Patent ID: 7144345

Claim:
A toothed belt transmission comprising: a toothed drive pulley; a toothed driven pulley; and a toothed belt trained around the two toothed pulleys and having a plurality of core wires embedded therein, wherein adjacent tooth portions of each toothed pulley are assigned as a first tooth portion and a second tooth portion forming a recess in which a tooth of the toothed belt is received, the first and second tooth portions each having a tooth outer edge having a first radius and a tooth recess surface, wherein tooth arcuate portions having a second radius are formed at corners between respective tooth outer edges and respective tooth recess surfaces of the first and second tooth portions, and wherein the tooth outer edges of the first and second tooth portions having the first radius merge at opposite ends thereof with respective tooth arcuate portions having the second radius at contact points where the first and second radii intersect, whereby when a common tangential line is drawn to come into contact with one tooth arcuate portion of the first tooth portion and an adjacent tooth arcuate portion of the second tooth portion and a first tangential line is drawn to pass through a contact point between the tooth outer edge and the one tooth arcuate portion of the first tooth portion where the first and second radii intersect, an angle between the common tangential line and the first tangential line is selected to have a value ranging from 6 to 14.40.