APPARATUS AND PROCESS FOR MEASURING THE UNROUNDNESS AND DIAMETER OF RAILWAY WHEELS

Apparatus and process for measuring the unroundness and diameter of railway wheels in which a rolling rail is provided on which rolls a railway wheel to be measured, and a guard-rail centers the wheel during the measurement process. Several light sources project light beams at the periphery of the wheel at different transverse locations, such that the light beams continuously intersect the flange and rolling band of the wheel. The images produced by the light beams pass through filters to video cameras which store the images, and sends them to a computer which can process the images and determine unroundness and wheel diameter. The measurement process is initiated by a trigger system which detects the presence of a wheel on the rail and activates the measuring equipment when the wheel is at the beginning of a measuring zone and deactivates the equipment when the wheel is at the end of the measuring zone. The invention is applicable to the repair and maintenance of railway wheels.