US3857174A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method of making varistor with passivating coating
Assignee: General Electric Co
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Filing: 1973-09-27
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Granted: 1974-12-31
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Expires: 1993-09-27
Abstract
Abstract Disclosed is a metal oxide varistor comprising a body portion that is composed essentially of a metal oxide and a small percentage of a plurality of preselected additives. A passivating coating is applied to the body portion prior to the application of metallic contacts. The passivating coating includes at least some of the preselected additives in order to enhance device stability and insure compatibility therewith.
Inventors
- 👤 J May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 20:18
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/102; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49099; Y10T29/49101
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
65 words
A METHOD FOR MANUFACTURING A VARISTOR COMPRISING THE STEPS OF: PROVIDING A BODY PORTION CONSISTING ESSENTIALLY OF A METAL OXIDE AND A RELATIVELY SMALL PORTION OF A REACTION PRODUCT OBTAINED BY MELTING TOGETHER A PLURALITY OF PRESELECTED ADDITIVES; APPLYING A PASSIVATING COATING TO SAID BODY PORTION, SAID COATING COMPRISING A SMALL QUANTITY OF THE REACTION PRODUCT; AND HEATING SAID BODY PORTION WITH SAID COATING THEREON.
Claim 2
Independent Claim
65 words
A METHOD FOR MANUFACTURING A VARISTOR COMPRISING THE STEPS OF: PROVIDING A BODY PORTION CONSISTING ESSENTIALLY OF A METAL OXIDE AND A RELATIVELY SMALL PORTION OF A REACTION PRODUCT OBTAINED BY MELTING TOGETHER A PLURALITY OF PRESELECTED ADDITIVES; APPLYING A PASSIVATING COATING TO SAID BODY PORTION, SAID COATING COMPRISING A SMALL QUANTITY OF THE REACTION PRODUCT; AND HEATING SAID BODY PORTION WITH SAID COATING THEREON.
Claim 3
Dependent Claim
12 words
A method according to claim 1 wherein said coating includes carrier means.
Claim 4
Dependent Claim
36 words
A method according to claim 2 wherein said step of heating said body portion with said coating thereon comprises heating to a temperature sufficient to fuse said carrier means but insufficient to melt said reaction product.
Claim 5
Dependent Claim
28 words
A method according to claim 3 wherein said carrier means comprises a compound of at least one member of the group consisting of bismuth, boron, antimony, and silicon.
Claim 6
Dependent Claim
26 words
A method according to claim 3 wherein said additives comprise the oxides of bismuth, cobalt, manganese and titanium, and wherein said metal oxide is zinc oxide.
Claim 7
Dependent Claim
22 words
A method according to claim 3 further comprising the step of applying metallic contacts to said body portion with said coating thereon.
Claim 8
Dependent Claim
13 words
A method according to claim 3 wherein said coating is free of silicon.
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) | 1977-12-30 | 1978-07-01 | 1978-12-31 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-30 | 1982-07-01 | 1982-12-31 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-30 | 1986-07-01 | 1986-12-31 | $7700.00 | Window Closed / Lapsed |