| 摘要 |
<p>An injection molding apparatus for use in-pro-ducing centrally-apertured video disc records. The apparatus includes first and second mold halves reciprocally movable with respect to each other between a closed position, wherein the two mold halves are in proximity to each other and molten plastic material is injected into a planar, annular cavity defined therebetween to form the record disc, and an open position, wherein the two mold halves are spaced apart from each other and the molded record disc can be removed. The molding apparatus further includes first and second annular rings carried by the respective first and second mold halves and defining the outer perimeter of the cavity. The first mold half includes two plates reciprocally movable with respect to each other, with a plurality of compression springs in the form of polyurethane blocks interposed between the two plates, to bias the two annular rings into compressive engagement with each other when a central aperture is being punched in the molded record disc.</p> |
