Rodent and lightning protective sheath system for cables

摘要

A sheath system (50) for a lightguide fiber cable (20) includes a corrugated inner shield (51) which is made of a metallic material having suitable electrical and thermal conductivity to dissipate lightning energy and a corrugated outer shield (60). The outer shield which has an overlapped longitudinal seam is a laminate comprising a corrosion-resistant metallic material (64) which has a relatively high elongation, at least a predetermined chromium content, and a relatively coarse outer surface, and an adhesive system (62). Included in the adhesive system is a first adhesive material (66) which bonds to the outer surface of the metallic material and a second adhesive material (68) which causes the outer shield to become bonded to a plastic jacket (70) which is extruded thereover. The bond between the jacket and the outer shield has sufficient peel strength to prevent the jacket from being separated readily from the outer shield. This causes the jacket and outer shield to function as a composite structure which inhibits the degradation of the sheath system by rodents and withstands the mechanical impact of a direct lightning strike.