| 摘要 |
<p>A roller carriage has a carriage bottom (10) below which a plurality of wheels (6, 8) is mounted, at least one of said wheels being mounted swingably about a substantially vertical axis (5) of swing. The roller carriage moreover has retention means to retain the swingable wheel (8) or wheels on an overlying roller carriage, said wheel retention means being constructed as a substantially horizontal guide track which extends along at least part of a circle. The guide track forms two engagement areas which restrict the movement of the swingable wheel or wheels of an overlying roller carriage.</p> |
