an injection molding apparatus capable of producing injection molded articles from at least two plastic melts , includes an additional mold mounting device between a fixed mold mounting plate and a movable mold mounting plate that is traversed along four essentially horizontal tie rods . the additional mold mounting device is also pivotable around a rotational axis aligned perpendicular to the longitudinal axis of the tie rods , and carries additional mold halves that cooperate with the mold halves mounted on the mold mounting plates on at least two side surfaces that are aligned with a spacing parallel to each other and relative to the rotational axis . the additional mold mounting device comprises upper and lower support blocks that are arranged at a spacing relative to each other in an essentially vertically aligned plane , with each support block being guided on at least of the two tie rods . a friction or pivot bearing is provided for vertically aligned pivots of a prismatic mold core support . the additional mold mounting device further includes at least two drive devices to change the relative spacing between the mold mounting plates and the support blocks .