| 摘要 |
The crane jib derricking mechanism transmits both pull and thrust forces, having a beam attached to the jib and tilting about a transverse axis on the crane superstructure in such a manner as to allow it to be moved lengthwise in the superstructure by a drive mechanism. This mechanism is formed by ropes (36, 37), engaging with points on the beam (17) on opposite sides of the transverse axis (13). The ropes are coupled to a winch (35) on the superstructure and which moves them in opposite directions. |
