摘要 |
A mechanism for clamping a web of thermoplastic material against the face of a female mold prior to closure of the mold includes a clamping ring assembly mounted on the machine frame for movement relative to the frame independently of the molds. The clamping assembly is driven to and from its web clamping position by a cam mounted on the rock shaft which drives the molds between their open and closed positions and a constant radius section on the cam holds the clamp in its clamping position throughout a substantial portion of the operating cycle.
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