim
16 words
The device of claim 4 wherein the inner and outer tubular members are circular in cross-section.
Claim 7
Dependent Claim
12 words
The device of claim 1 wherein the inner tubular member is thin-walled.
Claim 8
Dependent Claim
21 words
The device of claim 6 wherein the inner tubular member is relatively elastic and the outer tubular member is relatively inelastic.
Claim 9
Independent Claim
111 words
A device for producing a response proportional to pressure within a fluid transporting conduit, comprising: an inner tubular member having an inlet and an outlet adapted at the inlet and outlet to connect to the fluid-transporting conduit; a coating of piezo-conductive material applied to the exterior surface of the inner tubular member; two electrically conductive members held in contact with the coating of piezo-conductive material; restraining means for holding the two electrically conductive members in contact with the inner tubular member such that expansion of the inner tubular member will cause the piezo-conductive material to be compressed between the exterior wall of the inner tubular member and the electrically conductive members.
Claim 10
Independent Claim
111 words
A device for producing a response proportional to pressure within a fluid transporting conduit, comprising: an inner tubular member having an inlet and an outlet adapted at the inlet and outlet to connect to the fluid-transporting conduit; a coating of piezo-conductive material applied to the exterior surface of the inner tubular member; two electrically conductive members held in contact with the coating of piezo-conductive material; restraining means for holding the two electrically conductive members in contact with the inner tubular member such that expansion of the inner tubular member will cause the piezo-conductive material to be compressed between the exterior wall of the inner tubular member and the electrically conductive members.
Claim 11
Dependent Claim
12 words
The device of claim 8 wherein the inner tubular member is non-conductive.
References Cited (Backward Citations)
US3242449A
Cited
US3937087A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1981-01-02 | 1981-07-04 | 1982-01-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-01-02 | 1985-07-04 | 1986-01-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-01-02 | 1989-07-04 | 1990-01-03 | $7700.00 | Window Closed / Lapsed |