| 摘要 |
A mould particularly suitable for the moulding of objects of toroidal form from thermoplastic materials comprising a mould cavity 3 inside an outer casing 2 and at least one runner 5 for a liquid or pasty product intended to solidify in the cavity, the downstream end 7 of the runner terminating in the mould cavity and the upstream end 6 of the runner connection to inlet 4 ending outside the casing, an elastic element 9 forming at least part of an inflatable cavity located in the runner, one of the ends of the inflatable cavity being located level with the downstream end 7, and the other end of this inflatable cavity being located level with the upstream end of the runner 6, this inflatable cavity being capable of inflation to fill the volume contained between the upstream and downstream ends of the runner by means of a fluid fed via duct 11 under a pressure at least equal to the feed pressure of the material to be moulded in the mould cavity and being capable of taking the form of the wall 10 opposite to the upstream end of the runner when it is in the deflated state and under the effect of the feed pressure of the product to be moulded. <IMAGE> |
