Patent ID: 7530239

Claim:
A method of drawing a glass clad wire, comprising the steps of: sealing off one end of a first glass tube such that the first glass tube has an open end and a closed end; introducing PbTe inside the first glass tube; heating a portion of the first glass tube such that the glass partially melts forming first ampoule containing the PbTe to be used in a drawing operation; introducing the first ampoule containing the PbTe into a heating device; increasing the temperature within the heating device above the melting temperature of the PbTe such that the PbTe melts and such that the first glass ampoule is heated enough for it to be drawn; drawing the first ampoule to form a glass clad wire comprising a continuous wire of PbTe; breaking the glass clad wire into shorter pieces of glass clad wire: bunching the shorter pieces of glass clad wire together; introducing the bunched pieces of glass clad wire into a second glass tube having a sealed end and an open end; heating a portion of the second glass tube such that the glass partially melts and collapses thereby forming a second ampoule containing the bunched pieces of glass clad wire; introducing the second ampoule into the heating device; increasing the temperature of the second ampoule within the heating device such that the PbTe within the bunched pieces of glass clad wire melts and such that the second glass ampoule is heated enough for it to be drawn; and drawing the heated second ampoule one or more times in succession to produce a multi core cable having a plurality of individual PbTe wires that are insulated from each other by glass cladding.