A roof support having a stabilizing-guiding system for two spaced articulated quadrilateral linkages joined by a spacer element. The stabilizing-guiding system includes two coordinating links respectively, pivotably connected at one of the ends thereof to the canopy and the bottom sprag and at their other ends the links are connected together by a connecting element. The connecting element is supported in a guideway fixed to the spacer element. Hydraulic legs are connected to the bottom sprag rearwardly of a plane bounding a walkway space for the crew on the bottom sprag.
