US Patent 7731531 Power cord

A power cord which prevents breakage of a plug or cord/conductors even when treated roughly, and thus has a longer life. The power cord includes a plurality of cores of a synthetic resin, each for covering a connection section of a single blade among a plurality of blades, and an outer skin of a synthetic resin, for covering the plurality of cores together such that the blades are held at a specified interval spacing so as to form a plug. The synthetic resin forming the outer skin is softer than the synthetic resin forming the cores. The outer skin includes a thicker part for covering a border part of each cord having an internal covering member between a part covered with the core and a part exposed from the core.