There is provided a crane including a main body, a tower derrickably supported by the main body, a jib derrickably supported by the tower, an assist member that assist the jib to move along a ground, and a determination unit that determines whether or not the jib is stopped when the tower is lowered in a lowering work state where the jib is assisted by the assist member.

The invention relates to a bolting device having two bolts which are held rotationally secure and coupled to each other via a spindle element, wherein: a first bolt is connected via a threaded engagement to a corresponding thread of the spindle element; rotating the spindle element about its central longitudinal axis causes the first bolt to move along the longitudinal axis; and a second bolt is rotationally mounted on the spindle element in a fixed axial position. The invention also relates to a crane jib head comprising such a bolting device, for bolting a lattice masthead to a head adaptor.

The invention relates to a bolting device having two bolts which are held rotationally secure and coupled to each other via a spindle element, wherein: a first bolt is connected via a threaded engagement to a corresponding thread of the spindle element; rotating the spindle element about its central longitudinal axis causes the first bolt to move along the longitudinal axis; and a second bolt is rotationally mounted on the spindle element in a fixed axial position. The invention also relates to a crane jib head comprising such a bolting device, for bolting a lattice masthead to a head adaptor.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A method for installing and deploying concealed mounting points for a davit or jib crane on a roof patio or large balcony covered with stone pavers. Specifically, a metal plate assembly lower flange is affixed to the concrete roof slab with its contact points covered by waterproofing membrane. The metal assembly hard point upper flange holes correspond to the holes in the mounting base of the davit or jib crane. The metal assembly when installed is lower than the pavers supported by metal pedestal transition components. As such, the metal assembly hard point is concealed and covered by a removable cover plate that also sits on top of the metal pedestal transition components and is flush with the top of the pavers.

The present invention relates to a structural frame of a crane, lifting device, material handler or a similar machine, comprising at least one elongate structural-frame strut. The invention also relates to such a machine comprising such a structural frame. According to a first aspect, it is proposed not to weld or screw a separate doubled panel or separate retaining lugs to the structural-frame element as a reinforcement, but rather to provide the structural-frame strut with integrally formed, seam-free reinforcement layers in the required, highly loaded region, in order to achieve an organically produced increase in wall thickness and/or cross section in a smooth and harmonious manner. These reinforcement layers are produced using 3D printing.

The present invention relates to a structural frame of a crane, lifting device, material handler or a similar machine, comprising at least one elongate structural-frame strut. The invention also relates to such a machine comprising such a structural frame. According to a first aspect, it is proposed not to weld or screw a separate doubled panel or separate retaining lugs to the structural-frame element as a reinforcement, but rather to provide the structural-frame strut with integrally formed, seam-free reinforcement layers in the required, highly loaded region, in order to achieve an organically produced increase in wall thickness and/or cross section in a smooth and harmonious manner. These reinforcement layers are produced using 3D printing.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.

A marine knuckle boom crane includes a crane housing which is rotational relative to a pedestal about a vertical rotation axis and a knuckle boom assembly attached to the crane housing. The knuckle boom assembly includes a main boom, the inner end of which is connected pivotably about a first horizontal pivot axis to the crane housing; and a jib, the inner end of which is connected pivotably about a second horizontal pivot axis to the outer end of the main boom, wherein the jib is pivotable at least between an extended position in which the tip extends mainly forward from the main boom, and a folded position in which the jib is folded back, essentially parallel along the main boom. In order to position the jib with respect to the main boom, a tensioning member is provided extending between the crane housing and a curved extension guide connected to the jib.