TOOTHED TRANSMISSION PULLEY

PURPOSE:To contrive to enhance the accuracy and strength of the pulley and to reduce its manufacturing cost by a structure wherein the toothed transmission pulley is composed of a toothed ring and a pulley main part inscribedly jointed to the toothed ring. CONSTITUTION:A pulley main part P is composed of a disc plate 6, which is formed with metal sheet by press work and in a boss mounting hole 7 bored at the center of which a boss 6 is fittingly welded and at the same time at the outer periphery of which an annular ring holder part 9 is integrally formed by bending work. A plurality of the engaging projections 10 of the pulley main part P respectively engage with the recessed grooves 4 at every other back of a plurality of the teeth 1 of the toothed ring R. In addition, the inner surface of the tooth space 3 of the toothed ring R contacts with the outer surface of the ring holding part 9. Furthermore, each stopper piece 5 engages with an engaging surface 11 formed on one side surface of the outer peripheral part of the pulley main part P in order to axially position the toothed ring R to the pulley main part P.