| 摘要 |
A wheel set includes a primary wheel and two secondary wheels. The secondary wheels are disposed at two sides of the primary wheel, respectively. The primary wheel is provided with circular pivoting members at two sides of the primary wheel. Each secondary wheel is provided with a corresponding circular pivoting member to be pivotally connected to the primary wheel. When taking a turn, the primary wheel and the secondary wheels are separately turned to achieve a smooth turn.
|
