At&t Bell Laboratories

Karen D Dye

Kent B Connole

Valerie Jeanne Kuck

Raffaele A Sabia

David M Mitchell

Stanley Kaufman

Edward Dennis Nelson

Gabriel P Pellicciotti

Albert S Tingley

Timothy S Dougherty

Richard S Cuprak, Jr

Maureen Gillen Chan

Leonard D Loan, Deceased

Michael K McKee

An insulated conductor (20) for use in a communication cable which includes a filling material (30) includes a copper conductor (25) and a composite insulation system (27) comprising two concentric layers of insulation. An inner foam layer (28) of the insulation comprises a cellular plastic material (28) which includes a stabilizer system. An outer layer (29) of the insulation is referred to as a skin and comprises a stabilized solid plastic material. The stabilizer system in each of the cellular and solid layers includes a bifunctional portion that functions as an antioxidant and as a metal deactivator and that has a relatively high resistance to extraction. The level of the bifunctional portion of the stabilizer in the cellular material is substantially greater than that in the skin inasmuch as it has been found that the level of the stabilizer cellular layer contiguous to the copper wire determines the oxidation performance level of the composite insulation.

Metallic transmission medium disposed in stabilized plastic insulation

A bonded sheath cable (20) includes a core (22) and a longitudinally wrapped outer shield (36) which encloses the core. An outer surface of the shield is provided with a layer (39) of a copolymer adhesive material which causes the shield to bond to an outerlying plastic jacket (41). The shield is wrapped longitudinally about the core to have overlapping portions (51,53) which form a longitudinal seam (38). In order to avoid seam splitting of the jacket along a line aligned with the longitudinal edge (55) of the outer overlapping portion, control means (60) comprising a polymeric material is provided to extend in bicircumferential directions from the longitudinal edge thereby reducing the bond along the overlap seam and allowing the cable to bend and/or twist without causing a stress concentration in the plastic overlying the longitudinal edge.

Bonded sheath cable having enhanced resistance to jacket splitting

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Phoenix, AZ, United States of America

Karen D Dye