Patent US3950274A successfully refreshed from Google Patents.
US3950274A
Expired / Lapsed
US
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Process for making a low voltage varistor
Assignee: General Electric Co
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Filing: 1973-09-27
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Granted: 1976-04-13
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Expires: 1993-09-27
Abstract
Abstract Disclosed is an improved metal oxide varistor particularly suitable for varistor operation at low voltages such as 80 volts and less, and a method for the manufacture thereof. The varistor comprises a body portion compounded of a primary component and a plurality of additives. The additives are, before combination with the primary component, mixed thoroughly and reacted to form a crystalline reaction product. After grinding, the reaction product is mixed with the primary component and the body is further processed in the conventional manner.
Inventors
- 👤 John E. May
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-31 17:16
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/105; H01C7/108; H01C7/112
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
68 words
A method for making a varistor body comprising the steps of: mixing together and reacting a plurality of additives, said reacted additives forming a reaction product by heating them to a temperature above their melting points and then cooling them; grinding said reaction product; mixing ground reaction product with zinc oxide to form a final mixture; and forming said body of said final mixture by pressing and sintering.
Claim 2
Independent Claim
68 words
A method for making a varistor body comprising the steps of: mixing together and reacting a plurality of additives, said reacted additives forming a reaction product by heating them to a temperature above their melting points and then cooling them; grinding said reaction product; mixing ground reaction product with zinc oxide to form a final mixture; and forming said body of said final mixture by pressing and sintering.
Claim 3
Dependent Claim
25 words
A method according to claim 1 further comprising, following said step of heating said additives, a step of cooling said additives at a preselected rate.
Claim 4
Dependent Claim
23 words
A method according to claim 2 wherein said steps of heating and cooling said additives comprise fusing said additives into a fused solid.
Claim 5
Dependent Claim
12 words
A method according to claim 3 wherein said fused solid is crystalline.
Claim 6
Dependent Claim
25 words
A method according to claim 3 wherein said step of heating said additives comprises heating said additives to a temperature of above approximately 1000° Centigrade.
Claim 7
Dependent Claim
17 words
A method according to claim 1 wherein said additives comprise oxides of cobalt, manganese, bismuth and titanium.
References Cited (Backward Citations)
US3663458A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-13 | 1979-10-13 | 1980-04-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-13 | 1983-10-13 | 1984-04-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-13 | 1987-10-13 | 1988-04-13 | $7700.00 | Window Closed / Lapsed |