Riser device

摘要

The device has a nacelle (3) connected to a frame (2) by a plate (4), where the frame is fixed on a ground near a staircase (1). A vertical displacement unit is located between the plate and the frame. A horizontal displacement unit is arranged between the nacelle and the plate. A control unit controls combination of vertical and horizontal displacements to move the nacelle between the ground and a top step of the staircase according to a slope of the staircase. The two displacement units comprise electric cylinder type motorization.