Hitachi Cable, Inc.

Japan Atomic Energy Research Institute

Osamu Mochizuki

Satoshi Mizushima

Masaaki Aoyagi

Fumio Shimizu

Tsukasa Kasahara

Yoshinori Tsukamoto

Hideki Yagyu

Yousuke Morita

Waichiro Kawakami

Toshiaki Yagi

Seiji Kamimura

Takao Onishi

Yasutomi Shimizu

A twisted flat cable is provided which includes parallel fused portions and twisted pair portions alternating with the parallel fused portions. TPO (thermoplastic olefin) is used as an insulating material for an insulative layer that covers conductors to provide separately insulated conductors constituting the parallel fused portions and the twisted pair portions in the twisted flat cable. By virtue of this construction, the twisted flat cable has excellent transmission characteristics.

Twisted flat cable

A flat cable having a linear portion in at least a part thereof. The linear portion has a plurality of insulated conductors juxtaposed to one another with adjacent insulated conductors being adhered to each other to provide an integral insulative layer, and a resin tape applied to the surface of the integral insulative layer so as to conform to the shape of the surface. In the production of this flat cable, a plurality of insulated conductors, together with a resin tape, are feed into a mold. In the mold, adjacent insulated conductors in their insulative layers are fused to each other to form an integral insulative layer. The resin tape is applied to the integral insulative layer so as to conform to the shape of the surface of the integral insulative layer.

Flat cable and process for producing the same

A mold is disposed just behind twist ports for forming twisted pair portions of a flat cable. When a plurality of insulated conductors in their portion corresponding to a parallel portion, before fusion, of a flat cable are passed through the twist ports, the rotation of the twist ports is stopped to permit the plurality of insulated conductors to be parallel aligned with an identical pitch. The mold comprises a combination of two molds each having a plurality of grooves for accommodating therein the plurality of insulated conductors delivered from the twist ports. Upon accommodation of the plurality of insulated conductors within the grooves of the mold, fusion between adjacent insulated conductors in their insulative layers is carried out in the mold to form a parallel fused portion. The above constitution can realize a process and an apparatus for producing a flat cable that require neither a large space nor large equipment, can easily vary the spacing between parallel fused portions, and can properly fuse adjacent insulated conductors in their insulative layers to each other to form a parallel fused portion.

Process and apparatus for producing flat cable

In a flat cable including fused portions and twisted pair portions, the length of the twisted pair portions being not constant, the twist pitch of the twisted pair portions being substantially constant independently of the length of the twisted pair portions, some of the twisted pair portions being constituted by S twists with the other twisted pair portions being constituted by Z twists, the next twisted pair portion is twisted in such a manner that, when the number of twists in the S twisted pair portions in the longitudinal direction of the flat cable is added as &ldquo;plus (&plus;)&rdquo; value with the number of twists in the Z twisted pair portions being added as &ldquo;minus (&minus;)&rdquo; value, the twist sense in the next twisted pair portion is Z twist sense if the integrated value of the number of twists is plus (&plus;) while the twist sense in the next twisted pair portion is S twist sense if the integrated value of the number of twists is minus (&minus;). By virtue of the above constitution, a flat cable with the spacing of fused portions being not constant can be produced without requiring any twist back mechanism.

This invention relates to a method or apparatus by which comparatively low-voltage electric wires and cables laid at power stations and other locations can be diagnosed for deterioration of their polymer-insulation in a non-destructive way. The method or apparatus comprises applying a torsional force to the electric wire or cable, detecting the resulting repulsion as a torque, and estimating the degree of deterioration of the polymer-insulation in the electric wire or cable on the basis of the detected value of torque.

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Ibaraki, Japan

Osamu Mochizuki