Provided is an assembly method for a crane, by which method a crane including a strut can be assembled easily. The assembly method for the crane includes a strut coupling step of coupling a base end of a strut, a cylinder connecting step of extending a cylinder unit having one end supported by the strut, the cylinder unit being capable of extending/contracting, to connect the other end of the cylinder unit to the boom, a strut raising step of causing the cylinder unit to contract to raise the strut, and a strut supporting step of stretching a stretching member, such as a rear side guy line or a luffing cable, between a front end of the strut and a base end of the boom to support the strut in a raised state.

An automated collapsible tower crane comprising a mast with telescopic portions, a boom with boom sections articulated with each other by respective rotary joints, a boom folding system to unfold and fold the boom by the rotary joints wherein each proximal and distal rotary joint is associated with at least one hydraulic actuator to unfold and fold boom sections, a mast folding system to fold the mast down, wherein in the transport position the boom sections are folded down one on top of the other and on the mast, and the boom folding and unfolding system acts independently of the folding and telescoping system of the mast, and comprises hydraulic actuators to fold and unfold the boom sections.

A tower crane configured to fold and unfold between a working configuration and a transport configuration includes a boom hinged in rotation relative to a mast about a main axis of rotation. The tower crane includes a rear retainer fastened to a frame supporting the mast and to a stanchion. The stanchion extends the boom rearwardly of the main axis of rotation and is displaceable relative to the boom between a working position and a transport position. The tower crane further includes a lifting cable connected to a winding device exerting, on the lifting cable, a tension force applied on stanchion by a return system configured to cooperate with the lifting cable, so as to cause displacement of said stanchion from the working position to the transport position.

A tower crane configured to fold and unfold between a working configuration and a transport configuration includes a boom hinged in rotation relative to a mast about a main axis of rotation. The tower crane includes a rear retainer fastened to a frame supporting the mast and to a stanchion. The stanchion extends the boom rearwardly of the main axis of rotation and is displaceable relative to the boom between a working position and a transport position. The tower crane further includes a lifting cable connected to a winding device exerting, on the lifting cable, a tension force applied on stanchion by a return system configured to cooperate with the lifting cable, so as to cause displacement of said stanchion from the working position to the transport position.

An automated collapsible tower crane comprising a mast with telescopic portions, a boom with boom sections articulated with each other by respective rotary joints, a boom folding system to unfold and fold the boom by the rotary joints wherein each proximal and distal rotary joint is associated with at least one hydraulic actuator to unfold and fold boom sections, a mast folding system to fold the mast down, wherein in the transport position the boom sections are folded down one on top of the other and on the mast, and the boom folding and unfolding system acts independently of the folding and telescoping system of the mast, and comprises hydraulic actuators to fold and unfold the boom sections.

A crane includes: a boom; a jib; a front post that is swingably attached to a tip end side of the boom; a rear post that is swingably attached to the tip end side of the boom; a post-side pendant member, with one end of the post-side pendant member being attached to a tip end of the rear post; a boom-side pendant member, with one end of the boom-side pendant member being attached to another end of the post-side pendant member, and another end of the boom-side pendant member being attached to the boom; and a post driving device having a link mechanism that rotates the rear post in a range including a position at which the rear post is swung down to the front post side and a position at which the rear post is swung down to the boom side, while the boom is held down in a horizontal position.

Provided is an assembly method for a crane, by which method a crane including a strut can be assembled easily. The assembly method for the crane includes a strut coupling step of coupling a base end of a strut, a cylinder connecting step of extending a cylinder unit having one end supported by the strut, the cylinder unit being capable of extending/contracting, to connect the other end of the cylinder unit to the boom, a strut raising step of causing the cylinder unit to contract to raise the strut, and a strut supporting step of stretching a stretching member, such as a rear side guy line or a luffing cable, between a front end of the strut and a base end of the boom to support the strut in a raised state.