Magnetic support system for cable insertion tube

摘要

A ferromagnetic cable insertion tube is cantilevered from a polymeric conduit extruder and separates an electrical and/or optical cable being pulled through the conduit from the inner surface of the conduit until it has solidified. A d.c. current source is applied to a coil surrounding the cable insertion tube upstream of the extruder so as to induce a magnetic flux in the tube and create a north pole at the downstream free end of the tube and a south pole at the upstream free end of the tube. An array of magnets is assembled about the insertion tube at the downstream free end or north pole thereof. The magnets are arranged with their north poles confronting the north pole of the insertion tube so that the repulsive forces between the like poles magnetically levitate the free end of the insertion tube and keep it from sagging into contact with the extruded conduit.