Automatically controlled numbering machine

In an offset press comprising a printing machine, a delivery machine cooperatively arranged relative to the printing machine for receiving the printed material discharged therefrom and delivering them to a point of deposit, and a numbering assembly comprising a numbering machine cooperatively arranged on a shaft relative to the delivery machine to serially number the printed material passing therethrough an impression roller positioned beneath the numbering machine in cooperative relationship therewith and an inking device, said delivery machine including driving means and picking-up devices associated to said driving means for gripping the material discharged from the printing machine, said numbering machine including printing wheels having serial numbers thereon, a pawl for selectively stepping the printing wheels each time a number is to be impressed upon a sheet of printed material and a stop for actuating said pawl at each passage of a sheet of printed material, the combination therewith of a control assembly comprising:

• a first electrical circuit comprising detection means responsive to the presence and absence of gripped material, a first normally open switch and a relay connected in series, said detection means closing said first circuit when printed material is normally supplied and opening the same when printed material is missing, said first switch closing said first circuit for a short time at each rotation of the shaft of the numbering machine, said relay closing a second electric circuit for a predetermined period of time each time it receives an electric pulse,
• said second electrical circuit comprising a main switch, said relay and a first solenoid connected in series, said main switch selectively deactuating the numbering assembly, said first solenoid operating first mechanical means which in turn closes a third electrical circuit,
• said third electrical circuit comprising a switch operated by said first mechanical means, the main switch and a second solenoid, said second solenoid operating second mechanical means which brings the stop of the numbering machine in operative position into the path of the pawl so that the number to be impressed be stepped each time a sheet of printed material is passing through the numbering machine,
• said first mechanical means operated by the first solenoid of the second electrical circuit comprising a first lever which is mounted on a central pivot and permanently provided with an oscillatory movement generated by a pullback spring and a cam mounted on the shaft of the numbering machine, blocking means connected to the first solenoid for holding said first lever in an operative position relative to the switch of said third electrical circuit when the second circuit is closed, and connecting means mounted on the ends of the first lever for transmitting the oscillatory movement of the later to the impression roller and inking device.