Nitrojection Corporation

Jay F Moldovanyi

Tom W Johnson

An apparatus for use in fluid assisted injection molding of plastic material so as to form an injection molded product includes a pair of mold members defining when closed the sealed cavity, a first opening provided in one of the mold members for allowing the injection of plastic material into the cavity and the second opening provided in one of the mold members, and spaced from the first opening, for allowing the injection of the fluid into the cavity. A sleeve extends through the second opening. The sleeve has a longitudinally extending bore with an open first end. Preferably, the sleeve is rigidly secured in relation to the one of the mold members through which it extends. A pin extends through the sleeve with the pin having a first end, located adjacent the sleeve first end, and a second end. Preferably the pin is rigidly secured in relation to the sleeve. A fluid flow passage is defined between the pin and the sleeve. In another embodiment, the fluid flow passage is defined between a tube and a pin. The tube is secured at one end to a bushing body. The bushing is, in turn, positioned between a nozzle of an injection molding machine and a sprue of a mold cavity. In yet another embodiment, the pin is allowed to reciprocate in relation to the sleeve so as to selectively open and close a fluid flow passage defined between the pin and the sleeve.

Gas assisted injection molding apparatus utilizing sleeve and pin

A method for injecting a viscous fluid, such as a thermoplastic, and a non-viscous fluid, such as a gas, into a mold cavity of a mold body includes providing a valve element mounted for reciprocation in a nozzle body flow passage to regulate a flow of viscous fluid through the nozzle body discharge end and into a mold cavity. The valve element includes a barrel having a first end selectively engaging a portion of the nozzle body discharge end to prevent a flow of viscous fluid therepast and a second end. A bore extends longitudinally through the barrel and a pin is positioned in the barrel bore. The pin has a first end located adjacent the barrel first end and a second end. A non-viscous fluid flow passage is defined between the pin and the barrel. A viscous fluid flows through the nozzle body flow passage around the barrel and into a mold cavity. A non-viscous fluid flows through the non-viscous fluid flow passage defined between the barrel and the pin and into the mold cavity. A non-viscous fluid cavity is formed in the viscous fluid which then cools to form an injection molded part. An initial portion of the non-viscous fluid is then allowed to flow out of the non-viscous fluid cavity.

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Brecksville, OH, United States of America

Jay F Moldovanyi