Patent 7175421 was granted and assigned to Misumi on February, 2007 by the United States Patent and Trademark Office.
The configuration is such that there are provided a slide core 21 (21A) disposed to be movable toward and away from a cavity (molding space) 8a and driven at least in the direction toward the cavity 8a according to the closing action of a mold 8, and a guiding member (guiding means) 11 (11A) disposed at least on one mold member 7 of the mold and having a groove-shaped rail part 12a for supporting the slide core 21 in the directions toward and away from the cavity 8a, wherein one member out of the slide core 21 and guiding means 11 is provided with urging means for urging the slide core relative to the guiding member 11 in the direction away from the cavity 8a. This configuration makes it possible to reduce the size and the maintenance cost of the slide core.