The feed-in roller conveyors consist of solidly welded frames for the longitudinal transportation of the workpieces from the upstream processing machines to the paternosters of the stacking machines. The roller conveyors are driven by an adjustable geared motor so that the feed rate can be controlled. The roller conveyors are open on one side in a comb-like arrangement for the paternosters of the stacking machine. Damped and longitudinally adjustable limit stops which start the work cycle are located at the end of the roller conveyor.