The present disclosure relates to a telescopic boom for a crane, wherein the telescopic sections of the telescopic boom each comprise at least one main telescopic part and at least one additional telescopic part and wherein the main telescopic part and the additional telescopic part are arranged above one another. The disclosure further relates to a crane having a corresponding telescopic boom.

A confined-space davit, including a vertical, elongate mast provided by at least one annular tube; and, a boom that is pivotally connected to an upper end portion of the mast and that extends forwardly from the mast. The tube comprises a forward wall and an opposing rearward wall and comprises left and right opposing lateral sidewalls that each connect the forward wall to the rearward wall.

A balanced lifting device comprises at least two lifting arms arranged opposite to each other, each lifting arm comprises a balance arm and an actuating arm driving the balance arm to move, the balance arm is rotatably connected to the actuating arm at a rotatably connected part, and a first drive device is arranged between the balance arm and the actuating arm to drive the balance arm to a horizontal state throughout the lifting process. A vehicle-mounted exchange box system and a multi-oil cylinder synchronization method are also provided in the present invention. A cargo box may be lifted stably to improve the operation safety, the vehicle utilization rate is improved by saving the waiting time for loading and unloading in the transfer process.

A telescopic jib includes a main box, at least one inner box and at least one swing-out mast. The mast is arranged on the inner box such that the inner box is able to be pushed into the main box together with the mast in a swung-in or folded-in position to thereby provide a telescopic jib that more easily provides an increased load-bearing capacity. In a particular configuration such a telescopic jib is disposed on a vehicle crane having wheels, axles, a lower carriage and a superstructure, with the telescopic jib mounted to the superstructure.

A boom assembly includes a boom housing having a longitudinal, internal cavity. A telescoping boom moves in an axial direction relative to the boom housing and has a first end positioned within the longitudinal, internal cavity and a second end positioned outside the longitudinal, internal cavity. A winch assembly moves with the movement of the telescoping boom. A winch cable extends from the winch assembly and is guided by a pulley. A portion of the winch cable extends over the pulley in an outward direction from the pulley. The extending portion of the winch cable has a length, and the length of the extending portion of the winch cable remains the same regardless of the axial movement of the telescoping boom relative to the boom housing.

A telescopic side arm for a refuse vehicle has an inner and outer boom. A mounting assembly secures the outer boom with a refuse vehicle. A plurality of bearing pads is positioned between the inner and outer booms to provide smooth movement between the inner and outer booms. A plurality of shims is associated with the bearing pads to assure a tight fit between the inner and outer booms.

A boom for supporting a drilling and bolting tool includes a first portion including a first end and a second end, a longitudinal axis extending between the first end and the second end; a second portion including a proximal end and a distal end, the proximal end supported for translational movement relative to the first portion in a direction parallel to the longitudinal axis, the distal end configured to support the drilling and bolting tool; an actuator for moving the second portion relative to the first portion parallel to the longitudinal axis; and a fluid passage for conveying pressurized fluid between the first end of the first portion and the drilling and bolting tool adjacent the distal end of the second portion, the fluid passage positioned within the first portion and the second portion.

A foldable boom for conveying an item, said foldable boom being foldable about at least one folding axis, said foldable boom being locatable in a folded stowed position, and moveable to unfolded extended positions; said foldable boom having a near end arranged for pivotal movement about a first horizontal axis located on a turret, said turret being rotatable about a vertical axis; said foldable boom having first conveying apparatus to convey an item therealong, internally within said foldable boom, to a remote end of the foldable boom; wherein said foldable boom is foldable about a folding axis, and a pivoting shuttle equipped with a clamp to releasably hold an item is provided at said folding axis to transfer said item between said first conveying apparatus in boom elements connected about said folding axis.

The present invention provides a dynamic lift-off control device and a crane with which it is possible to quickly perform dynamic lift-off of a suspended load while suppressing vibration of the load. This dynamic lift-off control device D comprises: a boom (14); a winch (13); a load weight measurement means (22); and a controller (40) serving as a control unit, the controller (40) controlling operations of the boom (14) and the winch (13), deriving, when performing dynamic lift-off of the suspended load by hoisting the winch (13), an amount of change in a derricking angle of the boom (14) on the basis of the time change in the measured load weight, and raising the boom (14) so as to compensate for the amount of change.

Provided is a dynamic-lift-off determination device capable of quickly performing a dynamic-lift-off determination by a simple method, while suppressing swinging of a load. A dynamic-lift-off determination device C includes: a boom 14 that is configured so as to be freely raised and lowered; a winch 13 that lifts/lowers a suspended load via a wire rope 16; a load-weight measuring means 22 that measures a load weight acting on the boom 14; a rope-length and lifting-speed measuring means 24 that measures the rope length of the wire rope 16; and a control unit 40 that controls the boom 14 and the winch 13 and that determines, when the winch 13 winds up the rope to dynamically lift off the suspended load, the dynamic lift off on the basis of a temporal change in the measured load weight and a temporal change in the measured rope length.