There is provided a crane that is assemblable and disassemblable and is capable of changing a monitoring range for periphery monitoring according to an assembly state of the crane.

A leveling assembly for a lift device includes a carrier arm, an axle, a first actuator, and a second actuator. The carrier arm includes a base that defines a first interface configured to pivotally couple the carrier arm to a chassis of the lift device to facilitate a pitch adjustment of the leveling assembly, a projection that defines a second interface, and a transition that extends angularly between the base and the projection such that the projection is elevated relative to the base. The axle defines a third interface positioned to engage with the second interface to pivotally couple the axle to the carrier arm to facilitate a roll adjustment of the leveling assembly. The first actuator is pivotally coupled to a first lateral end of the axle. The second actuator is pivotally coupled to an opposing second lateral end of the axle.

A leveling assembly for a lift device includes a carrier arm, an axle, a first actuator, and a second actuator. The carrier arm includes a base that defines a first interface configured to pivotally couple the carrier arm to a chassis of the lift device to facilitate a pitch adjustment of the leveling assembly, a projection that defines a second interface, and a transition that extends angularly between the base and the projection such that the projection is elevated relative to the base. The axle defines a third interface positioned to engage with the second interface to pivotally couple the axle to the carrier arm to facilitate a roll adjustment of the leveling assembly. The first actuator is pivotally coupled to a first lateral end of the axle. The second actuator is pivotally coupled to an opposing second lateral end of the axle.

A crane, particularly a rubber-wheel container crane includes a frame which has, on opposite sides of its lower part, main beam structures at both ends of which, i.e. in the lower corners of the crane, there are two successive rubber wheels or wheel arrangements through which the crane is supported by its moving carrier. These wheels are supported by the main beam structure rigidly and in an unsuspended manner.

A crane, particularly a rubber-wheel container crane includes a frame which has, on opposite sides of its lower part, main beam structures at both ends of which, i.e. in the lower corners of the crane, there are two successive rubber wheels or wheel arrangements through which the crane is supported by its moving carrier. These wheels are supported by the main beam structure rigidly and in an unsuspended manner.

A cylinder retraction system causes a crawler side frame hoisting hydraulic cylinder, swingably suspended on a ventral surface side of a lower boom, to swing between a retracted attitude, in which the hydraulic cylinder is set along a ventral surface of the lower boom, and an operating attitude, in which the hydraulic cylinder is oriented along a vertical direction. As the rod of the hydraulic cylinder, currently having the operating attitude, is contracted by a predetermined extent, the rod front end of the hydraulic cylinder is guided by the guiding portion until the hydraulic cylinder takes on the retracted attitude. As the hydraulic cylinder, currently having the retracted attitude, is extended by a predetermined extent, engagement between the rod front end of the hydraulic cylinder and the guiding portion is released so as to allow the hydraulic cylinder to take on the operating attitude.

A cylinder retraction system causes a crawler side frame hoisting hydraulic cylinder, swingably suspended on a ventral surface side of a lower boom, to swing between a retracted attitude, in which the hydraulic cylinder is set along a ventral surface of the lower boom, and an operating attitude, in which the hydraulic cylinder is oriented along a vertical direction. As the rod of the hydraulic cylinder, currently having the operating attitude, is contracted by a predetermined extent, the rod front end of the hydraulic cylinder is guided by the guiding portion until the hydraulic cylinder takes on the retracted attitude. As the hydraulic cylinder, currently having the retracted attitude, is extended by a predetermined extent, engagement between the rod front end of the hydraulic cylinder and the guiding portion is released so as to allow the hydraulic cylinder to take on the operating attitude.

A laser positioning system is used in association with a crane within a manufacturing facility. The laser positioning system includes a laser source that is mounted on an immovable or non-moving wall or surface in the manufacturing facility. The laser source on the wall or surface ensures that the laser beam does not skew out of square relative to the movement of the crane to various locations in the facility.