Patent US3576940A successfully refreshed from Google Patents.
US3576940A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Flame-retardant wire and cable
Assignee: Marmon Group Inc
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Filing: 1968-12-03
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Granted: 1971-05-04
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Expires: 1988-12-03
Abstract
Abstract An electrical conductor or cable, capable of maintaining electrical integrity when exposed to open flame temperatures of 1000* F. without propagating a fire or resulting in falling burning particles or generating large volumes of smoke. The conductor or cable of this invention is comprised of a metallic conductor or plurality of conductors covered by a layer of primary insulation. Such conductors are then covered by a layer of silicone rubber which is, in turn, covered by a layer of glass fiber. The layer of glass fiber may then be covered by another layer of silicone rubber which is, in turn, covered by a layer of braided asbestos impregnated with an intumescent material. In the alternative, the second layer of silicone rubber may be covered by an asbestos tape which is then covered by a layer of elastomeric material having fire-retardant properties.
Inventors
- 👤 John G Stone
- 👤 George S Buetiner
- 👤 Christian A Alm
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 13:47
CPC Classifications
H; H01; H01B; H01B7/00; H01B7/17; H01B7/29; H01B7/295
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
22 words
The electrical conductor of claim 1, wherein the lay of the layers of glass fiber and asbestos is in the same direction.
Claim 2
Dependent Claim
27 words
The electrical conductor of claim 1, wherein the electrical conductor is selected from the group consisting of a single solid conductor and a plurality of solid conductors.
Claim 3
Dependent Claim
22 words
The electrical conductor of claim 1, wherein the glass fiber layer is covered on both sides with a layer of silicone rubber.
Claim 4
Dependent Claim
45 words
The electrical conductor of claim 1, wherein the primary insulation is selected from the class of compounds consisting of chemically cross-linked polyethylene compounds, silicone rubbers, heat-sealed polyester tapes such as polyethylene terephthalate, ethylene propylene rubber, nylon, butyl rubber, polysulfone, polyvinylchloride, polytetrafluoroethylene and fluorinated ethylene propylene.
Claim 5
Dependent Claim
35 words
The electrical conductor of claim 1, wherein the intumescent material is selected from the class consisting of raw isano oil, polyamide resins, amine formaldehyde resins, water insoluble metal metaphosphates, polypentaerythritols, sodium silicate and combinations thereof.
Claim 6
Dependent Claim
30 words
The electrical conductor of claim 1, wherein the glass fiber is selected from the group consisting of glass cloth, glass braid, glass mat and other glass fibers and combinations thereof.
Claim 7
Dependent Claim
111 words
An electrical insulated cable, capable of maintaining electrical integrity when exposed to open flame temperatures of at least 1000* F. without propagating a fire or resulting in falling burning particles or generating dense smoke, comprising: a. a plurality of metallic conductors, b. a layer of primary insulation which covers and separates the plurality of metallic conductors along their lengths such that each metallic conductor is insulated from the other conductors, c. a layer of glass fiber over said primary insulation, d. a layer of silicone rubber on one side of said layer of glass fiber; and e. a layer of asbestos which covers said layers of glass fiber and silicone rubber.
Claim 8
Dependent Claim
35 words
The electrical cable of claim 8, wherein the layer of asbestos comprises asbestos selected from the group consisting of asbestos braid, asbestos mat and asbestos felt, which asbestos material is impregnated with an intumescent material.
Claim 9
Dependent Claim
39 words
The electrical cable of claim 8, wherein the layer of asbestos comprises asbestos tape which is then covered by a layer of an elastomeric material selected from the group consisting of neoprene, butadiene acrylonitrile, chlorosulfonated polyethylene and butadiene styrene.
Claim 10
Dependent Claim
22 words
The electrical insulated cable of claim 8, wherein a layer of silicone rubber covers both sides of said layer of glass fiber.
Claim 11
Dependent Claim
49 words
The electrical insulated cable of claim 8, further including an intermediate layer of insulating material which covers the plurality of metallic conductors insulated with the primary insulation and is immediately beneath the layer of glass fiber, wherein said material is selected from the group consisting of neoprene and polyvinylchloride.
Claim 12
Dependent Claim
26 words
The electrical cable of claim 10, wherein the lay of the wires, the glass fiber layer and the asbestos tape layer is in the same direction.
Claim 13
Dependent Claim
45 words
The electrical cable of claim 8, wherein the primary insulation is selected from the class of compounds Consisting of chemically cross-linked polyethylene compounds, silicone rubber, heat-sealed polyester tapes such as polyethylene terephthalate, ethylene propylene rubber, nylon, butyl rubber, polysulfane, polyvinylchloride, polytetrafluoroethylene and fluorinated ethylene propylene.
Claim 14
Dependent Claim
35 words
The electrical cable of claim 9, wherein the intumescent material is selected from the class consisting of raw isano oil, polyamide resins, amine formaldehyde resins, water insoluble metal metaphosphates, polypentaerythritols, sodium silicate and combinations thereof.
Claim 15
Dependent Claim
30 words
The electrical cable of claim 8, wherein the glass fiber is selected from the class consisting of glass cloth, glass braid, glass mat and other glass fibers and combinations thereof.
Claim 16
Dependent Claim
16 words
The electrical conductor of claim 10, wherein the elastomeric material has compounded therein a chlorinated parafin.
Claim 17
Dependent Claim
26 words
The electrical conductor of claim 10, wherein the elastomeric material has additionally compounded therein halogenated phenols selected from the group consisting of tetrabromobisphenol, hexachlorophene and dichlorophene.
Claim 18
Dependent Claim
31 words
The electrical conductor of claim 10, wherein the elastomeric material has additionally compounded therein fire-retardant inorganic compounds selected from the group consisting of antimony trioxide, zinc borate, tricresylphosphate, trioctylphosphate and triphenylphosphate.
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) | 1974-05-03 | 1974-11-02 | 1975-05-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1978-05-03 | 1978-11-02 | 1979-05-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1982-05-03 | 1982-11-02 | 1983-05-04 | $7700.00 | Window Closed / Lapsed |