| 摘要 |
<p>A hot sprue bushing and an open bore system for injection molding plastic articles. The system includes an open bore (56), hot bushing (6) adapted to convey molten material from a hot manifold (4) into the bore in a cold mold (10). The bore extends into the upper surface of the cold mold, and defines a gate (60) at its bottom. The bushing at least partially fits within, and in spaced relation to, the bore. The bushing includes a lumen (42) therethrough which opens into its distal end, and which is generally aligned with the gate. The bushing also defines a groove in its outer surface surrounding the opening of the lumen into the distal end thereof. A thin-walled, substantially thermally non-conductive seal (8) is provided. The seal in the preferred embodiments is metallic, and includes at least a portion having a substantially arc-shped transverse cross-section.</p> |
