Abstract: A method of manufacturing stems for vacuum tubes is disclosed. The method makes it possible, in particular, to improve the quality of the seal between the metallic bushings and the glass of the stem. The method consists in loading a bottom mold with a first glass piece and a second glass piece and metallic conductors, and then in heating the glass pieces before pressing them against each other between the bottom mold and the top mold. According to one characteristic of the invention, the first piece, which constitutes an external piece partially fixed in the bottom mold, is directly heated only on an upper part which is not fixed, and the two glass pieces are pressed against each other as soon as the upper part has reached a so-called working temperature in order to prevent prolonged contact between the upper part and a limited surface of the conductors.

Abstract: A method for the manufacture of vacuum tube bases wherein to mould bases of electronic tubes shaving conductors of different lengths, a widened opening is made in the upper mould and a distance sleeve with a dead hole is placed in it. This distance sleeve compensates for the difference in length with respect to the longest conductors. Also set forth is a device for application of this method.