| 摘要 |
In addition to the castor wheels (3) at the opposite ends, the trolley has two large diameter non-steering wheels (8) at the sides, and the distance between the axis of these wheels and those of the castor wheels is adjustable. One of the pairs of castor wheels can be adjustable for height, and is lockable. The large wheels can be so attached to the frame that they can be lifted clear of the ground, to allow the trolley to be pushed sideways. The hubs of the central wheels can be attached to internal and external horizontal U-shaped members lockable in the raised position to hold them clear. |
