Automatically folding and unfolding tower crane

An automated collapsible tower crane movable between a transport position and a working position, comprising:

• a telescopically extending mast with at least an upper telescopic portion with an upper end part, and a lower telescopic portion with a lower part rotatably anchored in a vertical plane to a lower base platform of the tower crane;
• a mast locking mechanism to lock the lower telescopic portion in a locked position in a substantially vertical plane with respect to a lower base platform of the tower crane;
• a telescoping system of the mast to telescopically extend and retract the mast between a retracted vertical position in which the mast is in a non-extended vertical position and an extended vertical position in which the mast extends upwards, the telescoping system comprising a combination of cable and pulleys driven by a winch;
• a boom comprising a plurality of boom sections articulated in respective rotary joints along respective rotation angles limited to substantially 180° around respective horizontal axes to stiffen the boom when it is extended, the boom sections including a first boom section articulated with the upper end part of the upper telescopic portion of the mast and at one end of the proximal portion of a second boom section;
• a boom folding system for unfolding and folding the boom by the rotary joints between a folded position and at least one linearly unfolded working position along a substantially horizontal plane,
• a mast folding system for moving the mast between a folded transport position and an unfolded position along a substantially vertical plane, the mast folding system comprising a bracing sling anchored to:
• the lower base platform;
• a first superiorly articulated vertically rotatable support strut of a proximal portion of the first boom section;
• a second vertically rotatable support strut articulated posteriorly of the proximal portion of the first boom section;
• and
• at least a third superiorly articulated vertically rotatable support strut of a distal portion of the first boom section of the boom;
• wherein:
• the sling is connected to the support struts;
• in the transport position the boom sections are folded down over one another and on the mast in folding planes;
• the boom folding and unfolding system acts independently of the combination of cables and pulleys driven by the winch of the mast folding and telescoping system, and comprises hydraulic actuators hydraulically powered by hydraulic equipment for folding and unfolding the boom sections;
• and
• wherein each proximal and distal rotary joint is associated with at least one hydraulic actuator arranged to unfold and fold boom sections relative to one another.