Patent ID: 8007700
Filing Date: 2011-08-30
Classification: H01B

Abstract:
1. A method of sheathing at least one conductor in a PTFE sheath having at least one continuous cell, said method comprising the following steps: compressing a lubricant-impregnated PTFE powder in a converging chamber arranged in an extrusion die and around a guide for guiding said at least one conductor, the impregnated PTFE powder thus being thrust towards an extrusion orifice to form an extrudate; causing said extrudate to pass from said orifice along an extrusion passage inside the die, in which it is shaped around a downstream tube-shaped portion of said guide; passing said extrudate around at least two solid bars presenting, at least over a distance within the extrusion passage, the same section as said at least one continuous cell and thereby preventing the extrudate from occupying the section that is to be occupied by said at least one continuous cell, the at least one continuous cell being formed from the downstream end surface of the at least two solid bars and extending downstream therefrom; extracting the lubricant by evaporation; and sintering the resulting assembly so as to stabilize the material of the sheath, wherein the at least two solid bars each have a substantially constant section inscribed in an annulus and forming an angular sector whose outer radius is equal to the outer radius of the downstream tube-shaped portion, and wherein a passage forming a through hole between the at least two solid bars enables the extrudate to pass from the outside of the annulus to the inside thereof in contact with the at least one conductor.