Gas assisted injection molding apparatus utilizing sleeve and pin arrangement

The apparatus of claim .›.1.!. 28 wherein said first means for rigidly securing comprises:

• a sleeve second end;
• a support base to which said sleeve second end is secured;
• and,
• a fastener for securing said flange to said one of said mold members.

A bushing for an injection molding machine and positioned between a nozzle thereof and a sprue of a mold, comprising:

• a body having a longitudinal axis, a front end, a rear end and an exterior periphery:
• a first bore which extends parallel to said longitudinal axis from said rear end to said front end of said body for accommodating a first fluid;
• a bridge extending transversely across said first bore between opposing walls of said bore adjacent said body first end, fluid flow being allowed in said first bore around said bridge;
• a second bore which extends in said bridge and in said body for accommodating a second fluid, said second bore terminating adjacent said body front end;
• a sleeve having a first end and a second end, said sleeve first end being secured to said body front end and said sleeve extending away therefrom such that said sleeve second end is located forwardly of said body, said sleeve having a through bore which is in fluid communication with said second bore;
• a pin extending longitudinally in said sleeve through bore;
• and,
• a fluid flow passage defined between said sleeve and said pin.

An apparatus for injecting a molten thermoplastic material and a fluid, comprising:

• a pair of mold members defining, when closed, a sealed cavity;
• a first opening provided in one of said mold members for allowing the injection of a plastic material into said cavity;
• a second opening provided in one of said mold members, and spaced from said first opening, for allowing the injection of a fluid into said cavity;
• and,
• a fluid injection assembly disposed for reciprocating movement in said second opening in relation to said sealed cavity to control a flow of fluid into said cavity, said assembly comprising:
• a pin,
• a sleeve coaxial with said pin and encircling said pin, and
• a fluid flow passage defined between said pin and said sleeve said pin and sleeve being fixedly secured in relation to each other.

An apparatus for injecting a molten thermoplastic material and a fluid comprising:

• a pair of mold members defining when closed, a sealed cavity and a runner;
• a first opening provided in one of said mold members for allowing the injection of a plastic material into said runner and said cavity;
• a second opening provided in one of said mold members and spaced from said first opening for allowing the injection of a fluid into at least one of said cavity and said runner;
• and,
• a fluid injection and exhaust assembly disposed in said second opening to direct a flow of fluid into and out of said at least one of said cavity and said runner, said fluid injection and exhaust assembly comprising:
• a pin,
• a sleeve coaxial with said pin and encircling said pin, and
• a fluid flow passage defined between said pin and said sleeve, wherein said fluid flow passage is open at all times during the operation of the apparatus.