| 摘要 |
The invention relates to forming apparatus for forming hollow articles from a thermoplastic web. The apparatus of the type comprising a mold block and a counter-mold block provided with as many cylindrical cavities as the mold block has forming chambers, with each cylindrical cavity containing a forming punch having an inactive top portion and an active bottom portion, which active bottom portion is suitable for penetrating vertically into the corresponding forming chamber. The inactive portion of each forming punch extends over an axial height that is shorter than the maximum width of the punch. Each forming punch is surmounted by a guide piston which slides in sealed manner inside the corresponding cylindrical cavity of the counter-mold block. The annular space beneath the guide piston is suitable for communicating periodically with a source of compressed gas via at least one link duct.
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