Dual piston valve stem actuator

An injection molding apparatus comprising:

• a valve support structure having an internal channel for directing a flow of melted resin past the valve support structure to a mold cavity;
• a first valve actuator operatively connected to the valve support structure and to a valve stem, the valve stem extending at least partially through a valve aperture in the valve support structure to control the flow of resin through the channel;
• a bushing fitted in the valve aperture;
• and
• a second valve actuator located adjacent the first valve actuator, the second valve actuator operatively connected to a sleeve member, the sleeve member having a hollow interior dimensioned to slidingly engage the valve stem and an exterior surface dimensioned for sliding movement in the bushing, the second valve actuator selectively moving the sleeve member between a retracted position where the sleeve member moves toward the bushing and an extended position where the sleeve moves away from the bushing.