| 摘要 |
A trolley (100) for mounting on a beam (12) of a gantry (10), comprising: a first plate (103); a roller assembly (102, 104), mounted at an end of the first plate; a shaft (112), extending outwardly of the first plate; and a second plate (116), rotatably mounted on the shaft such that the second plate can move between a closed position, in which the second plate engages with the roller assembly and an open position in which the second plate does not engage with the roller assembly. |
