US Patent 11396937 Chainring

A sprocket for engagement with a drive chain has a first and a second group of teeth, wherein the teeth of the first group and the second group are alternately arranged and each tooth of the second group is wider than each tooth of the first group. The profile of each tooth of the second group has a first protrusion in the front half of the tooth on a first lateral surface and a second protrusion in the rear half of the tooth on a second, opposite lateral surface of the tooth. In particular, the portion of each tooth of the second group engaging the chain may have a center plane that is rotated or twisted during forming about the radial center line of the tooth with respect to the central plane of the sprocket.