Abstract: A device for driving loads on a horizontal roller conveyor support between pick-up and delivery stations including a carriage mounted to travel back and forth below the conveyor level. The lower end of an upstanding lever arm is pivoted on the carriage and at the upper end of the arm a load engaging cylinder or roll is mounted with its axis forwardly (i.e. in a downstream direction) adjacent the vertical center line of the arm which is yieldably urged to remain at right angles to the plane of conveyor support. In the latter position the top of the roll is slightly elevated by a fraction of an inch above said load support plane. In operation at the pick-up station near the upstream end of carriage travel the roll can freely rotate under a load and the lever is thereby angularly set at an acute angle in the load driving direction.