Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/18—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes
  • B66C23/36—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes specially adapted for use in particular purposes mounted on road or rail vehicles; Manually-movable jib-cranes for use in workshops; Floating cranes
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B66—HOISTING; LIFTING; HAULING
  • B66C—CRANES; LOAD-ENGAGING ELEMENTS OR DEVICES FOR CRANES, CAPSTANS, WINCHES, OR TACKLES
  • B66C23/00—Cranes comprising essentially a beam, boom, or triangular structure acting as a cantilever and mounted for translatory of swinging movements in vertical or horizontal planes or a combination of such movements, e.g. jib-cranes, derricks, tower cranes
  • B66C23/62—Constructional features or details
  • B66C23/72—Counterweights or supports for balancing lifting couples
  • B66C23/74—Counterweights or supports for balancing lifting couples separate from jib

Definitions

• the present invention relates to a mobile crane, preferably a self-propelled mobile crane, of the type having a travelling base structure which allows for travel of said crane over a surface and furthermore having a revolving superstructure mounted on said base structure and rotatable about a vertical revolving axis with respect to the base structure.
• the present invention also relates to a method for operating such a mobile crane.
• the crane further has a boom and a backmast, said boom and backmast each being hinged about an associated horizontal pivot axis to said superstructure.
• a main load hoisting means is associated with said boom for hoisting the load.
• the crane also has a superstructure ballast and the superstructure is adapted for supporting said superstructure ballast thereon.
• the crane For performing so-called “superlifts” the crane has a superlift ballast.
• Associated connection means commonly a multiple fall cable, serves to connect said superlift ballast to said backmast while said superlift ballast is resting on said surface and/or suspended from said backmast above said surface at a large distance from the base structure.
• the crane can resist very large overturning moments created by the load.
• the superlift ballast can weigh hundred or even several hundred metric tons.
• the ballast is usually composed of a stack of heavy steel plates.
• Mobile cranes of this type are often employed for several lift jobs at a single construction site, e.g. of a chemical plant. This means that for each job the crane has to be moved, e.g. several tens or hundreds of meters, to a new location and prepared for the new job.
• a disadvantage of prior art mobile cranes of the type described above relates to the practice described above, wherein the crane is moved from one location to the next. With most prior art cranes it is necessary to provide additional cranes and transport vehicles in order to move the superlift ballast to the new location. This is time consuming and poses additional safety hazards to personnel.
• the Demag CC 8800 crane has a superlift ballast car (max 600 ton) attached to the base structure via a telescopic beam.
• This crane further has a superstructure ballast mounted on the rear end of the superstructure.
• a "central ballast" (max 100 ton) is provided on the chassis of the base structure. This is done by providing the front and rear beam of the base structure with a centrally arranged support platform on which metal ballast plates can be stacked.
• a further prior art mobile crane is disclosed in US 6 568 547, wherein the crane is not provided with a superstructure ballast.
• This crane has a horizontal beam attached to the superstructure, which beam carries the superlift ballast.
• the present invention aims to provide an improved mobile crane, having provisions for handling the superlift ballast which allow for a more efficient use of the crane at affordable costs.
• the present invention provides a mobile crane according to the preamble of claim 1, which is characterized in that said travelling base structure is provided with superlift ballast support means which allow for supporting said superlift ballast on said base structure so that said superlift ballast is movable along with the mobile crane while being supported by said base structure.
• the present invention thus proposes to use the travelling base of the crane itself, which is preferably self-propelled, as means to support and transport the superlift ballast when moving the crane from one job site to the next. This can result in a crane of lower costs than the complex prior art designs and/or a crane which can be operated far more efficiently.
• the present invention also relates to a method for operating such a mobile crane.
• Fig. 1 shows an example of a crawler crane according to the present invention in side view
• Fig. 2 the crane of figure 1 in a different set-up in a front view
• Fig. 3a-c in successive side views the positioning a superlift ballast part onto the base structure of the crane of figure 1
• Figs. 4a-f in successive plan views the positioning of both superlift ballast parts onto the base structure of the crane of figure 1
• Fig.5 in plan view the central chassis and the superlift ballast parts supported by said chassis of the crane of figure 1
• Figs. 6a,b in elevational cross-section two trays of a superlift ballast part of figure 5 in assembled and disassembled state respectively
• Fig. 6a,b in elevational cross-section two trays of a superlift ballast part of figure 5 in assembled and disassembled state respectively
• Fig. 6a,b in elevational cross-section two trays of a superlift ballast part of figure 5 in assembled and disassembled state respectively
• FIG. 7 a longitudinal cross-section of the ballast parts as in the view of figure 5, and Fig. 8 a view from the front showing a ballast tray and superlift ballast plates stacked on said tray.
• the figures 1 and 2 show in different set-ups for different lift jobs crawler crane 1 designed for lifting loads of several hundred metric tons, in a preferred embodiment up to 1200 metric tons or even more .
• the crane 1 is a self-propelled crane and has a travelling base structure 2 which allows for travel of said crane over a surface. In many cases said surface will be the ground, possibly reinforced by a suitable foundation, but it is also envisaged that the crane is used on a large pontoon or the like.
• a revolving superstructure 3 is mounted on said base structure 2, so that the superstructure 3 can rotate about a vertical revolving axis with respect to the base structure 2.
• the crane 1 further has a boom 4 and a backmast 5.
• the boom is hinged to the superstructure 3 so that the boom 4 pivots about horizontal pivot axis 6.
• the backmast 5 is also hinged to the superstructure 3 about a horizontal pivot axis 7.
• both the boom 4 and the backmast 5 have a lattice structure, which is preferably modular to allow for easy transport of the entire crane from one construction site to the next.
• both the boom 4 has an A- frame design, with two elongated boom sections 4a, 4b separately connected to the superstructure and merging towards each other near the top of the boom 4.
• the backmast 5 has a inverted Y-frame design with two lower backmast sections 5a, 5b pivoted to the superstructure 3 and merging into a single section 5c.
• a luffing fly jib arrangement 8 including jib 8a and stay beams 8b, 8c which are connected to the top of the boom 4.
• a main load hoisting means is associated with the boom 4 for hoisting a load.
• FIG 1 a hoisting cable 11 is shown, which is guided over cable pulleys 12 mounted on the top of the backmast 5, on the stay beams 8b, 8c and on the top of the jib 8a.
• a crane hook 13 is suspended from the hoisting cable 11.
• a main load-hoisting winch 13a is mounted on the revolving superstructure 3.
• a superstructure ballast 15 is provided, composed of a stack of steel ballast plates. The rear end of the superstructure 3 is adapted for supporting said superstructure ballast 15 thereon.
• the crane 1 further has a superlift ballast 20 and associated connection means 30 serving to connect said superlift ballast 20 to the backmast 5 while the superlift ballast 20 is resting on the surface (as in figure 1) and/or suspended from said backmast 5 above said surface.
• the connection means 30 are formed here by a superlift ballast cable 31 guided over a cable pulley 32 in the top of the backmast 5 and connected to a superlift ballast winch 33 mounted on the superstructure 3.
• the travelling base structure 2 is provided with superlift ballast support means which allow for supporting said superlift ballast 20 on said base structure 2 so that said superlift ballast 20 is movable along with the crane 1 while being supported by said base structure 2.
• the travelling base structure 2 comprises a central chassis 40 (shown in detail in figure 5) and a first and second carriage assembly 41, 42 on opposite lateral sides of the chassis 40.
• the carriage assemblies are designed as crawler assemblies each having a track.
• Other designs are also envisaged such as wheeled carriage assemblies (for smaller cranes) or skid arrangements and the like.
• the first and second crawler assemblies 41, 42 protrude forward and rearward with respect to the central chassis 40.
• the travelling base structure 2, in this example the chassis 40 thereof, is provided with a first and a second superlift ballast support means 50, 55 located on opposite sides thereof, in this example to the front and to the rear of the chassis 40.
• the superlift ballast 20 here comprises a first and a second superlift ballast part 20a, 20b, which are supportable on said first and second superlift ballast support means 50, 55 respectively.
• the first and second superlift ballast support means 50, 55 are adapted such that said first superlift ballast part 20a is supported essentially in front of the chassis 40 between the forward protruding carriage assembly parts and the second super lift ballast part 20b is supported essentially to the rear of the chassis 40 between the rearward protruding carriage assembly parts.
• the superlift ballast parts 20a, 20b are supported such on said travelling base structure 2 that unhindered revolving motion of the superstructure 3 is possible when the ballast parts are supported on the chassis.
• the first and second super lift ballast parts 20a, 20b here each include two interconnectable ballast trays 16 and multiple ballast plates 17 stackable on said each of said ballast trays 16.
• Each tray 16 has a bottom 16a and sidewalls 16b.
• the sidewalls 16b have a connection member 16c at one edge allowing for a sort of tongue-and-groove connection to the associated tray 16 and also to a corresponding vertical connection member 43 on the chassis 40.
• the chassis 40 has two transverse beams 44, 45 extending between the crawler assemblies and two longitudinal beams 46, 47 interconnecting the transverse beams 44, 45.
• a slew ring 47a is mounted onto which a number of bogies 48 having rollers are supported. These bogies 48 support the superstructure 3 on the slew ring 47a in a rotatable manner (see e.g. fig. 2) .
• the entire super ballast 20 is brought closer to the base structure 2 by lifting the ballast 20 from the surface and topping the backmast 5. Then said ballast 20 is lowered onto the ground and the ballast parts 20a, 20b are disconnected from each other. The ballast lifting cable 31 is then connected only to the ballast part 20a, which is then lifted. By slewing the superstructure 3 the ballast part 20a is brought between the forward part of the crawler assemblies and then lowered so that this ballast part 20a comes to rest on the associated support means 50 of the chassis 40 (see figures 3c and 4c) . The ballast lifting cable is then disconnected from the ballast part 20a.
• the superstructure 3 is slewed back so that the cable can be attached to the other super lift ballast part 20b.
• This ballast part 20b is then lifted and by slewing the superstructure and topping the backmast 5, the ballast part 20b is brought between the rear end of the crawler assemblies.
• the ballast part 20b is then lowered onto the associated support means 55 of the chassis 40.
• ballast parts 20a, 20b on the structure 2 are also possible.
• the mobile crane 1 can be moved to another job location and the superlift ballast 20 is taken along with the (self-propelled) crane 1. It will be clear that the handling of the superlift ballast 20 in this manner is efficient and requires no additional cranes and transport vehicles when moving the crane from one job site to the next.
• the superlift ballast 20 could consist of one part only, which is then supported on a suitable location on the travelling base structure. It is however preferred to have multiple superlift ballast parts supported on opposite sides of the chassis.

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• Engineering & Computer Science (AREA)
• Mechanical Engineering (AREA)
• Jib Cranes (AREA)
• Vehicle Body Suspensions (AREA)
• Control And Safety Of Cranes (AREA)

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Cited By (5)

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Citations (5)

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• 2003
  • 2003-10-02 AU AU2003276776A patent/AU2003276776A1/en not_active Abandoned
  • 2003-10-02 CN CNB2003801107519A patent/CN100436303C/zh not_active Expired - Fee Related
  • 2003-10-02 DE DE60316358T patent/DE60316358T2/de not_active Expired - Lifetime
  • 2003-10-02 WO PCT/NL2003/000674 patent/WO2005030632A1/en active IP Right Grant
  • 2003-10-02 AT AT03818801T patent/ATE372951T1/de not_active IP Right Cessation
  • 2003-10-02 EP EP03818801A patent/EP1673304B1/de not_active Expired - Lifetime

Patent Citations (5)

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