Method and device for manufacturing a sheath aerated in an insulating material around a conductor, and coaxial cable provided with such a sheath

摘要

The present invention relates to a method of manufacture of a cellular insulator (5) in an insulating material around a conductor (4), this sheath comprising a longitudinal passage (51) in which is housed the conductor (4) as well as the closed cells (52) extending longitudinally and separated from each other by radial walls (53), the method comprising the following operations: & br / - it is extruded the insulating material (35) to the viscous state by giving it the desired shape by means of shaping means (2, 3) to form the cells (52), & br / - is applied to the insulating material thus formed on the conductor, & br / - is made to cool the insulating material in order to obtain the sheath, & br / characterized in that the insulating material is applied to the conductor at a distance from the output of the shaping means, such as the material is sufficiently attenuated so that the walls (53, 54) of the cells (52) do not collapse, without the use of an overpressure inside the cells.