| 摘要 |
There is a clear distinction between hand driven, simple wheel chairs and much higher developed motor driven wheel chairs. The invention provides for a compromise, where a wheel chair of a simple design is or can be provided with a special driving unit (30), which as a self-contained unit, may serve to drive the wheel chair by having one or more driving wheels (32) located between the main wheels (26) of the chair in direct driving engagement with the ground. The driving unit can be secured in such a manner that the driving wheel or wheels (32) may move up and down relative to the main wheels (26), such that a driving engagement can be maintained during driving along a non-planar ground surface. The unit is well suited for mounting on both new and existing wheel chairs. When the driving wheel or wheels (32) are placed accurately midways between the ground engaging portions of the main wheels there will be no problems with respect to lateral dragging of the driving wheels in response to changes of the driving direction. |
