Abstract: A mobile lift crane includes a carbody having movable ground engaging members; a rotating bed rotatably connected to the carbody; a boom pivotally mounted on the rotating bed; a first hoist drum mounted in a first frame connected to the rotating bed; a second hoist drum mounted in a second frame connected to the rotating bed. Connectors used to connect the load hoist drum frames to the rotating bed include engagement members and alignment surfaces such that as the two crane components are brought close to their operational position during an assembly operation, the engagement member and the alignment surface of the connectors come into contact with one another to guide the crane components into their operational orientation so that a main pin can be placed through the through-holes of the extensions of the connectors.

Abstract: A connector for a column segment, such as a boom segment, of a crane includes n extensions, where n is a positive integer. Each extension has a first base and an aperture extends through the extension from a first side to a second side. The first connector also includes at least (n+y) plates, where y is selected from the group consisting of (?1, +1) such that the sum of (n+y) is a positive integer. The plate or plates are positioned in and coupled to the extensions in an alternating arrangement. Each plate includes a plate base aligned substantially in a plane with the first base of the extension to form a first connector mounting surface. A plurality of welds couple the plates to the extensions and the fabricated connector is then welded to the column segment. At least one extension is formed of steel having a grain structure elongated in a direction of rolling that is substantially perpendicular to the first base.

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 counterweight block apparatus includes a pair of interconnecting counterweight blocks having top and bottom surfaces, the counterweight blocks forming a plane of interconnection along adjacent sides thereof; and a shear bar releasably secured between the adjacent sides of the interconnecting counterweight blocks, generally perpendicular to the plane of interconnection, to provide resistance to relative vertical movement of the interconnecting counterweight blocks along the plane of interconnection. In another aspect, each counterweight block includes in at least one side thereof an indentation from a top of the counterweight block to a depth more shallow than the thickness of the counterweight block, the indentation defining a lip for hand grabbing. An aperture may be formed through the rest of the thickness of the counterweigh block at each indentation, wherein a securing strap can be run through each aperture of a stacked plurality of counterweight blocks to secure them to each other.

Abstract: A compressible stop member for use on a crane includes: a housing having a first sealed end, a second end, a first cylindrical surface and a second cylindrical surface; a free piston slidably contained within the housing in a sealing engagement with the first cylindrical surface; a compressed gas chamber in the housing between the free piston and the first sealed end; and a rod comprising a cylindrical portion with a diameter less than the diameter of the second cylindrical surface and a rod support portion that separates a first liquid chamber comprising the volume inside the housing between the free piston and the rod support portion from a second liquid chamber comprising the volume between the rod support portion and the second end of the housing. Also, the rod support portion includes at least one flow channel allowing liquid to flow between the first and second liquid chambers.

Abstract: An apparatus is provided that quickly elevates and maintain a construction equipment engine coolant to operating temperature in order to lower the dwell time for the operator's cab to reach a comfortable temperature level during a period when the engine is in idle and main crane functions are not operated. The apparatus includes an auxiliary hydraulic circuit for rapidly bringing engine coolant temperature up to operating temperature. Engine coolant operating temperature is achieved by inducing a hydraulic load to the engine. By inducing a hydraulic load, a horsepower load is exerted on the engine causing the engine to generate heat sufficient to raise the engine coolant to operating temperature for heating the cabin. A pressure reducing relieving valve and a pilot operated relief valve result in precise hydraulic horsepower load to the construction equipment engine. Operation of the pilot operated relief valve also warms hydraulic fluid for a hydraulic reservoir.

Abstract: A power generator is associated with a crane boom at or near the tip of the boom. The generator responds to movement of the lifting cable to initiate the transmission of a signal to a crane controller. The signal serves as a start-up or a wake-up signal to the crane controller which may then immediately analyze operation of, for example, an anti-two block device associated with the boom tip. The crane controller may then control the operation of the crane in accordance with signals received from the anti-two block device or immediately identify malfunctions of the anti-two block device and control the crane operations accordingly.

Abstract: An extendable beam measurement system includes a support; a beam mounted on the support and movable with respect to the support along an axis of movement; a series of sensory points mounted along either the beam or the support in an orientation that is not parallel to the axis of movement of the beam; and a sensor attached to the other of the beam or the support in a direction that crosses the series of sensory points at different positions during movement of the beam along said axis. The sensor generates a first signal varying as the beam is moved along the axis to thereby provide a signal indicating the position of the beam with respect to the support. The system is useful on an outrigger for supporting a crane. Optionally the system can provide a second signal indicative of whether a jack on the outrigger is contacting a support surface and supporting the crane.

Abstract: A method of assembling a mobile lift crane that includes, during operation, i) a rotating bed having attached thereto a luffing jib hoist drum and line, and a rigging winch drum and line, ii) a boom pivotally mounted on the rotating bed, iii) a luffing jib pivotally mounted to the end of the boom, iv) a first strut also pivotally connected to the end of the boom, and v) a second strut connected to the boom below the connection point of the first strut, the method including: a) pivotally connecting the first strut to the end of the boom; b) pivotally connecting a first section of the second strut near the top of the boom; c) connecting the rigging winch line to the top of the first section; d) pivotally attaching a second section of the second strut to the first section such that the second section lies folded onto the first section, forming a folded second strut; and e) lifting the second section while retracting the rigging winch line to thereby bring the first and second sections into alignment with each ot

Abstract: A system for storing a conduit on a crane includes a crane that has a structure to which a mooring point is attached. A first strap is configured to wrap at least partly around the conduit. The strap includes a first end and a second end spaced apart from the first end by a length of the strap. The strap includes at least one loop affixed to it, as well as a first hook affixed to either the first end or the second end of the strap. The strap may also include a second hook affixed at the end of the strap opposite from the first hook. A support strap is configured to couple the strap to the crane at a location different from the mooring point.

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 connector for a column segment, such as a boom segment, of a crane includes n extensions, where n is a positive integer. Each extension has a first base and an aperture extends through the extension from a first side to a second side. The first connector also includes at least (n+y) plates, where y is selected from the group consisting of (?1, +1) such that the sum of (n+y) is a positive integer. The plate or plates are positioned in and coupled to the extensions in an alternating arrangement. Each plate includes a plate base aligned substantially in a plane with the first base of the extension to form a first connector mounting surface. A plurality of welds couple the plates to the extensions and the fabricated connector is then welded to the column segment. At least one extension is formed of steel having a grain structure elongated in a direction of rolling that is substantially perpendicular to the first base.

Abstract: A crane includes first and second column segments. At least a first, third and fifth connector are located on the first segment, respectively mating with at least a second, fourth and sixth connector on the second segment. Each of the connectors includes at least a first extension having a through-hole positioned in the extension such that the through-holes of mating connectors are aligned when the column segments are aligned. A first pin fits tightly through the through-hole of the first extension on the first connector and the through-hole of the first extension on the second connector to hold the first and second connectors together. A second pin fits loosely through the through-hole of the first extension on the third connector and the through-hole of the first extension on the fourth connector to hold the second and fourth connectors together. The connectors also include a compressive load bearing surface.

Abstract: An apparatus for compensating for fluid contraction in a hydraulic powered telescoping boom may include a monitor determining the elevation angle of the telescoping boom, a supply of hydraulic fluid, and a fluid control responsive to the monitor. The fluid control provides the hydraulic fluid from the supply to a hydraulic cylinder controlling extension of the telescoping boom when the elevation angle exceeds a predetermined threshold angle to compensate for thermal contraction of hydraulic fluid and thus prevent uncommanded boom retraction. A method in accordance with the invention is also disclosed.

Abstract: 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.

Abstract: A drum tensioning method is provided for operating a crane having a continuously reeved load hoist line, with a first end of the load hoist line connected to a first drum and a second end of the load hoist line connected to a second drum, with the load hoist line reeved through boom sheaves and a hook block. The method includes the steps of applying a hold-back force to the second drum; applying a winding force to the first drum greater than the hold back force on the second drum; and applying the winding and hold back forces while limiting movement of the hook block, thereby spooling the load hoist line from the second drum through the boom sheaves and hook block to the first drum while maintaining tension in the load hoist line such that the load hoist line is wound under more tension on the first drum than it had previously been wound on the second drum.

Abstract: An apparatus for compensating for fluid contraction in a hydraulic powered telescoping boom may include a monitor determining the elevation angle of the telescoping boom, a supply of hydraulic fluid, and a fluid control responsive to the monitor. The fluid control provides the hydraulic fluid from the supply to a hydraulic cylinder controlling extension of the telescoping boom when the elevation angle exceeds a predetermined threshold angle to compensate for thermal contraction of hydraulic fluid and thus prevent uncommanded boom retraction. A method in accordance with the invention is also disclosed.

Abstract: A mobile lift crane includes a boom pivotally mounted on a rotating bed and a boom hoist drum mounted in a frame connected to the rotating bed. A boom hoist line is wound on the boom hoist drum and connected to an upper equalizer and a lower equalizer, with the upper equalizer connected to the top of the boom, such that rotation of the boom hoist drum changes the amount of boom hoist line between the lower equalizer and the upper equalizer, thereby changing the angle between the rotating bed and the boom. The boom hoist drum frame, the lower equalizer and the upper equalizer each include cooperating attachment structures whereby the equalizers can be detachably connected to the frame so that the boom hoist drum, the lower equalizer, the upper equalizer and the boom hoist line can be transported between job sites as a combined assembly.

Abstract: A method of assembling a hook block for a crane includes: providing a sheave housing containing a plurality of sheaves with a pivotal connection link secured to the top of the sheave housing, the sheave housing including extended portions each with a hole therethrough and a housing frame positioned below the plurality of sheaves, the housing frame having a locking surface; placing a cross beam on its side, the cross beam having stabilizing feet resting on the ground; positioning the extended portions of the sheave housing within a plurality of brackets of the cross beam, each bracket with a hole therethrough; aligning the holes of the extended portions of the sheave housing with the holes of the brackets; inserting a shaft through the aligned holes; securing a cap to an end of the shaft to resist lateral movement relative to the holes; and inserting a locking bar between the locking surface of the housing frame and a surface of a bracket of the cross beam, to resist relative movement between the sheave housin

Abstract: A crane includes i) a lower structure comprising ground engaging members ii) an upper structure rotatably connected to the lower structure such that the upper structure can swing with respect to the lower structure, wherein one of the lower structure and upper structure comprises a first structure having a ring gear having teeth on a surface thereof, and the other of the lower structure and upper structure comprises a second structure; and iii) a boom pivotally mounted on the upper structure. The crane further includes a drive system comprising at least two pinion gears mounted on a common frame and in driving contact with the ring gear teeth; and a link connecting the frame to the second structure with two pivot axes between the frame and the second structure.