Closing unit for an injection molding machine with stack mold

1. A closing unit for an injection molding machine, comprising:

first and second platens, at least one of which being movable;

an intermediate plate disposed between the first and second platens;

a molding tool disposed between one of the first and second platens and the intermediate plate;

means adapted for disabling a molding operation between the other one of the first and second platens and the intermediate plate, wherein the means include a dummy tool which is disposed between the other one of the first and second platens and the intermediate plate and in which no product is made; and

at least one ejector arranged in or on the intermediate plate.

2. The closing unit of claim 1 , wherein the intermediate plate is firmly secured to the other one of the first and second platens for disabling the molding operation.

3. The closing unit of claim 1 , wherein the intermediate plate is stationary, said first and second platens constructed for relative movement toward one another.

4. The closing unit of claim 1 , wherein the intermediate plate is constructed for linear movement.

5. The closing unit of claim 1 , wherein the intermediate plate is constructed as a rotatable swivel platen.

6. The closing unit of claim 1 , wherein the dummy tool is made of two parts, one part mounted to the other one of the first and second platens, and another part mounted to the intermediate plate, with both parts bearing upon one another in a clamped state of the closing unit.

7. The closing unit of claim 1 , wherein the dummy tool is of single-piece construction and mounted to one member selected from the group consisting of the other one of the first and second platens and the intermediate plate, said dummy tool bearing upon the other member of the group consisting of the other one of the first and second platens and the intermediate plate, in a clamped state of the closing unit.

8. The closing unit of claim 1 , wherein the dummy tool is mounted to the other one of the first and second platens and to the intermediate plate, thereby forming a unitary structure comprised of the other one of the first and second platens, dummy tool, and intermediate plate.

9. The closing unit of claim 1 , wherein the intermediate plate is constructed to move conjointly with an opening or closing movement of the movable one of the first and second platens.

10. The closing unit of claim 1 , wherein the ejector is constructed with its own drive so as to be self-propelled.

11. A closing unit for an injection molding machine, comprising:

first and second platens, at least one of which being movable;

an intermediate plate disposed between the first and second platens;

a molding tool disposed between one of the first and second platens and the intermediate plate;

means adapted for disabling a molding operation between the other one of the first and second platens and the intermediate plate;

at least two ejectors arranged in or on the intermediate plate;

a single drive commonly operating both ejectors; and

a linkage for interconnecting the drive with the ejectors, with the linkage being constructed so as to render a connection between the drive and one of the ejectors no longer effective.

12. The closing unit of claim 11 , wherein the linkage is a toggle mechanism.

13. A system for converting a closing unit for a stack mold to a single-face mold, with the closing unit including first and second platens, of which at least one being movable, an intermediate plate disposed between the first and second platens, said system comprising:

a molding tool disposed between one of the first and second platens and the intermediate plate;

a dummy tool which is disposed between the other one of the first and second platens and the intermediate plate and in which no product is made for disabling a molding operation between the other one of the first and second platens and the intermediate plate; and

at least one ejector arranged in or on the intermediate plate for expellingan end product.