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
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 11:20
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 |