| 摘要 |
A reciprocal ram at commencement of a forward strokes engages a cup-shaped article carrying it through metal working dies and against a doming die at reversal into a rearward stroke immediately followed by stripping of the article from the ram. The ram has an internal chamber constantly fed pressurized air through a rearward restricted orifice, the chamber opening freely of the ram forward end portion and internally of the article when thereon. By preselecting orifice size, chamber and article volumes matched with air pressure, a predetermined volume of air at predetermined pressure is confined in the ram forwardly against the article immediately prior to stripping and preferably engagement of the article by an external stripper results in an internal stripping assist by the confined pressurized air, the increasing exposed volume of the article increasing the air confinement volume reducing the air pressure progressively to substantially atmospheric at completion of article stripping. For particularly difficult article stripping, a forwardly open and rearwardly closed check valve may be positioned intermediate the ram chamber causing increased air pressure forwardly of the check valve through reduction of contained volume caused by the article doming operation, the increased air pressure giving an initial stripping boost during article stripping.
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