| 摘要 |
<p>The roller skates ball shaped roller consists of two roller halves which are axially connected by an axle unit leaving a short distance between the halves. The connection extends from about the centre of one half to the centre of the other half and the connection between the roller and the frame of the roller skate is made through the middle, i.e. through the short gap between the two halves. This permits the use of roller skates for taking curves and can also be applied to figure skating.</p> |
