Lifter systems are one method used to free a molded part from an undercut or restriction. In some simple part geometry cases, the undercut can be freed up by lifting a collapsing core or an expanding cavity block. While other systems are more ingenious and accomplish the same thing.
Lifter System – Application
The Lifter System shown is made of standard components to simplify mold design and construction. The radiused dovetail design lets the core blade seat automatically at the required angle with the mold closed. The U-coupling travels freely in the T-Gib when the mold opens. The core blades are made of H-13 for easy conventional machining and a broad size selection is available.
Lifter System – Actuation
The mold shown, when closed, has the ejector assembly back and the undercut on the core blade in its molding position. The ejector half of the mold base opens and travels to its full open position. The press ejector rod is actuated and it forces the ejector assembly forward. This pushes the ejector pins and core blade forward, freeing the undercut and allowing part ejection from the mold. Note how the core blade and U-coupling are free to travel as required.
Page 2 of 5