GB1231261A - - Google Patents

Abstract

1,231,261. Multi-platen compacting press. CINCINNATI SHAPER CO. 24 April, 1968 [19 May, 1967], No. 19294/68. Heading B5A. In a powder compacting press such as that disclosed in Specification 1,025,977 in which stepped articles are compression moulded in a die defined by die parts carried by floating platens 13, 14 and 15, platens 14 and 15 of which move downwardly into contact with releasable stop rods 23 and 24 respectively during the compaction stroke and which, after the compaction stroke are released for downward ejecting movement by rods 25 and 26 carried by platens 13 and 14 respectively, means are provided to enable a " shelf type " die part to be used in the upper platen 13 without causing the rods 25 to release rods 23 and thus platen 14 during the compaction stroke which release would render compaction impossible. A shelf type die is one whose cavity is so shaped that it will experience, by downward transmission through the material being compressed, and not merely by the frictional interaction of the cavity walls with said material, a portion of the vertical pressing load. It can be seen that if such a die were used in a press as disclosed in Specification 1,025,977 the upper platen would not come to rest during the compaction at an intermediate position, as in the above Specification, but would be forced downward until its rods 25 released the platen 14 thereby eventually causing downward movement of all platens and rendering compaction impossible. Said means comprises spacer blocks 30 mounted upon platen 14 and extension means 32d which extend the triggers 32 of rods 23 upwardly through the platen 13 and associated bodies 25f. Additionally the rods 25 are withdrawn so that they do not contact the plates 31 carried by the upper ends of triggers 32 and a nut 25e is provided upon cam operated main ejection rods 25g over extensions 22 of which the bodies 25f of the platen 13 slide. In operation during the compaction stroke the upper platen 13 floats downwardly into contact with the block 30 after which both platen 13 and 14 float downwardly in unison until platen 14 abuts rods 23. At the same time platen 15 has floated downwardly into contact with rods 24. At the end of the compaction stroke the rods 25g are driven downwards and slide within bodies 25f until nuts 25e contact extensions 32d thereby releasing platen 14. Further movement of the rods causes both platens to move down together, thereby ejecting the upper parts of the article, and then all the platens to move downwardly as rods 26 release rods 24, thereby ejecting the rest of the article.