sole - bars bear on axles by elastic suspensions with frictional damping . the bolster bears by elastic blocks on the lower side of a window through each sole - bar . each elastic block bears on a face of the sole - bar which has , in relation to the longitudinal direction of the bolster , an inclination such that the compressive force of the elastic block has a horizontal component which pushes the sole - bar so as to bear by its reference face against a parallel reference face belonging to the bolster . thus , the sole - bars are constantly returned to a favored configuration of perpendicularity in relation to the bolster . use for effectively combatting parasitic deformations and sideways movements of deformable - frame bogies .