A trailer assembly includes first and second axles supporting first and second wheels which are coupled to first and second actuators of a steering system. The steering system includes a control circuit connected to the actuators and the control circuit includes a driving device configurable in a low speed maneuvering mode with: a synchronized sub-mode in which the actuators can be actuated in a synchronized manner to steer the wheels in a synchronized manner, and a desynchronized sub-mode in which the first and second actuators can be actuated individually and independently to steer only the first wheels or only the second wheels. A control device is connected to the driving device to: select one of the sub-modes in the low speed maneuvering mode, and select an actuation either of the first actuator or of the second actuator, in the desynchronized sub-mode.

A self-erecting crane including a mast mounted on a rotating platform and supporting a boom is configurable between a transport configuration and a working configuration. The mast supports a hitch element suitable for being coupled on a fifth wheel provided on a rear platform of a tractor truck, the hitch element being located in a front hitch area of the mast which is dimensioned to come above the rear platform. The self-erecting crane also includes a mooring system located on the front hitch area and a removable ballasting element. In the transport configuration, the removable ballasting element is configured to be temporarily moored on the mast by the mooring system so that the removable ballasting element is located under the mast in the front hitch area. In the working configuration, the removable ballasting element is mounted on the rotating platform.

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.

Expandable heavy equipment 1, comprising a first frame element 5, a connector 11, at least one elongated pull element 14, and further frame elements 7. The pull element 14 is connected to the first frame element 5 with a first coupler 31 and to one 9 of the further frame elements 7 with a second coupler 35. The pull element 14 is in a folded state in a transport condition and in an extended state in a working condition. The pull element 14 comprises load bearing fibers/fibres 141 extending from the first coupler 31 to the second coupler 35. The pull element 14 comprises at least one flexible part 43 and at least two stiff parts 45. The flexible part 43 has a lower bending stiffness than the two stiff parts 45 and enables the pull element 14 to be arranged in the folded state.

A lifting unit includes a jib foot forming a proximal part of a jib in a service configuration, a counter jib supporting a balancing ballast, a securing part between the jib foot and the counter jib to secure the lifting unit to a mast, and a cylinder connected to the jib foot such that the jib foot is movable between a lowered position and a lifted position. A second cylinder is connected to the securing part.

A wheeled crane and self-demounting and self-mounting methods for supporting legs thereof is disclosed. The wheeled crane includes a vehicle frame and auxiliary supports, and the auxiliary supports can enable the vehicle frame to keep balance. Since the wheeled crane has auxiliary supports, when the supporting legs are demounted or mounted, the auxiliary supports function as supporting legs, so that the supporting legs can be mounted and demounted by the operation part of the wheeled crane with no need of using an auxiliary crane, and thus the self-mounting and self-demounting of the supporting legs of the wheeled crane are realized.

A connecting device connects a first attachment and a second attachment constituting a working machine with each other. The connecting device includes a first connected member, a second connected member, and a connecting member (connecting pin 15). The first connected member extends outward from a first side surface of the first attachment, the first side surface extending in a longitudinal direction of the first attachment. The second connected member extends outward from a second side surface of the second attachment, the second side surface extending in a longitudinal direction of the second attachment, the second connected member facing the first connected member when the first attachment and the second attachment come into a connection state. The connecting member connects the first connected member and the second connected member with each other.

This automatic unfolding and folding tower crane comprises a mast and a jib which are movable between an operation configuration and a transport configuration. The mast has a first mast section (2.1) and a second mast section (2.2). The jib has a first jib section (4.1) and a second (4.2) jib section. The first jib section (4.1) has an upper limit (4.11) and a lower limit (4.12) defining a height (H4.1) of the first jib section (4.1). The first mast section (2.1) is rotatably connected to the first jib section (4.1) about a hinge axis (Y24). The jib direction (X4) is shifted with respect to the mast direction (Z2) parallel to the hinge axis (Y24). A distance between the hinge axis (Y24) and the lower limit (4.12) is greater than 75% of the height (H4.1) of the first jib section (4.1).

A stacking block for supporting one or more lattice boom crane elements in a stacked storage condition. The stacking block may be formed of a lightweight plastic or resilient material that can easily be lifted overhead. The stacking block provides the space needed in between boom elements in order to safely stack the elements on a ground surface or on top of one another, without damaging parts.

A mobile crane is configured so that a boom is raised by a derrick cylinder in response to a raise signal output from a derrick lever and the derrick cylinder is stopped in response to the derrick angle of the boom reaching the maximum angle corresponding to the hoisted-down length of a rope.