Abstract: A mobile lift crane includes a carbody, moveable ground engaging members, a rotating bed, a boom, a mast, and a backhitch. A linear actuation device is pivotally connected to the rotating bed and a moveable counterweight unit is coupled to the linear actuation device. A tension member is coupled to the mast and to one of the linear actuation device and the moveable counterweight unit. The linear actuation device is operable to move the moveable counterweight unit toward and away from the rotating bed during a pick, move, and set operation by extending the linear actuation device. The mobile lift crane is configured such that the moveable counterweight unit is never supported by the ground other than indirectly by the moveable ground engaging members on the carbody throughout all pick, move, and set operations.

Abstract: 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.

Abstract: 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.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A pin puller is mounted between first and second connectors, preferably connectors on a lift crane, each of the connectors having a hole there though. The pin puller includes: a) first and second support frame members; b) a first pin with a first end located in the hole of the first connector and a second end inside the first support frame member; c) a second pin with a first end located in the hole of the second connector and a second end inside the second support frame member; d) at least one linear actuator connected to the first and second pins; and e) a length adjustment device between the first and second support frame members, with its length adjusted so as to force the first support frame member into contact with the first connector and the second support frame member into contact with the second connector.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; and a moveable counterweight unit. The crane is configured such that the counterweight unit is never supported by the ground other than indirectly by moveable ground engaging members on the carbody throughout a pick, move and set operation. In a first aspect, the crane is operable to move the counterweight unit to at least a first position in front of a fixed rearmost portion of the rotating bed and a second position behind the fixed rearmost portion of the rotating bed. In a second aspect, the crane also includes a first linear actuation device operable to move the counterweight unit toward and away from the front portion of the rotating bed by extending and retracting the linear actuation device. The counterweight unit may be moved a greater distance than a stroke of the first linear actuation device.

Abstract: A pin puller is mounted between first and second connectors, preferably connectors on a lift crane, each of the connectors having a hole there though. The pin puller includes: a) first and second support frame members; b) a first pin with a first end located in the hole of the first connector and a second end inside the first support frame member; c) a second pin with a first end located in the hole of the second connector and a second end inside the second support frame member; d) at least one linear actuator connected to the first and second pins; and e) a length adjustment device between the first and second support frame members, with its length adjusted so as to force the first support frame member into contact with the first connector and the second support frame member into contact with the second connector.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight unit is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; and a moveable counterweight unit. The crane is configured such that the counterweight unit is never supported by the ground other than indirectly by moveable ground engaging members on the carbody throughout a pick, move and set operation. In a first aspect, the crane is operable to move the counterweight unit to at least a first position in front of a fixed rearmost portion of the rotating bed and a second position behind the fixed rearmost portion of the rotating bed. In a second aspect, the crane also includes a first linear actuation device operable to move the counterweight unit toward and away from the front portion of the rotating bed by extending and retracting the linear actuation device. The counterweight unit may be moved a greater distance than a stroke of the first linear actuation device.

Abstract: A crawler has a track tensioning system. The crawler includes a crawler frame having a bottom; at least one drive tumbler supported on the frame; a track made of a plurality of connected track shoes and is wrapped around the drive tumbler so that a plurality of the shoes are in contact with the drive tumbler. The track tensioning system, mounted to the frame, includes a roller engaging the inside surface of the track; and a roller positioning structure attached to the frame that can raise the roller relative to the bottom of the frame to thereby increase the tension of the track.

Abstract: A crawler has a track connection system. The crawler includes a crawler frame; at least one drive tumbler supported on the frame; a track made of a plurality of track shoes connected in series to produce a track having a first end and second end that can be connected together to form the track into an endless track. The track is wrapped around the frame, with the first and second ends spaced apart but each adjacent a section of the frame. The track connection system is mounted to the frame and includes a mover device connected to the frame; and a track engagement member coupled between the mover device and the track; iii) whereby actuation of the mover device causes the track engagement member to move the track into a position where the first and second ends can be connected.

Abstract: A mobile lift crane includes a carbody; a rotating bed; a boom; a moveable counterweight unit; at least one linear actuation device; and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit compared to the rotating bed. In one method of operation, the counterweight is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody. The linear actuation device can include at least one rack and pinion assembly or hydraulic cylinder.

Abstract: A mobile lift crane includes a carbody and at least four crawlers attached to the carbody, each crawler having a crawler frame attached to the carbody by a trunnion having an axis. The crawler frame is attached to the carbody so as to be able to pivot with respect to the carbody about the axis of the trunnion. The crane also includes a rotating bed rotatably connected to the carbody such that the rotating bed can swing with respect to the crawlers and a boom pivotally mounted on a front portion of the rotating bed. A linear actuator is connected between the crawler frame and the carbody and extends through the trunnion. The linear actuator is part of a self attachment mechanism. The trunnion includes a tubular member with a longitudinal axis, a first end configured for connection to the crane carbody and a second end configured for connection to the crawler frame. At least one of the ends is configured to allow rotational movement of the crawler frame relative to the carbody about the longitudinal axis.

Abstract: A mobile lift crane includes a carbody, a rotating bed, a boom, a moveable counterweight unit, at least one linear actuation device and at least one arm pivotally connected at a first end to the rotating bed and at a second end to the linear actuation device. The arm and linear actuation device are connected between the rotating bed and the counterweight unit such that extension and retraction of the linear actuation device changes the position of the counterweight unit. In one method of operation, the counterweight is never supported by the ground during crane pick, move and set operations other than indirectly by the ground engaging members on the carbody. One embodiment includes a counterweight movement structure having a rectangular rack with at least first and third pinion gears engaged with teeth on one side and second and fourth pinion gears engaged with teeth on the opposing side.