| 摘要 |
1357718 Breaking PHILIPS ELECTRONIC & ASSOCIATED INDUSTRIES Ltd 13 March 1973 [16 March 1972] 11970/73 Heading B3E [Also in Divisions H1 and H5] A method of manufacturing a chain of helically wound wire filaments, i.e. filaments separated by intermediate wire portions, includes clamping members 3 and 4 on to a helically wound wire 1 on a mandrel 2 and moving member 4 in the direction of arrow P so as to break the mandrel between the members and also uncoil a part of the helically wound wire to form the intermediate portion 7. To ensure breaking of the mandrel between the members it is heated by an electric current passing between the members. The wire may be of tungsten and the mandrel of molybdenum. The process may be repeated to form a chain of filaments, the mandrel being removed by etching. The chain may not be broken until in a lamp assembly machine, where lamp filaments with straight ends are achieved. The filaments may be used in incandescent lamps or discharge lamps. |
