US4074221A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Epoxy bonded silicon carbide lightning-protection valve
Assignee: Landis and Gyr Metering Inc
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Filing: 1976-09-30
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Granted: 1978-02-14
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Expires: 1996-09-30
Abstract
Abstract Lightning protection is provided by an electronic valve molded mainly of silicon carbide powder. The manufacturing cost and high reject rate of previous ceramic bonding is greatly reduced by bonding with epoxy resin, the mixture being pressure molded. The surface-tracking characteristic of epoxy resin is rendered harmless by covering the periphery of the molded piece with insulation and by inclusion of alumina powder in the mix. The insulating sleeve is extended to provide a hood preventing harmful migration of an ionized arcing path.
Inventors
- 👤 James W. Milligan
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:18
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/105; H01C7/118
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
55 words
A lightning protection valve pressure molded from silicon carbide powder with the particles thereof coated with a resin binder and interstices between the coated particles largely filled with aluminum oxide to prevent internal tracking; the valve including opposed terminal faces and the sides of the valve between the faces being substantially free of tracking characteristics.
Claim 2
Dependent Claim
55 words
A lightning protection valve pressure molded from silicon carbide powder with the particles thereof coated with a resin binder and interstices between the coated particles largely filled with aluminum oxide to prevent internal tracking; the valve including opposed terminal faces and the sides of the valve between the faces being substantially free of tracking characteristics.
Claim 3
Dependent Claim
56 words
A lightning protection valve pressure molded from silicon carbide powder with the particles thereof coated with a resin binder and interstices between the coated particles largely filled with aluminum oxide to prevent internal tracking; the valve including opposed terminal faces and the sides between said faces being protected from surface tracking by an ultra-intimate insulative coating.
Claim 4
Dependent Claim
56 words
A lightning protection valve pressure molded from silicon carbide powder with the particles thereof coated with a resin binder and interstices between the coated particles largely filled with aluminum oxide to prevent internal tracking; the valve including opposed terminal faces and the sides between said faces being protected from surface tracking by an ultra-intimate insulative coating.
References Cited (Backward Citations)
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US2806005A
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US3017539A
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US3040282A
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US3207624A
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US3310766A
Cited
US3725745A
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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) | 1981-02-13 | 1981-08-15 | 1982-02-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-02-13 | 1985-08-15 | 1986-02-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-02-13 | 1989-08-15 | 1990-02-14 | $7700.00 | Window Closed / Lapsed |