An auger attachment system for an extendable boom having a first stage, and a second stage, the auger attachment system having a fixed mounting configured to couple to an auger, the fixed mounting being coupled to the second stage of the extendable boom, an extendable mounting, configured to couple to the auger, the extendable mounting being coupled to the first stage of the extendable boom, and a linear actuator configured to extend and retract the extendable mounting to transfer the auger from the extendable mounting to the fixed mounting.

Telescopic arm for a crane for lifting loads, which comprises a first tubular segment, a second tubular segment located in the first segment and extractable with respect to the first segment along an extraction axis (X). The telescopic arm comprises a clamping device configured to axially and selectively clamp, along the extraction axis (X), the first segment and the second segment. The clamping device comprises a clamping seating provided in the first segment and a clamping pin associated with the second segment, sliding along a sliding axis (Z) transverse to the extraction axis (X) and able to be selectively inserted in the clamping seating.

A system and method for retaining a linear actuator on a crane component such as a mast is disclosed. In the system a retaining mechanism is mounted on either a body of the linear actuator or the crane component and a catch is mounted to the other of the body or the crane component. Retraction of a rod of the linear actuator causes a cap on the rod to contact the retaining mechanism, which causes the retaining mechanism to move into a latched configuration securing the linear actuator.

This work machine includes: a first hydraulic cylinder and a second hydraulic cylinder that telescope a telescopic boom on the basis of hydraulic oil supply and discharge, a switching valve that is disposed on a pressure relief circuit for connecting the first hydraulic cylinder and the second hydraulic cylinder to a tank, and a control unit that causes the switching valve to connect the first hydraulic cylinder to the tank and releases the pressure in the first hydraulic cylinder when contracting or extending the second hydraulic cylinder in a condition in which the first hydraulic cylinder is contracted.

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 disclosure provides a lifting device comprising: a telescopic boom, comprising a basic section, at least one primary telescopic section and at least one secondary telescopic section; a telescopic control mechanism, comprising a primary telescopic drive mechanism that controls synchronous telescoping of the at least one primary telescopic section and a secondary telescopic drive mechanism that controls synchronous telescoping of the at least one secondary telescopic section; a torque limiter, comprising a first length sensor and a second length sensor, wherein a first sensor body and a telescopic end of a first length measuring cable of the first length sensor are respectively connected to tails of adjacent two section in the basic section and the at least one primary telescopic section; and a second sensor body and a telescopic end of a second length measuring cable of the second length sensor are respectively connected to tails of adjacent two section in the primary telescopic section adjacent to the at least one secondary telescopic section and the at least one secondary telescopic section. The lifting device of the present disclosure can reduce the length of the length measuring cable of a length sensor and thus reduce its volume and weight.

An expansion/contraction mechanism includes a telescopic cylinder, boom fixing means, cylinder-boom connecting means, and a hydraulic-pressure supply unit, and telescopes a plurality of booms except a base boom by telescoping the telescopic cylinder. The hydraulic-pressure supply unit includes a pneumatic-pressure source, a selector valve which selects a destination of air provided from the pneumatic-pressure source, a first pneumatic path through which first air sent from the selector valve circulates, a second pneumatic path through which second air sent from the selector valve circulates, a first pneumatic-to-hydraulic conversion unit which converts a pneumatic pressure provided by the first air to a hydraulic pressure and supplies the hydraulic pressure to a first hydraulic cylinder, and a second pneumatic-to-hydraulic conversion unit which converts a pneumatic pressure provided by the second air to a hydraulic pressure and supplies the hydraulic pressure to a second hydraulic cylinder.

A method for operating a telescopic device and the elongated telescopic device per se comprises a support element formed to encompass first and second telescopic element mounted so as to be telescopically slidable relative each other in a longitudinal direction; the support element comprises a support element fluid actuator assembly; the first telescopic element is arranged to encompass the second telescopic element and comprises a first fluid actuator assembly. The support element fluid actuator assembly is fixed to an interior portion of the support element and is arranged for engagement or disengagement to a first envelope surface of the first telescopic element and wherein the first fluid actuator assembly is fixed to a first interior portion of the first telescopic element and is arranged for engagement or disengagement to a second envelope surface of the second telescopic element.

A self-propelled vehicle used to lay pipe sections within trenches located on sloped terrain, and a method for using it, including: an undercarriage carrying a vehicle chassis and capable of climbing sloped terrain; a rotating platform which can be maintained level relative to the sloped terrain; and a boom with an angled boom head, capable of using two independent winch cables to lift and position individual pipe sections having differing lengths and diameters. The vehicle may be used to sequentially lift two or more pipe sections, one at a time, and to swing and position the pipe sections in a trench, end-to-end.

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.