초록 ▼

A coinjection molding system for injecting skin and core material into a mold cavity. The system includes a three position actuator for moving a valve pin into a closed position in which neither skin nor core flow is permitted, a middle position in which only skin flow is permitted, and an open posi

A coinjection molding system for injecting skin and core material into a mold cavity. The system includes a three position actuator for moving a valve pin into a closed position in which neither skin nor core flow is permitted, a middle position in which only skin flow is permitted, and an open position in which skin and core flow is permitted. The actuator includes a first piston slidably mounted in an actuator housing, and a second piston, attached to the valve pin, slidably mounted within the first piston. A shut-off is provided in the manifold for preventing skin flow to a particular nozzle during sequential gating.

대표청구항 ▼

[ What is claimed is:] [1.] A valve pin actuator for a coinjection molding system in which the valve pin actuator supports a valve pin adapted to control skin material flow and core material flow at a gate to a mold cavity, comprising:an actuator body;a first member movably mounted within said actua

[ What is claimed is:] [1.] A valve pin actuator for a coinjection molding system in which the valve pin actuator supports a valve pin adapted to control skin material flow and core material flow at a gate to a mold cavity, comprising:an actuator body;a first member movably mounted within said actuator body;a second member movably mounted within said actuator body, said second member adapted to support said valve pin such that movement of said second member causes movement of said valve pin, wherein said first and second members are each movable to a plurality of positions to control movement of the valve pin to reciprocate to three separate positions, including:a first position in which the valve pin alone closes the gate and blocks both skin and core material flow to the gate;a second position remote from the gate relative to the first position, in which movement of the valve pin to the second position permits skin material flow and blocks core material flow to the gate; anda third position remote from the gate relative to the second position, in which movement of the valve pin to the third position permits both skin material flow and core material flow to the gate.