| 摘要 |
PURPOSE:To enable a mold to be simplified and air flow to be effectively controlled by providing a rib connected to the peripheral edges of both surfaces of a base plate along the whole periphery and improving the rigidity of the base plate itself while causing the rib to make air tight contact with the base plate by the mold depressing the edge of rib. CONSTITUTION:The outer side ribs 3, 3 are projectingly provided at the peripheral edges of both surfaces of a base plate 1, a valve body, along the whole periphery continuously. Also, the inner side ribs 4, 4 spaced from said outside ribs 3 are formed continuously along the whole periphery. In a goove portion 5 surrounded by siad outer side rib 3 and the inner side rib 4 are provided peripherally a plurality of through holes 8 spaced from each other. Buffer seal materials 9 at both surfaces are coupled integrally with each other by connecting members 10 extending through the through holes 8. The base plate 1 may not be deflected easily even if its thickness is thined, since its rigidity is improved by the outer and inner side ribs 3, 4. |
