Development of Nonpowered Lift for Wheelchair Users

Wheelchair users need lifts to climb up/down steps at entrances with limited space. Lifts driven by motors or hydraulic equipment are large and expensive. They also need switches to start/stop actuators. The aim of our study is to develop a compact nonpowered lift for wheelchair users. We propose a lift driven by the wheels of a wheelchair on it. Coil springs are installed in the lift to decrease driving torque and some mechanisms are attached to the lift so that the small front casters of a wheelchair can cross the lift stage and the large rear wheels can drive the lift. After the lifting speed, driving force, and conditions for driving the rollers were analyzed and a prototype lift was designed and fabricated. The developed lift succeeded in raising a wheelchair with a user, and a continuous motion of a wheelchair from entering to exiting the stage was executed smoothly.