The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 16, 1982
Filed:
Feb. 17, 1981
Candido J Arroyo, Lilburn, GA (US);
Nicholas J Cogelia, Duluth, GA (US);
Ralph J Darsey, Lawrenceville, GA (US);
Bell Telephone Laboratories, Incorporated, Murray Hill, NJ (US);
Western Electric Company, Inc., New York, NY (US);
Abstract
A method of making a cable (20) specially suited for use in building plenums because of its low flame spread and smoke evolution includes enclosing a multiconductor core (22) in a sheath comprising an inorganic, cellular core wrap (31), a corrugated metallic barrier (40) and dual layers (51) and (52) of a polyimide tape. The tapes are wrapped helically about the barrier in a manner that avoids a compression of the core wrap. The sheath is effective to resist heat transfer inwardly toward the core by conduction while the metallic barrier reflects radiant heat. Advantageously, the sheath containerizes the core without unduly compressing it and thereby allows the intumescence of conductor insulation during a fire to form char which is effective to suppress the evolution of smoke and the propagation of flame.