Width detector system

A width detector system for constantly monitoring and measuring the width of moving elongated strip materials, comprising:

• a pair of carriages, one movably mounted adjacent each lateral edge of a strip of material to be measured;
• a pair of sensor means mounted, one on each carriage, for movement therewith along parallel paths transversely of the elongated axis of said strip material;
• each sensor means comprising a light source and a photo sensitive cell disposed on opposite faces of said strip material and productive of signals proportional to the intensity of light received by said cell;
• a pair of drive means, one for bidirectionally moving each carriage and sensor means;
• a pair of pulse generators, one operatively driven by each drive means, and operable to generate positive and negative output signals dependent on the direction of travel of said carriages along said paths;
• control means responsive to signals from each sensor means for controlling its associated said drive means whereby to cause each sensor means to independently follow an adjacent edge of said material, and measurement means responsive to the combined output signals of said generators for constantly monitoring the distances of said sensor means from a fixed datum including means for totalizing said distances whereby to determine the measured distance between said sensor means representing the width of said material.