Apparatus for operating an injection cylinder of a molding machine

In a molding machine of the type comprising spaced apart first and second stationary platens, a stationary die secured to said first platen, a movable die which cooperates with the stationary die to mold molten metal, an injection cylinder disposed between the second stationary platen and the stationary and movable die for driving an injection plunger, and an injection sleeve disposed in front of the injection cylinder, said injection plunger being slidable in said injection sleeve, wherein the molten metal is injected when axes of the injection cylinder and of the molten metal passage align with each other, and the molten metal is teemed into the injection cylinder when the axis of the injection cylinder is out of alignment with the axes of the stationary and movable dies, an apparatus for moving the injection cylinder between the injection position and the teeming position, which comprises:

• a drive means (20);
• a link mechanism (16,17) disposed between a first pin (13) on the side of the injection cylinder (7) and a stationary second pin (15) secured to the second platen (3) so as to be expanded and collaped by the drive means (2);
• a cam plate (24) secured to oppose the side of the injection cylinder and including a guide slot (27) comprised of a longitudinal slot (25) parallel with the axis of the injection cylinder when it is in the injection position and an inclined slot (26) contiguous with the longitudinal slot;
• a first roller (28) secured to the side of the injection cylinder (7) to be movable along the guide slot (27);
• a guide member provided with a slot (30) for moving the injection cylinder in the axial direction in the injection position;
• and
• a second roller (31) positioned in the slot of the guide member to act as a center of swinging motion of the injection cylinder.