A folding step structure (7) comprises an elongate base (11) to be laid on or parallel to a ground surface (1); a frame (15) connected to the base; a step (14) connected to the frame such that the frame and the step member are together pivotal, about pivot points (20, 21) towards one end of the base,...http://www.google.de/patents/US5009282?utm_source=gb-gplus-sharePatent US5009282 - Folding steps
