Mold centering system for injection-molding machine

An injection-molding assembly comprising:

• a fixed mold plate carrying a centering ring;
• a fixed mold half carrying a centering ring snugly interfitted with the fixed-plate centering ring;
• a movable mold plate carrying a centering ring;
• a movable mold half carrying a centering ring snugly interfitted with the movable-plate centering ring, one of the rings being formed of
• an outer ring part having a substantially circular outer periphery and a substantially circular inner periphery and
• an inner ring part having a substantially circular outer periphery and a substantially circular inner periphery,
• the outer periphery of one of the ring parts having a center of curvature offset radially from a center of curvature of the respective inner periphery;
• and
• means for relatively angularly displacing the ring parts of the one ring to respectively radially shift the respective mold plate and the respective mold half relative to each other and for clamping the ring parts relative to each other.