Abstract: A feed roll for transporting a material web and measuring a web tension of the material web which is continually moved in a roller rotary printing machine. The feed roll is rotationally supported at both sides in two levers which are pivotably arranged in the frame of the machine. A force acting on the axis of the feed roll and proportional to a web tension is measured by a measure value-receiver which detects a path of movement of a translating lever rigidly connected to at least one of the pivotable levers.

Abstract: A device for measuring web tension of a continually movable web transported on a rotated cylindrical roller of a printing machine includes two eccentrics connected to two ends of the roller for supporting the latter for rotation and each includng a supporting pin. The supporting pin of one of the eccentrics has its end rigidly connected to a machine frame and is able to twist proportionally to the web tension. A lever having one end rigidly connected to the twistable supporting pin has its other end positioned between a light transmitter and a light detector of an optoelectronic sensor which detects the amount of twisting of the supporting pin.