Abstract: A cooling bed for cooling and straightening rods or bars which are delivered hot from a rolling mill as side-by-side conveyor chains provided with projections between which pockets for the articles are defined. Reversal sprocket wheels at the infeed end are interconnected so that the pockets at the infeed end remain accurately in alignment, notwithstanding chain wear and differential expansion under the heat conditions. Reversal sprocket wheels at the discharge end are not drivingly interconnected, at least under normal operating conditions. Individual hydraulic drive motors drive the reversal wheels as shown or separate drive wheels which cooperate with the lower runs of the conveyor chains to keep the upper runs taut individually. The individually driven sprocket wheels are mounted with angular lost motion on a connection shaft to avoid one of the motors being overloaded under exceptional circumstances.