DOSAGE APPARATUS FOR PLACING MOLD CHARGES IN A COMPRESSION MOLDING MACHINE

摘要

An apparatus for placing mold charges into a mold of a compression molding machine includes at least one mold charge pick-up cup (332) for receiving a severed charge of molten plastic, a vacuum source (408) for applying a vacuum to the pick-up cup to retain the mold charge in the cup, and a source (401) of gas (such as air) under pressure for periodically applying gas to the cup to release the mold charge from the cup. In one exemplary embodiment, the vacuum source applies a continuous vacuum to the cup, and the source of gas under pressure periodically applies gas to the cup to overcome the continuous vacuum at the cup. In another exemplary embodiment, vacuum and gas under pressure, are alternately applied to the cup. The vacuum source preferably includes a vacuum generator (408) coupled to the source (401) of gas under pressure for generating the vacuum to be applied to the cup. The source of gas under pressure preferably includes a valve (404) for periodically applying gas under pressure to the cup. The apparatus preferably includes a carrier (320) for moving the cup from a source of severed charges of molten plastic to the mold of the compression molding machine, with the cup, the vacuum pump and the valve preferably being mounted on the carrier. The vacuum source preferably includes a vacuum limiter (410) that also is mounted on the carrier.