| Patent application number | Description | Published |
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| 20080203045 | Mobile Lift Crane With Variable Position Counterweight - 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. In another embodiment, the crane comprises a counterweight movement structure including a rack and pinion assembly having a housing and a rack, the rack having a rectangular cross section with first and second sides opposite one another and third and fourth sides opposite one another, and having teeth on the first side and second sides, and at least first and third pinion gears engaged with the teeth on the first side of the rack and second and fourth pinion gears engaged with the teeth on the second side of the rack, and wherein each pinion gear is driven by a separate hydraulic motor, and wherein the motor driving the first pinion gear is mounted on the housing adjacent an opposite side of the rack from the motor driving the third pinion gear, and wherein the motor driving the second pinion gear is mounted on the housing adjacent an opposite side of the rack from the motor driving the fourth pinion gear. In another embodiment the crane includes a counterweight support structure attached to the counterweight unit. The counterweight support structure includes at least two ground engaging members that can provide support to the counterweight in the event of a sudden release of the load. The support structure comprises a telescoping structure connected to and between the ground engaging members such that the distance between the ground engaging members can be adjusted between a first and second position. | 08-28-2008 |
| 20090200860 | Drive Tumbler and Track Drive for Mobile Vehicles, Including Lift Cranes - A combination of a drive tumbler and a track includes a track made of a plurality of connected track shoes and a plurality of driven surfaces. The track is wrapped around the drive tumbler so that a plurality of the shoes are in contact with the drive tumbler. The drive tumbler has a plurality of drive surfaces and a circumferential rim surface that includes a plurality of shoe contact surfaces that each contact the inside surface of one of the track shoes that are in contact with the tumbler. The shoe contact surface has a shape such that a line normal to the tangent of the shoe contact surface does not pass through the axis of rotation of the drive tumbler, thereby allowing the shoe contact surfaces on the rim of the drive tumbler to transmit a tractive force to the track. A preferred drive tumbler comprises a center hub and a plurality of individual tooth members connected to the center hub by welds. | 08-13-2009 |
| 20090200861 | Track Tensioning System For Mobile Vehicles, Including Lift Cranes - 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. | 08-13-2009 |
| 20100072155 | Carbody Connection System and Crane Using Same - A mobile lift crane includes a carbody made from two side members and two end cross members connected to each other with a carbody connection that can be disconnected such that the side members and end cross members can be individually transported between job sites and reassembled at a new job site. Preferably the two side members are interchangeable with each other when making the carbody, and the two end cross members are also interchangeable with each other. Further, each of the side members and end cross members preferably has a section of a roller path and section of a ring gear attached to them while being transported and assembled. | 03-25-2010 |
| 20100116766 | MOBILE LIFT CRANE WITH LIFT ENHANCING ATTACHMENT - A mobile lift crane includes a central crane unit, a boom unit and a counterweight unit. The central crane unit has a carbody, moveable ground engaging members and a rotating bed mounted to the ground engaging members with a rotatable connection such that the rotating bed can swing with respect to the ground engaging members. The boom unit has a support member, at least one moveable ground engaging member, and a boom pivotally mounted on the support member. The counterweight unit has counterweight on a support member. Rigging connects the boom and counterweight unit such that a load lifted by the boom can be counterbalanced by the counterweight. The boom unit and counterweight unit are connected to the central crane unit by structural members that carry compressive loads and maintain the boom unit, the rotating bed and the counterweight unit in lateral alignment with each other, but allow relative vertical movement between the boom unit, the rotating bed and the counterweight unit. A main mast is pivotally mounted on the combination of the central crane unit, the boom unit and the structural member between the central crane unit and the boom unit. In another embodiment, a counterweight unit with a swing axis and boom unit are connected directly together with a structural member. Ground engaging members on the boom unit can be rotated relative to a boom unit support member such that the boom unit i) can travel in an arc around the swing axis of the counterweight unit and ii) travel in direction in line with the structural member. | 05-13-2010 |
| 20100276385 | CRANE WITH BOOM RAISING ASSIST STRUCTURE - A lift crane includes a carbody; ground engaging members elevating the carbody off the ground; a rotating bed rotatably connected to the carbody; a boom pivotally mounted at a first end to the rotating bed with a load hoist line extending adjacent a second end of the boom; a boom hoist mechanism that can be used to change the angle of the boom relative to the rotating bed during crane operation; and a boom raising assist structure connected to the boom. The boom raising assist structure preferably includes at least one ground engaging member in contact with the ground; and a boom elevating member extending between the assist structure ground engaging member and the boom. The boom elevating member supports at least a part of the weight of the boom. | 11-04-2010 |
| 20110031202 | LIFT CRANE WITH MOVEABLE COUNTERWEIGHT - 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. | 02-10-2011 |
| 20110247992 | MOBILE LIFT CRANE WITH VARIABLE POSITION COUNTERWEIGHT - 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. In another embodiment, the crane comprises a counterweight movement structure including a rack and pinion assembly having housing and a rack, the rack having a rectangular cross section with first and second sides opposite one another and third and fourth sides opposite one another, and having teeth on the first side and second sides, and at least first and third pinion gears engaged with the teeth on the first side of the rack and second and fourth pinion gears engaged with the teeth on the second side of the rack, and wherein each pinion gear is driven by a separate hydraulic motor, and wherein the motor driving the first pinion gear is mounted on the housing adjacent an opposite side of the rack from the motor driving the third pinion gear, and wherein the motor driving the second pinion gear is mounted on the housing adjacent an opposite side of the rack from the motor driving the fourth pinion gear. In another embodiment the crane includes a counterweight support structure attached to the counterweight unit. The counterweight support structure includes at least two ground engaging members that can provide support to the counterweight in the event of a sudden release of the load. The support structure comprises a telescoping structure connected to and between the ground engaging members such that the distance between the ground engaging members can be adjusted between a first and second position. | 10-13-2011 |
