Process for controlling and maintaining register of a web of preprinted material with initial automatic register adjustment

Abstract

Abstract 1. Process for the regulation or keeping in register of a continuous strip of material in a working station of a machine, by means of reference marks provided on the strip and of an index impulse of the working element of the said station, in which a train of position impulses is produced, the relative position of which in relation to the index impulse is a measure of the momentary position of the working element in the course of each of its cycles, and the frequency of which is a measure of its speed of displacement, a reference mark pre-impressed on the strip is selected and its ordered position is determined, and a detector signal is picked up continuously, which is a function of the difference of property between the bottom of the strip and the marks which it bears, from which one determines the offset between the real position and the ordered position of the reference mark and, as from the offset thus determined, the desired correction is applied to return the offset towards zero, characterised in that for the purpose of permitting an automatic initial setting into register and an automatic maintenance of register of a pre-impressed strip in an off-line machine, it consists in : determining and storing, in the form of a numerical sequence, at least one characteristic of the selected reference mark, acting upon the detector signal, sampling the detector signal continuously in synchronous manner on the position impulses, between the index impulses, and writing the results into the memory, in the form of numerical values, at successive addresses, periodically analysing the content of the memory in order to locate therein the sequence of numerical values which best corresponds to that determined as a function of the selected reference mark, and calculating the offset between the real position and the ordered position of the reference mark, from a specific address of the said sequence, and of the associated position of the working element.

Inventors

• 👤 Marc Gustave Minschart

Bibliographic Details