Mold centering arrangement for injection molding apparatus

摘要

A centering arrangement for controlling relative movement between a series of mold support plates in a stack mold having three or more levels. The centering arrangement uses a plurality of centering devices which are substantially identical, each spanning two mold levels and being connected to three adjacent mold support plates. Each centering device has a shaft generally parallel to an axis of the mold and having an intermediate portion journalled in an intermediate connector to allow rotational movement about a shaft axis, but to restrain relative axial movement between the shaft and the intermediate connector. Helical splines extend from the intermediate portion toward opposite ends of the shaft in oppositely twisting helices. End connectors having cooperating splines engage the splined portions of the shaft and connect the centering device to the outermost of the mold plates to which it is connected. The intermediate connector secures the centering device to the intermediate of the three mold plates to which the centering device is connected. Relative axial movement between the end connectors and the adjacent intermediate connector requires simultaneous translation and rotation of the shaft in equal amounts in both end connectors, thereby maintaining the intermediate connector centered between the two adjacent end connectors.