US Patent 7082637 Compact foldable ramp

A multi-section ramp hinged longitudinally end-to-end uncurls from a portable mode into an arc of hinged sections in open, or operational mode, each adjacent section pair limited in opening rotation at less than 180 degrees as adjacent section ends come into abutment. In its folded position, more upper ramp sections nest in respective adjacent next lower ramp sections, in a stacked nesting configuration resulting in a tightly compact, mobile unit easily storable in a small volume and transported by hand. Each section comprises a runway in the form of a plate with vertical panels on each runway lateral side extending downward from the runway and with vertical end members on each runway longitudinal end, forming an inverted open box. Longitudinal strengthening ribs run between end members and pass into aligned slots in more inner runway sections upon ramp folding so inner sections can nest more within the larger sections without impacting the ribs.