Abstract: The invention relates to a lifting device for machines intended for the gathering and roll baling of all types of harvest, said machine comprising a frame on which is rotatably mounted at its lower part a cut hay pick-up member, said frame bearing at its upper part means defining a forming chamber for the round bale and being mounted on a pair of wheels in contact with the ground. The pick-up member is fixed relative to the hay bale-forming chamber and the wheels are mounted on the frame by means for regulating the height of the frame and the pick-up member relative to the ground. The invention is used for harvesting.