Abstract: The invention is a drive system for folding blades for the folding of flat material, preferably paper, in folding devices working by the principle of blade folding, consisting of one or several universal joints interposed between the drive and output shafts of the folding-blade drive. Universal joints may be used so that the shafts are in different planes and the angle of intersection of the shafts is greater than zero. The irregularity of the angular velocity achieved will cause an extreme displacement of the point of return, so that the folding blade will contact the sheet with a small velocity and will then be considerably accelerated to reach the velocity of the folding rollers prevailing at the moment of transferring the sheet to be folded to the folding rollers. The drive and output shafts may also be telescopic shafts.