Patent ID: 6939504

Claim:
A method for making an injection molded plastic article with at least one hollow portions said method comprising the steps of: providing a mold with an article defining cavity; providing a moveable insert member in said article defining cavity; locking said moveable insert member against movement; subsequently injecting a quantity of a plastic material into the mold cavity, the quantity of plastic material sufficient to completely fill the mold cavity; packing said plastic material in said mold cavity; injecting a fluid material into said packed plastic material in said mold cavity; unlocking said insert member and thereby allowing the pressure from the plastic material and injected fluid material to move said insert member allowing plastic material to fill the area formerly occupied by said insert member and thereby creating a hollow portion in said plastic material forming said article; allowing the completed plastic article to cool and solidify in the mold cavity, exhausting said fluid material from the hollow portion of the plastic article; and removing the plastic material from the mold cavity.