Pin in barrel injection molding nozzle using short pin

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

• a nozzle body comprising a discharge end which communicates with said mold cavity and a flow passage for the viscous fluid extending to said discharge end;
• a valve element mounted for 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 multi-part barrel including at least a rear section and a detachable tip located at a first end of said rear section, said tip being adapted to engage a section of said nozzle body to prevent a flow of the viscous fluid therepast when said valve element is in one end position during reciprocation, and first and second bores extending longitudinally through said tip and rear section respectively, said first and second bores communicating with each other;
• a pin located in at least said first bore, said pin including a first end and an enlarged section spaced from said first end, said enlarged section enabling said pin to be secured to said barrel within a cavity defined between said rear section and said tip such that said pin can be removed from said barrel when said tip is detached from said rear section;
• and,
• a 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.

An easy to clean nozzle for injecting a viscous fluid and a non-viscous fluid, comprising:

• a nozzle body having a discharge end and a flow passage for the viscous fluid extending 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 by engaging said nozzle body when in an end position during reciprocation to prevent the flow of the viscous fluid therepast, said barrel including a rear section and a removable tip;
• a bore extending in said shut off barrel and terminating at an end of said tip thereof;
• a pin mounted in at least the portion of said shut off barrel bore within said tip, wherein said pin includes a first end and an enlarged section spaced from said first end, said enlarged section being located in a cavity defined between said rear section and said tip when said tip is secured to said rear section, said pin being removable from said barrel when said tip is removed;
• and,
• a non-viscous fluid flow passage defined between said pin and said barrel through which the non-viscous fluid selectively flows, wherein said pin can be selectively removed from said barrel to allow a cleaning of said shut off barrel bore.

A gas assisted injection molding nozzle comprising:

• a nozzle body having a flow passage for molten thermoplastic extending therein;
• a valve element mounted for reciprocation in said nozzle body flow passage to control a flow of the molten thermoplastic by engaging said nozzle body when said valve element is in an end position during reciprocation to prevent the flow of the molten thermoplastic therepast, said valve element comprising:
• a barrel,
• a tip detachably secured to an end of said barrel,
• a cavity defined between said tip and said barrel,
• a first gas flow passage extending through at least a portion of said barrel, and
• a second gas flow passage extending through said tip, wherein said second gas flow passage communicates with said first gas flow passage;
• and,
• a pin located in at least said second gas flow passage, said pin comprising a first section and an enlarged diameter section spaced therefrom, said enlarged diameter section being detachably securable in the cavity defined between said tip and said barrel to prevent longitudinal movement of said pin in relation to said barrel, said pin and said valve element defining a gas flow passage therebetween.