Abstract: An expandable support structure including a pair of spaced-apart lazy tongs linkages acting as the load supporting beams of the structure and wherein the floor of the structure is formed by planks extending laterally between the two linkages; each adjacent pair of the planks is pivotally connected near a lower endwise junction of two of the links of the lazy tongs linkages, the pivot point of each plank being near an edge thereof with the other edge free to rotate upward as the linkage is contracted; the free ends of two adjacent planks are linked together to cause them to be lifted when the linkage is contracted and a slide mechanism guides these free ends upward. The apparatus is usable as a ramp for loading wheeled vehicles into the bed of a pickup truck and for such usage may be provided with a slide mounting in the rear of the bed of the pickup truck to reach over the tailgate hinge and at the same time allow the structure to be folded back completely within the pickup bed and the tailgate closed.