Abstract: A device for automatic angular positioning of indexable rotary elements, ecially for postal franking machines and the like comprises a common indexing-control gear-wheel rigidly fixed to a cylindrical indexing-control rod, and an indexing-control rotating primary shaft which forms a ball cage. The balls are engaged in an annular groove of a shaft bearing and in helical grooves of the control rod which can be temporarily locked either against rotational motion or against sliding motion, a support being provided for the bearing and capable of moving towards the series of indexable rotary elements.

Abstract: Printing wheels carried by a printing drum which is driven in rotation dug one cycle are manually set at the desired prepayment values for the purpose of franking postal envelopes, parcels and wrappers. Intermediate stopping of the machine can be effected if necessary on completion of a first part of the cycle prior to printing. Electronic means are provided for the acquisition of the prepayment value during the first part of the cycle, for the detection of fault conditions during operation, for the inhibition of the intermediate stopping means, and for transferring the prepayment value from the acquisition means to means for recording the total prepayment values.