Abstract: A blow molding machine is disclosed for hollow plastic articles. The machine includes a clamp mechanism for a pair of mold sections. It comprises a body disposed below an extruder at an extruding station and a blow pin at a blow station and carrying opposed platens for supporting the mold sections. Each of a pair of levers is pivotally coupled with a respective platen and with the body and the levers are connected together by a pull bar. An actuating means displaces one of the platens relative to the body and equal and opposite motion is transmitted through the levers and the pull bar to the other platen for opening and closing the clamp. A lifting mechanism supports the clamp for movement between the extruding station and the blow station. The lifting mechanism is adapted for vertical motion by a hydraulic motor acting on a lifting frame. The frame is mounted by pivot links on the machine base and pairs of links are connected by a shaft with a crank arm, the crank arms being connected together by a tie rod.

Abstract: A blow molding machine for the manufacture of products such as bottles from a continuously extruded parison of plastic material. Two pairs of horizontally reciprocable mold sections alternately take a parison from a central station and transport it to either of two blow molding stations having vertically movable blow pins. The mold section platens carry laterally extending trimming elements and, when each pair of mold sections returns to retrieve another parison, the trimming elements trim flash from the molded product which hangs from the blow pin. The product is then transported to a delivery station by the trimming elements as the mold sections return to the blow molding station. The platens and blow pin stations are all supported by the vertically reciprocable table. As a knife severs the parison held by a pair of mold sections from the extruder and the mold sections start moving toward the mold station, the table lowers to prevent resticking of the material being continuously extruded.

Abstract: A blow molding machine for the manufacture of products such as bottles from a continuously extruded parison of plastic material. Two pairs of horizontally reciprocable mold sections are shown which alternately take a parison from a central station and transport it to either of two blow molding stations having vertically movable blow pins. The mold section platens carry laterally extending trimming elements and, when each pair of mold sections returns to retrieve another parison, the trimming elements trim flash from the molded product which hangs from the blow pin. The product is then transported to a delivery station by the trimming elements as the mold sections return to the blow molding station. The platens and blow pin stations are all supported by a vertically reciprocable table. As a knife severs the parison held by a pair or mold sections from the extruder and the mold sections start moving toward the mold station, the table lowers to prevent resticking of the material being continuously extruded.

Abstract: 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.