Automatic device for bringing into register a tool mounted on a rotary cylinder for processing products in sheet form

Apparatus for achieving automatic register for a processing installation for products in sheet form, which utilizes a rotary cylinder and comprising means for the cyclic feeding of sheets to a tool holder cylinder (1) driven by the general kinematic chain of a machine in such a manner that the interval of introduction of the successive sheets corresponds to the development of the tool holder, or to a multiple thereof, the drive of the tool holder cylinder comprising a device (7) for angular adjustment, relative to the general kinematic chain, under the control of an adjusting motor, said apparatus comprising

• (a) a first coding device (22) connected to the general kinematic chain (30) and supplying information representing the theoretical speed of advance of the sheets;
• (b) a second coding device (23) connected to the adjustment device (8) and providing information representing the angular adjustment value given to the tool holder;
• (c) a first detector (20) of the passage of a selected reference mark (15) on the sheet, this detector being disposed upstream of the tool holder cylinder at a distance less than the theoretical distance between two successive sheets;
• (d) a second detector (36) coupled to the general kinematic chain (30) and providing electric pulses linked to the feed cycle of the sheets;
• and
• (e) a computing and correction unit receiving and analyzing the information provided by said first and second detectors (20, 36) and coding devices (22, 23) and accordingly providing for each cycle of said machine one or more commands for the correction of the tool holder in response to the difference between the actual position of the sheet introduced and its theoretical position.