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US 5,169,648 AGranted
Apparatus for injection molding articles of thermoplastic materials
AssigneeBattenfeld GmbH
InventorsHelmut Eckardt, Jurgen Ehritt
Life of this patent
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AssigneeBattenfeld GmbH
InventorsHelmut Eckardt, Jurgen Ehritt
Estimating the term…
A method and an apparatus of injection molding articles of thermoplastic material. The method includes initially forcing molten plastics material into an injection mold in an amount sufficient for forming the article. Subsequently, a flowable medium is forced into the injection mold with a pressure which distributes the plastics material uniformly over the surface of the mold cavity of the injection mold so as to form a hollow body. The hollow body is then cooled while the pressure of the medium is maintained. Finally, the pressure of the medium is released and the molded article is removed from the injection mold. The pressure of the medium in the mold cavity is controlled and/or varied at least temporarily until the plastics material has cooled. The apparatus for carrying out the method includes a pressure reservoir for the medium which is connectible to the injection mold through lines. The lines include control and/or regulating elements.
In an apparatus for injection molding articles of thermoplastic material, the apparatus including a source for a pressurized medium to be supplied to an injection mold, lines for connecting the pressurized medium source to the injection mold, and control elements and regulating elements provided in the lines, wherein the control elements are directional control valves and the regulating elements are pressure valves, the improvement comprising a plurality of lines connected in parallel between the pressurized medium source and the injection mold, one of said directional control valves being provided in each line, and one of said pressure valves being provided downstream of each directional control valve.
In an apparatus for injection molding articles of thermoplastic material, the apparatus including a source for a pressurized medium to be supplied to an injection mold, lines for connecting the pressurized medium source to the injection mold, and control elements and regulating elements provided in the lines, wherein the control elements are directional control valves and the regulating elements are pressure regulating valves, the improvement comprising a plurality of lines connected in parallel to the pressurized medium source, a directional control valve being provided in each line, a pressure regulating valve being arranged downstream of each directional control valve, wherein each line is connected downstream of the pressure regulating valve to a separate injection mold, and wherein all pressure regulating valves are regulatable independently of each other.
Dependencies are inferred from the claim text.