Manufacturing procedure of helicoidally wound coiled filaments and coiled filaments manufactured using said procedure

摘要

The production of a helically wound body, especially an incandescent element, comprises heat treating a high melting material wire (3) in the region of its recrystallisation temperature and then immediately winding the wire (3) on a core (1). Preferably, the wire (3) is a tungsten wire and is heat treated by an argon/nitrogen or argon/helium plasma torch (4) at just below, preferably 60-90% of, the recrystallisation temperature. Also claimed are: (i) a coil, especially an incandescent element, or electrode produced by the above process; and (ii) a lamp equipped with the above coil or electrode.