Abstract: A belt tensioning device for use in a copying machine. The tension device includes two pairs of levers each lever having a first and second arm. A pair of floating rollers are provided to tension the belt by formation of loops in front of and behind, respectively, of an intermittent contact point between the belt and a pressure element moving at a different speed. Each floating roller is suspended in the ends of the first arms of the respective levers. The end of other arms of one pair of levers is connected to the end of the corresponding second arm of the other pair of levers by a tension spring system. One pair of levers has a larger transmission ratio than the other, so that the floating rollers return to their old positions after contact between the belt and pressure element.