POWER CABLE LAID IN DUCT

PURPOSE:To form a power cable laid in a duct integrated with a sheath, by forming a filament material, wound around a cable core in spiral and capable of being pressed with the sheath. CONSTITUTION:A filament material 3 having a high rigidity and flexibility, for example, a metal steel wire, is wound around the periphery of a cable core 2 in spiral with a predetermined pitch, and this periphery is formed by integral extrusion molding and covering of the plastic sheath 4 to form a cable 1 laid in a duct. Consequently, a projection 5 is formed on the periphery of the spiral filament material 3, and since the filament material 3 is buried in the projection 5, the strength of the projection 5 is considerably stronger than in the case of integral formation only with the plastic sheath. Consequently, a danger that a pitch of the spiral projection is changed at the time of pulling the cable 1 into a duct is eliminated, and a snake can be expected in the duct.