| 摘要 |
The track is made from tubes in arcs of circles inscribed in a sphere. There are four strips of circulation which cross at two places and are in contact with the ground. The tubes of our crosses are joined together at their ends. There are four arcs and the tubes of these join the middle of the circulation strips to the end of the crosses. Four plates are fixed to the ends of the tubes and retractable wheels are fixed to these.
|
