US4237415A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for measuring conductivity in electrical feedthrough
Assignee: ABB Inc USA
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Filing: 1978-11-13
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Granted: 1980-12-02
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Expires: 1998-11-13
Abstract
Abstract Feedthrough bushings containing electrically conductive coatings on the porcelain outer shell are provided with means for electrically monitoring the state of conductivity of the coatings. An electrical feedthrough connecting with the electrically conductive coating at one end provides an efficient means for connecting with current measuring devices to determine the current through the coating while the bushing remains energized.
Inventors
- 👤 John K. Easley
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 09:36
CPC Classifications
G; G01; G01R; G01R27/00; G01R27/02; G01R31/00; G01R31/12; G01R31/1227; G01R31/1245
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
64 words
A method for measuring the current through a conductive coating on a porcelain bushing jacket comprising the steps of: providing an insulated electrical feedthrough intermediate the ends of the jacket and connected at one end to the conductive coating; connecting the feedthrough at the other end to one side of a current reading ammeter; and connecting the other side of the ammeter to ground.
Claim 2
Independent Claim
64 words
A method for measuring the current through a conductive coating on a porcelain bushing jacket comprising the steps of: providing an insulated electrical feedthrough intermediate the ends of the jacket and connected at one end to the conductive coating; connecting the feedthrough at the other end to one side of a current reading ammeter; and connecting the other side of the ammeter to ground.
Claim 3
Dependent Claim
40 words
The method of claim 1 further including the step of electrically connecting a switch in shunt relation between the ammeter and ground; and opening the switch to provide current transfer through the ammeter for determining the current through the coating.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-12-02 | 1984-06-02 | 1984-12-02 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-12-02 | 1988-06-02 | 1988-12-02 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-12-02 | 1992-06-02 | 1992-12-02 | $7700.00 | Window Closed / Lapsed |