Abstract:
A collapsible hoisting device for use in the construction of large metal containers and to a removable accessory applicable thereto. It facilitates construction procedures by reducing project times and costs. The collapsible device includes a column ( 2 ) along which respective upper bodies ( 6 ) and lower bodies ( 7 ) that have been inserted into said column ( 2 ) move. The bodies ( 6, 7 ) are linked by an extendable means ( 8 ). The upper bodies ( 6 ) and lower bodies ( 7 ) have a corresponding mechanism to lock or attach ( 9 ) to the column ( 2 ), The column ( 2 ) is mounted so that it pivots with respect to a base ( 1 ) and the upper body ( 6 ) has a housing ( 609 ) suitable for the insertion of a removable, fingernail-shaped accessory ( 12 ).

Description:
CROSS-REFERENCE TO COPENDING PATENT APPLICATIONS 
       [0001]    The present application is a continuation-in-part of international patent application PCT/ES2011/070494 filed Jul. 6, 2011, which in turns claims the benefit of priority from Argentinian patent application P20100102451 filed Jul. 7, 2010. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of Invention 
         [0003]    The present invention refers to a folding lifting device to be used in the construction of large metal containers, and a removable fitting applicable to such device. That is, to a collapsible hoisting device for use in the construction of large metal containers, and removable accessory applicable thereto. The characteristics of the present invention facilitate the construction procedures reducing construction time and costs. 
         [0004]    2. Description of Related Art 
         [0005]    It is known that in order to perform the assembly of various structures it is necessary to have a system that is able to lift part or the whole of the structure. In particular, for the construction of large metal tanks or containers applying the method which consists of constructing first a ring and the roof attached to it, and subsequently lifting the structure and attaching new rings, always working close to the floor, the use of devices able to lift the growing structure in a safe and effective way without disturbing the assembly process becomes critical. 
         [0000]    Currently, in the present state of the art some of the disclosed lifting devices are limited in general to several models of hydraulic or mechanic jacks, which show drawbacks in their use that the present device has solved. 
         [0006]    Among said jacks, those described in the U.S. Pat. No. 7,500,592 B1 (Yaksic) dated Mar. 10, 2009 describing the use of non-folding hydraulic jacks can be mentioned. 
         [0007]    Spanish Utility model application ES 1045850 U (Carinox) dated Apr. 4, 2000 and Spanish patent ES 2 208042 B1 (Carinox) dated Feb. 28, 2005 disclose hydraulic jacks especially aimed at assembling and disassembling vertical tanks, which among other differences with the present invention, do not feature removable support fittings. 
         [0008]    Regarding jacks layout, said U.S. Pat. No. 7,500,592 B1 (Yksic) discloses the use of three independent but coordinated hydraulic systems. Thus, the number of hydraulic jacks used must be a multiple of 3. Spanish patent ES 2 211 268 B1 (Cariñox) dated Mar. 8, 2005 describes the operating station for hydraulic systems of this type, whereas Spanish patent ES 2 213 436 (Cariñox) dated Jun. 29, 2005 shows a hydraulic lifting system for assembling and disassembling vertical tanks, where the hydraulic jacks are divided into groups of independent operation for the optimum control of structure verticality. 
         [0009]    On the one hand, the lifting device must be able to grasp or hold the structure safely. To this purpose, the technologies known usually weld accessory supports in the structure as a kind of handles, that the jack uses as a lock or bearing point to support the structure during the lifting operations. On completion of the work, said supports must be removed, which requires considerable manpower and affects the work finishing. 
         [0010]    On the other hand, the presence of a jack prevents operators from working freely. This detail is of vital importance in the construction of metal tanks, since it is crucial to ensure the welding quality of the layers constituting the walls of the container to guarantee the structure strength of the whole. In this case, the device supporting the structure while a new ring is assembled prevents automatic welding machines from being used. 
         [0011]    Additionally, the device itself must be firmly placed, which in general, implies welding its base to the bottom of the tank with the subsequent expense of necessary resources to unweld it once the job is complete. 
         [0012]    The device of the present invention solves all these problems, reducing the temporary welding necessary for assembly to the minimum and allowing its folding so as to allow improvement on the construction conditions of containers. 
       SUMMARY OF THE INVENTION 
       [0013]    The invention relates to a collapsible hoisting device for use in the construction of large metal containers and to a removable accessory applicable thereto, characterized in that it facilitates construction procedures by reducing project times and costs. The collapsible device includes a column ( 2 ) along which respective upper bodies ( 6 ) and lower bodies ( 7 ) that have been inserted into said column ( 2 ) move, said bodies ( 6 ,  7 ) being linked by an extendable means ( 8 ), and said upper bodies ( 6 ) and lower bodies ( 7 ) having a corresponding means of locking or attaching ( 9 ) to said column ( 2 ); said column ( 2 ) being mounted so that it pivots with respect to a base ( 1 ) and said upper body ( 6 ) having a housing ( 609 ) suitable for the insertion of a removable, fingernail-shaped accessory ( 12 ). 
         [0014]    That is, the invention relates to folding lifting device to be used in the construction of large metal tanks, and a removable fitting applicable to said device, the characteristics of which facilitate the construction procedures reducing construction time and costs. The folding lifting device comprises a column ( 2 ) on which the respective upper ( 6 ) and lower ( 7 ) bodies that are inserted in said column ( 2 ) move, being said bodies ( 6 ,  7 ) are linked by means of a tensile element ( 8 ), and said upper ( 6 ) and lower ( 7 ) bodies having a lock or fixing means ( 9 ) to said column ( 2 ); being said column ( 2 ) assembled in a pivot way regarding a base ( 1 ) and said upper body ( 6 ) having a housing ( 609 ) capable of permitting the insertion of a removable fitting with a pawl shape ( 12 ). 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0015]    The present invention is illustrated with schematic figures in its preferred embodiment as follows: 
           [0016]      FIG. 1  illustrates a perspective front view of the folding device, object of the present invention; 
           [0017]      FIG. 2  shows a rear view of the folding device in  FIG. 1 ; 
           [0018]      FIG. 3   a  illustrates a perspective front view of the upper box of the folding device in  FIGS. 1 and 2 . 
           [0019]      FIG. 3   b  shows a perspective rear view of the upper box of the folding device in  FIGS. 1 and 2 . 
           [0020]      FIG. 4   a  illustrates a perspective front view of the lower box of the folding device in  FIGS. 1 and 2 . 
           [0021]      FIG. 4   b  illustrates a perspective rear view of the lower box of the folding device in  FIGS. 1 and 2 . 
           [0022]      FIG. 5  illustrates a perspective front view of the assembly of the hydraulic folding device of the present invention. 
           [0023]      FIG. 6  illustrates a perspective view of the tensile element, preferably a hydraulic piston used in the folding device of the present invention. 
           [0024]      FIG. 7  illustrates a perspective front view of the removable supporting pawls of the folding device of the present invention. 
           [0025]      FIG. 8  is a detail of a wing attached to the base so as to allow the spinning of the column of the folding device of the present invention. 
           [0026]      FIG. 9  illustrates a perspective lower view of one of the symmetrical parts constituting the removable supporting flange of the folding device of the present invention. 
       
    
    
       [0027]    In all the figures already mentioned, equal reference numbers correspond to identical elements of the invention. 
       DETAILED DESCRIPTION OF THE INVENTION 
       [0028]      FIG. 1  shows that the removable device of the present invention, which allows the coupling of accessory supports to fasten various parts of a tank under construction, in a preferred embodiment comprises a pivoted base  1  surface where the jack column  2  is set, and it consists of a rectangular metallic plate folded at 90° at both longer sides, as a upside down “U” shaped tray. These folds  101  at 90° grant the structure resistance and allow the passage of a pivoted shaft  13  (illustrated in  FIG. 8 ). 
         [0029]    Near one of the ends of the longer side (rear end A) of said base  1  a perforation of both folds  101  is done on the plate where the pivoted shaft is to pass so that shaft  13  is parallel to the shorter sides of base  1  and that base  1  is able to spin with a center near one of the extremes of the longer sides. Column  2  of the pivoted shaft is not welded centered on base  1  but near one of the shorter sides of the end opposite to the pivoted shafts (front end B), centered regarding the shorter side. 
         [0030]    Said column  2  is preferably a hollow metal column of a square section, made of an iron sheet. Its lower end is welded to base  1  and the upper end is covered with a welded plate (of which lateral edges are shown in  FIGS. 1 and 2 ) to column  2 . Said plate is perforated so that the stop part and end of run  4  can be screwed. The side close to the pivoted shafts (rear side A) is welded to rack  3 , being located centered on the side regarding the vertical shaft of column  2 . Said rack  3  consists of a metal plate  301 , of the same length of column  2  being the teeth  302  of the rack welded at regular intervals on one of the sides of the plate, consisting said teeth of metal bars of square section, perpendicular to the longer sides of plate  301 . The opposite side of plate  301  is welded to the rear side of column  2 . 
         [0031]    The stop part or body and end of run  4  is formed by a square metallic plate of a slightly longer side than the side of square section of column  2 . The supports of the stretchers  5  to 120° regarding the side, one on each corner are welded on the ends of the front side. The stop and end of run  4  is screwed to the cap of column  2 , centered regarding said cap of column. 
         [0032]    The supporting parts of the stretchers  5 , shown in  FIGS. 1 ,  2  and  5 , are formed by a short steel plate with a perforation  501  near one of its ends so as to allow securing the stretchers. The supports  5  are welded to the end of run and stop body  4  to one of the longer sides, so that they are perpendicular to said body, and protrude an approximate distance equal to half of its longer side. 
         [0033]    Upper box  6  and lower box  7  are assembled along column  2  by means of openings  608  and  701 , moving along said column. Said upper box  6  as well as lower box  7  shown in  FIGS. 3   a  and  3   b  has a safety lock  9  on the rack side  3  of the column (rear side). 
         [0034]    A hydraulic piston  8  joins upper box  6  by means of a shaft  801  which allows one degree of freedom of spinning regarding the shaft perpendicular to column  2 , which is located on the front side, opposite the safety lock system  9 . The fitting support system  10  together with the hydraulic piston  8  are located on the front side. 
         [0035]    Upper box  6  has means to minimize friction when moving along column  2 , being said means formed by parts  605  which fit into the “L” shaped corner parts  606 . In a preferred embodiment, upper box  6  is made of iron sheet, folded and welded, and the means to minimize friction  605  are rectangular teflon pads arranged as a set square on metal plates square folded  606 , located on the corners where the upper box  6  rubs against column  2 , two on the upper rear corners and two on the lower front corners. 
         [0036]    Lower box  7 , shown in  FIGS. 4   a  and  4   b , as well as upper box  6 , has a safety lock  9  on the rack side  3  of the column (rear side), and a support for the hydraulic piston  8  on the opposite side. The hydraulic piston  8  joins lower box  7  by means of shaft  802 , which allows one degree of freedom of spinning with the shaft perpendicular to column  2 . The lower box  7  is preferably made of iron sheet folded and welded. 
         [0037]    Said hydraulic piston  8  shown individually in  FIG. 6  is preferably a standard hydraulic piston linking the upper box  6  with the lower box  7  by their ends  803  and  804  linked respectively to bodies  607  and  703  so as to permit two degrees of freedom to compensate for small variations in both upper  6  and lower  7  box verticality. 
         [0038]    Regarding safety locks of the upper  6  and lower  7  boxes are preferably standard trigger gravity locks or pawl  901  with balance weight  902  permitting free vertical displacement of the box to the top but avoids displacement to the bottom. 
         [0039]      FIGS. 3   a  and  3   b  show the upper box  6  in which the fitting support system  10  is defined comprising two sets of supports  601 , each one formed by two horizontal plates  602  separated by two metallic bars with square section  603  so as to leave a space  609  between both plates, which as a kind of “box frame” allow the insertion of a removable fitting  12  shown in  FIG. 7 . The whole set  602 - 603  is firmly welded to each other and to the upper box  6  in its front side. Each support  602  has a pass-through perforation  604  near the end, by which a through piece is introduced (not shown), such as a bolt or metallic bar, fixing the removable fitting  12  inserted in each box  609 . 
         [0040]    The design of said removable fitting  12  will depend on the object to seize and lift, but all of them should have as a common characteristic one or two protrusive plates  201 , preferably metallic ones, of the space measures within the fitting support system  10 , with a pass-through hole  202  that coinciding with perforation  104  of the fitting support system  10 , will enable being locked by a bolt or similar system. These plates should be placed in the removable fitting  12  in the necessary position for the correct location of the removable fitting  12  in the fitting support system  10 . 
         [0041]    In a preferred embodiment, the removable fitting  12  is a pair of pawls, each one formed by a horizontal plate  201  with a perforation  202  near its end, which will be inserted in one of the “box frames” of the fitting support system  10 . In the opposite end, another plate  203  placed at 90° in vertical position has a threaded hole  204  where an adjusting screw is introduced. 
         [0042]    In another preferred embodiment, the removable fitting  12  is a device of the “fastener” type designed to seize a pipe or vertical cylinder, with two protrusive perforated horizontal plates near its end, which are inserted in the “box frames”  609  of the accessory support system  10 . In  FIG. 9 , a preferred embodiment of this type of fitting can be seen, formed by two equal and opposite plates or parts, each one having a rectangular metallic plate of considerable thickness  901  with a semicircular hole in the middle of one of its longer sides. The two equal and opposite plates or parts have the same diameter that the outside diameter of the vertical pipe may seize. The corresponding supports  902  are welded to the shorter sides, each one with a hole  903  allowing the passage of a bolt (not shown) to link said equal and opposite plates or parts. 
         [0043]    In the lower side of each plate of a considerable thickness  901  a device is welded. Said device is formed by two equal rectangular plates  904  of a smaller size than the plate of considerable thickness  901 , each with a semicircular hole in the middle of one of its longer sides, separated by four metal bars of a square section  905  so as to form two “box frames”  906  of an equal geometry of the “box frames” of the fitting support system  10 , being the whole set firmly welded. Two passing perforations  907  in each part allow securing by means of bolts or other similar system the corresponding horizontal plates with a perforation near each end, which will be inserted in the “box frames” of the fitting support system  10  and the “box” of the “fastener” type device  906  thus attaching the removable fitting “fastener” type to the fitting support system  10  of one or two folding devices of the present invention facing one another, according to the required weight to lift. 
         [0044]    Changing the geometry of the plates of considerable thickness  901  it is possible to adapt this removable fitting to seize different types of objects to be lifted. 
         [0045]    Finally,  FIG. 8  shows wings  11  that allow the spinning of column  2 . Both wings  11  welded to each lateral of base  1  is formed by a perforated iron plate which allows the passage of shaft  13  that links them to the pivoted base  1  welded or fixed to the floor, one at each side of the pivoted base  1  and allows the spinning of the folding device. 
         [0046]    The folding device of the present invention is located on the chosen site so that its front side faces the object to be lifted, at a suitable distance from said object for the proper operation of the removable fitting  12  used to seize the object to be lifted. 
         [0047]    In a preferred embodiment, the removable fitting  12  is a metallic “pawl” designed to seize a metallic plate by its lower edge. In another preferred embodiment, the removable fitting  12  is a metallic device designed to seize cylindrical parts with a fastener at the end, such as sections of a column. 
         [0048]    The folding device is firmly anchored to the floor, thus fixing to this purpose the wings  11  for the spinning of column  2  and the stretchers (not illustrated) on the one hand to the floor and on the other hand to the supporting bodies of the stretchers  5  located on the stop and end of run part  4  of column  2 . In a preferred embodiment the folding device is placed on a metal floor and the attachment of the wings  11  as well as of the stretchers ends to the floor is achieved by welding. 
         [0049]    The following step is to connect the hydraulic system that actuates the hydraulic piston  8 . In a preferred embodiment, the hydraulic system is driven by a central unit ruling and coordinating a multiplicity of similar folding devices that work together as a set to lift a structure. 
         [0050]    They move by actuating the hydraulic cylinder  8 , the upper  6  and lower  7  boxes so that said cylinders remain in the closest position, and at a suitable height to place the removable fitting  12  attached to the object to be lifted. The removable fitting  12  is placed inside the cavities of the fitting support system  10  and they are locked by means of a pin, bolt or similar system. 
         [0051]    In a preferred embodiment, both boxes  609  are placed in their corresponding positions closest to the floor, and the removable fitting  12  used is a pair of “pawls” that fasten a vertical plate by its lower end. 
         [0000]    It is verified that the trigger of the safety lock  9  of the lower box  7  is correctly assembled to lock said box. 
         [0052]    The hydraulic piston  8  is then activated. Said piston tends to separate both boxes  609 , pushing lower box  7  downwards and upper box  6  upwards, which due to the safety lock  9  makes the upper box  6  move upwards, thus moving at the same time the structure attached by the removable fitting  12  attached to the fitting support system  10 . 
         [0053]    In a preferred embodiment, a multiplicity of hydraulic folding devices actuated as a whole lifts a structure of considerable dimensions. 
         [0000]    In a preferred embodiment, the structure of considerable dimensions is a metal tank under construction, held and lifted by the lower edge of the lower ring and the lower ends of the internal columns by means of a multiplicity of folding devices of the present invention: 
         [0054]    Once at the maximum stretching point of the hydraulic piston  8 , it is verified that the trigger of the safety lock  9  of the upper box  6  is properly assembled to lock it, and the hydraulic piston  8  is returned, which tends to pull both boxes together, pushing lower box  7  upwards and upper box  6  downwards. Lower box  7  moves upwards due to the safety lock  9  that immobilizes upper box  6 . 
         [0055]    In a preferred embodiment, a multiplicity of hydraulic jacks that lift a structure of considerable dimensions are actuated as a set to cause pistons to return coordinately. 
         [0056]    The process of verification of the proper lock of the lower box  7 , activating the hydraulic piston  8  to lift the upper box  6  and the structure held by means of said piston using lower box  7  as a supporting point, verifying the proper lock of upper box  6  and returning hydraulic piston  8  to lift lower box  7  is repeated the number of times required to lift the structure to the desired height or until upper box  6  reaches the stop and end of run  4  located at the upper end of the riser. 
         [0057]    In a preferred embodiment, in the construction process of a metal tank of considerable dimensions the roof of the tank attached to one or more rings is lifted by means of this system held by the lower edge of the lower ring up to a proper height so as to allow the insertion of a new lower ring. In this embodiment, the sheets constituting the new ring are placed in position and separated in a uniform manner regarding the upper ring by means of spacers, the thickness of which is slightly greater than the thickness of the supporting “pawls” inserted in the accessory support system  10  of the hydraulic folding device. 
         [0058]    Once the lifted structure is placed in position, it is proceeded to disassemble and remove the removable fittings  12 . 
         [0059]    In a preferred embodiment described above, the “pawls” are removed leaving the tank resting on the spacers of the new ring. 
         [0060]    The stretchers which hold the removable fitting by means of the stretcher supports are released and said fitting is removed by rotating it on the shaft of its pivoted base  1 . 
         [0061]    In the preferred embodiment described above, the folding device is folded at 90°. 
         [0062]    The easiness provided by the folding device design to remove the removable fittings  12  and to be folded, allows the free access to the surface of the structure under construction by operators and tools, preventing the folding device from becoming an obstacle. 
         [0063]    In the preferred embodiment described above, an automatic welding system is placed, which moves along the ring under construction, welding it to the upper ring. 
         [0064]    In a preferred embodiment, a multiplicity of folding devices that lift a structure of large dimensions coordinately are folded sequentially to allow the passage of a welding robot over the whole surface of the structure under construction. In a preferred embodiment, this surface is a ring of a cylindrical tank under construction. 
         [0065]    Once the works on the structure are finished, and if required by the process, the jack is placed again in vertical position, the stretchers to hold the folding device by means of stretcher supports are restored, and the structure lifting process is repeated. 
         [0066]    In the preferred embodiment mentioned above, the process is repeated until the total number of desired rings is added to the tank of considerable dimensions, and the structure is then placed on the tank floor. 
         [0067]    To conclude, the folding device is disassembled and removed. 
         [0000]    In a preferred embodiment, the wings  11  are cut to allow the column to spin and wings  11  for the anchorage of the stretchers welded to the floor and the metal surface of the floor is trimmed to obtain a neat finish. 
         [0068]    With the folding device claimed in this invention the operation following the jack disassembly is minimized, being reduced to just dewelding four small fittings on the structure floor.