| 摘要 |
PURPOSE:To prevent any natural breakdown of a flare by improving the manufacture process of the flare so that the flare is not expanded from the sealing part when the flare is treated with heat after the flare is fused to the bulb. CONSTITUTION:A stem mount 4 is made of a flare 1, which is formed from lead glass so that the peripheral parts (m) extending outward are thinner than the other parts of the flare 1. Next, the end of the flare 1 of the stem mount 1 is fused to the opening end of a straight bulb 8 which is made of soda glass or low-lead glass, and a concave part 9 extending along the circumference of the bulb 8 is formed on the end part of the bulb 8. After that, the bulb 8 is curved into a circular shape by chucking the concave part 9 of the bulb 8. |
