Fay, Sharpe, Beall, Fagan, Minnich & McKee
Self-current-limiting devices and method of making same
 A self-current-limiting device and a method of making self-current-limiting devices. These devices typically comprise melt processable, self-temperature regulating, irradiation cross-linked, electrically semi-conductive polymeric compositions having positive temperature coefficients of electrical resistance. The semi-conductive compositions contain electrically conductive particles, such as carbon black, dispersed throughout the composition in an amount ranging from about 15% to about 20% of the total weight of the composition. Heating cables made in accordance with the invention comprise two or more elongate substantially parallel spaced-apart electrical conductors that are electrically inter-connected by extruded forms of the compositions. The method is characterized by an efficient three step process wherein the semi-conductive composition is extruded over the conductors, radiation cross-linked and annealed. The method of the invention does not require the application of a shape retaining jacket to the cable prior to annealing. Additionally, only one annealing step is utilized. 
Fluorocarbon Company
H H Y H
H05B H01C Y10T H05B
inventional inventional additional inventional
Louis A. Eric G. Richard W. David A.
Miller Hilston Farkas Rock