Nozzle for gas assisted injection molding

A nozzle for injecting a viscous fluid into a mold cavity of a mold body, said nozzle comprising:

• a nozzle body positioned adjacent the mold body, said nozzle body comprising an inlet end, an opposite discharge end which communicates with said mold cavity and a flow passage for the viscous fluid extending from said inlet end to said discharge end;
• a valve element mounted or reciprocation in said nozzle body flow passage to control a flow of the viscous fluid through said nozzle body discharge end wherein said valve element comprises a barrel having a first end, adapted to selectively engage a portion of a tip section of said nozzle body to prevent a flow of the viscous fluid therepast and wherein a bore extends longitudinally in said barrel;
• a pin located in said longitudinally extending bore of said barrel, said pin and said barrel being secured to a reciprocating means so that said pin reciprocates with said barrel;
• and,
• an annular flow passage defined between said pin and said barrel, said flow passage allowing a flow of a non-viscous fluid through said barrel and into the mold cavity.

A nozzle for injecting a viscous fluid and a non-viscous fluid, comprising:

• a nozzle body having an inlet end, a discharge end and a flow passage for the viscous fluid extending from said inlet end to said discharge end;
• a shut off barrel disposed for reciprocating movement in said nozzle body flow passage to control a flow of the viscous fluid through said nozzle body discharge end;
• a cross link bar oriented generally normal to a longitudinal axis of said barrel, said barrel being secured to said cross link bar;
• a passage extending in said shut off barrel and terminating at a front end thereof;
• a pin extending through said shut off barrel passage, said pin being fixedly mounted to said cross link bar so as to reciprocate when said shut off barrel reciprocates;
• and,
• a first flow passage defined between said pin and said barrel through which the non-viscous fluid selectively flows.