Patent ID: 8308476

Claim:
An injection molding apparatus, comprising: an actuated part movable in opening stroke and closing stroke directions; a magnetic valve pin coupling disposed within the actuated part and having a magnetic component and a valve pin component that are separated by a gap G under normal operating conditions, wherein the magnetic component is longitudinally repositionable relative to the valve pin component to adjust a width of the gap G to thereby adjust strength of an attractive force of the magnetic component acting on the valve pin component; and a valve pin movable with the valve pin component wherein when the actuated part moves in the closing stroke direction a closing force is transferred to the valve pin component to thereby seat the valve pin within a mold gate, and wherein when the actuated part moves in the opening stroke direction an opening force is transferred to the valve pin component by magnetic attraction between the magnetic component and the valve pin component to thereby unseat the valve pin from the mold gate.