This work machine comprises: a telescoping actuator that moves a first boom with respect to a second boom; an electrical drive source that is disposed in a movable portion of the telescoping actuator; a first biasing mechanism that maintains the connection state between the telescoping actuator and the first boom; a first connection mechanism that switches the connection state between the telescoping actuator and the first boom on the basis of the power of the electrical drive source; a second biasing mechanism that maintains the connection state between the first boom and the second boom; a second connection mechanism that switches the connection state between the first boom and the second boom on the basis of the power of the electrical drive source; and a clutch that discretionally intermittently transmits the power of the electrical drive source to the first connection mechanism and the second connection mechanism.

A hydraulic actuator for a mobile crane, in particular for a locking device of a telescoping device. The hydraulic actuator has a double chamber cylinder with a first cylinder chamber and a second cylinder chamber oriented in an opposite direction to the first cylinder chamber, a first piston rod for the first cylinder chamber, and a second piston rod for the second cylinder chamber. A first restoring spring restores the first piston rod to its main position and a second restoring spring restores the second piston rod to its main position. The main position of the first piston rod is its pushed-in position and the main position of the second piston rod is its extended position.

This expansion device is an expansion device that expands and contracts an boom, the expansion device including: a first hydraulic source that discharges a first working fluid; an expandable cylinder that has a fixed part and a movable part and is operated by the first working fluid; a second hydraulic source that is provided to the movable part, discharges the second working fluid, and is a separate hydraulic source from the first hydraulic source; a first connecting mechanism that is operated by the second working fluid and switches between a connected state and a disconnected state of the first boom element and the movable part; and a second connecting mechanism that is operated by the second working fluid and switches between a connected state and a disconnected state of the first boom element and the second boom element.

A telescoping boom includes a boom actuator having a fixed part and a movable part, the movable part configured to move along a length the fixed part, a rotary actuator operably connected to the movable part and configured to rotate relative to the movable part, a coupling pin connected to and configured to rotate with the rotary actuator, and a telescoping boom having a plurality of boom sections including a base section and one or more telescoping sections configured for telescoping movement along a longitudinal boom axis relative to the base section. A rotary extension and locking system is mounted on at least one telescoping section and is configured for selective coupling to the boom actuator and selective locking with a nearest outwardly adjacent boom section.

An auto-lock assembly for a telescoping mast having a plurality of telescoping tube sections configurable between a retracted position and an extended position is disclosed herein. Also disclosed herein is a telescoping mast, which includes a plurality of telescoping mast sections including a base tube, an intermediate tube, and an end tube, the intermediate and end tube adapted to be telescopically received in the base tube, a base auto-lock having a collar for mounting to the base tube, and an intermediate auto-lock having a collar for mounting to the intermediate tube. Further disclosed herein is an auto-lock for use with a telescoping mast having a plurality of tube sections.

The present invention relates to a telescopic device of single-cylinder latch type and a crane. The telescopic device of single-cylinder latch type is applied to a telescopic boom system and includes: a telescopic cylinder, for driving telescopic boom sections of the telescopic boom system to execute a telescopic action relative to a basic boom section; double boom pin structures, arranged on both sides of the tails of the telescopic boom sections to lock and unlock the telescopic boom sections; an boom pin pulling and plugging mechanism, arranged on the cylinder barrel of the telescopic cylinder to execute pulling and plugging operations on the double boom pin structures; and a cylinder pin structure and a cylinder pin cylinder, both arranged on the cylinder barrel of the telescopic cylinder and to lock and unlock the cylinder barrel of the telescopic cylinder and the telescopic boom sections. In the present invention, the double boom pin structures are arranged on both sides of the tails of the telescopic boom sections, compared with the existing upper boom pin solution, the double boom pin structures in the present invention are arranged on both sides of the telescopic boom sections, so that the stress is more uniform compared with a structure which is singly arranged on the upper side of a telescopic boom, and the influence of flexural deformation of a telescopic boom on the position of a pin hole and the stress of an boom pin is reduced.

A work machine includes: an actuator that extends and retracts a telescopic boom; an electric drive source that is provided in the actuator and drives using power supplied from a power source; an operating unit that operates based on power of the electric drive source; and a joint that has a drive-side element fixed to a first transmission shaft that rotates on the basis of the power of the electric drive source and a driven-side element fixed to a second transmission shaft connected to the operating unit, the joint being able to take a transmission state in which both the drive-side element and the driven-side element rotate and a non-transmission state in which only either the drive-side element or the driven-side element rotates.

A hoisting crane or multi configurations crane system for use on an offshore vessel, such a vessel and methods for operating are disclosed. The hoisting crane comprises a boom having a proximal portion, an intermediate portion and a distal portion. An extension mechanism is provided that is configured to allow the distal portion to be slid relative to the intermediate portion from a retracted configuration to an extended configuration. In the retracted configuration, the intermediate portion is arranged substantially within the distal portion.

The invention relates to a cylinder head body, a single cylinder bolt system and a crane, wherein, the cylinder head body comprises at least two branch bodies of cylinder head body, a cooperative positioning structure and a fixed connection structure are provided between two adjacent branch bodies of cylinder head body of the at least two branch bodies of cylinder head body, the branch body of cylinder head body has a cylindrical branch body structure, the cylindrical branch body structures of the at least two branch bodies of cylinder head body are cooperatively positioned by means of the cooperative positioning structure and are detachably connected by means of the fixed connection structure to form a barrel. The cylinder head body is composed of at least two branch bodies of cylinder head body in a dismountable way, which are cooperatively positioned and detachably connected by the cooperative positioning structure and the fixed connection structure, respectively, such that the cylinder head body may be dismounted into branch body structures during assembling, assembling manner thereof is not restricted by traditional assembling sequence, thereby improving the assembling efficiency and production efficiency. Moreover, the branch body structure of the cylinder had body is easy to dismount and maintain, which saves maintenance cost.

A telescoping crane boom having a rotary locking mechanism. A motor drives a rotating element about an axis parallel to the axis of the crane boom. The rotation of the rotating member causes a pin to selectively lock and unlock sections of the telescoping crane boom.