A stair step exerciser is mounted on a frame having horizontal and vertical components. A carriage comprised of a pair of side plates is pivoted to one end of a horizontal component and is retained at the other end in one of a series of vertical stops to selectively determine the angle of the carriage...http://www.google.de/patents/US5328420?utm_source=gb-gplus-sharePatent US5328420 - Stair step exercise machine
