Patent ID: RE39291

Claim:
In a metallic material injection molding machine, an injection nozzle joined to an injection barrel of said injection molding machine, a stationary platen holding a portion of a mold, a sprue bushing mounted in said mold, said nozzle engaging said sprue bushing when said metallic material is injected through said nozzle and into said sprue bushing into said mold , at least one of said nozzle and said sprue bushing having a spigot portion, and at least the other one of said nozzle and said sprue bushing having a complementary channel formed therein, wherein, in use, said spigot portion which extends into a said channel in said sprue bushing , an outer periphery of said spigot fitting within a surface of said channel so as to create a gap between between said surface and said periphery of said spigot that permits a limited amount of metallic material to enter the gap and solidify in the gap to form a seal and thereby prevent loss of metallic material through the interface between said nozzle and said sprue bushing during an injection cycle, said limited amount of material being attached to a sprue and removed therewith.