A stair lift is a mechanical device for lifting people up and down stairs. For sufficiently wide stairs, a rail is mounted to the treads of the stairs. A chair or lifting platform is attached to the rail. A person on the chair or platform is lifted as the chair moves along the rail.
Stair lifts are known variously as stair lifts, stair-lifts, chair lifts, stair gliders and by other names. This type of chair lift should not be confused with the chairlift used by skiers. The term stair climber can refer either to stair lifts, or more commonly to the exercise equipment by the same name.
Some of the first stair lifts to be produced commercially were advertised and sold in the USA in the 1930s by the Inclinator Company of America. Many users at the time were victims of polio.
Now they are seen for use in elderly, fall-prone individuals, and the disabled who are unable to navigate stairs safely. Modern stair lifts can be found with a wide variety of features such as adjustable seat height, battery isolation switches, call stations, 'flip-up' rail, key switch, folding step, speed governor, seat belt, soft start and soft stop.