Multiple injection moulding apparatus

A multiple injection moulding apparatus for making parisons provided with a bottle neck socket, said parisons having application for the manufacture of bottles by the blow moulding method, comprising:

• a fixed plate on nozzle side of the injection moulding machine;
• a plurality of outer moulds on said fixed plate, each of which defines a substantially cylindrical outer section of the parison;
• a plurality of mould elements recessed into the fixed plate, said mould elements defining the mould contour which forms the base of the parison, each of said mold elements also including a filling channel;
• a core-carrying plate movable within the injection moulding machine and to which there are fixed a plurality of cores respectively engageable with said outer moulds;
• pairs of mould end plates movable at right angles to the axis of said outer moulds, said mould end plates having an internal contour dimensioned for molding the socket of the bottle neck, said bottle neck including a radiallyprojecting stopper-engaging contour and a neck ring having a diameter greater than that of the stopper-engaging contour;
• an intermediate plate on which said mould end plates are mounted and which is movable relative to said core-carrying plate and said fixed plate in order to withdraw said cores out of the parisons and the parisons out of said outer moulds;
• a plurality of inner housings in each of which one of said outer moulds is formed;
• a separate pair of said mould end plates being assigned to each of said outer moulds;
• each pair of mould end plates having an outer frustoconical surface, said outer moulds having internal frusto-conical surfaces which are respectively cooperative with said outer frusto-conical end plate surfaces, each of said mould end plates also including an inner frusto-conical surface which is coaxial with the socket of the bottle neck to be formed on the parison, said mould end plates being cooperative, respectively, with outer frustoconical surfaces on said cores;
• a plurality of separate guides, each extending at right angles to the direction in which the injection moulding apparatus opens, each pair of said mould end plates being mounted in said guides;
• a common hydraulic drive for a plurality of adjacent pairs of said mould end plates to open and close the pairs of said mould end plates;
• driving means operable for adjusting said intermediate plate relative to said core-carrying plate during the opening movement of the latter;
• control means operable such that, during the opening movement of the injection moulding apparatus after release of said frusto-conical surfaces of said outer mould, the pairs of mould plates are moved through a first opening movement over a distance which is greater than the radial height of the stopperengaging contour but smaller than the radial height of said neck ring;
• and
• additional control means operable such that said pairs of mould end plates are moved to complete the opening movement thereof after the parison have been released form said cores.