SELF-TAPPING SUPPORT FOR SHELL MOLDS

摘要

SELF-TAPPING SUPPORT FOR SHELL MOLDSAbstract of the DisclosureA method of casting metal in a gas permeableshell mold in which a vacuum is applied to an externalupper mold surface by engaging the mold in thedownwardly facing opening of a generally cylindricalvacuum chamber, defined by a chamber wall with athreaded region sized and shaped to snuggly engage aside mold surface. Engagement is effected by forcingthe mold into the chamber opening while causing relativerotation of the mold and chamber.