Abstract: A transport device for supplying developer powder from a lower-level reservoir to a developing station by a rotatable spiral spring contained in a transport tube, which transport tube has an inlet aperture near the lowest point of the reservoir, together with a spiral spring, blades which rotate around the inlet aperture provided with an inlet blade to push developer powder in the transport tube in order to ensure upwards transportation of developer powder, even in the event of a low level in the tube. A low-level detection element is coupled to the rotating blades to prevent the conveyor pipe emptying and a pipeline effect occurring as a result of the developer powder in the reservoir running out.