A crane having an undercarriage, a superstructure pivotable about a slewing axis relative to the undercarriage, a counterweight unit and a counterweight adjustment device. The counterweight adjustment device includes a telescopic frame which is fastened to the superstructure and has a telescopic longitudinal member, a counterweight unit arranged to be displaceable along the frame, a drive unit for displacing the counterweight unit and a kinematic unit to telescope the frame in a driven manner. A jetty is fastened to a rear end, remote from the slewing axis, of the longitudinal member, the counterweight unit is displaceable along the frame in the region of the superstructure as far as the jetty, the counterweight unit is able to be fastened to the jetty and the counterweight unit is able to be telescoped in and out on the jetty with the frame.

A lift crane includes a carbody; a rotating bed comprising a counterweight support frame; a boom; a counterweight unit supported on the counterweight support frame in a moveable relationship with respect to the counterweight support frame; and a counterweight unit movement device connected between the rotating bed and the counterweight unit to move the counterweight unit toward and away from the boom. The crane is configured such that during crane operation, the moment generated by the counterweight unit acts on the rotating bed predominantly through the counterweight support frame. Alternatively, the crane can include a mast. In some embodiments the same basic crane is configured to be set-up with two different counterweight options, i) a counterweight unit directly supported on the counterweight support frame and ii) a counterweight support beam moveably connected to the remainder of the rotating bed and a counterweight unit supported on the counterweight support beam.

A lift crane includes a carbody; a rotating bed comprising a counterweight support frame; a boom; a counterweight unit supported on the counterweight support frame in a moveable relationship with respect to the counterweight support frame; and a counterweight unit movement device connected between the rotating bed and the counterweight unit to move the counterweight unit toward and away from the boom. The crane is configured such that during crane operation, the moment generated by the counterweight unit acts on the rotating bed predominantly through the counterweight support frame. Alternatively, the crane can include a mast. In some embodiments the same basic crane is configured to be set-up with two different counterweight options, i) a counterweight unit directly supported on the counterweight support frame and ii) a counterweight support beam moveably connected to the remainder of the rotating bed and a counterweight unit supported on the counterweight support beam.

A mobile lift crane includes a carbody, movable ground engaging members, a rotating bed, and a boom. A first structure is pivotally coupled to the rotating bed. A second structure is pivotally coupled to the first structure at a first end of the second structure. A moveable counterweight unit is coupled to a second end of the second structure. A linear actuation device moves the moveable counterweight unit toward and away from the rotating bed during a pick, move, and set operation by retracting and extending the linear actuation device, respectively. The moveable counterweight unit is never supported by the ground other than indirectly by the moveable ground engaging members. The linear actuation device moves the movable counterweight unit a greater horizontal distance from the rotating bed than a distance of a stroke of the linear actuation device that causes the moveable counterweight unit to move.

A mobile lift crane includes a carbody, movable ground engaging members, a rotating bed, and a boom. A first structure is pivotally coupled to the rotating bed. A second structure is pivotally coupled to the first structure at a first end of the second structure. A moveable counterweight unit is coupled to a second end of the second structure. A linear actuation device moves the moveable counterweight unit toward and away from the rotating bed during a pick, move, and set operation by retracting and extending the linear actuation device, respectively. The moveable counterweight unit is never supported by the ground other than indirectly by the moveable ground engaging members. The linear actuation device moves the movable counterweight unit a greater horizontal distance from the rotating bed than a distance of a stroke of the linear actuation device that causes the moveable counterweight unit to move.

A crane includes: a machine body; a tiltable body having a tiltable body proximal end supported on the machine body and being turnable in a tilting direction; a counterweight; a base weight having a placement surface that allows placement of the counterweight and being detachably attached to the machine body in either at least a front position or a rear position located behind the front position with the base weight projecting rearward further from the machine body than in the front position; and an auxiliary coupling member for coupling a portion of the base weight located in the rear position and the machine body to each other, the portion projecting rearward from the machine body.

A crane includes: a machine body; a tiltable body having a tiltable body proximal end supported on the machine body and being turnable in a tilting direction; a counterweight; a base weight having a placement surface that allows placement of the counterweight and being detachably attached to the machine body in either at least a front position or a rear position located behind the front position with the base weight projecting rearward further from the machine body than in the front position; and an auxiliary coupling member for coupling a portion of the base weight located in the rear position and the machine body to each other, the portion projecting rearward from the machine body.

The invention relates to a tower crane having a slewing platform, an adjustable boom articulated in a derricking manner on the slewing platform and counter-ballast mounted on the slewing platform, characterized in that an adjusting mechanism is provided that permits a positional change to the counter-ballast independent of the luffing angle of the adjustable boom.

The invention relates to a tower crane having a slewing platform, an adjustable boom articulated in a derricking manner on the slewing platform and counter-ballast mounted on the slewing platform, characterized in that an adjusting mechanism is provided that permits a positional change to the counter-ballast independent of the luffing angle of the adjustable boom.

A counterweight mounting device, which is installed on a frame supporting a counterweight, includes a first link of which a lower end is coupled to the frame so that the first link is rotatable about a first hinge shaft, a second link including a slot guide into which a second hinge shaft coupled to an upper end of the first link is inserted and in which the second hinge shaft slides, a hydraulic cylinder of which a lower end is coupled to the frame so that the hydraulic cylinder is rotatable about a cylinder rotation shaft and an upper end is coupled to the second hinge shaft and rotates the first link, and a connection member installed on an upper end of the second link and connected to the counterweight.