A load crane (1) main boom (3) comprises: a fixed tubular first boom section (4.sup.I), a tubular second boom section (4.sup.II) telescopically arranged and movable relative to the first fixed boom section (4.sup.I) between a retracted position and an extended position, and at least a tubular third boom section (4.sup.III) telescopically arranged and movable relative to the movable second boom section (4.sup.II) between a retracted position and an extended position; a hydraulic system (6) comprising: a first cylinder-piston group (7.sup.I) axially extending within the main boom (3), integrally connected with the fixed first boom section (4.sup.I) and connected to the movable second boom section (4.sup.II) so to move the latter relative to the fixed first boom section (4.sup.I) under the action of a pressurized working fluid; a second cylinder-piston group (7.sup.II) axially extending within the main boom (3), integrally connected with the movable second boom section (4.sup.II) and connected to the movable third boom section (4.sup.III) so to move the latter relative to the movable second boom section (4.sup.II) under the action of said pressurized working fluid; a first opening (13) and a second opening (20) at the first cylinder-piston group (7.sup.I) for injecting/discharging said pressurized working fluid into/from the hydraulic system (6); a first tube (14) and a sixth tube (19) hydraulically connecting the first (7.sup.I) and the second (7.sup.II) cylinder-piston groups, at least partially extending near the second cylinder-piston group (7.sup.II) along the axial direction thereof and connected to the latter in such a manner so that they form respective bends (27, 28),

The main boom (3) further comprises: a transversal second main rod (29.sup.II) connected to the second boom section (4.sup.II) supporting the second cylinder-piston group (7.sup.II), a second reinforcing plate (30.sup.II) connected to the second boom section (4.sup.II), comprising: a first (31) and second (32) opposite lateral portions internally fixed to the second boom section (4.sup.II) and comprising through holes where the second main rod (29.sup.II) is arranged, so to form first and second reinforcing elements for the latter; a central portion (33) connecting said first and second lateral portions (31, 32) and comprising a raised section (36), a lowered section (37) and a section

The present invention relates to the field of engineering mechanics and more particularly, relates to an engineering work vehicle, and most particularly, relates to a vehicle with a low gravity center and aerial work platform. The vehicle includes a vehicle frame, a power system, a fuel tank, and a hydraulic tank all of which are mounted at a side of the frame. Correspondingly, the embodiment of the invention also provides an aerial work platform which provides better off-road performance and grade-ability, can work in complicated environment, and owns a longer horizontal reach and larger working range. Moreover, maintenance and repair cost is decreased, lifetime is extended, integrity is higher and appearance looks better.

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.

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.

A boom assembly for a lift device includes a plurality of telescoping boom sections. The plurality of telescoping boom sections include a base boom section, a mid boom section, and a fly boom section. The plurality of telescoping boom sections define an inner volume. The boom assembly also includes a push tube and a support member positioned within the inner volume. The boom assembly also includes a power track positioned within the inner volume that includes a plurality of movable links and a supported portion that interfaces with the support member. The push tube includes a second end portion opposite the first end portion of the push tube. The second end portion of the push tube is directly coupled to the base boom section.

A crane 1, the hook (main hook 24) of which is stored on the lower end of a boom 7, and the winch (main winch 9) of which can be moved by a hydraulic motor 37, said crane being provided with a pressure sensor 55 capable of detecting the pressure of hydraulic fluid being delivered to the hydraulic motor 37, and a controller 61 capable of recognizing changes in the pressure of the hydraulic fluid on the basis of a signal from the pressure sensor 55, and also being provided with an anomaly warning means Mi capable of providing warning of anomalies pertaining to the storage of at least the hook (24), the controller 61 activating the anomaly warning means Mi when it is determined that the pressure of the hydraulic fluid when the hook has been stored is below a minimum value.

A boom-extending wire locking structure has a wire locking tool, provided at a base end side of a first boom member and/or a base end side of a third boom member, that locks an extending wire by winding a lock part of each wire member. The wire locking tool includes: a pair of fixing pieces provided on both sides in an orthogonal direction orthogonal to a boom-extending direction and fixed to the first boom member and/or the third boom member; and wire locking parts, provided between the pair of fixing pieces, including arch-shaped grooves for winding the respective lock parts of the wire members. The wire locking parts are arranged in a central axis direction of the arc shape between the pair of fixing pieces. Central axes of the wire locking parts are arranged at different positions in the orthogonal direction from respective adjacent wire locking parts.

An apparatus assists in retaining a rope in connection with a sheave on a boom. The apparatus includes a retainer supported by the boom for swinging outwardly relative to the sheave from a first position adjacent to the sheave for assisting in retaining the rope therein and a second position for facilitating removing the rope from the sheave. A holder may be provided for holding the retainer in the second position, so that the operator's hands are freed for other tasks. A receiver may also be provided for temporarily receiving a locking pin once removed from the retainer, thus helping to guard against loss.

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.

Example embodiments relate to a lightweight crane. In one nonlimiting embodiment the crane is comprised of a telescoping boom having a first boom nested in a second boom which in turn is nested in a third boom. The first, second, and third booms may be made from aluminum to reduce the weight of the crane. The first boom may have a first open section and a second closed section wherein the open section is configured to accommodate a structural member to which an actuator is attached. The first and second booms have lower surfaces with inclined surfaces so that the first boom self-aligns with the second boom and the second boom self-aligns with the third boom.