Abstract: A roll mill, more specially for coal, has a turning pan and a number of rolls running thereon for producing a milling effect. Each roll is supported on a rocker arm, able to be turned about a horizontal axis which is roughly tangential to the pan. The rocker arm and the roll on it are forced down against the pan by a hydraulic cylinder joined with a fork which, in turn, is joined with the rocker arm for turning it about the turnpin. The fork may be unjoined from the rocker arm for upkeep work on the roll. Each rocker arm has a gas-tight cover structure which is part of the casing of the mill.