Patent ID: 6375449
Filing Date: 2002-04-23
Classification: B29C

Abstract:
A plastic injection molding system comprising a mold with a part-forming cavity therein, said mold having a first opening for entry of a molten plastic material into said cavity and having a second opening for entry of gas into said cavity;a pin member positioned in said second opening without a sleeve therearound; said pin member comprising an elongated body member having a first end facing said cavity, an exterior lateral surface along the sides thereof positioned within said second opening, and a second end at a distance from said cavity; said pin member having a first longitudinally extending gas passageway extending from said second end longitudinally part of the way through said pin member and at least one second gas passageway substantially transverse to said first gas passageway and in connection with said first gas passageway, each of said second passageways having at least one opening on said exterior lateral surface of said pin member, wherein gas passing through said first and second passageways enters into said second opening in the mold and into the part-forming cavity; a source of pressurized gas, said gas being introduced into said cavity through said second opening; and wherein said pin member is stationary relative to said second opening and mold, and said gas is introduced into said cavity in annular space between said pin member and said second opening.