| 摘要 |
The base has a rectangular frame (1) provided with lower wheels in a lower part and attachment units formed of a finger (5) and a ring (6) at each end. The ring is carried by a tiller (7). The frame has an upper plate (3) mounted to pivot around a vertical central axle (4) of the frame. A fixing plate (9) fixes the tiller to the frame. The frame has a fixing unit of the plate and/or a spacer (10) interposed between the frame and the plate of tiller in a removable manner. The spacer has length equal to a half-difference between a diagonal (d) and a longitudinal dimension (l) of the frame. |
