Abstract: An injection moulded part design which may be reflected in a part and the mould for making the part has a continuous alternating arrangement of thicker and thinner panels each extending from a gate area along a direction of flow to a transition line. Beyond the transition line the arrangement of thicker and thinner panels is inverted with the thicker panels continuing as thinner panels and vice versa along the direction of flow.

Abstract: A cooling arrangement is provided for a mold centering device for multi-level stack molds having a spline shaft with a central region journaled to an intermediate mold level with involute spline pathways extending in oppositely twisting helices from the central region toward opposite ends thereof and respective spline nuts secured to adjacent mold levels threadedly engaging the spline pathways to run therealong for converting linear motion into rotational motion and vice versa thereby controlling relative opening and closing rates of the adjacent mold levels relative to the intermediate mold levels therebetween. The cooling arrangement has an internal fluid passageway extending along the spline shaft into a region of the spline shaft received in the spline nuts. A fluid inlet communicates with and supplies fluid to the fluid passageway. A fluid outlet communicates with and discharges fluid from the fluid passageway.

Abstract: A cooling arrangement is provided for a mold centering device for multi-level stack molds having a spline shaft with a central region journaled to an intermediate mold level with involute spline pathways extending in oppositely twisting helices from the central region toward opposite ends thereof and respective spline nuts secured to adjacent mold levels threadedly engaging the spline pathways to run therealong for converting linear motion into rotational motion and vice versa thereby controlling relative opening and closing rates of the adjacent mold levels relative to the intermediate mold levels therebetween. The cooling arrangement has an internal fluid passageway extending along the spline shaft into a region of the spline shaft received in the spline nuts. A fluid inlet communicates with and supplies fluid to the fluid passageway. A fluid outlet communicates with and discharges fluid from the fluid passageway.