摘要 |
1,249,637. Metal-to-vitreous silica seals. PATENT-TREUHAND-GES. FUR ELEKTRISCHE GLUHLAMPEN m.b.H. 25 Nov., 1968 [30 Nov., 1967], No. 55771/68. Heading C1M. A metal-to-vitreous silica seal comprises a cup-shaped member 2 of refractory metal (e.g. Mo) the inner and outer sides of which converge to form a cutting edge 10, the base of the member 2 being hermetically sealed around a rod-shaped lead 1 (e.g. of W) and the member 2 receiving the tapered end of a vitreous silica capillary tube 3, the end of the tube being spaced from the base of the cup-shaped member 2, and a vitreous silica tube 5 enveloping the cup-shaped member 2 and collapsed thereon by heating, the heating causing the capillary tube and enveloping tube to be fused to the cupshaped member to give a vacuum-tight seal. Vitreous silica tube 5 may be evacuated while heating it to assist its collapse. |