Overhanging storage mechanism for jib

A jib overhanging storage mechanism for overhanging/storing a jib with respect to an extendable/contractible boom, the jib overhanging storage mechanism comprising:

• a guide roller that is provided at one of the jib and the boom;
• a guide that is provided at the other one of the jib and the boom, and guides the guide roller;
• a jib fixing pin that is provided at one of the jib and the boom;
• and
• a pin socket that is provided at the other one of the jib and the boom, and has an insertion hole into which the jib fixing pin can be inserted,
• wherein the guide is configured such that the jib is pulled around a distal end side of the boom as a rotation center toward a bottom surface of the boom, and subsequently the jib moves along the boom, by the guide roller being guided with contraction of the boom;
• the jib fixing pin and the insertion hole are disposed such that when the jib moves along the boom with contraction of the boom, the jib fixing pin is inserted into the insertion hole;
• an inside dimension of a front end opening portion of the insertion hole is larger than an outside dimension of the jib fixing pin;
• and
• the front end opening portion of the insertion hole is a vertical hole along a vertical direction of a cross section of the boom,
• wherein the jib fixing pin has a distal end portion formed in a conical shape;
• the pin socket has a front end rib and a rear end rib;
• a front end insertion hole configuring a front end opening portion of the insertion hole is formed in the front end rib;
• a rear end insertion hole configuring a rear end opening portion of the insertion hole is formed in the rear end rib;
• and
• an inside dimension of the rear end opening portion is substantially the same as the outside dimension of the jib fixing pin.