Maintenance of stocks for workpieces to be machined and/or worked represents a considerable problem, in particular in large shops with a large number of machining stations.  As a rule, such workpieces are located beside the processing machine in a corresponding storage bin, a desired amount of stock being maintained in this storage bin. 
In many cases the processing machines stand so close together that it is not possible for ordinary transport vehicles, such as, for example, forklifts or the like, to move between the machines.  For this reason the relevant workpieces still are taken to the storage bins on simple carts and the bins are then filled by hand.  This is time-consuming and unsatisfactory.  The task of the present invention is to develop a device of the above-mentioned type by means of which maintenance of stock may be at least partially automated.