Abstract:
In a method of transporting a latticed boom crane including counterweights for road transport by exploiting a maximum carrying capability of low loaders as well as prescribed loading height and loading width to keep the number of low loaders to a minimum, and for naval transport to implement a cost-efficient specific weight, latticed boom members of the boom are used for transporting counterweights, with the counterweights being secured in or at the boom members.

Description:
CROSS-REFERENCES TO RELATED APPLICATIONS  
         [0001]    This application claims the priority of German Patent Application Serial No. 100 56 647.2, filed Nov. 9, 2000, the subject matter of which is incorporated herein by reference.  
         BACKGROUND OF THE INVENTION  
         [0002]    The present invention relates to a method of transporting a latticed boom crane, and to an apparatus for carrying out the method.  
           [0003]    In the context of transporting latticed boom cranes, it is important to optimize all the devices for road transport and rail transport as well as also naval transport. The number of low loaders should be minimized for a transport on roads while exploiting a maximum carrying capability of low loaders as well as admissible loading height and loading width. At a naval transport, either the volume being consumed or the weight will be calculated, whereby the calculation is based on the parameter that is more unfavorable.  
           [0004]    It has already been proposed to push smaller intermediate boom members of the auxiliary boom into greater intermediate boom members of the main boom to thereby provide a better configuration for the transport. Depending on the construction of the auxiliary boom, the use of small intermediate boom members may, however, be omitted altogether so that the afore-described advantage cannot be exploited.  
           [0005]    German Pat. No. DE-AS 1, 279, 904 describes a mobile crane having a latticed boom comprised of intermediate boom members of rectangular cross section which progressively tapers along the longitudinal axis from the foot area to the head area. As a result, individual intermediate boom members can be moved within one another to realize a reduction in volume for the transport. However, when intermediate boom members of constant cross section are involved, a nesting within one another becomes impossible.  
           [0006]    German utility model DE-GM 1,937,030 describes a tower crane with a tower composed of intermediate boom members which are formed of angular pieces that are detachably connected together and provided in a same number as the sides of the tower. Each side of an angle piece has a width which corresponds to half the width of the tower side. When dismantled, the angular pieces can be stowed within one another in a space-saving manner. Such a stowing option is not feasible, when intermediate pieces are involved that form a fixed structural unit. Described in this prior art is also the incorporation of other crane components, such as crane ladder, inside the construction space that is formed by the assembled tower. This proposal corresponds basically to the procedure to place smaller intermediate boom members of an auxiliary boom within greater intermediate boom members of a main boom.  
           [0007]    It would be desirable and advantageous to provide an improved method and apparatus for the transport of latticed boom cranes to obviate prior art shortcomings and to significantly reduce a required number of transport movements, regardless of the configuration of an auxiliary boom or the capability to dismantle the crane or the cross sectional constancy of the respective intermediate boom sections.  
         SUMMARY OF THE INVENTION  
         [0008]    According to one aspect of the present invention, a method includes the steps of employing latticed boom members of the boom for transporting counterweights; and securing the counterweights in place in or at the respective boom members. In this way, the ratio of volume and weight of the boom components are optimized for the transport. The securement may be implemented through force-fitting engagement. Currently preferred is however a form-fitting engagement.  
           [0009]    According to another aspect of the present invention, an apparatus is proposed for transporting a latticed boom crane with a counterweight and an intermediate boom member, which exhibits a latticed configuration and has end sides provided with at least one connection element with an attachment point, whereby the counterweight is securely fixed in place in or at the intermediate boom member.  
           [0010]    According to another feature of the present invention, the corner points of the counterweight has at least one attachment point for bolting this attachment point to the attachment points at the end face of the intermediate boom member which attachment points of the intermediate boom member are provided to connect intermediate boom members to one another, when the latticed boom is assembled. Suitably, each of both end faces of the intermediate boom member is used for attachment of a counterweight in order to realize an even weight distribution as a result of the symmetric arrangement.  
           [0011]    Another option includes the connection of the counterweight to the inner side of the sidewall of the intermediate boom member by securing a fastening frame to the inner side to serve as guide, and insert and attach the counterweight in the fastening frame. Insertion of a counterweight into the fastening frame may be realized selectively from above, from the side or from the end face. Bolts, belts, chains, screws or brackets may be used to effect a securement.  
           [0012]    Suitably, the fastening frame may be composed of sheet metal profiles which, depending on the direction of insertion of the weight element may form an open U in upward direction, to the side or to the end face. As an alternative, the fastening frame may also be composed of angular sheets and have a L-shaped configuration. Depending on the situation at hand, it also possible to combine both types of attachment of the counterweight.  
           [0013]    According to another feature of the present invention, it is also possible to place the counterweight from the end face of the intermediate boom member onto the inner side of the bottom boom side. In this case, the own weight of the counterweight provides some positional securement which is complemented by an additional attachment. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWING  
       [0014]    Other features and advantages of the present invention will be more readily apparent upon reading the following description of preferred exemplified embodiments of the invention with reference to the accompanying drawing, in which:  
         [0015]    [0015]FIG. 1 is a perspective illustration of a conventional intermediate boom member of a boom of a latticed boom crane;  
         [0016]    [0016]FIG. 2 is a perspective illustration of a stack of counterweights according to the present invention;  
         [0017]    [0017]FIG. 3 is a perspective illustration of an intermediate boom member during an initial phase of attachment of counterweights according to the present invention;  
         [0018]    [0018]FIG. 4 is a perspective illustration of the intermediate boom member of FIG. 3 during a next phase of attachment of counterweights according to the present invention;  
         [0019]    [0019]FIG. 5 is a perspective illustration of an intermediate boom member upon attachment of counterweights according to the invention by way of an alternative method to show a variation of a transport arrangement;  
         [0020]    [0020]FIG. 6 is a perspective illustration of an intermediate boom member upon attachment of counterweights according to the invention by way of an alternative method to show another variation of a transport arrangement;  
         [0021]    [0021]FIG. 7 a  is a detailed perspective illustration of a fastening frame for use in the transport arrangement of FIG. 6;  
         [0022]    [0022]FIG. 7 b  is a detailed perspective illustration of another fastening frame for attachment to the boom member of FIG. 6;  
         [0023]    [0023]FIG. 8 is a perspective illustration of a carriage for supporting stacks of counterweights; and  
         [0024]    [0024]FIG. 9 is a perspective illustration of a base plate for supporting stacks of counterweights. 
     
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS  
       [0025]    Turning now to the drawing, and in particular to FIG. 1, there is shown a perspective illustration of an exemplified conventional intermediate boom member, generally designated by reference numeral  1  and forming part of a, not shown, boom of a latticed boom crane. In the example of FIG. 1, the boom member  1  has a generally rectangular cross section, especially square cross section, and includes an upper boom side  2 , a bottom boom side  3  and opposite side walls  4 . At one end face, the boom member  1  is provided with connecting elements for defining two attachment points  5 ,  5 ′, and at the opposite end face, the boom member  1  is provided with connecting elements for defining three attachment points  6 ,  6 ′,  6 ″. The boom member  1  has been detached from other boom members of the boom and is ready for transport, with the pertaining guy rods  7  having been placed onto the upper boom side  2 .  
         [0026]    Referring now to FIG. 2, there is shown a perspective illustration of a stack of counterweights  8 ,  9  according to the present invention, whereby the counterweights  8 ,  9  are stacked in alternating sequence. Each of the counterweights  8 ,  9  is formed at each corner zone with an attachment point  10 , whereby the attachment point  10  of counterweight  9  is positioned inwardly of the attachment point  10  of the counterweight  8  to realize the stack configuration shown in FIG. 2. In addition, each of the counterweights  8 ,  9  is formed on two opposite sides with at least one eyelet  12  for suspension of the counterweights  8 ,  9  to a, not shown, hoist, independently from the attachment points  10 . In the nonlimiting example of FIG. 2, two eyelets  12  are provided on one side inwardly of the attachment points  10  and one eyelet  12  is provided on the opposite side substantially in mid-section.  
         [0027]    Attachment of the counterweights  8 ,  9  to the boom member  1  is shown in more detail in FIGS. 3 and 4, with FIG. 3 illustrating the initial phase comprised of working steps I and II, and FIG. 4 illustrating the next phase comprised of working steps III and IV. In working step I, a counterweight  8  is positioned at one end face of the boom member  1  in a way that the attachment point  10  is in alignment between the two attachment points  5 ,  5 ′ of the bottom boom side  3  of the boom member  1 . FIG. 3 also shows the attachment of three ropes  14   a ,  14   b ,  14   c  to the respective eyelets  12 . In working step II, bolts  15  are inserted through aligned bores of the attachment points  5 ,  10  to rotatably secure the counterweight  8  to the bottom boom side  3 . After removing the inner ropes  14   a ,  14   b , the outer rope  14   c  is used to swing the counterweight  8  upwards in working step III, as shown in FIG. 4, to align the outer attachment points  10  with the attachment points  5  of the upper boom side  2  of the boom member  1 . After being placed through the aligned holes, bolts  16  are hammered in to secure the counterweight in position. The rope  14   c  can now be detached because the bolts  16  lock the counterweight  8  to the end face of the boom member  1 .  
         [0028]    A counterweight  9  is positioned and secured in a same manner at the opposite end face of the boom member  1  so that a detailed description is omitted for the sake of simplicity.  
         [0029]    Referring now to FIG. 5, there is shown a perspective illustration of an intermediate boom member  1  upon attachment of counterweights  17  according to the invention by way of an alternative method to show a variation of a transport arrangement. The attachment of the counterweights  17  is implemented through placement of the counterweights  17  upon the inner side of the bottom boom side  3  of the boom member  1 . By way of their own weight and a, not shown, fixation, e.g. brackets, the counterweights  17  can be secured immovably in place within the interior space of the boom member  1  for subsequent transport. Although not shown in detail, this type of attachment requires, however, a separate lifting device to place the counterweights  17  from the end face of the boom member  1  into the interior space thereof.  
         [0030]    Another preferred embodiment is shown in FIG. 6. In this embodiment, opposite sidewalls  4  of the boom member  1  have attached thereon a fastening frame  18  and a fastening frame  18   a . Of course, the illustration of FIG. 6 is intended for illustrative purposes to depict different types of fastening frames, but it is certainly possible to use only one or the other type for attachment of fastening frame  18 ,  18   a . The fastening frames  18 ,  18   a , involved here, are shown in more detail in FIGS. 7 a  and  7   b , and so configured that the counterweights  17  can be placed from above into the fastening frame  18 ,  18   a  and secured therein. Securement of the fastening frames  18 ,  18   a  upon the sidewalls  4  of the boom member  1  may be realized in many ways, e.g., by welding, or via brackets, or by bolting. The fastening frames  18 ,  18   a  are composed of sheet metal profiles which may form an open U toward the top of the fastening frame, or toward the side of the fastening frame, or toward the end face of the fastening frame.  
         [0031]    The fastening frame  18  of FIG. 7 a  has parallel profiles  23  of substantially L-shaped configuration, which have upper and lower arched pockets  24  for snap attachment to complementary struts  11  of the boom member  1 . The profiles  23  are interconnected across by a retention bar  22  so as to prevent a counterweight  17 , placed from above into the fastening frame  18 , from tipping over. At its bottom, the fastening frame  18  includes two-spaced apart arched brackets  25  which are inwardly convex and prevent the counterweight  17  from slipping downwards. The arched configuration of the brackets  25  is intended to provide space for lobes  26  of the counterweight  17 . Thus, although the square counterweight  17  may have lobes  26  in the peripheral area thereof, the counterweight  17  may be placed into the fastening frame  18  in any position, as one or the other bracket  25  is able to receive the lobes  25 .  
         [0032]    The fastening frame  18   a  of FIG. 7 b  is composed of U-shaped profiles  27 , facing outwards in order to allow securement of counterweights  17  of different thickness. Each counterweight  17  is formed with a central breakthrough  19  for threaded engagement by a fastening screw  20  which is inserted from outside through an aligned hole in a crossbar  21  of the fastening frame  18   a . In this way, the counterweight  17  is held securely in place within the fastening frame  18   a . The central breakthrough  19  is normally already provided in the counterweight  17  to receive a tie rod, not shown, for suspension of a crane.  
         [0033]    [0033]FIGS. 8 and 9 show examples of particular support devices for the counterweights  8 ,  9  for use in conjunction with a latticed boom crane, with FIG. 8 depicting an exemplified cart  28  upon which the counterweights  8 ,  9  are stacked, and with FIG. 9 depicting an exemplified base plate  29  for stacking the counterweights  8 ,  9 .  
         [0034]    While the invention has been illustrated and described as embodied in a method and apparatus for transporting latticed boom cranes, it is not intended to be limited to the details shown since various modifications and structural changes may be made without departing in any way from the spirit of the present invention.