US Patent 9238158 Stair climber apparatuses and stair apparatuses

A stair climber apparatus has a frame and a plurality of stairs that are pivotably connected together in series and travel in a loop with respect to the frame. The plurality of stairs comprises a first stair having a tread and a riser. The tread and riser are pivotably connected together at a first pivot axis. The tread has a tread surface that supports an operator's foot. A stopping member is on the tread. The stopping member has a stop surface that extends transversely to and upwardly from the tread surface and prevents the operator's foot from overshooting the first pivot axis and engaging the riser as the operator steps onto the tread surface when the riser is pivoted away from the tread.