Multiple mold rotary casting apparatus

A rotational casting apparatus comprising:

• mold means including at least one hollow mold for molding synthetic plastic material into hollow articles by rotation of said molds when they contain said plastic;
• an oven including heating means for heating said mold above the melting temperature of said plastic, said oven being fixed in position;
• rotational mounting means for mounting said mold for rotation within said oven;
• and
• cooling means separate from said heating means for cooling said mold and the molded article therein while they are in said oven to a temperature below said melting temperature, said cooling means including a fan for providing an air stream, external water spray means for spraying water into the air inlet of said fan outside said oven to provide a stream of cool, moist air external to the oven and input means for transmitting said stream of moist air into said oven to cool said mold.

A rotational casting apparatus comprising:

• mold means including a plurality of hollow molds for molding synthetic plastic material into hollow articles by rotation of said molds when they contain said plastic;
• heating means including an oven enclosing said molds for heating said molds, said oven being fixed in position;
• cooling means for cooling said molds and the molded articles therein while they are in said oven;
• rotation means for rotating said molds within said oven, including a common drive shaft for rotating all of the molds about a common axis, a plurality of rotor means for rotating each of said molds about a fixed bearing shaft extending at an angle to said common axis, and support means for supporting each of said molds on said common drive shaft;
• and
• scraper rings of low adhesion material attached to the bearing shafts within such molds so that the scraper rings are each spaced a predetermined distance from the inner surface of a side portion of one end of the mold to provide the molded article with a portion of predetermined thickness and inner diameter.