| 摘要 |
<p>PURPOSE:To improve the supporting accuracy of a center lead straight portion and the productivity by attaching a ring-shaped metal element on the spacer center hole penetrating part of the center lead and by soldering a filament to the upper and lower shields. CONSTITUTION:A center lead 4 is inserted through the center hole of a spacer 10, and this spacer 10 is fitted into the through-hole of a lower end shield 3. Right under the center hole of the spacer 10, an O-ring 12 made of a high melting point metal wire such as Mo or W wire is forcibly fitted on. A filament 1 is fixed to the lower end shield 3 and the upper end shield 2 by use of a soldering material 13. The O-ring, which is made of Mo or W wire and formed into a C- ring shape, becomes smooth in fitting by moving up and down along the center lead 4, and the positioning adjustment in the vertical direction can be easily made. With such a configuration, it is possible to support the straight portion of the center lead 4 with high accuracy and to improve the productivity.</p> |
