joint combination 22 8 when the car roof 2 is lowered the climbing ladder 22 can be pivoted by a maintenance person who is standing on the floor through an angle of approximately 270 u00b0 from its horizontal position on the car roof into a virtually vertical climbing position in the region of the opened elevator door 24 so that the maintenance person can comfortably climb onto the car roof 2 lowered as maintenance platform the foot of the climbing ladder 22 is in that case supported in a position on the car floor which makes it possible to close the elevator doors 24 26 and to move the elevator car 1 at inspection speed to the inspection locations in the elevator shaft fig1 shows the pivot process of the climbing ladder 22 in detail thanks to the joint combination 22 8 which comprises two joints and the collapsible form of embodiment of the climbing ladder this can be pivoted below the door transom 25 of the open car door 26 when the car roof 2 is lowered and be brought into its almost vertical climbing position the rectangular tubes 22 1 22 2 22 3 which form three sections of the climbing ladder 22 are subsequently pulled out and mutually locked so that a rung 22 6 of the lower rectangular tube 22 3 reaches the car door threshold 27 or the shaft door threshold 28 and.