Industrie Pirelli Societa Per Azioni

Piero Lavezzari

Antonio Portinari

A process and apparatus for forming the stranded conductor portion of a fully-filled electric cable in which the components of the strand in side-by-side relation are fed through an inlet die at one end of a chamber in which a filling medium at a temperature at least 5.degree. C above the dropping point temperature of the medium and under a pressure above atmospheric pressure is circulated in a direction opposite to the conductor feed direction. In the chamber, the components, preferably groups of conductors, are spread apart by a perforated disc through which they pass and are then twisted together at an outlet die at the opposite end of the chamber to form a strand with a coating of the medium and with the medium filling the spaces between components. From the outlet die the strand passes directly into a bath of the medium in a temperature controlled tank at atmospheric pressure but which maintains the medium at least 5.degree. C above its dropping point temperature. From the tank, the strand is fed through a water cooled sizing tube which cools the medium below its dropping point temperature and shapes and smooths the medium on the exterior of the strand.

Method for impregnating stranded wires during stranding thereof

Apparatus for forming the stranded conductor portion of a fully-filled electric cable in which the components of the strand in side-by-side relation are fed through an inlet die at one end of a chamber in which a filling medium at a temperature at least 5.degree. C. above the dropping point temperature of the medium and under a pressure above atmospheric pressure is circulated in a direction opposite to the conductor feed direction. In the chamber, the components, preferably groups of conductors, are spread apart by a perforated disc through which they pass and are then twisted together at an outlet die at the opposite end of the chamber to form a strand with a coating of the medium and with the medium filling the spaces between components. From the outlet die the strand passes directly into a bath of the medium in a temperature controlled tank at atmospheric pressure but which maintains the medium at least 5.degree. C. above its dropping point temperature. From the tank, the strand is fed through a water cooled sizing tube which cools the medium below its dropping point temperature and shapes and smooths the medium on the exterior of the strand.

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Desio (Milan), Italy

Piero Lavezzari