CROSS REFERENCE TO RELATED APPLICATIONS

This application is the National Stage of PCT/EP2019/060753 filed on Apr. 26, 2019, which claims priority under 35 U.S.C. §119 of German Application No. 10 2018 110 427.8 filed on May 1, 2018, the disclosure of which is incorporated by reference. The international application under PCT article 21(2) was not published in English.

The invention relates to a cold runner block in a vertically operating injection molding machine for processing elastomer materials, with an upper fixed molding platen and a molding platen arranged thereunder which is movable relative to the fixed molding platen, between which a molding tool having a plurality of mold cavities is arranged and wherein the cold runner block is arranged between the fixed molding platen and the molding tool, the cold runner block containing a distribution plate having the cold runners and containing a nozzle plate with nozzles each assigned to one of the plurality of mold cavities.

In these previously known cold runner systems (e.g. from DE 195 22 328 A1 or U.S. Pat. No. 5,798,127), in which elastomers are distributed to various nozzle positions at a controlled temperature, the distribution channels have to be thoroughly cleaned when changing over to a different elastomer. This generally takes place outside the machine, which is quite time-consuming since the generally heavy cold runner block can only be dismantled using a crane.

The invention is therefore based on the object of configuring a cold runner block of the type mentioned above such that the distribution plate or the distribution channels that are arranged in this distribution plate can also be cleaned in the machine.

To achieve this object, the present invention proposes that the distribution plate formed from a plurality of distribution strips is arranged on a retaining plate, which can be fastened to the fixed, feed-side molding platen, in such a way that each distribution strip is connected to the retaining plate by means of two bolts in that the head of each bolt facing away from the distribution strip forms a retaining element which is T-shaped in section, the retaining element being displaceably guided in the direction transverse to the distribution strip's longitudinal axis in guide rails which are formed in the retaining plate and are designed in section to complement the bolt head.

In this way it is possible, after releasing the connection between nozzle plate and distribution plate or the retaining plate, to displace the individual distribution strips, which at this stage hang down from the retaining plate, such that a sufficiently large space is produced between the individual strips for the channel portions that are present in the individual strips to be accessible for cleaning.

After cleaning, the individual distribution strips are reassembled to form the distribution plate, and the nozzle plate is moved upwards and connected to the retaining plate such that the distribution plate formed from the individual distribution strips is locked between the retaining plate and the nozzle plate in the manner of a sandwich.

Because the distribution strips hang down from the retaining plate after the injection molding machine has been opened and are freely accessible, so that they can be slid towards each other or away from each other in the guide rails, it becomes possible to clean the channels in the individual strips inside the machine.

This gives rise to the advantage that, without manipulations using a crane, the time needed to clean these channels is reduced significantly.

It is also possible that the individual distribution strips are held and guided directly in corresponding guide grooves in the upper molding platen.

In order to ensure that the individual distribution strips can also be removed from the machine, the guide grooves or guide rails are configured such that they are open at the ends.

A central runner passing through the retaining plate and leading to the distribution plate is used for feeding the plasticated material.

