Patent ID: 9738497
Date: 2017-08-22
CPC Classifications: B66C

Claim:
1. A jib attachment/detachment mechanism which includes a jib main body and a jib support rotatably provided to a rear portion of the jib main body and is configured to pull up a jib suspended by a wire to a boom head and detachably fix the jib to the boom head, the jib attachment/detachment mechanism comprising: a first connecting portion provided to an upper portion of a tip of the boom head; a second connecting portion provided to an upper portion of a rear end of the jib support, the second connection portion being detachably connected to the first connecting portion; a locking portion provided to one of a lower portion of the tip of the boom head and a lower portion of the rear end of the jib support; an engaging portion provided to the other of the lower portions and configured to engage with the locking portion; and a guide mechanism configured to guide the jib to a position where the locking portion or the engaging portion of the jib support is engaged with the engaging portion or the locking portion of the boom head and a position where the second connecting portion of the jib support is connected to the first connecting portion of the boom head, when the jib is pulled up by the wire, wherein the guide mechanism includes a guide unit provided on the rear end of the jib support and a guided member provided to the tip of the boom head and configured to be guided by the guide unit, the engaging portion or the locking portion of the jib support is engaged with the locking portion or the engaging portion of the boom head in such a way that the guided member is guided by the guide unit while the guide unit is pulled up and brought into contact with the guided member with the wire, the guided member is detachably attached to a side portion of the jib support, and when the guide unit is pulled up by the wire, the guided member is detached from the side portion of the jib support and detachably mounted on the tip of the boom head.