| 摘要 |
<p>The present invention relates to a non-return valve that can be configured for use anywhere along a molding material flow path in a molding system. The non-return valve of the present invention includes an improved means to restrict the backflow of melt therethrough during injection. In particular, a spigot-seal is configurable, during injection, between overlapping, closely-spaced, and mutually parallel complementary male and female spigot portions that are configured between complementary valve members. The spigot-seal advantageously maintains an effective backflow restriction even in the eventuality of transient movement between the spigot portions during injection. Preferably, the non-return valve of the present invention is also configured to include a means for mutually aligning and/or guiding the complementary valve components that ensures a proper alignment between the complementary spigot portions, and may also serve to improve the function and longevity of a face-seal, when present. The non-return valve of the present invention provides particularly advantageous utility when configured for use in a barrel assembly of an injection unit for the injection molding of a metal alloy.</p> |
