Abstract: A universal mountable and demountable rack-and-pinion structure for a stack mold includes mounting plates affixed to the mold parts and rack-and-pinion mounting elements which are mountable to and demountable from the mounting plates. This arrangement permits the rack and pinion elements first to be mounted in an approximately correct position for the appropriate proportionation of movement within a molding machine. The device includes an adjustment feature which permits the relative distances between the mold parts to be finely adjusted to ensure correct proportionation of movement. The rack-and-pinion structure is interchangeable for various stack molds.

Abstract: A compensating device for an injection molding machine is provided which enables the moveable mold part to be supported on stationary platen guide rails of the molding machine, thereby relieving the bending force normally applied by the moveable mold part on the platen bearings and avoiding bearing wear. The compensating device is constructed to permit multiple directional adjustment, including vertical mold adjustment to permit existing bearing wear to be compensated for.

Abstract: A shut-off cut-off nozzle for a plastic injection machine is constructed to ensure even heating and thereby avoid seizure of moving parts and to provide efficient and reliable mechanism.