| 摘要 |
<p>Transfer molding apparatus is disclosed comprising a multi-cavity mold, an injection unit having a primary chamber from which elastomeric stock can be transferred, an adapter for defining a secondary chamber communicating with the primary chamber, a valve interposed between the primary and secondary chambers for permitting alastomeric stock to flow unidirectionally from the primary chamber to the secondary chamber, an apertured end plate carried by, and axially movable in the secondary chamber of, the adapter in confronting relation with the mold, and a system for moving the injection unit and mold relative to one another to effect engagement of the mold with the end plate and thereby shift the latter inwardly of the secondary chamber to reduce the axial extent of the latter and expel elastomeric stock through the end plate and into the mold cavities, the valve cooperating with the end plate during the inward movement of the latter and preventing backflow of elastomeric stock into the primary chamber from the secondary chamber despite the occurance of any pressure drop in the primary chamber.</p> |
