reciprocating carriage

The invention relates to apparatus for blow moulding machine hollow bodies, in particular bottles, containers, tubes or the like from thermoplastic synthetic material, of the kind comprising a hollow sectional mould which is preferably moved to and fro along a linear path between a receiving station associated with the extrusion nozzle of an blow molding machine and a mould release station in which the moulded hollow body is removed from the hollow mould.

It is an object of the invention to provide an apparatus of the kind defined having mould moving means which are simple and permit inspection of the apparatus. It is desirable to provide a central drive without, however, the movements of the hollow mould and those of the individual parts of the hollow mould being interdependent such that one movement is directly derived from the other. On the other hand, the invention should provide the possibility of positively synchronizing the individual sequences of movement using simple means, with the object of being able to select the type of opening movement of the hollow mould independently of the shape of the hollow body to be blow moulding machinery.

In order to fulfil these objects, the invention firstly proposes that a drive roller provided with at least one cam is provided, with which a cam roller or the like associated with the hollow mould co-operates. Generally one begins with the fact that the parts of the hollow mould are provided with a lever system transmitting closing and opening movements to the latter. A further advantage of the blow moulding machine is that by means of the drive roller it is readily possible to convert a basic rotational drive, which produces the rotation of the drive roller, by means of the latter into reciprocating movements of the mould or parts of the mould. Thus, according to a further proposal of the invention, the arrangement is such that the drive roller is rotated discontinuously. The choice between these two possibilities depends essentially on the diameter of the roller and thus on the length of the cams, which correspond to the individual working cycles of the blow moulding machine.

In one embodiment which has proved particularly advantageous, the carriage is provided with guides, along which is guided an intermediate part, for examples a crossbar, which supports the cam roller associated with the lever system and has a pivot. The guides may be constructed as beams preferably extending parallel to the reciprocating movement. Moreover, the possibility exists of providing on the guides, a second lockable intermediate part, on which is located the cam roller for the reciprocating movement to be imparted to the carriage. By a corresponding adjustment of this intermediate part, for example by moving it on the beams, it is also readily possible to adjust the relative position of the parts with respect to each other depending on the respective facts.