A blow moulding machine comprising a heating wheel provided with a plurality of reception means for preforms and having a substantially vertical axis of rotation, and a blow wheel provided with a plurality of blow stations for hollow bodies such as for bottles, and having a substantially vertical axis of rotation. The heating wheel and the blow wheel are arranged on different levels and overlap each other at least partially. The preforms are moved from the level of the heating wheel to the level of the blow wheel by means of a transfer device. A substantial reduction of the floor space and of the production costs for the blow moulding machine is achieved in this way.
A blow moulding machine according to FIG. 1 to 5 is equipped for producing bottles 2 for beverages from injection- moulded preforms 1 consisting of a thermoplastic material, e.g. PET. It comprises a frame 8 composed of steel sections and having a boxlike basic shape, said frame 8 being provided with a perpendicular, hollow central column 18. This central column 18 has attached thereto a blow wheel 5 on a lower level and, on top of said blow wheel 5, a heating wheel 3 on an upper level, each of said wheels being rotatably supported on said central column. Hence, the heat of the heating wheel 3 can escape at the top unhindered. The heating wheel 3 and the blow wheel 5 have a common axis of rotation 7 and rotate in horizontal planes which are vertically displaced relative to each other. By means of a motor 19 and a transmission 20 comprising a plurality of gears, the heating wheel 3 and blow wheel 5 are driven in synchronism with each other, but at different speeds, in the direction of the arrow. The blow wheel 5 is fully covered by the heating wheel 3. The floor space of the frame 8 is therefore defined by the diameter of the heating wheel 3 or of the blow wheel 5 alone, depending on which of the two wheels is larger. The floor space is essentially one half of that of a conventional blow moulding machine in which the blow wheel and the heating wheel are arranged side by side.
