| 摘要 |
PURPOSE:To prevent contact of glass solder serving as a sealing material with an enclosure, by deviating penetrating position of a lead-in wire from the center of a blocking body and providing a recessed part for storing a surplus enclosure on the internal surface side of the blocking body and in the position avoiding the lead-in wire. CONSTITUTION:A lead-in wire 4 airtightly penetrates a hole 2a provided in the position deviated from the center of a blocking body 2 through glass solder 3. Further, a recessed part 6 is provided in the position avoiding the lead-in wire 4 on the internal surface side of the blocking body 2. Since this recessed part 6 becomes the coolest part, a natrium amalgam 7 of the excessively sealed enclosure is stored here. The natrium amalgam 7 excessively sealed in this way is stored in the recessed part 6 by avoiding direct contact with the respective sealing part glass solder 3, 3 between the blocking body 2 and a luminous bulb 1 as well as between the blocking body 2 and the lead-in wire 4. Thereby, reaction due to the contact of natrium amalgam 7 with glass solder 3 is prevented.
|
