| 摘要 |
PURPOSE:To prevent any crack generation which might be caused at the sealing part of a tubular bulb by adjusting the distance between the inner wall of the glass bulb and the flare of a stem member to a specified range, and adjusting the distance between the end of the said flare and the end of the said bulb protruding from the end of the said flare to a specified range. CONSTITUTION:After a bulb 2 for a fluorescent lamp is supported upright with the help of a chuck 3, and flare 6 of a stem member 5 is placed on a mount pin 4, and inserted inside the bulb 2. Next, the distance (d) between the flare 6 and the inner wall of the bulb 2 is adjusted to 1.0-2.0mm.. At the same time, the length (L) between the end of the flare 6 and the end of the bulb 2 which protrudes from the end of the flare 6 is adjusted to 0.5-1.5mm., 1.0-2.5mm. and 2.0- 5.0mm., respectively, when the outer diameter of the bulb 2 is less than 18.0mm., from 18.0 to less than 28.0mm. and from 28.0 to less than 31.0mm.. After that, the end of the bulb 2 is fused to the end of the flare 6 by means of a burner 7. As a result, crack generation which is caused when a firmly-supported concave part is provided at the sealing part in making a circular fluorescent lamp, can be widely reduced. |
