| 摘要 |
A current lead-through conductor, comprising a plate formed with a tapered tubular section 1 open at both ends in which an electrical conductor 2 is sealed by means of a glass bead having a hemispherical end 9, has the glass bead formed of two portions 10, 11 of different compositions. The portion 10 is formed of a glass which crystallizes readily, e.g. of the composition by weight, 3.5% K2O, 3% Al2O3, 81.5% SiO2, 12% Li2O, while the glass of the portion 11 does not crystallize and may have the composition 69.4% SiO2, 8.1% Na2O, 6.7% K2O, 5.4% Al2O3, 0.1% Fe2O3, 10.3% BaO to which may be added a small amount of cobalt oxide to improve adhesion of the two glasses. A fernico plate may have a number of tapered sections each with its own conductor. |
