Apparatus for molding a plastic closure with air-assisted ejection

An apparatus for molding a plastic closure having a top wall portion and an annular skirt portion, the apparatus comprising:

• a male mold assembly comprising a central forming pin, an outer pin sleeve within which said forming pin is positioned, and disposed coaxially about said forming pin and said outer pin sleeve, an ejector sleeve comprising:
• (i) a surface to sealingly engage a free end of said annular skirt portion of a closure molded upon said male mold assembly, said sealing engagement being characterized by its ability to maintain sufficient pressure in the closure during closure ejection to sustain a bulge in the closure annular skirt;
• and (ii) means to engage a closure molded upon said male mold assembly when moved axially relative to said mold assembly, thereby ejecting said closure from said male mold assembly;
• and
• a female mold which cooperates with said male mold assembly to define a mold cavity in which to form said plastic closure,
• wherein said male mold assembly and said female mold are characterized further in that they are axially moveable relative to each other and,
• said male mold assembly is further characterized in having at least one air passageway in fluid communication with an inside surface of said skirt portion of a closure molded thereupon, said passageway being positioned to permit pressurized gas conveyed through said passageway to contact at least a portion of said inside surface of said skirt portion.