A vehicle crane, such as a mobile crane or a crawler crane, includes a main boom, a main boom extension, and an adapter that is located between the main boom and the main boom extension and which has a first connection plane and a second connection plane. The adapter is configured to be movable such that the first connection plane can be moved relative to the second connection plane, where the adapter is designed in the manner of a double lever in order to provide a vehicle crane that has improved load-bearing capacity and simplified set-up.

Provided is an auxiliary sheave device with a simple and lightweight structure and a crane including the same. The auxiliary sheave device, provided in the crane including a derrick member guy line, includes an auxiliary sheave frame and an auxiliary sheave guy line supporting the auxiliary sheave. The derrick member guy line is connected to the distal end portion of the derrick member. The auxiliary sheave frame is attached to the distal end portion of the derrick member so as to be capable of making rotational movement and taking a projecting posture of projecting in the distal end direction from the distal end portion of the derrick member. The auxiliary sheave guy line is connected to the distal end portion of the auxiliary sheave frame and a guy line connection portion of the derrick member so as to keep the auxiliary sheave frame in the projecting posture.

A telescoping jib with an extended envelope preferably includes a telescopic boom, a telescopic jib boom and an electronic control module. A bottom of the telescopic boom is pivotally engaged with a base movable member. A top of the telescopic boom is pivotally engaged with a bottom of the telescopic jib boom. The telescopic jib boom includes a jib rotator assembly, a jib telescoping member, a basket rotator assembly and a user basket. The jib rotator assembly and a jib hydraulic cylinder are used to change an angle of the telescopic jib member. The basket rotator assembly is secured to a top end of the telescopic jib member. The user basket is retained by basket rotator assembly. A software program in the electronic control module is modified such that, a bottom of the jib rotatory assembly is tilted counter clockwise by about 10 degrees to create an extended envelope.

A vehicle crane, such as a mobile crane, includes a main jib and a main jib extension that is mounted thereon and can be luffed by at least one luffing cable. The vehicle crane includes at least one anchoring support that is arranged on the main jib and guides the luffing cable in order to anchor the main jib to provided improved load-bearing capacity.

Provided is a jib connection structure capable of connecting a jib base end engagement part and a jib connection shaft even when a boom undergoes natural extension, and capable of restraining a jib from swinging sideways in a state where the jib is projected. This jib connection structure includes: jib connection shafts projecting horizontally toward both sides from a boom tip end part; and jib base end engagement parts respectively provided to bifurcated jib base end parts. Each jib base end engagement part is U-shaped into which the jib connection shaft can be fitted, and is provided with an insertion hole into which a pin for preventing the jib connection shaft from slipping out is inserted. When the jib base end engagement part and jib connection shaft are connected, a gap is formed between the pin and jib connection shaft. When a jib is projected, the gap becomes smaller.

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 mobile crane is configured so that a boom is raised by a derrick cylinder in response to a raise signal output from a derrick lever and the derrick cylinder is stopped in response to the derrick angle of the boom reaching the maximum angle γ corresponding to the hoisted-down length of a rope.

A jib attachment/detachment mechanism to mount a jib on a boom head includes a guide mechanism including a guide roller and a guide support configured to guide engaging portions of a jib support to positions of engagement with shaft pins of a boom head when the jib support is pulled up with a wire by using a winch and to prevent change of a state of the wire pulled up by the winch when the jib support is rotated around the shaft pins by contracting a cylinder.

A vehicle crane having a telescoping jib, comprising a basic box with linearly displaceable inner boxes and a lifting cable with a load picking-up device. A fastening region is arranged on the basic box or on a head end of one of the inner boxes, and a bracing apparatus is securable to the fastening region by a connecting end. To simplify rigging/de-rigging of the vehicle crane in relation to the bracing apparatus, the fastening region is formed for mounting the bracing apparatus on the basic box or on one of the inner boxes such that a bracing apparatus that is freely suspended on the lifting cable is coupled to the fastening region with the connecting end being brought close to the fastening region by movements of the vehicle crane, retraction and extension of the inner boxes, raising and lowering of the load picking-up device, and/or luffing of the telescoping jib.

The work machine includes: a telescoping actuator that moves a first boom in the telescoping direction with respect to a second boom; an electrical drive source that is disposed in a movable portion of the telescoping actuator; a first connection mechanism that switches a connection state between the telescoping actuator and the first boom on the basis of the power of the electrical drive source; a second connection mechanism that switches a connection state between the first boom and the second boom on the basis of the power of the electrical drive source; and a torque limiter that is disposed between the electrical drive source and the first connection mechanism or the second connection mechanism, the torque limiter maintaining, at a predetermined value or less, a load acting on a mechanical element constituting a power transmission path from the electrical drive source.