Western Electric Company, Inc.

At&t Technologies, Inc.

At&t Bell Laboratories

Raymond K Swartz

Harry M Dillow

Anthony E Sansone

Talmage P Bursh, Jr

Dean I Davis

Horst L Woellner

John T Slominski

A cable which provides suitable shielding over a relatively wide range of frequencies includes a core (22), and inner shield (32), an outer shield (34) which engages electrically the inner shield, and a jacket (60). Each shield is a laminate which includes a metallic layer comprising a suitable metallic shielding material and a plastic layer. The inner shield has its plastic layer (38) disposed toward the core whereas the plastic layer (52) of the outer shield is oriented toward the jacket. Also, each shield is formed with an unjoined, longitudinal overlapped seam. In order to insure continued shielding when the cable is flexed, the longitudinal seams of the cable are displaced from each other as measured in a direction circumferentially of the core.

Shielded cable

An elongated metallic conductor is insulated with an inner layer of a plasticized polyvinyl chloride composition and an outer layer of a plasticized, irradiation cross-linked polyvinyl chloride composition. The outer layer has a low coefficient of friction to facilitate pulling in central office racks, has mechanical properties which are required for installation and use and, in a preferred embodiment, has a thickness which is substantially less than that of the inner layer. The layers are extruded in the same extruder crosshead that seemingly causes the outer layer to bond to the inner layer to facilitate stripping of the composite insulation from the conductor.

Methods of making a compositely insulated conductor having a layer of

Compositely insulated conductor having a layer of irradiation

A tinned conductor is advanced through each of a plurality of successively smaller die openings in a drawing apparatus to reduce the diameter of the tinned conductor after which it is annealed. After the tinned conductor has been annealed, it is moved through the opening of a die which is slightly smaller than the final die opening in the drawing apparatus. This reconfigures any of the tin coating that may have reflowed during annealing and formed protrusions to remove any such protrusions and form an essentially smooth surface. As a result, the adhesion of a subsequently extruded plastic covering to the tinned conductor is controlled to be within a predetermined range and to be substantially uniform along the length of the conductor.

Methods of and apparatus for controlling plastic-to-conductor adhesion

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Lilburn, GA, United States of America

Raymond K Swartz