Injection molding machine for the manufacture of information carrier discs

Claim 1

An upright injection-compression pressing machine for the manufacture of an information carrier disc, which comprises, in combination: upper and lower fixed plates positioned one above the other and connected to each other in face-to-face and spaced relation.by means of tie bars; an upper mold carried by the upper fixed plate; a lower mold carried by a movable plate in face-to-face relation to said upper mold, said movable plate being movable between the upper and lower fixed plates while the tie bars serve as guides therefor; a first drive means adapted to be reciprocately moved in a vertical direction and operatively coupled to the movable plate for moving the movable plate to any one of first, second and third positions wherein the information carrier disc can be removed out of the clearance between the upper and lower molds, wherein the upper and lower molds are spaced a small distance from each other and wherein the upper and lower molds are clamped together, respectively; guide members mounted on the upper fixed plate so as to extend in a vertical direction; a holder assembly rotatably and slidably mounted on the guide members; a second drive means for reciprocately driving the holder assembly along the guide members in the vertical direction; an injection cylinder having an upper..end inserted in and rigidly secured to the holder assembly and extending in a vertical direction therefrom,.said injection cylinder having a feed screw incorporated therein; a screw drive means operatively coupled to an upper end of the feed screw; and a third drive means provided in the holder assembly and operable to reciprocately drive the feed screw in the vertical direction, said injection cylinder having a nozzle portion which extends through the upper fixed plate and is so positioned as to supply a material in a radially outward direction from the center of the upper mold.