METHOD FOR PRODUCING STEEL-CORE COPPER CONDUCTORS OF ENHANCED ELECTRIC CONDUCTIVITY Russian patent published in 2007 - IPC H01B5/08 

FIELD: railway transport; conductors for choke , choke-to-choke, track, track-to-track jumpers and electric-traction connectors of rail circuits in electrified railways using direct- and alternating-current traction.

SUBSTANCE: proposed steel-core copper wires whose electric conductivity amounts to 50-60% of that of copper wires of same sectional area are twisted to form stranded conductor incorporating definite number of wires; stranded conductor is subjected to flexible plastic bend at least in two relatively perpendicular planes through at least size of conductor diameter and to heat treatment by way of annealing in acid-free atmosphere at temperature of 720-820 °C for 4-6 h followed by cooling down to 180-200 °C in same atmosphere, and final cooling in the open. Stranded conductor is twisted in at least four lays applied sequentially in alternating directions of lays , pitch ratio of external lays being 1.3 to 1.5 fold lower than that of internal ones, Stranded-conductor jumpers and connectors are flexible and reliably function under cyclic bend and twist conditions at heavy load currents of DC and AC traction circuits.

EFFECT: enhanced reliability and service life of jumpers and connectors made of proposed conductors.

2 cl, 3 dwg, 1 tbl