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:
Nov. 10, 1992
Filed:
Jul. 31, 1991
Luc W Adriaenssens, Doraville, GA (US);
Richard D Beggs, Buford, GA (US);
Harold W Friesen, Dunwoody, GA (US);
Wendell G Nutt, Dunwoody, GA (US);
AT&T Bell Laboratories, Murray Hill, NJ (US);
Abstract
A fire-resistant cable (20) which is suitable for the transmission of high frequency signals in a local area network includes a core which comprises a plurality of twisted pairs (22,22) of insulated conductors (24,24) and a jacket (35). Each insulated conductor of each pair includes an elongated metallic member (26) and an insulation system (28). The insulation system which is characterized by a suitable low dissipation factor includes dual layers, an outer one of which includes a flame-retardant plastic material. Also, the insulation system is characterized by a suitably low dielectric constant and by compatibility with a relatively short pair twist scheme. In one embodiment, the insulation system includes an inner layer (30) of a polyolefin plastic material and an outer layer (32) of a flame-retardant polyolefin plastic material. The jacket comprises a plastic material characterized by a suitably low dissipation factor and dielectric constant and in a preferred embodiment comprises a flame-retardant polyolefin plastic material. Preferably, the twist length of each pair does not exceed the product of about forty and the outer diameter of an insulated conductor of each pair.