Abstract: Disclosed is an accumulator for paper sheets which are conveyed by conveyor belts to a receiving area comprised of parallel support members having spaces therebetween. The conveyor belts are mounted on rollers, at least one set of which is mounted on a first track-mounted movable carriage, and at least one other set of which is mounted on a second track-mounted movable carriage. The two carriages are linked so that motion of said first carriage to adjust the length of the receiving areas causes motion of said second carriage in a direction opposite to the motion of said first carriage to thereby maintain the conveyor belts under constant tension. The support members may be constituted of either plastic or metallic strips or rods. At least one set of rollers also has bristle means to aid in the conveyance of the paper sheets.