US 4,035,211 AGranted

Forming sealed seams in moisture barriers for cable

AssigneeWestern Electric Company, Inc.

InventorsRobert George Bill, Edward Louis Franke, Jr.

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Abstract

In the manufacture of a communications cable, a moisture barrier comprising a corrugated metallic tape having inwardly and outwardly facing major surfaces is wrapped longitudinally about an advancing cable core to form an overlapping seam, with at least a portion of each of the major surfaces which form the seam being precoated with an adhesive copolymer material. Heat is applied to at least the portions of the moisture barrier which form the seam while the portions are spaced apart a distance sufficient to permit a stripe of adhesive copolymer material in molten form to be introduced into engagement with a longitudinal edge portion of the precoated outwardly facing surface which is destined to form the seam and which is disposed generally horizontally. Then the cable core and moisture barrier are advanced between coacting rollers which apply forces to the moisture barrier to cause the spaced apart portions to engage each other with the stripe engaging the precoated longitudinal edge portion of the inwardly facing surface which forms the seam and filling the spaces between associated corrugations to form an essentially continuously sealed seam. A longitudinally extending mandrel supports the barrier during the application of the forces to preserve the configuration of the enclosed core and to prevent damage to the core or the moisture barrier.

Claims8

Dependent claims

A method of manufacturing a cable, which includes the steps of:

advancing a cable core along a path;
applying a corrugated metallic strip around the core with at least one overlapped seam, the strip having inwardly and outwardly facing major surfaces, the inwardly facing surface facing the core, each of which major surfaces is at least partially precoated with an adhesive copolymer material, the adhesive copolymer material being positioned along each of the adjacent, mating portions of the major surfaces of the metallic strip which face each other and form the overlapped seam, the adhesive copolymer material being characterized by being capable of maintaining a definite form at ambient temperature and being capable of developing an adhesive bond with the metallic strip at a predetermined temperature above ambient temperature;
spacing apart the overlapping edge portions such that the outwardly facing surface of the innermost longitudinal edge portion of the strip in the overlapped seam is oriented substantially horizontally;
applying heat transfer convectively to the overlapped seam of the strip;
flowing molten adhesive copolymer material into engagement with the precoating on the outwardly facing surface of the longitudinal edge portion of the innermost longitudinal portion of the strip which comprises the seam, the adhesive copolymer material flowed into engagement with the precoated adhesive copolymer material capable of developing an adhesive bond at a predetermined temperature above ambient with the precoated adhesive copolymer material on the adjacent inwardly facing surface of the outermost longitudinal edge portion of the strip which comprises the seam;
applying forces to the strip to reform the overlapped seam and to cause the molten adhesive material supported in engagement with the precoating on the innermost longitudinal edge portion to engage the precoating on the inwardly facing surface of the outermost longitudinal edge portion to seal the seam;
and
cooling the overlapped seam to cooperate with the application of forces thereto to facilitate sealing the seam;
while
providing support for the strip during the reforming of the seam to prevent damage to the core and to the strip.

7 more elements

An apparatus for manufacturing a cable, which includes:

means for advancing a cable core along a path;
means for applying a corrugated metallic strip around the core with at least one overlapped seam, the strip having inwardly and outwardly facing major surfaces, the inwardly facing surface facing the core, each of the major surfaces being partially precoated with an adhesive copolymer material, the adhesive copolymer material positioned along each of the adjacent, mating portions of the major surfaces of the metallic strip which face each other and form the overlapped seam, the adhesive copolymer material being characterized by being capable of maintaining a definite form at ambient temperature and being capable of developing an adhesive bond with the metallic strip at a predetermined temperature above ambient temperature;
means for spacing apart the overlapped edge portions such that the outwardly facing surface of the innermost longitudinal edge portion of the strip in the overlapped seam is oriented substantially horizontally;
means for applying heat transfer convectively to the overlapped seam of the strip;
means for flowing molten adhesive copolymer material into engagement with the precoating on the outwardly facing surface of the longitudinal edge portion of the innermost longitudinal portion of the strip which comprises the seam, the adhesive copolymer material flowed into engagement with the precoated adhesive copolymer material capable of developing an adhesive bond at a predetermined temperature above ambient with the precoated adhesive copolymer material on the adjacent inwardly facing surface of the outermost longitudinal edge portion of the outermost portion of the strip which comprises the seam;
and
means for reforming the overlapped seam to cause the molten adhesive material and the precoating material to cooperate to form a sealed seam between overlapping portions of the corrugated metallic strip.

4 more elements

Dependencies are inferred from the claim text.