Collapsible Cores – Application
The collapsible core shown can be used to mold internal threads, protrusions, dimples, interrupted threads, and cut outs. Molding can be economically done on high or low volume requirements. Up to 80% full threads or undercuts can be molded. Threads do not have to run to the top of the mold as with unscrewing molds. The collapsing core also permits threads to stop at any point along the molded length. A longer threaded area can be formed, without adding to cycle time or requiring long rack and pinion mechanisms. Sizes vary from as small as 13mm.
Collapsible Cores – Actuation
After molding, the ejection half of the mold base travels back to its full open position. The press ejector rod is actuated and forces the ejector assembly forward, along with the stripper plate, collapsible threaded core, and molded part. As the ejector assembly and collapsible core move forward, the center pin pulls out of the inside of the core, (since it is fixed) and allows the core to collapse. In case the core should stick, the positive collapsible sleeve insures the core will collapse. A limit switch is activated and the air cylinder extends the ejector plate, forcing the part to be ejected off the collapsed core.
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