发明名称 SPRITZGUSSFORM ZUM HERSTELLEN VON FITTINGS AUS THERMOPLASTISCHEN KUNSTSTOFFEN IM URFORMPROZESS
摘要 Undercut tubular synthetic plastic articles, such as fittings, are formed in the mold cavity of an injection molding machine on a one- or two-piece core a portion of which is surrounded by the undercut portion of the article and a first smaller-diameter portion at one side of the undercut portion. If the core consists of two components, a cylindrical component of the core slidably guides the aforementioned portion and is surrounded by a second smaller-diameter portion of the article at the other side of the undercut portion. When the injection of plasticized material is completed, the housing of the mold is opened to expose the undercut portion and the first smaller-diameter portion of the article on the core, the first smaller-diameter portion and the undercut portion are heated to or maintained at a temperature at which they can undergo elastic deformation, and the aforementioned portion of the core is moved axially of the article and of the cylindrical component so that the first smaller-diameter portion of the article is expanded by an external ring-shaped projection which forms part of the core portion and was surrounded by the undercut portion. The first smaller-diameter portion of the article thereupon contracts so that its inner diameter is again less than the inner diameter of the undercut portion. The article is allowed to harden prior to complete separation from the core, and the first smaller-diameter portion is held against excessive contraction during hardening of the article.
申请公布号 DE2633050(B2) 申请公布日期 1978.02.09
申请号 DE19762633050 申请日期 1976.07.22
申请人 发明人
分类号 B29C45/00;B29B13/00;B29C33/00;B29C33/02;B29C33/44;B29C33/48;B29C33/76;B29C37/00;B29C41/00;B29C43/00;B29C45/26;B29C45/36;B29C45/37;B29C45/44;B29C45/73;B29C57/02 主分类号 B29C45/00
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