Abstract: The invention pertains to a pulley for belt conveyors, particularly belt conveyors used in the conveying of stones, gravel, and the like wherein the pulley structure is self-cleaning of foreign matter received within the confines of the pulley to prevent belt damage. The pulley consists of a plurality of helically disposed webs spiralled about a rotatable shaft. A plurality of webs are defined upon the shaft on each side of the pulley central region wherein at least two separate webs define a set of multiple pitch helices, and each set is spiralled about the axis of rotation in an opposite direction wherein foreign matter received between the webs is moved to the pulley ends in a self-cleaning manner. A disc is utilized at the pulley central region to which the inner ends of the web sets are affixed and the periphery of the webs is of a greater axial dimension than the web plate to increase the belt surface loading area.