摘要 |
A mechanism for the transport of an object across relatively level surfaces as well as to ascend and descend stairways. The mechanism is described particularly with respect to a wheel chair for handicapped persons and is provided with a frame and a pair of support wheels on each side of the frame. A climbing chain with lugs is associated with each wheel on the frame; these chains being inclined at an angle providing a desired lifting height. The wheel chair is either powered by the occupant or by electrical or other corresponding power means. Appropriate sensing means on the frame ascertain a nonlevel condition in pitch or yaw during ascent or descent of the stairs whereby corrections are made in the driving means such that a level orientation is re-established. Braking is provided by appropriate gearing whereby an interruption of the driving power holds the climbing chains in their current position. In one embodiment, the mechanism is provided with means for selectively varying the relative rotational speed of the various climbing chains to facilitate the substantially simultaneous loading of each climbing chain. Specific embodiments of drive trains and climbing chains are described.
|