Patent ID: 9206021
Filing Date: 2015-12-08
Classification: B66C,Y10T

Abstract:
1. A crane comprising: a crane body; a boom attached to the crane body in a raisable and lowerable manner, the boom having two opposite ends, one end of the two opposite ends being a base end attached to the crane body, the other end of the two opposite ends being a head which is a distal end of the boom; a luffing jib which is a structural body for suspending a load through a wire rope and a hook, the luffing jib being attached to the head of the boom in a raisable and lowerable manner; and a strut attached to the head of the boom in a raisable and lowerable manner, and configured to raise and lower the luffing jib, the strut having a base end attached to the head of the boom; wherein the luffing jib comprises: a lower jib making up a first portion of the luffing jib, the first portion extending over a specific range from a base end of the luffing jib toward a tip of the luffing jib, the lower jib being attached to the head of the boom in a raisable and lowerable manner, at a position located below an attaching position of a base end of the strut to the head of the boom in a state in which the boom is lowered and laid down; and an upper jib making up a second portion of the luffing jib, the second portion positioned between the tip of the luffing jib and the lower jib, the upper jib being coupled to the lower jib in such a manner as to be separable from the lower jib, and wherein the lower jib is attached to the head of the boom to have a laid-down posture at a position between the boom and the strut when the upper jib is separated from the lower jib, when the boom is lowered and laid down to allow the head of the boom to come into contact with the ground and when the strut is lowered and laid down to allow a distal end of the strut to come into contact with the ground, the lower jib having a length which causes no interference with the strut when the lower jib has the laid-down posture at the position between the boom and the strut.