Patent ID: 7569169

Claim:
In a molding machine having a manifold for distributing a melt material flowing under pressure through a passage leading to a gate of a mold cavity wherein the rate of flow of the melt material is determined by positioning of a pin that is controllably movable through the channel to create a gap of controllable size between the pin and the passage, wherein the pin is disposed within the melt material on which the melt material exerts a melt pressure force, an apparatus for controlling positioning of the pin comprising: an actuator adapted to receive and controllably oppose the force exerted on the actuator by the melt material through the pin and adjust the rate of material flow by positioning of the pin and controlling the size of the gap, a controller controlling the actuator to oppose the melt pressure force received through the pin according to a predetermined profile of pressure corresponding to the melt pressure force that is indicative of a desired rate of material flow through the passage and into the cavity over the course of an injection cycle.