| 摘要 |
The top beam of the I-section rail is modified from being a generally rectangular cross-section to one which is cylindrical. The wheels are also correspondingly modified and instead of having a rectangular groove, which runs on the rail, the groove in the modified wheel has a semi-circular form. This allows the rail to absorb the forces which are generated at angles from the left (14) and the right (13), as well as those generated normally (12). |
