Abstract: The invention pertains to an automotive tractor unit, more particularly for riding and working on vertical walls and ceilings, of the type which consists mainly of a frame; of belt shaped progression elements or tracks which are appropriately driven and are provided with adhesion devices such as suction discs or magnets as well as with elements for attaching appropriate accessories or tools such as a spraying piston or suchlike to the tractor. The belts or tracks are fitted so as to hinge with respect to the frame and around shafts which extend in the longitudinal sense of the tractor.