Fire resistant corrugated coaxial cable
AssigneeAmerican Fire Wire, Inc.
InventorWilliam E. Rogers
Life of this patent
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Abstract
A fire resistant corrugated coaxial cable is described that employs a high-temperature, insulating alkaline earth silicate (AES) wool dielectric. The AES wool dielectric is devoid of water as a constituent. The AES wool may be survivable under conditions of high heat, such as temperatures specified by common fire test standards (e.g., 1850° F./1010° C. for two hours). The cable is configured to maintain a relatively coaxial relation between a center conductor and an outer conductor even under aforementioned fire tests. A layer of ceramifiable silicone rubber or refractory fiber wrap can surround the outer conductor and continues to insulate it from the outside if a low-smoke zero-halogen (LSZH) jacket burns away.
Claims24
A fire resistant corrugated coaxial cable apparatus comprising:
- a center conductor;
- a corrugated outer conductor surrounding the center conductor;
- and
- an alkaline earth silicate (AES) wool dielectric extending between the center conductor and the outer conductor, the AES wool dielectric being substantially devoid of chemically bound or free water and being configured to maintain a predetermined dielectric spacing between the center conductor and the outer conductor when exposed to heat at or above 1010° C. in order to continue to propagate radio frequency (RF) signals therein.
A method of manufacturing a fire resistant coaxial cable, the method comprising:
- surrounding a center conductor with an alkaline earth silicate (AES) wool dielectric, wherein the AES wool dielectric is substantially devoid of chemically bound or free water and is configured to maintain a predetermined dielectric spacing between the center conductor and an outer conductor when exposed to heat at or above 1010° C. in order to continue to propagate radio frequency (RF) signals therein;
- and
- encasing the AES wool dielectric with an outer conductor, the outer conductor maintained at a predetermined spacing from the center conductor by the AES wool dielectric.
A fire resistant corrugated coaxial cable apparatus comprising:
- a center conductor;
- a corrugated outer conductor surrounding the center conductor;
- and
- an alkaline earth silicate (AES) wool dielectric extending between the center conductor and the outer conductor, the AES wool dielectric being substantially devoid of chemically bound or free water and being configured to propagate radio frequency (RF) signals therein, wherein the AES wool comprises fibers have a composition weight percentage of:
- (a) 58.5%<SiO2<68.9%
- (b) 18.1%<CaO<40.5%
- (c) 0.11%<MgO<16.4%
- (d) 0<Al2O3<1.5%
- (e) 0<ZrO2<4.5%
- (f) 0<B2O3<8.41%
- (g) 0<Fe2O3<2.9%
- (h) 0<Na2O<2.6%
- (i) 0<TiO2<10%
- wherein the total quantity of Al2O3, ZrO2, TiO2, B2O3 and iron oxides does not exceed 10 wt % based upon the total fiber composition.
A fire resistant corrugated coaxial cable apparatus comprising:
- a center conductor;
- a corrugated outer conductor surrounding the center conductor;
- and
- an alkaline earth silicate (AES) wool dielectric extending between the center conductor and the outer conductor, the AES wool dielectric being substantially devoid of chemically bound or free water and being configured to propagate radio frequency (RF) signals therein, wherein the AES wool comprises fibers have a composition weight percentage of:
- 72%<SiO2<86%
- 0<MgO<10%
- 14%<CaO<28%
- Al2O3<2%
- ZrO2<3%
- B2O3<5%
- P2O5<5%
- 95%<SiO2+CaO+MgO+Al2O3+ZrO2+B2O3+P2O5.
Dependencies are inferred from the claim text.