| 摘要 |
PURPOSE:To prevent any hole from remaining in the outer surface of a seat ring after it is molded, by arranging a suitable number of supports having suitable elasticity to a core metal section between pins for forming a valve shaft insert hole, injecting an elastomer to be molded, and allowing said supports to serve as part of a seat ring member. CONSTITUTION:The plurality of the supports having suitable elasticity are mounted around the core metal 12 supported in a toroidal space in the mold by the pins 5, 6 thereby supporting and positioning the core metal. Therefore, when the molds are closed, the supports are pressed backwards by the molds and are inclined to spread radially, so that the core metal 12 is pressed radially inwards significantly to be secured there firmly. After the injection and molding of the elastomer, the supports 9 are not required to be withdrawn and they may be used as part of the seat ring member. |
