Abstract: A sprocket for a chain including a thick hub portion and a plurality of thinner sprocket rings mounted on the hub. The hub has a rounded polygon peripheral configuration and the rings have complementary bores to receive the hub. The rings have sprocket teeth defined about their outer edges. When the sprocket rings are mounted in face-to-face nesting arrangement on the hub the teeth on adjacent sprocket rings are aligned axially of the hub. A pair of side plates having a greater diameter than the sprocket rings confine the rings on the hub and aid in holding a chain thereon during operation.

Abstract: A chain saw bar nose has a rotatable sprocket. The sprocket assembly is adapted to conform in shape to the drive tang portions of the saw chain whereby the nose sprocket may receive operational forces imposed by the saw chain substantially as compressive forces as opposed to tensile forces. As a result, the nose sprocket assembly better withstands the harsh operating conditions imposed by cutting applications.