| 摘要 |
PROBLEM TO BE SOLVED: To provide a gantry structured to easily change an attitude of the gantry, regarding a gantry having two kinds of working attitudes.SOLUTION: A tension member 4 constituting a gantry 1 includes three link members 5, 6, 7. In a lower end portion of the first link 6 among the three link members, a semicircular recess is formed which is opened downwards. When the gantry 1 is brought into a first working attitude, a first attitude holding pin 28 is engaged to the recess, such that a dead weight of moving the tension member 4 (the third link 5 and the first link 6) downwards is received by the first attitude holding pin 28. Since the recess to which the first attitude holding pin 28 is engaged is opened downwards, after a boom is mounted to the gantry 1, a tensile force from the boom does not act on the first attitude holding pin 28. Therefore, the first attitude holding pin 28 can have a reduced diameter and can be made lightweight. |
