Abstract: The present invention provides a method of handling a structure and an equipment of handling the structure which can make swing of the structure to be transported small when the structure in a reactor building is curried out from the reactor building and/or when the structure is carried into the reactor building from the outside of the reactor building.

Abstract: The invention provides a load measurement in a crane hoist system. A parameter adaptation process uses a model of the system in order to measure the lifted load. A controller monitors hoist speed and hoist torque feedbacks that are input into the model and processed using a filter, as well as a previously determined load value. The model adapts automatically to determine the weight of the lifted load.

Abstract: The invention relates to the mounting of the revolving part of a tower crane, at the top of the mast. A first assembly, formed by the counterjib (8), its tie rod (19) and a rear part (22) of the jib bearer (5), made in two separable parts, is pre-built on the ground, then lifted up and assembled by pinning (at 18) on the revolving pivot or the mast-cab (10) and is held temporarily in place by retaining link rods (48). Another assembly, formed by the jib (6), its tie rods (13, 14) and the front part (21) of the jib bearer, is also pre-built on the ground, then lifted up and assembled by pinning (at 77) on the revolving pivot or the mast-cab (10). The respective tops (28, 47) of the front part (21) and of the rear part (22) of the jib bearer (5) are then joined together by temporary pinning along an axis (78), followed by definitive pinning along an axis (79).

Abstract: Load-bearing apparatus, such as a boom lift, including first and second arm portions, in which at least one element, such as a hydraulic cylinder, is provided for selectively imparting a predetermined dependent relationship as well as a predetermined independent relationship between the first and second arm portions. The manufacture of such load-bearing apparatus can be customized by preselecting the dependent and independent relationships by altering given parameters.

Abstract: An improved method of lifting a load includes supporting a load on a first section of an extendible lift assembly, the first section being surrounded by a second section, a hydraulic cylinder being operatively coupled to the first section so as to be capable of lifting the first section, and the first and second sections being supported on and vertically extendible with respect to a base. Then, while the load is supported on the first section, the hydraulic cylinder is extended to extend the first section relative to the second section and the base, thereby lifting the load to a first height. Then, the first section is secured to the second section so as to at least substantially prevent downward movement of the first section relative to the second section. The cylinder is then retracted and operatively coupled to the second section.

Abstract: An overhead support system. A riding surface is located over a space and supports at least one overhead cart from which a load is supported by a tension element. A plurality of spherical elements are positioned between the riding surface and overhead cart and are attached to either the cart or the riding surface. The load can be moved horizontally in the space by applying a horizontal force to the load causing the cart to move over the riding surface while carrying the load in the horizontal direction. In preferred embodiments the riding surface is an array of spoked rimless wheels. In other preferred embodiments the riding surface is a slot track, or the riding surface may be a combination of the array and slot tracks. In other preferred embodiments a hoist assembly is used to raise and lower the load. In a preferred embodiment the hoist assembly is located below the riding surface. In another preferred embodiment, the hoist assembly is located above the riding surface.

Abstract: A method for handling an equipment inside a building by a crane installed outside; the method being employed when leading the wire hanging from the boom of a crane installed outside of a building (nuclear reactor containment vessel, into the building through an opening provided on the building, and lifting up or down an equipment inside said building by said wire. The said method includes a process for measuring by a three-dimensional measuring device which is positioned apart from the crane the shift of the boom caused by transfer of dead load of the equipment to the wire, in the course of transferring dead weight of the equipment between the wire and a structure inside the building, and correcting the position of the boom, by moving said boom up or down, back to a direction opposite to the shift so as to lift up the equipment vertically.

Abstract: An Integrated Balanced Wire Rope Reeving System for Cargo Container Handling Cranes wherein the same ropes perform both load hoist and trolley traversing operations.

Abstract: A telescopic turret crane (126) is detachably connectable to a pedestal (118) that is incorporated into a concrete building structure that is under construction. The telescopic turret crane is provided with a base (122) that is detachably connected to the pedestal (118). The same pedestal (118) is sometimes used for supporting an articulated concrete placement boom (126). This boom (126) includes the similar base that is detachably connectable to the same pedestal (118). The concrete placement boom (126) is attached to the pedestal (118) and is used to pour a new upper floor in the building. Following this use, the articulated concrete placement boom (126) is detached from the pedestal (118) and is moved away from the pedestal (118). Then, the telescopic turret crane is brought to the pedestal (118) and is connected to the pedestal (118). The telescopic turret crane is used during the performance of tasks on or above the newly poured floor, in the vicinity of the pedestal (118).

Abstract: A method of logging utilizes a combination log yarder and processor vehicle having a basic vehicle structure not unlike that of a track-type excavating machine, but with a boom arm assembly arranged for operation in conjunction with a log processing head apparatus and its particular requirements for the handling and processing of felled logs and trees. The vehicle mounts a collapsible yarder tower arrangement which rotatably mounts a cable guide head member for relative rotation between the cable guide head and the vehicle on the same center axis of rotation as the vehicle turntable rotates on its undercarriage, thereby permitting the vehicle full rotational capabilities and operation of its boom arm apparatus when the yarder apparatus' cables are extended and anchored and in operation, and thereby permits a yarding operation of felled trees to be conducted simultaneously with a log processing, log sorting and log loading operation by a single personnel at a destination location at a logging site.

Abstract: A multiple boom lifting arrangement includes a plurality of preferably four carriages, each carriage having a boom with its lower end portion pinned to the carriage. Two of the carriages are placed on a common travel path with the upper end portion of their respective booms being pinned. This provides two spaced apart pairs of carriages and booms for lifting. A horizontal beam extends between the first pair of booms and the second pair of booms being attached to the pinned connection of each pair of booms with a sling. A powered motor-driven winch is used to power a cable that is wound between sheaves on the lower end portions of a pair of booms that are connected together. During use, the winches are simultaneously or nearly simultaneously operated to elevate the first pair of the booms and the second pair of booms at about the same time so that the horizontal beam that spans in between the pinned connections of-the first and second pairs of booms is elevated.

Abstract: For the positional correction of a load carrier (34) suspended on a trolley (22) a cable member (50′) of the lifting cable system interposed between the trolley (22) and the load carrier (34) is displaced in a horizontal direction at a location near the trolley (22) relative to the trolley (22) by imparting a movement onto a cable course influencing member (56) which is adjustably guided on the trolley in a horizontal direction and is subjected to the action of movement means (60) which again are supported on the trolley (22).

Abstract: A gantry crane is provided which is equipped with standard wheels having rubber tires for free maneuverability on a road surface, such as asphalt, gravel, pavement, etc., wherein the crane is additionally equipped with a plurality of railwheels to provide auxiliary support one or more rails in the loading area. In a first mode, the crane is supported only on rubber tires for driving on a paved surface, and in other modes, one or both sides of the crane are supported via the railwheels on rails. In an embodiment, a railwheel may be securely mounted coaxially to the steel rim of the respective steel wheels, forming a dual or combination wheel. The railwheels are sized relative to the tires of the standard wheels so that the railwheel does not impair non-rail loading operations, i.e., the railwheel vertically clears the ground even when the tires deflect as the crane is fully loaded. Railwheels may be provided on one or both sides of the crane.

Abstract: A method and device for damping the oscillation of a load suspended from a rope on a crane is presented. A digital filter accepts an arbitrary velocity input signal and produces a velocity signal output similar to the input and that runs a bridge or trolley drive while damping the load's swing. One version of the damping filter may be implemented by programming a microprocessor to output a simple average of the input signal and the input signal delayed by one-half period of the pendulum motion of the load. A second version of the invention averages the input signals over the period of the pendulum motion to producing a damping signal. A third version of the invention averages the input signal with two delayed versions of the input signal. The third version will produce motion that will dampen load swing for a large range of rope lengths. Furthermore, if an additional signal representing rope length is taken, all three versions can be adapted to dampen swing for a full range of rope lengths.

Abstract: A convertible crane with a movable sheave assembly which is operable in two distinct positions. In the first position, the sheave is adjacent the body of a crane to enable it to operate in relatively restricted space without interference from obstacles adjacent the rear end of the base. In the second position, the sheave extends away from the body of a crane where it may be attached to an auxiliary counterweight to enable a crane to lift larger loads. The movable sheave assembly enables a crane to be easily and rapidly converted between normal and enhanced lifting modes.

Abstract: A cargo handling path setting method and apparatus determine arbitrary hoisting and lowering speeds of a suspended load and the times required for hoisting and lowering to set hoisting and lowering speed patterns, determine an arbitrary traversing speed of the suspended load and the time required for traversing to set a traversing speed pattern, set the positions and heights of obstacles present around the cargo handling path based on data from stacked load sensors, and further set an arbitrary waiting time for traversing and an arbitrary waiting time for lowering; then conduct a theoretical simulation test based on these set conditions to compute a cargo handling path, and if it is determined that the suspended load passing along the cargo handling path will collide with the obstacles, repeat the procedure of revising the set conditions and conducting a theoretical simulation test again.

Abstract: A method for moving a carriage of a crane a short distance while simultaneously damping the oscillation of its load. The method includes: determining the period of oscillation T of the load; moving the carriage a first displacement from an initial position to a desired final position; moving said carriage a second displacement from the desired final position back to said initial position, a time T/6 after said first displacement; and repeating the first displacement to provide a third displacement from the initial position back to said desired final position, a time T/6 after said second displacement; while causing load oscillations to be damped.

Abstract: A method is provided to automatically control a cranes's rider block lifte and taglines. Current position of the crane's rider block is determined in terms of its horizontal and vertical coordinates, as well as in terms of the inhaul angle of the liftline. A matrix is then generated that defines i) incremental change in the rider block's horizontal coordinate with respect to incremental change in each of the boom angle, a length of the liftline and a length of the taglines, ii) incremental change in the vertical coordinate with respect to incremental change in each of the boom angle and lengths of the liftline and taglines, and iii) incremental change in the sine of the inhaul angle with respect to incremental change in each of the boom angle and lengths of the liftline and taglines. A vector defining velocity criteria for the rider block is provided. The velocity criteria is defined in terms of horizontal motion of the rider block, vertical motion of the rider block and rate of change of the inhaul angle.

Abstract: The present invention relates to an apparatus and a method for extending and storing a jib of a crane which make it possible to simplify the operation of changing a wire rope. The apparatus includes an end sheave (23), which is detachably attached to the front lower end of a boom (3); a rotating device, (80) for rotating a rotary bracket (30); and a link (123), which vertically rotatably connects the end sheave (23) and the front upper portion of the boom (3) and positions the end sheave (23) above and in front of the boom (3) when the rotary bracket (30) is rotated in the forward direction of the boom (3).

Abstract: A platform assembly designed for use in supporting a crane during the construction of a multi-story building is described. The assembly includes a platform for supporting a crane and means for fixedly attaching the platform to differing locations along the length of a structural column of such building during construction of the latter.

Abstract: A multiple boom lifting arrangement includes a plurality of preferably four carriages, each carriage having a boom with its lower end portion pinned to the carriage. Two of the carriages are placed on a common travel path with the upper end portion of their respective booms being pinned. This provides two spaced apart pairs of carriages and booms for lifting. A horizontal beam extends between the first pair of booms and the second pair of booms being attached to the pinned connection of each pair of booms with a sling. A powered motor-driven winch is used to power a cable that is wound between sheaves on the lower end portions of a pair of booms that are connected together. During use, the winches are simultaneously or nearly simultaneously operated to elevate the first pair of the booms and the second pair of booms at about the same time so that the horizontal beam that spans in between the pinned connections of the first and second pairs of booms is elevated.

Abstract: A method for rapid transportation and loading of stacks of cartons aboard vessels is provided which may include the mounting of slings about the stacks of cartons, transporting the cartons to the dock by a flatbed vehicle, hoisting the stacks of cartons off the flatbed vehicle and into the hold, depositing the cargo onto a landing pad, lifting the cargo off the landing pad with a lift truck, preferably a load push type lift truck, and depositing the cargo in the hold at the appropriate location. A sling pallet and a landing pad for use with the method are also disclosed. The method provides the advantages of improving the quality of the product by, inter alia, reducing the risk of thawing or spoilage, reducing costs by eliminating labor, eliminating the need to remove pallets and debris from within the vessel, reducing the likelihood of injury to workers, saving demurrage charges and speeding the transportation to and loading of the vessel.

Abstract: A method and device for damping the oscillation of a load suspended from a rope on a crane is presented. A digital filter accepts an arbitrary velocity input signal and produces a velocity signal output similar to the input and that runs a bridge or trolley drive while damping the load's swing. One version of the damping filter may be implemented by programming a microprocessor to output a simple average of the input signal and the input signal delayed by one-half period of the pendulum motion of the load. A second version of the invention averages the input signals over the period of the pendulum motion to producing a damping signal. A third version of the invention averages the input signal with two delayed versions of the input signal. The third version will produce motion that will dampen load swing for a large range of rope lengths. Furthermore, if an additional signal representing rope length is taken, all three versions can be adapted to dampen swing for a full range of rope lengths.

Abstract: An object of this invention is to provide a high performance and low cost crane rope steadying control method and apparatus for which mechanical or optical swing angle detecting means are not necessary.The invention provides a rope steadying control method for a crane or the like having a trolley driving apparatus for causing a load suspended by a rope of a crane or the like to travel, wherein swinging of a load suspended by a rope is stopped by calculating a swing load signal I.sub.2W * proportional to the rope swing angle and the load by computationally estimating a motor torque estimate signal .tau..sub.M * not including load torque fluctuations caused by swinging of the rope on the basis of gain coefficients and equivalent time constants of the control system and the drive system, and comparing this estimate signal .tau..sub.M * with an actual load torque .tau..sub.M and negatively feeding back to a trolley speed command N.sub.S of the trolley driving apparatus (1) a speed signal N.sub.

Abstract: A lowering collision avoidance device includes a container detector, a rope winding speed detector, a rangefinder for detecting the distance to an adjacent container, a rope length detector, and a controller which controls a hoisting/lowering drive motor, thereby controlling the lowering speed, in such a manner that when the container detector becomes ON, a lowering stop action is performed to start decreasing the lowering speed at a predetermined rate; even during this period, the remaining lowering distance and a normal stopping distance are computed; and when the container detector becomes OFF for one period of swing computed from the rope length detected by the rope length detector, and after a judgment is made that the risk of collision of a lowered container with the adjacent container has vanished, lowering is resumed if the remaining lowering distance is larger than the normal stopping distance, or an emergency stop action is performed if the remaining lowering distance is not larger than the normal s

Abstract: The crane comprises a generally horizontal boom or other supporting structure having at least one rail thereon, a trolley having a reversible drive for moving the trolley in either direction along the rail, a wire rope hoist suspended from the trolley, and a load carrying device suspended from the hoist for selectively grasping and releasing a freight container or some other load. The crane has a control system which causes the trolley drive to stop the trolley momentarily at a first stopping position. Due to the control system, the drive then restarts the trolley and stops it at a second stopping position directly over a transfer position where the load is to be delivered and released. If the load is a freight container, the transfer position may be directly over a cell of a container ship. The control system includes an encoder for determining the length of the pendulum comprising the trolley, the hoist, the load carrying device and the load.

Abstract: An apparatus and method of controlling a load oscillation dampener for a crane from which a load is suspended by a hoisting rope attached to a carriage driven by a motor controlled by a motion controller. A first direction signal corresponding to a first direction is applied to the motion controller for initiating motion of the carriage in the first direction and it is determined whether a second direction signal corresponding to a second direction is applied to the motion controller while the carriage is traveling in the first direction, the second direction being opposite the first direction. If the second direction signal was detected, the load oscillation dampener is deactivated to prevent uncontrolled motion of the carriage, and if the second direction signal was not detected, the load oscillation dampener is allowed to cause motion of the carriage to damp load oscillations.

Abstract: Method and device for controlling the swinging motion of an oscillating load suspended from a movable support, wherein the movement of the support is controlled by a speed setpoint. The method includes a step (AS1) for automatically controlling the actual swaying value of the oscillating load by means of a zero swaying value and a step (37) for adjusting the speed setpoint (CV) of the support according to a correction value (E1) determined during the automatic swaying control step (AS1). The invention can be used, for example, for moving a load by means of a harbour crane.

Abstract: A multiple boom lifting arrangement includes a plurality of preferably four carriages, each carriage having a boom with its lower end portion pinned to the carriage. Two of the carriages are placed on a common travel path with the upper end portion of their respective booms being pinned. This provides two spaced apart pairs of carriages and booms for lifting. A horizontal beam extends between the first pair of booms and the second pair of booms being attached to the pinned connection of each pair of booms with a sling. A powered motor-driven winch is used to power a cable that is wound between sheaves on the lower end portions of a pair of booms that are connected together. During use, the winches are simultaneously or nearly simultaneously operated to elevate the first pair of the booms and the second pair of booms at about the same time so that the horizontal beam that spans in between the pinned connections of the first and second pairs of booms is elevated.

Abstract: An apparatus and method of controlling a load oscillation dampener for a crane from which a load is suspended by a hoisting rope attached to a carriage which is driven by a motor controlled by a motion controller. A motion command having a duration is applied to the motion controller, the carriage is moved in response to the motion command, and it is determined whether the duration of the motion command is greater than a given time interval. If the duration of the motion command was less than the given time interval, the load oscillation dampener is deactivated to prevent uncontrolled motion of the carriage, and if the duration of the motion command was greater than the given time interval, the load oscillation dampener is allowed to cause motion of the carriage to damp load oscillation.

Abstract: A method for controlling the motion of a crane lifting carriage, or trolley, a load suspended from it, a swing damping system, and/or an operator control cab whereby an ideal sequence of accelerations for moving the lifting carriage is defined that will bring the load to a swing-free condition at the end of the sequence of accelerations, and corresponding lifting carriage speed change signals are developed. A pendulum swing angle of the load corresponding with the ideal sequence of lifting carriage accelerations is calculated. The swing angle calculation and a geometric model of the swing damping system are used to determine a swing damping system control signal which makes the swing damping system follow the swing angle of the load.

Abstract: The object of the invention is a method to control a harmonically oscillating load, in which method the load is transferred from a beginning state to a final state of the load oscillation and to a final velocity (V.sub.ref) of the point of suspension by controlling the load with control sequences which comprise consecutive acceleration pulses, whereby the beginning and final states of load oscillation and the beginning and final velocities of the point of suspension are measured or estimated. The control sequence a(t) of the load is formed from many standard duration acceleration pulses (a.sub.1, a.sub.2, a.sub.3) calculated on the basis of random beginning and final states of the load.

Abstract: The invention relates to a method for damping the load swing of a crane during the traversing motion of a load-carrying trolley and/or a trolley-carrying bridge. The method comprises determining substantially continuously the acceleration of the trolley/bridge and the instantaneous swing time constant, swing velocity (v) and deviation (s) from equilibrium of the pendulum formed by the load. When the velocity reference changes, the acceleration providing the desired change in velocity is determined, said acceleration being switched on immediately, and the acceleration compensating for the swing prevailing at the moment of change of the velocity reference is determined, said acceleration being switched on either immediately or, if the compensating acceleration exceeds the maximum acceleration permissible to the traversing drive when switched on immediately, when the pendulum formed by the load has reached its extreme position.

Abstract: An apparatus and a method for controlling the operation of a reach tower crane, in which a horizontal boom can safely and securely be operated or stored by one operator in the cab, and in which even if sensors are out of order, the stability of the crane can be secured. The system has a plurality of sensors for detecting a condition of an actuator (6) actuating an apparatus to operate or store a horizontal boom (5), a controller (36) for sending a control signal based on signals from the sensors, and hydraulic apparatuses for controlling various actuators in accordance with the control signal. Further, an operation lever and an operation switch are used to extend or store the horizontal boom (5).

Abstract: The crane comprises a horizontal boom or other support structure having at least one rail thereon, a trolley along the rail, a rope hoist, and a load carrying device. A control system causes the driven trolley to be stopped momentarily at a first position. The control system then restarts the trolley and stops it at a second position directly over a transfer position. The control system includes an encoder for determining the total length of the pendulum of the crane and the load. The stopping of the trolley at the first position causes the load to swing forwardly into the first quarter of a pendulum cycle. The control system includes means for adjusting the distance between the first and second positions to correspond with the horizontal component traveled by the load during the first quarter of the pendulum cycle whereby the load is stopped without any residual swinging movements.

Abstract: In a vehicle mounted digger derrick or crane, the moment applied to the boom by a lift cylinder is controlled in a customized manner to more fully utilize the structural strength of the machine at different working positions of the boom. In one embodiment, the moment is controlled by controlling the moment arm through a pivot link which carries the base end of the lift cylinder and which is pivoted by an auxiliary cylinder. In another embodiment, the force component of the moment is controlled in response to changes in the boom angle or moment sensed by a linear position transducer or other sensor.

Abstract: A longitudinally divisible crane boom segment includes at least a first and a second section that are easily nested together for transport. The sections each include at least one chord member, at least one bracket attached to the section, and a plurality of partial lacing elements. Each partial lacing element has a first end permanently attached to the at least one chord member and a second end. The second end of at least one of the plurality of partial lacing elements of the first section is connectable to a bracket attached to the second section to hold the sections in a nested fashion.

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 system and method for aligning the upper works assembly to the lower works assembly of a crane to facilitate redecking of the assemblies. The system and method involves suspending, preferably by pendants, the lower works from the upper works in such a manner that the influence of gravity will automatically level and align the lower works with the upper works. Alignment and redecking are accomplished without transferring the weight of the upper works assembly to lower works assembly.

Abstract: A working machine equipped with a boom, an arm and a bucket and is mounted on a construction vehicle, the working machine being capable of being folded compactly at rest. The working machine is easily brought into an operating position without any special apparatus. The boom is divided into two portions that allow it to be folded compactly. The two boom portions are pivotally attached to each other and the first of the two boom portions is pivotally attached to the chassis of the machine. The boom portions work in cooperation with at least one hydraulic cylinder to move between operative and inoperative positions. A retaining device, which can be in the form of another hydraulic cylinder or pins, is used to hold the boom portions in position with respect to each other.

Abstract: An apparatus and method for providing a boom extension for retractable booms of gantry cranes which does not require lowering the boom during attachment of the extension, or increasing the lift capacity of the boom hoist machinery, nor does the boom extension add bending moment to the retractable boom.

Abstract: An apparatus for transferring leaking drums to a salvage drum utilizing a liftgate assembly having a vertical rail for supporting a liftgate and a drive mechanism for raising and lowering the vertical rail, the apparatus including a lift boom assembly having a chain mounted thereon with a drum lifting clamp secured to the chain for engaging the leaking drum and a pair of tubular pocket assemblies mounted in a vertically spaced relation on the vertical rail and a pair of pin assemblies mounted on the lift boom assembly for matingly engaging the pocket assembly whereby the lift boom assembly can be pivoted with respect to the liftgate assembly and removed for storage in the vehicle.

Abstract: In a container crane installation, swinging movements during the lowering of the spreader are suppressed in that the spreader, after the reaching of the ideal position of the hoist cable carrier in each case, is brought into swing-damping contact with the crane carriage. According to a further form of embodiment the position of the spreader in relation to the standing position to be approached is ascertained by a remote recognition system fitted on the spreader.

Abstract: The invention relates to a handling boom comprising a main boom and an additional boom which is pivotally mounted relative to the main boom about a first axis, the additional boom comprising a support frame pivotally mounted on the main boom about a first axis and a manipulation jib pivotally mounted on the support frame about a horizontal second axis. According to the invention, the second pivot axis is disposed close to the top face of the additional boom in such a manner as to enable the manipulation jib to be pivoted upwards from a first deployed configuration of the additional boom. The invention is applicable to making a handling boom including a telescopic main boom and which is relatively lightweight and reliable.

Abstract: A safety system helps prevent injury from falls from stacks of containers while loading and unloading container ships using an overhead trolley crane. The crane is of the type including a frame movable in fore and aft gantry directions, a trolley track supported by the frame and a trolley movable along the trolley track in on shore and off shore trolley directions. The trolley includes a container bridle which lifts and lowers the containers during loading and unloading operations. Workers walk on the containers to place and retrieve stacking cones at the corners of the containers. The workers ride in a cage on the bridle in getting onto and off of the containers. The operational status of the crane-normal speed, slow speed or stopped-is visually indicated to the worker by colored lights on the cab. Each worker is tethered to the bridle by a short (6'), two piece safety line in case the worker falls off the stack of containers.

Abstract: A crane vessel (20) has a temporary load support structure (23) on which to support a load (22) in transit. For installation, the load is hooked up to the vessel crane (21) and the temporary support structure is removed to enable the vessel to set down the load on its tower structure (24).

Abstract: A method for converting the angulate form boom of a digging machine such as a backhoe or the like into a substantially straight lifting boom. The original angulate form boom is separated into two parts in the vicinity of the angular transition and is realigned so that the top sides are substantially co-planar. A union then is formed to rejoin the separated portion. By initially separating the boom with an elongate parting locus passing near the lifting point of the original boom, and the employment of elongate top and bottom plates, improved structural integrity is achieved and an advantageous shifting of the lifting point to the bottom of the resultant lifting boom is realized.

Abstract: In a control method of a crane in which a parcel suspended by a rope is laterally transported by a trolley, the accelerating time and decelerating time of the trolley are obtained on the basis of the mass of trolley, mass of suspended parcel including a suspending device, and rope length, and when the trolley is started, the accelerating force which is necessary to allow the velocity of trolley to become an objective velocity for the accelerating time is instructed, and after this accelerating time has elapsed, the trolley is allowed to uniformly run at the objective velocity. During the constant speed running, the stop position of the trolley is predicted on the basis of the decelerating time. When the trolley reaches the start position of the decelerating operation such that the trolley can be stopped at the objective position, the decelerating force which is necessary to reduce the trolley velocity to zero for the decelerating time is instructed.

Abstract: A method for stretching and folding an extension jib in a wheeled type crane including a telescopic boom, and a suspension-rod-supported compression column type extension jib to be supported in a flat posture at the fore end of the boom in stretched state through right and left jib foot portions rotatably engaged with horizontal boom point pins extending transversely of the boom at the fore end thereof, the method including the steps of (a) providing on opposite sides of the extension jib right and left jib foot portions disengageably engageable with the boom point pins, one of the jib foot portions being rotatable relative to the boom about an axis extending in the axial direction of the jib; (b) stretching the jib from a folded position in which the top and bottom sides of the jib are disposed in an upright posture along one side of the boom, by engaging the one jib foot portion with the boom point pin on the folding side and turning the boom into an inclined position from a horizontal position, rotating th

Abstract: A method and apparatus is disclosed for controlling the angle of a pivoted, pendant supported extensible boom and the mast-boom angle between working positions and a transport position. The structure for controlling the angle includes a wire rope driven by a winch and trained over a boom supporting hoist and over a pendant take-up hoist which includes a floating sheave assembly connected to an extensible portion of the boom by a fixed length pendant. Another fixed length pendant determines the mast-boom angle when the boom is in working position, and a floating sheave stop is pivoted to the mast in position to cradle and/or abut a portion of the floating sheave assembly for enabling complete control of the mast when moved between its transport position and working positions relative to the boom.