Patent ID: 7824175

Claim:
A shutoff nozzle assembly for injection molding, said shutoff nozzle assembly comprising: a nozzle body having: one end defining a nozzle front body portion; and an opposite end defining a nozzle rear body portion mounted to said front body portion, said nozzle body having a central passageway having a valve seat, said central passageway extending partially into said nozzle front body portion and partially into said nozzle rear body portion; an inlet passage formed at one end of said nozzle front body portion of said nozzle body in fluid communication with said central passageway; a discharge opening formed at an opposite end of said nozzle rear body portion of said nozzle body, said discharge opening being in fluid communication with said central passageway; a valve body disposed in said central passageway of said nozzle body, said central passageway being sealed when said valve body is in a first position and being open when said valve body is in a second position; and a sprue plunger slidably mounted in said discharge opening of said rear body of said nozzle body when said valve body is in said first position, said sprue plunger having a male threaded end portion at one end thereof and a plurality of internal passages such that fluid communication through said discharge opening is terminated when said valve body is in said first position and said plurality of internal passages are in fluid communication with said central passageway to flow molten plastic resign through said nozzle body when said valve body is in said second position; means for biasing said valve body into said first position such that said central passageway is sealed.