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; 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, 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.

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 ring-supported lift crane is provided with a counterweight handling system to facilitate repositioning of the crane. The ring-supported crane includes a ring, a crane upper works and a crane lower works, a boom supported on rollers on the ring and a counterweight assembly also supported on rollers on the ring. The counterweight assembly preferably includes a counterweight carrier on which at least one stack of counterweight boxes or units are placed. A counterweight holder is interposed between the at least one stack of counterweight units and the counterweight carrier with a friction reduction device, such as rollers or slider pads, interposed between the counterweight holder and the counterweight carrier. When the ring-supported crane is to be repositioned for a second lift at a construction site, the counterweight holder with the stack of counterweight units is moved off of the counterweight carrier onto a separate counterweight support member, which may be mobile or stationary.

Abstract: A method and apparatus for self-assembling and self-disassembling a large capacity crawler crane. The method uses the load hoist line of a crane to remove the equalizer from the boom. The method also uses a hydraulic cylinder to support, raise and lower the boom after the equalizer has been removed from the boom. Finally, the boom butt can be disassembled into several parts.

Abstract: A mobile truck crane having an elongated main frame that forms the carriage for the crane as well as forming a fore and aft elongated outrigger for stabilization in the crane operative position. A pair of transversely swingable outriggers are attached intermediate the length of the main frame and act to stabilize the crane in transverse directions. The main frame is formed of rectangular tubular cross section and is of such shape as to have a high strength-to-weight ratio and which is particularly rigid and capable of transmitting high, concentrated loads in an efficient manner from a revolvable upper that includes a telescoping boom. The main frame includes an intermediate tub which is fabricated to transmit loads from the upper superstructure to all four outriggers of the main frame.

Abstract: A crane of the type having a boom and which requires transversely swingable outriggers to stabilize the crane when the boom is in operation. Power operated means are provided between the main frame of the crane and the outriggers for swinging the outriggers to any one of a number of positions. Power operated locking means are also provided between the main frame of the crane and the outriggers for locking the latter in their selected position.