| 摘要 |
A wheelchair has more than two wheels (7) and a separate drive for each wheel (7). Each drive is preferably in the form of an electric motor (1) which is preferably connected to the wheel (7) by means of a worm (5) and a worm-wheel (4). The helix angle of the worm (5) and worm-wheel (4) is preferably less than 8 DEG for automatic braking of the wheels (7), and preferably between 7 DEG and 7 DEG 50' for rapid but controlled braking. A preferred helix angle is substantially 7 DEG 35'. <IMAGE> |
