Patent US5608747A successfully refreshed from Google Patents.
Patent US5294374A successfully refreshed from Google Patents.
← Back to Patent Explorer
US5294374A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrical overstress materials and method of manufacture

Assignee: Leviton Manufacturing Co Inc
•
Filing: 1992-03-20
•
Granted: 1994-03-15
•
Expires: 2012-03-20
📄 Original PDF 🌐 Google Patents 🔄 Sync Now

Abstract

Abstract This invention provides a method of preparing an electrical overstress material having a nonlinear resistance which declines sharply in response to an electric field exceeding a clamping voltage so as to be able to shunt out transient surges which method comprises using an adhesive binder, for example a silicone rubber or a ceramics dispersion, and thorough mixing therein of small conductive, and optionally semiconductive particles, for example nickel particles of various morphologies and silicon carbide particles respectively, followed by molding under pressure and curing. The invention is also directed to the electrical overstress material itself which has excellent strength and integrity as well as survivability from multiple surges and has multiple applications in, for example, electrical outlet strips and power cables. The invention is also directed to a power outlet strip comprising a plurality of surge arresting elements composed of the electrical overstress material of the invention.

Inventors

  • 👤 Henry Martinez
  • 👤 Joann Yastine
  • 👤 Steven Chen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-09 11:29
CPC Classifications
H; H01; H01C; H01C7/00; H01C7/13; Y; Y10; Y10T; Y10T428/00; Y10T428/25; Y10T428/254; Y10T428/256; Y10T428/257

Claims Analysis

Total Claims: 23
Claim 1
Independent Claim 198 words
A method of preparing a nonlinear electrical resistance material useful for protecting electrical equipment against transient surges which method comprises the steps of: composing a mixture comprising a curable adhesive fluid binder of substantially insulative electrical resistivity, and electrical filler material comprising conductor particles having an applied coating of not less than 70 Angstroms nor more than 1 Micron, and semiconductor particles having no applied coating, wherein the electrical filler material is present in an amount from 15 to 97 volume percent of said mixture; mixing said mixture until a uniform consistency is obtained of said particles in said binder and the particles are substantially all coated with said binder; molding said mixture under pressure into a shaped, coherent self-supporting material to pack the particles closely together with interparticle spaces filled with binder and substantially free of voids to provide a material having a clamping voltage such that it presents substantially an open circuit to voltage surges below said clamping voltage, said material being capable of maintaining said clamping voltage after repeated surges in excess of said clamping voltage, and said material being capable of repeatedly conducting said surges in excess of said clamping voltage by electron transport.
Claim 2
Independent Claim 198 words
A method of preparing a nonlinear electrical resistance material useful for protecting electrical equipment against transient surges which method comprises the steps of: composing a mixture comprising a curable adhesive fluid binder of substantially insulative electrical resistivity, and electrical filler material comprising conductor particles having an applied coating of not less than 70 Angstroms nor more than 1 Micron, and semiconductor particles having no applied coating, wherein the electrical filler material is present in an amount from 15 to 97 volume percent of said mixture; mixing said mixture until a uniform consistency is obtained of said particles in said binder and the particles are substantially all coated with said binder; molding said mixture under pressure into a shaped, coherent self-supporting material to pack the particles closely together with interparticle spaces filled with binder and substantially free of voids to provide a material having a clamping voltage such that it presents substantially an open circuit to voltage surges below said clamping voltage, said material being capable of maintaining said clamping voltage after repeated surges in excess of said clamping voltage, and said material being capable of repeatedly conducting said surges in excess of said clamping voltage by electron transport.
Claim 3
Dependent Claim 24 words
The method of claim 1, further comprising selecting median particle sizes for both conductor and semiconductive particles of from 100 angstroms to 100 microns.
Claim 4
Dependent Claim 22 words
The method of claim 1, further comprising coating at least some of said conductor particles with insulative material before composing said mixture.
Claim 5
Dependent Claim 22 words
The method of claim 1, further comprising coating at least some of said conductor particles with semiconductive material before composing said mixture.
Claim 6
Dependent Claim 30 words
The method of claim 1 further comprising using at least 50 volume percent of conductor particles and at most 50 volume percent of semiconductor particles in said electrical filler material.
Claim 7
Dependent Claim 131 words
A nonlinear electrical resistance material comprising: a binder of substantially insulative electrical resistivity; electrical filler material comprising conductor particles having an applied coating of not less than 70 Angstroms nor more than 1 Micron and semiconductor particles having no applied coating, said conductor particles and said semiconductor particles being distributed throughout said binder such that said material is substantially homogeneous and free of voids, and wherein the electrical filler material is present in an amount from 15 to 97 volume percent of said nonlinear electrical resistance material; said nonlinear electrical resistance material having a clamping voltage such that it presents substantially an open circuit to voltages below said clamping voltage, and said nonlinear resistance material being capable of repeatedly conducting voltage surges in excess of said clamping voltage by electron transport.
Claim 8
Dependent Claim 131 words
A nonlinear electrical resistance material comprising: a binder of substantially insulative electrical resistivity; electrical filler material comprising conductor particles having an applied coating of not less than 70 Angstroms nor more than 1 Micron and semiconductor particles having no applied coating, said conductor particles and said semiconductor particles being distributed throughout said binder such that said material is substantially homogeneous and free of voids, and wherein the electrical filler material is present in an amount from 15 to 97 volume percent of said nonlinear electrical resistance material; said nonlinear electrical resistance material having a clamping voltage such that it presents substantially an open circuit to voltages below said clamping voltage, and said nonlinear resistance material being capable of repeatedly conducting voltage surges in excess of said clamping voltage by electron transport.
Claim 9
Dependent Claim 30 words
The nonlinear electrical resistance material of claim 6 wherein at least some of said conductor particles each comprise an interior of insulative material surrounded by a layer of conductive material.
Claim 10
Dependent Claim 30 words
The nonlinear electrical resistance material of claim 6 wherein at least some of said conductor particles each comprise an interior of semiconductive material surrounded by a layer of conductive material.
Claim 11
Dependent Claim 15 words
The nonlinear electrical resistance material of claim 6 wherein said binder comprises an elastomeric polymer.
Claim 12
Dependent Claim 15 words
The nonlinear electrical resistance material of claim 9 wherein said elastomeric polymer is silicone rubber.
Claim 13
Dependent Claim 29 words
The nonlinear electrical resistance material of claim 10 wherein said silicone rubber consists of a polysiloxane of general formula R 2 SiO-- where R is a monovalent organic radical.
Claim 14
Dependent Claim 16 words
The nonlinear electrical resistance material of claim 9 wherein said binder further comprises an inert filler.
Claim 15
Dependent Claim 15 words
The nonlinear electrical resistance material of claim 12 wherein said inert filler is calcium carbonate.
Claim 16
Dependent Claim 16 words
The nonlinear electrical resistance material of claim 12 wherein said inert filler is a silicon compound.
Claim 17
Dependent Claim 21 words
The nonlinear electrical resistance material of claim 6 further comprising an insulative coating for at least some of said conductor particles.
Claim 18
Dependent Claim 21 words
The nonlinear electrical resistance material of claim 6 further comprising a semiconductive coating for at least some of said conductor particles.
Claim 19
Dependent Claim 16 words
The nonlinear electrical resistance material of claim 6 wherein said binder is a paste-like ceramic material.
Claim 20
Dependent Claim 25 words
The nonlinear electrical resistance material of claim 6 wherein said conductor particles are made of nickel and said semiconductor particles are made of silicon carbide.
Claim 21
Dependent Claim 29 words
The nonlinear electrical resistance material of claim 6 wherein said electrical filler material comprises at least 50 volume percent conductor particles and at most 50 volume percent semiconductor particles.
Claim 22
Dependent Claim 119 words
A nonlinear electrical resistance material comprising: a binder of substantially insulative electrical resistivity; electrical filler material comprising conductor particles having no coating and semiconductor particles having an insulative coating, said conductor particles and said semiconductor particles being distributed throughout said binder such that said material is substantially homogeneous and free of voids, and wherein the electrical filler material is present in an amount from 15 to 97 volume percent of said nonlinear electrical resistance material; said nonlinear electrical resistance material having a clamping voltage such that it presents substantially an open circuit to voltages below said clamping voltage, and said nonlinear resistance material being capable of repeatedly conducting voltage surges in excess of said clamping voltage by electron transport.
Claim 23
Dependent Claim 119 words
A nonlinear electrical resistance material comprising: a binder of substantially insulative electrical resistivity; electrical filler material comprising conductor particles having no coating and semiconductor particles having an insulative coating, said conductor particles and said semiconductor particles being distributed throughout said binder such that said material is substantially homogeneous and free of voids, and wherein the electrical filler material is present in an amount from 15 to 97 volume percent of said nonlinear electrical resistance material; said nonlinear electrical resistance material having a clamping voltage such that it presents substantially an open circuit to voltages below said clamping voltage, and said nonlinear resistance material being capable of repeatedly conducting voltage surges in excess of said clamping voltage by electron transport.

References Cited (Backward Citations)

US2796505A Cited
US2978665A Cited
US2952761A Cited
US3210461A Cited
US3210460A Cited
GB1135076A Cited
US3412200A Cited
GB1253239A Cited
GB1294665A Cited
US3936396A Cited
US3576387A Cited
US3687871A Cited
US3682841A Cited
US3896480A Cited
US3863193A Cited
US3950604A Cited
US4252692A Cited
US3849333A Cited
US4470898A Cited
US3900432A Cited
US3938725A Cited
US3859569A Cited
US4011360A Cited
US4431861A Cited
US4032965A Cited
US3954419A Cited
US4097834A Cited
US4127511A Cited
US4184984A Cited
US4103274A Cited
US4333861A Cited
US4278961A Cited
US4219862A Cited
US4146677A Cited
US4172922A Cited
US4234902A Cited
US4364021A Cited
US4163204A Cited
US4174530A Cited
US4290041A Cited
US4549981A Cited
US4166159A Cited
US4306214A Cited
US4207482A Cited
US4205298A Cited
US4420737A Cited
US4347505A Cited
US4316171A Cited
US4338223A Cited
US4450426A Cited
US4430255A Cited
US4383237A Cited
US4320436A Cited
US4541974A Cited
US4519942A Cited
US4331948A Cited
US4397773A Cited
US4507359A Cited
US4438158A Cited
US4463268A Cited
US4397775A Cited
US4545929A Cited
US4472239A Cited
US4624137A Cited
US4460623A Cited
US4444351A Cited
US4490318A Cited
US4438214A Cited
US4497533A Cited
US4439807A Cited
US4547314A Cited
US4473765A Cited
US4579702A Cited
US4452729A Cited
US4473812A Cited
US4510112A Cited
US4452728A Cited
US4460497A Cited
US4540604A Cited
US4586074A Cited
US4624990A Cited
US4575440A Cited
US4581621A Cited
US4613645A Cited
US4726991A Cited
US4977357A Cited
US4992333A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1997-03-14 1997-09-13 1998-03-15 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2001-03-14 2001-09-13 2002-03-15 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2005-03-14 2005-09-13 2006-03-15 $7700.00 Window Closed / Lapsed

Assigned Categories & Tags

No categories assigned to this patent yet.

Assign Category Tag