| 摘要 |
A trolley includes driven wheels 8 and castor wheels 6a,6b,6c and 6d. The driven wheels 8 may be moved to a position clear of the ground or to a position in which they contact the ground with the adjacent castor wheels 6c and 6d being raised off the ground. Movement between these two positions is effected by pivoting a sub-frame 16 to which the driven wheels 8 and the castor wheels 6c and 6d are connected. During this movement the region of the trolley above the driven wheel is first lowered and then raised slightly such that the end elevation of the support for a patient remains the same. |
