摘要 |
<p>BLOW MOLDING MACHINE A construction for neck forming in a blow molding machine of the type having a retractable blow pin at a station separate from the parison extruding station. The construction results in a clean, non-fuzzy neck edge requiring no subsequent cleaning operation, and facilitating stripping of the product from the blow pin. The machine comprises a floating hardened shear ring as part of the blow pin assembly which has an interference fit with flared hardened inserts on the neck portion of the mold halves,thus creating a sharply defined upper neck edge. Means are provided for momentarily releasing downward pressure on the blow pin assembly as the mold halves are being retracted to prevent damage to the inserts. The blow pin assembly incorporates a self-centering arrangement for this shear ring and a controlled compressed air leakage system which cools and spreads the hot flash in the vicinity of the blow pin.</p> |