field and it is independent of the structure of the elevator although it has to permit in all cases the displacement of the load along the z axis the central area of each support section portion 25 has in its upper part a flat surface in which the horizontal plate 29 abuts being this latter provided with a plurality of orifices 30 for securing the extraction device 11 the plurality of guiding wheels 33 34 35 are located on metallic supports 39 defined by various interconnected profiles secured on the upper part of the crossbars 26 so that said guiding wheels 33 34 35 roll along on the main vertical column 2 along the axes x and z and roll on the auxiliary vertical column 3 along the z axis as shown in fig1 said figure shows the rotation axes of the guiding wheels 33 34 35 as well as the elevation guide 23 which has been shown in cross section some of the elements having been omitted to facilitate the understanding thanks to this feature the efforts along the x axis are not transferred to the auxiliary vertical column 3 avoiding overguidance problems as shown in fig1 and 11 the wheels 34 35 are assembled in groups 36 of two wheels mounted on a plate 37 which is articulated to a free rotating shaft 38 so that the contact is ensured at any time on the surface on which they slide the fact that the guiding wheels along z axis are articulated forming groups of two wheels permit to absorb larger reaction forces with smaller dimensions enabling.