Modern biaxial cable consists of two parallel insulated wires embedded within a common insulating covering or sheath, such as may be of an extruded thermoplastic resin. Ideally, the outside covering for such a cable may be provided with an axially extending groove or indentation, providing a line of weakness to facilitate manual separation of the conductors, such as for splicing and to make connections to receptacles and junction boxes. The manufacture of such cable, and of other forms of insulated electrical conductors used for household and industrial wiring applications, involves operations that are difficult to control and expensive to carry out.
It is therefore a primary object of the present invention to provide a novel method and apparatus by which a common insulating coating can readily be produced upon a set of parallel wires.
A more specific object of the invention is to provide such a method and apparatus for the production of such a coating having a cross-sectional configuration which facilitates severance of the individual conductors from one another by manual tearing.
Another object of the invention is to provide such a novel method and apparatus for producing a biaxial cable consisting of two insulated conductors embedded within an exterior sheath of synthetic thermoplastic resinous material.
Yet another object of the invention is to provide such a method and apparatus which are relatively simple, and by which cable can readily be produced at high rates, with good control and at relatively low cost.
Still another object of the invention is to provide a novel cable produced by the method of the invention.