An electric winch device causes an operative part to perform an operation for hoisting work by winding up or letting out a rope connected to the operative part, the electric winch device including: a winch drum having an axis, provided on the mobile crane to be rotatable about the axis and wound with the rope therearound; a plurality of motors located on one side of the winch drum in an axial direction in which the axis of the winch drum extends, and arranged side by side in a direction perpendicular to the axial direction; a gear mechanism which combines torques output from the plurality of motors; and a transmitting part which transmits a resultant of torques combined by the gear mechanism to the winch drum to rotate the winch drum to thereby cause the winch drum to wind up or let out the rope.

The invention relates to a mobile crane, that comprises a mobile undercarriage and a superstructure rotatably supported on the undercarriage and having a boom and a ballasting device. The ballasting device picks up or places down one or more counterweight elements by means of a hoisting device. In accordance with the invention, a placement device is provided that is connected to the undercarriage and comprises at least one movable placement part that is movable from a travel position into a placement position and vice versa. In this respect, the travel position is characterized in that the length of the undercarriage is reduced, and the crane is travelable on the construction site, whereas the placement position is characterized in that counterweight elements can be placed on the placement part by means of the ballasting device and the length of the undercarriage is increased in comparison with the travel position.

A vehicle crane comprising a jib that is raised and lowered by at least one main tensile connector, and a counter jib, where the main tensile connector extends between a first connecting point in the region of a jib head and a second connecting point in the region of a counter jib head. To reduce loading on the jib, in particular during raising and lowering and increase its bearing load overall, the jib has a third connecting point between the first connecting point and its foot opposite the head, and a secondary tensile connector extends between the third connecting point and a fourth connecting point in the region of the head of the counter jib, or the secondary tensile connector extends between the third connecting point via a seventh connecting point on the main tensile connector and a fourth connecting point in the region of the main jib foot.

A crane (2), more particularly a mobile fast-erecting crane, having at least one supply connection to which a supply line (16), more particularly a power cable, can be connected, wherein the supply line can be wound on a cable drum (15), which can be mounted on a drum mount (10) on the crane, with the cable drum being mounted to rotate on a drum support frame (18), which has running gear (18) for moving the cable drum over the ground and which has releasable mounting means, shaped to match the drum mount of the crane, for separably mounting the drum support frame on the drum mount of the crane. The invention further relates to a cable drum unit for winding a supply line (16) of a crane (2).

A work vehicle includes: an operation tool that is operated by an operator; and a controller that determines a target flow rate for hydraulic oil fed to a hydraulic device on a basis of the amount of operation of the operation tool. The controller calculates a bleed-off target flow rate on a basis of the flow rate of hydraulic oil fed from a hydraulic oil pump and the target flow rate for hydraulic oil fed to the hydraulic device, calculates a bleed-off throttle differential pressure on a basis of a pressure of hydraulic oil fed from the hydraulic oil pump and a pressure of hydraulic oil in a hydraulic oil tank, calculates a bleed-off target opening area on a basis of the bleed-off target flow rate and the bleed-off throttle differential pressure, and controls a hydraulic oil control valve such that the bleed-off target opening area is achieved.

A height adjustment assistance device includes an initial state determination part for determining whether a suspended cargo has been lifted from a ground at a start of lifting work, a height detection part for detecting a height of a counterweight from the ground, a storage part for storing an initial height, a calculation part for calculating a target value for correcting the height of the counterweight from the ground based on the initial height and a post-work height, a notification part for notifying an operator of information regarding the target value, and a length adjustment device for adjusting a length of a hanging member by operating in a manner to change the length of the hanging member extending from a tip of a mast to the counterweight.

A mobile crane has an undercarriage, a superstructure arranged on the undercarriage, a slewing gear by which the superstructure may be rotated relative to the undercarriage, a slewing gear brake that acts on the slewing gear to brake a rotation of the superstructure, and a jib mounted on the superstructure as to be adjustable in luffing angle and/or in length. The mobile crane additionally contains a dolly coupling arranged on the jib and by which the jib is coupled to a mobile crane dolly during dolly travel with the superstructure in an extended position. The mobile crane further has a sensor interface for connecting a dolly coupling sensor, and a controller that is adapted to ascertain during dolly travel, in dependence on a signal received from the dolly coupling sensor, whether the jib rests on the mobile crane doll, and to activate the slewing gear brake if it does not.

A lift crane includes a carbody and movable ground engaging members mounted on the carbody. A rotating bed is rotatably connected to the carbody and includes a counterweight support frame including a rack coupled directly to a lower surface of the rotating bed. A boom is pivotally mounted to the rotating bed. A counterweight unit includes a trolley, the counterweight unit being in a movable relationship with respect to the rotating bed. A counterweight unit movement device is configured to move the counterweight unit toward and away from the boom. Other embodiments include a counterweight support beam movably connected to the rotating bed, the counterweight support beam including another rack coupled to a lower surface of the counterweight support beam. A counterweight support beam movement device is connected between the counterweight support beam and the counterweight support frame.

To provide a crane capable of stably traveling a transporter capable of supporting a counterweight in cooperation with slewing of an upper slewing body. The crane has a connecting body connecting the self-propelled transporter and the upper traveling body, a transporter angle detecting unit, and a steering angle setting unit. A transporter connecting portion of the connecting body is rotatably connected to the self-propelled transporter about a rotation center axis, and moves relative to a slewing body connecting portion whereby the relative distance between the self-propelled transporter and the upper slewing body is variable. The steering angle setting unit sets the steering angle of the wheels of the self-propelled transporter according to the transporter angle detected by the transporter angle detecting unit so that the transporter angle approaches 90 degrees.

The present invention addresses the problem of providing a crane that can ascertain the state of an area surrounding a hook or a cargo suspended on the hook and that can simultaneously ascertain a braking distance during stopping operations. The invention comprises: drive devices 31-34 that move a boom 7; a control apparatus 20 that controls the operation state of the drive devices 31-34; a camera 41 that photographs, from the distal end portion of the boom 7, an area below said portion; and image display devices 43 and 65 that display the image photographed by the camera 41. For the purpose of stopping the movement of the boom 7, the control apparatus 20 filters basic control signals S for the drive devices 31-34 to create filtered control signals Sf, controls the drive devices 31-34 on the basis of the filtered control signals Sf, estimates the braking distance for the boom 7, and displays the same on the image display devices 43 and 65.