| 摘要 |
The horizontal, transverse, front wheel (24) support (12.1) is joined by two sloping supports (12.2) to the front ends of two side, longitudinal supports (12.3). The two back wheels (18) of a pair of wheels are joined by a tubular axle (14). The transverse front wheel support, together with the sloping supports and the longitudinal supports form a three-dimensional, U-shaped integral support (12). The back ends of the longitudinal supports are joined to the tubular axle. The back wheels are mounted by plug-in axles in angled adaptor sleeves joined to the tubular axle. |
