Patent ID: 7018313

Claim:
A sprocket having an axis of rotation, sprocket teeth disposed along an edge of the sprocket, said sprocket teeth being spaced radially from said axis of rotation and circumferentially from one another, said sprocket teeth having side surfaces disposed in transverse relationship to the direction of said axis of rotation, and each of said sprocket teeth having a pair of chain roller-engaging surfaces on opposite faces of the tooth with respect to the circumferential direction of the sprocket, and a pair of discrete wear limit markers, on a side surface of one of said sprocket teeth, for indicating whether or not the sprocket teeth have reached a predetermined wear limit, said markers being located adiacent, but spaced inwardly from, the respective chain roller-engaging surfaces on said one of the sprocket teeth, each said wear limit marker being disposed on an imaginary line extending in the direction of the pressure angle from a point on the sprocket pitch line at which the center of a chain roller would be located when said chain roller is engaged with, and applying a force to, said one of the sprocket teeth, and each said wear limit marker extending to predetermined limits on both sides of the imaginary line on which it is disposed.