Abstract: A toothed roller having a cylindrical body with circumferential rows of teeth fixed on the outer surface of the body. The rows of teeth are longitudinally spaced apart on the body. A cleaning ring is loosely mounted on the body between each adjacent pair of rows of teeth. Each cleaning ring has an inner diameter slightly larger than the outer diameter of the body and an outer diameter slightly smaller than the outer diameter of a row of teeth whereby when one portion of the cleaning ring abuts the body, the diametrically opposed portion of the ring is nearly level with the ends of the teeth so as to be able to push out material and debris caught between, and on, the rows of teeth.