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US4148135A Expired / Lapsed US ⏱️ 0.0 years remaining

Method of treating metal oxide varistors to reduce power loss

Assignee: General Electric Co
•
Filing: 1978-03-10
•
Granted: 1979-04-10
•
Expires: 1998-03-10
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Abstract

Abstract Metal oxide varistors having a uniform wattage gradient across the varistor surfaces are provided by removing a thin layer of metal oxide surface material from the periphery of the varistors prior to applying an insulating collar and a silicone rubber encapsulation for the purpose of heat dissipation.

Inventors

  • 👤 Eugene C. Sakshaug
  • 👤 Howard F. Ellis

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 11:48
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/10; H01C7/102; Y; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49082; Y10T29/49101

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 67 words
A method of treating zinc oxide varistors to reduce watts loss, said varistors being of the type consisting of a disc having a pair of metal electrodes on opposing disc surfaces and a collar of insulating material on the surface of the disc periphery comprising the steps of: removing a layer of zinc oxide material from the periphery of the disc, and then applying the insulating collar.
Claim 2
Independent Claim 67 words
A method of treating zinc oxide varistors to reduce watts loss, said varistors being of the type consisting of a disc having a pair of metal electrodes on opposing disc surfaces and a collar of insulating material on the surface of the disc periphery comprising the steps of: removing a layer of zinc oxide material from the periphery of the disc, and then applying the insulating collar.
Claim 3
Dependent Claim 17 words
The method of claim 1 wherein the step of removing the zinc oxide material comprises mechanical grinding.
Claim 4
Dependent Claim 27 words
The method of claim 1 including the step of removing a layer of zinc oxide material from the opposing disc surfaces prior to applying the metal electrodes.
Claim 5
Dependent Claim 27 words
The method of claim 1 wherein the step of removing the zinc oxide material comprises the application of an abrasive material to the surface of the periphery.
Claim 6
Dependent Claim 16 words
The method of claim 4 wherein the method of applying the abrasive material comprises grit blasting.
Claim 7
Dependent Claim 19 words
The method of claim 1 wherein the surface material is removed to a depth of at least 0.002 inches.
Claim 8
Dependent Claim 20 words
The method of claim 6 wherein the surface material is removed to a depth of from 0.002 to 0.004 inches.
Claim 9
Dependent Claim 18 words
The method of claim 1 further including the step of applying the insulating collar from a ceramic composition.
Claim 10
Dependent Claim 22 words
The method of claim 8 further including the step of encapsulating at least one of the discs in a silicone rubber composition.
Claim 11
Independent Claim 80 words
A method of manufacturing low loss zinc oxide varistors discs comprising the steps of: providing a plurality of sintered zinc oxide varistor discs having a pair of opposing surface faces and a perimeter; applying metal electrodes to the two opposing faces for electrical connection with the zinc oxide; mechanically abrading the perimeter of the discs to remove a surface layer of the zinc oxide; and applying a layer of ceramic material to the abraded perimeter to form an insulating collar.
Claim 12
Independent Claim 80 words
A method of manufacturing low loss zinc oxide varistors discs comprising the steps of: providing a plurality of sintered zinc oxide varistor discs having a pair of opposing surface faces and a perimeter; applying metal electrodes to the two opposing faces for electrical connection with the zinc oxide; mechanically abrading the perimeter of the discs to remove a surface layer of the zinc oxide; and applying a layer of ceramic material to the abraded perimeter to form an insulating collar.
Claim 13
Dependent Claim 27 words
The method of claim 10 wherein the step of mechanical abrasion comprises: grit blasting the disc perimeter to remove a layer of zinc oxide from the perimeter.
Claim 14
Dependent Claim 20 words
The method of claim 11 wherein the zinc oxide is removed to a depth of from 0.002 to 0.004 inches.

References Cited (Backward Citations)

US3723175A Cited
US3795048A Cited
US3928245A Cited
US3857174A Cited
US4031498A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1982-04-09 1982-10-09 1983-04-10 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1986-04-09 1986-10-09 1987-04-10 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1990-04-09 1990-10-09 1991-04-10 $7700.00 Window Closed / Lapsed

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