Abstract:
The invention concerns a linking system ( 10 ) for fixing building elements ( 20, 30 ) such as natural or artificial stones. The linking system ( 10 ) comprises: a first dowel ( 60 ) having a first internal orifice ( 80 ) comprising a first hole axis, and which is introduced into a first building element ( 20 ) by being adapted to be fixed into a first hole ( 40 ) which has a first hole axis; and a second dowel ( 70 ) having a second internal hole ( 90 ), and which is introduced into a second building element ( 30 ) by being adapted to be fixed into a second hole ( 50 ) which has a second hole axis. Between the first dowel ( 60 ) and the second dowel ( 70 ) is provided a sleeve ( 100 ) wherein a rod ( 110 ) is inserted.

Description:
FIELD OF THE INVENTION 
       [0001]    The invention relates to a linking system for producing a link between at least two building elements. 
       BACKGROUND OF THE INVENTION 
       [0002]    In the art of linking there are known a number of linking systems, for example for linking building elements such as natural or artificial stones and beams from wood or metal. In house building, load-bearing walls are often made of brick stones, the brick stones being linked with mortar made of cement. The result is a rigidly linked wall, the wall being relatively inelastic. The inelasticity of the links makes such walls susceptible to vibrations and shocks caused by earth quakes, for example. 
         [0003]    The construction of mortared brick walls comprises, in addition to laying the brick stones, the step of preparing the mortar, a step of applying the mortar to the brick stones and the step of letting the mortar set during which the linking between the building elements is formed. The step of applying the mortar must occur within a predetermined time span after preparation of the mortar and before the mortar starts setting. The laying of brick stones is restricted to a number of rows, for further rows of brick stones can be laid on top of those brick stones which are linked by the set mortar. This causes delays because of during the construction work. 
         [0004]    Environmental factors are further restricting for the use of mortar, for example the typical temperature for using mortar made of cement being above 5° C. Temperatures below 0° C. pose a problem because the water which is normally used for the preparation of the mortar freezes. Furthermore, the properties and use of certain mortars are subject to higher temperatures and humidity. 
         [0005]    The position of the individual brick stones is determined by their positioning during their laying. Therefore, in order to obtain an accurate wall, certain craftsmanship is necessary and an expensive trained workforce required. 
         [0006]    Nowadays, the building elements of inner and/or non-load-bearing walls are often linked by means of glue. Restrictions for the use of glue are similar to the ones discussed above in connection with the use of mortar. 
         [0007]    Especially in the field of Do-It-Yourself, there are number of systems for inner walls with positioning devices, the positioning devices being operative for positioning the building elements relative to each other. Those positioning devices, for example tongue and groove systems, must be arranged on the building elements while those building elements are being produced. Then, on the construction site the thus formed building elements can then be joined and linked for example with glue. 
         [0008]    Links without glue of building elements are for example known from wooden links. Number of different pin links for example are known in the art of joinery, for example dove tailings which allows an interlocking link between two building elements. The use of glue-free dowel linkings is also known for wooden building elements. German Patent DE 1 107 910 teaches a link between two building elements, the link being effected by a pliable dowel. The pliable dowel is introduced in two holes in two building elements. The axis of the holes are slightly slanted relatively to the normals of the surfaces of the building elements. The holes in the building elements form an obtuse angle, and pressure is exerted on the building elements and the dowel is bent according to this obtuse angle. Preferably, one uses two or more dowels. The inclination of the hole axis towards the surface points into another direction than the inclination of the corresponding hole axis of the hole in the abutting building element. The teaching of the &#39;910 patent is restricted to wooden materials. The &#39;910 patent is especially concerned with the problem of enclosures of air between the dowel and the hole which may result in a link bursting in an explosive manner in case rising ambient temperature causes the enclosed air to expand. The &#39;910 patent discloses a method according to which such severance of the link can be avoided by milling structures within the dowel. 
         [0009]    Bolt-like linking systems are very versatile. A problem with those linking systems is the accessibility of the head of the bolts and nuts, for example when a plurality of rows of building elements like building blocks are joined in order to form a wall. The underside of a building block is not easily accessible once the rows have been fixed. A further problem is the loosening of bolt-like links. Furthermore access to bolts which happen inserted along the direction to which the wall proceeds while being constructed is no longer possible once the wall has been finished. 
         [0010]    Problems with accessibility to bolt heads and nuts and possible positions for the bolts have led to solutions as disclosed in the European patent application EP-A-1 389 687. Application &#39;687 teaches a system for linking building elements in which special linking elements are arranged on the building elements. The linking elements are fixed to the building elements by means of bolts before the building elements are being linked. While assembling the building elements the linking elements effect mashing of the building elements, rendering a non-destructive disassembling of the building elements after their assembly next to impossible. Such systems can be used for the construction of prefabricated houses as disclosed in German patent DE-A-100 266 769. The &#39;769 patent teaches utilising such linking elements for buildings intended for long, as well as medium-term use, for example makeshift housings after earthquakes or military barracks. The patent emphasises advantages in assembling time, costs and the possibility to build houses with less trained workers in contrast to the method like erecting a brick stone wall using mortar. 
         [0011]    The disadvantages of the systems as disclosed in the &#39;769 and the &#39;687 patents are that both systems add further linking elements to the building elements. Those linking elements themselves are rather complicated. 
         [0012]    Another solution for a mortar-free method for erecting brick stone walls is given by the bolt-like linking system for building systems disclosed in European patent application EP-A-1 382 761. Proceeding from similar problems as the &#39;769 patent, the &#39;761 application teaches a linking system wherein starting from a basis plate individual brick stones are secured to the row of brick stones above and below. According to one aspect they are arranged in a lower female thread in the upper fixing means. Lower fixing means start from the base plate, the lower fixing means having a length substantially equal to the height of a brick stone and being arranged with a male upper thread. Brick stones have holes arranged to receive the lower fixing means of the fixing system. Whilst laying one row, the lower fixing means are inserted through the holes of the brick stones. The upper fixing means are bolted to the lower fixing means. The upper part of the upper fixing means is arranged such as to be usable as lower fixing means for the next row. The &#39;761 application discloses a system allowing non destructive disassembling and reassembling of the building elements. According to a preferred aspect, the &#39;761 application discloses positioning devices in order keep the brick stones in place. The &#39;761 application is directed to brick stone walls, facades or buildings having wooden frame constructions. The &#39;761 application does not disclose information about the load-bearing capacities of the walls. 
       OBJECTIVE OF THE INVENTION 
       [0013]    It is therefore an objective of the invention, to provide a versatile stable linking system for different kinds of building elements. 
         [0014]    It is a further objective of the invention to provide a link between building elements, allowing an elastic relative motion of the building elements. 
         [0015]    It is a further objective of the invention to provide a linking system for quick and efficient construction of buildings such as houses under difficult environmental conditions. 
         [0016]    These and other objectives are addressed by providing a linking system for linking the first building element and the second building element. The linking system comprises a first dowel with a first dowel inner hole having a first dowel inner hole axis, fixingly inserted in a first hole with a first hole axis in a first building element, and a second dowel with a second dowel inner hole having a second dowel inner hole axis fixably inserted in a second hole with a second hole axis of a second building element. A sleeve with an inner and outer sleeve radius is being inserted between the dowels into the first dowel inner hole and the second dowel inner hole. The rod with a rod radius is inserted into the sleeve. 
         [0017]    Using of the linking system according to the invention allows linking building elements of a plurality of materials for sufficiently stable boreholes. The materials for the dowel, the sleeve and the rod are adaptable with respect to the structure, for example the surface structure. 
         [0018]    Materials for the dowel, the sleeve and the rod are adaptable with respect to the properties such as elasticity to the materials of the building elements. The diameter of the boreholes is in a range that allows an efficient drilling of holes into the material of the building elements. 
         [0019]    The motion of the linked building elements is mainly determined by the elastic properties of the link, as the link between the building elements is only effected by the linking systems at certain points as well as by frictional forces between the linked building elements. In particular the elastic properties of those links are adaptable in connection with the materials used for the linking systems. This elastic construction of non-rigid walls is particularly suitable for walls in areas prone to earthquakes. 
         [0020]    The use of the disclosed linking system is independent of the ambient temperature. The holes within the building elements can be provided either before being shipped to the construction site or on the spot. Assembling the building elements is suitable for untrained work forces. There is no need for waiting for the mortar to set. 
         [0021]    The link can be for example effected by plying the rod and the sleeve into an obtuse angle. The resulting elastic forces in the plastic deformations within the linking system causes mashing the linking system with the building elements. The link can be effected by deformation of the sleeve and the rods by means of an eccentricity of an upper dowel hole axis with respect to a lower dowel hole axis. This causes the sleeves and the rods to be pressed against a wall of the dowel to a dowel wall, consequently holding the whole linking system with the building elements. 
         [0022]    The link can be affected by deformations and tensions caused by the dowel inner hole axis of the building first dowel not coinciding with the dowel inner hole axis of the second dowel. 
         [0023]    The linking can be affected by deformation and tension caused by, for example, compressing the sleeve dowel and rod, for example, by inserting the rod into a conically arranged dowel inner hole if, for example, the rod has a larger diameter than the conically arranged dowel inner hole of the corresponding depth of insertion. 
     
    
     
       DESCRIPTION OF THE FIGURES 
         [0024]      FIG. 1  shows a disassembled linking system according to the invention. 
           [0025]      FIG. 2   a  shows a two-part dowel for the linking system. 
           [0026]      FIG. 2   b  shows a dowel upper part from  FIG. 2   a.    
           [0027]      FIG. 2   c  shows a dowel lower part from  FIG. 2   a.    
           [0028]      FIG. 3  shows an assembled linking system. 
           [0029]      FIG. 4  shows a further example of an assembled linking system. 
           [0030]      FIG. 5  shows an example of a dowel according to the invention. 
           [0031]      FIG. 6  shows a further example of a dowel according to the invention. 
           [0032]      FIG. 7  shows a further example of a dowel according to the invention. 
           [0033]      FIG. 8  shows an example of a sleeve according to the invention. 
           [0034]      FIG. 9   a  shows an example of a rod according to the invention. 
           [0035]      FIG. 9   b  shows a further example of a rod according to the invention. 
           [0036]      FIG. 9   c  shows two further examples of a rod according to the invention. 
           [0037]      FIG. 10  shows four building elements linked according to the invention. 
           [0038]      FIG. 11  shows a wall construction utilising the linking system according to the invention. 
           [0039]      FIG. 12  shows a building constructed by means of the linking system according to the invention. 
           [0040]      FIG. 13  shows a plurality of links according to the linking system according to the invention. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0041]      FIG. 1  shows a dissembled linking system  10  according to the invention. The first building element  20  is to be linked with a second building element  30 . The first building element  20  and the second building element  30  may be of arbitrary building materials including but not restricted to stones, bricks, concrete or wood. A first hole  40  is drilled into the first building element  20  and a second hole  50  is drilled into the second building element  30 . The first dowel  60  is inserted into the first hole  40  and a second dowel  70  is inserted into the second hole  50 . The first dowel  60  has a first dowel inner hole  80  and the second dowel  70  has a second dowel inner hole  90 . 
         [0042]    According to a preferred aspect of the invention the first dowel  60  and the second dowel  70  are each divided in two sections. The first dowel  60  has a first dowel upper part  62  and a first dowel lower part  64 . The first dowel upper part  62  abuts the surface of the first building element  20  and the first dowel lower part  64  is within the first building element  20 . The first dowel upper part  62  and the first dowel lower part  64  are linked by a conical middle portion  66 . The dowel inner hole diameter of the first dowel upper part  62  is greater than the dowel inner hole diameter of the first dowel lower part  64 . 
         [0043]    Similarly the second dowel  70  has a second dowel upper part  72  and a second dowel lower part  74 . The second dowel upper part  72  abuts the surface of the second building element  30  and the second dowel lower part  74  is within the second building element  30 . The second dowel upper part  72  and the second dowel lower part  74  are connected by a conical middle portion  76 . The dowel inner hole diameter of the second dowel upper part  72  is greater than the dowel inner hole diameter of the second dowel lower part  74 . 
         [0044]    The first dowel upper part  62  and the second dowel upper part  72  are substantially the same length and are referred to by reference D in  FIG. 1 . Similarly the depth of the first hole  40  and the second hole  50  are substantially the same and are referred to by reference C. 
         [0045]    A sleeve  100  is inserted into the first dowel inner hole  80  up to a depth of about ⅓ and a rod  110  is inserted into the second hole  50 . The sleeve  100  is typically arranged as a hollow cylinder. Rod  110  is for example arranged as a hollow cylinder or as a solid cylinder. 
         [0046]    In an exemplary aspect of the invention the first building element  20  and the second building element  30  are concrete slabs. The first dowel  60  and the second dowel  70  are made of plastic or some silica polymer. Silica particles can, for example, be added to a plastic, for example polyethylene, in order to furnish a silica based enforcement. The first dowel  60  and the second dowel  70  are provided with a ceramic coating. By means of the ceramic coating or the silica based enforcement are, for example suitable to increase the friction between the building elements  20  and  30 , the dowel  60  and  70  and the sleeve  100  and the rod  110  where concerned. 
         [0047]    The first dowel upper part  62  and the second dowel upper part  72  have length of 120 mm, a dowel inner hole diameter of 25.8 mm and a dowel outer diameter of 49.6 mm. The first dowel lower part  64  and the second dowel lower part  74  have a length of 80 mm, a dowel inner hole diameter of 20.2 mm and a dowel outer diameter of 49.6 mm. The rod  110  is made of St37 steel with a length of 398 mm and a diameter of 19 mm. The first hole  40  and the second hole  50  have a hole diameter of 50 mm and a depth of 200 mm. 
         [0048]    The sleeve  100  is made of St37 steel having a sleeve inner diameter of 19.8 mm and a sleeve outer diameter of 25 mm and a length of 238 mm. The dimensions provided are exemplary and shall not be construed to limit the scope of the invention. 
         [0049]    According to one aspect of the invention the first dowel  60  and the second dowel  70  are arranged as one piece. According to another aspect of the invention the first dowel  60  and the second dowel  70  are provided as two separate pieces corresponding to dowel upper parts  62  and  72  and the dowel lower parts  64  and  74 . From a manufacturing point of view the two piece dowel is probably easier to produce. 
         [0050]      FIG. 2   a  shows a further aspect of the invention according to which first dowel  60  as well as the second dowel  70  are arranged each as two piece dowels. According to this aspect of the invention the first dowel  60  is divided into a first dowel upper part  62  having a first upper dowel inner hole  82  and a first dowel lower part  64  having a first lower dowel inner hole  84 , the first dowel upper part  62  and the first dowel lower part  64  being arranged each as separate pieces. Similarly, the second dowel  70  is divided into a second dowel upper part  72  having a second upper dowel inner hole  92  and a second dowel lower part  74  having a second lower dowel inner hole  84 , the second dowel upper part  72  and the second dowel lower part  74  being arranged each as separate pieces. The first dowel upper part  62  and the second dowel upper part  72  having a length of 54 mm with an outer diameter of 44 mm and a dowel inner hole diameter of 21.5 mm. The first dowel lower part  64  and the second dowel lower part  74  having a length of 36 mm with an outer diameter of 44 mm and a dowel inner hole diameter of 18 mm. The dowel inner hole  82  of the first dowel upper part  62  and the dowel inner hole  84  of the first dowel lower part  64  are not coaxially arranged according to one aspect of the invention, i.e. the dowel inner hole axis  63  of the first dowel upper part  62  and the dowel inner hole axis  65  of the first dowel lower part  64  are offset against each other and the dowel inner hole axis  63  of the first dowel upper part  62  and the dowel inner hole axis  65  of the first dowel lower part  64  are eccentrically arranged. Similarly the dowel inner hole  92  of the second dowel upper part  72  and dowel inner hole  94  of the second dowel lower part  84  are not arranged coaxially according to one aspect of the invention, i.e., the dowel inner hole axis  73  of the second dowel upper part  72  and the dowel inner hole axis  75  of the second dowel lower part  74  are offset against each other and dowel inner hole axis  73 ,  75  are eccentrically arranged. For example, the dowel inner hole axis  63  of the first dowel upper part  62  and the dowel inner hole axis  73  of the second dowel upper part  72  or the dowel inner hole axis  65  of the first dowel upper part  64  and the dowel inner axis  75  of the second dowel lower part  74 , respectively, may be shifted by about 1 mm against the respective hole axis of the work pieces, the respective dowel axis coinciding with the axis of the boreholes. The first dowel upper part  72  and the second dowel upper part  74  are rotated by 15° against the first dowel lower part  62  and the second dowel lower part  72 , respectively in the first hole  40  and the second hole  50  respectively in order to link with the eccentricities. Furthermore, the eccentricities of the first dowel  60  and the eccentricities of the second dowel  70  may be rotatably arranged against each other. For the material of the first dowel  60  and the second dowel  70  polyethylene may be used having 8.9% silicate particles per weight. The linking system  10  and the rod  110  produced from steel, having a length of 180 mm and a diameter of 80 mm and a sleeve  100  made of steel having a sleeve inner diameter of 80 mm, a sleeve outer diameter of 21.5 mm and a length of 108 mm. 
         [0051]    In  FIG. 2   b  the dowel upper part  230  which corresponds to the dowel upper part  62 ,  72  in  FIG. 2   a  are separately represented for the first or the second dowel. In  FIG. 2   c  the dowel lower part  220  which corresponds to the dowel lower parts  64 ,  74  from  FIG. 2   a  are separately represented for the first or the second dowel. According to the represented aspect of the invention, the dowel lower part  220  has tongues  232  ranged to engage with the grooves  222  of the dowel upper parts  230  in order to prevent a mutual rotation of the dowel upper parts  230  and the dowel lower parts  220 . 
         [0052]      FIG. 3  shows the assembled linking system  10  from  FIG. 1 . Rod  110  is completely inserted into sleeve  100 . The rod  110  and the sleeve  100  held into position by forces (F) exerted by the first dowel  60  and the second dowel  70  on the sleeve  100 . 
         [0053]      FIG. 4  shows an aspect of the invention in which the dowel inner hole axis  63  of the first dowel upper part  62  and the dowel inner hole axis  65  of the first dowel lower part  64  and the dowel inner lower axis  73  of the second dowel upper part  72  and the dowel inner hole axis  75  of the second dowel lower part  74  are not coaxially arranged. In this manner, a stronger force is exerted on the sleeve  100 . 
         [0054]    Further aspects of the linking system according to the invention are shown in  FIGS. 5 to 7 . In these aspects of the invention the material used for the first dowel  60  and the second dowel  70  is polyethylene having 8.9% silicate particles per weight. The rod  110  (shown separately by example in  FIG. 9   a ) is made of steel and has a length of 180 mm and a diameter of 18 mm. The sleeve  100  (shown separately by example in  FIG. 8 ) is made from steel having a sleeve inner diameter of 18 mm and a sleeve outer diameter of 21.5 mm and a length of 108 mm. The first dowel  60  and the second dowel  70  each comprise a dowel upper part  62 ,  72  and a dowel lower part  64 ,  74 . The first dowel lower part  64  and the second dowel lower part  74  each comprise retaining fastening hooks  240 . The retaining fastening hooks  240  may be arranged as stays with a thickness of 3 mm and a width of 6 mm and a length of 33 mm, protruding from the first dowel lower part  64  and the second dowel lower part  74 . There are two versions of the first dowel  60  and the second dowel  70  of the linking system  10 ; 
       Example 1 
       [0055]    ( FIG. 5 ): The dowel upper part  230  has a length of 55 mm and a dowel inner hole diameter  250 , the dowel inner hole diameter  250  being arranged to conically taper from 24 mm to 21.5 mm and to remain constant at a value of 21.5 mm for the next 11 mm of its length and a dowel outer diameter of 44 mm. The dowel lower part  220  has a length of 33 mm, the dowel outer diameter 44 mm and the dowel inner hole diameter  225  conically tapering from 19 mm to 18 mm. Transition between the dowel upper part  230  and the dowel lower part  220  is arranged by means of a conically extending middle portion  255  having a length of 1 mm. The dowel lower part  220  may be arranged with a slit or slits. 
       Example 2 
       [0056]    ( FIG. 6 ): The dowel upper part  310  has a length of 55 mm and a dowel inner hole diameter  315  of 24 mm and a dowel outer diameter of 44 mm. The dowel lower part  320  has a length of 33 mm and a dowel inner hole diameter  325  of 18 mm and a dowel outer diameter of 44 mm. Transition between the dowel upper part  310  and the dowel lower part  320  is arranged by means of a conically extending middle portion  330  having a length of 3 mm. The dowel inner hole axis  301  of the dowel lower part  320  is shifted by 2 mm against the dowel inner hole axis  316  of the dowel upper part  310  corresponding to the dowel axis. According to this aspect of the invention the dowel axis is arranged to coincide with the hole axis. The positions of the axis are shown in cross sectional view in  FIG. 6 . 
       Example 3 
       [0057]    Given the dimensions of the dowel  200  from the first example ( FIG. 5 ) the dowel inner hole  415  of the dowel upper part  410  and the dowel inner hole  425  of the dowel lower part  420  is eccentrically offset against the dowel  400 . That is the common axis  416  of an upper dowel inner hole  415  and a lower dowel inner hole  425  is offset, for example by 2 mm against the dowel axis  401  as shown in cross sectional view in  FIG. 7 . If dowel  400  is used in the linking system according to the invention, the dowel axis  401  would coincide with the hole axis. If dowel  400  is used as the first dowel  60  and as the second dowel  70  then the first dowel  60  and the second dowel  70  inserted into the first and second hole while being rotated against each other by 15°, i.e. the eccentricities of the common axis  416  of the first dowel  60  and the common axis  416  of the second dowel  70  are not aligned. 
         [0058]    Three further aspects of the rod  110  are shown in  FIGS. 9   b  and  c . According to the aspect of the invention as shown in  FIG. 9   c  the rod  110  has a lengthways groove  810  as shown in more detailed in  FIG. 9   c . The rod  110  has an outer diameter of 18 mm. The depth (3.5 mm) of the fluted periphery  810  is larger than the eccentricity of the dowel inner hole axis of the corresponding dowels  60 ,  70 . Two aspects of the rods  110  according to the present invention are shown in  FIG. 9   b . In both aspects of the present invention the rods  910  and  920  are have lengthways grooves on the surface of the rods. In one aspect of the invention rod  910  has deep grooves  930  whereas according to another aspect of the invention the rod  920  has shallow grooves  930 . 
         [0059]      FIG. 10  shows a system  1000  comprising two building elements  1010  and  1020  having pre-mounted dowels  1030 , sleeves  1040  and rods  1050 . The dowels  1030 , sleeves  1040  and rods  1050  may be pre-mounted in one of the building elements  1010  and  1020 , for example in the factory producing building elements such as to facilitate fast assembling on the construction site of the building elements  1010 ,  1020 . 
         [0060]    Another version of the system  1000  is shown in  FIG. 11 . The wall comprises a variety of building elements  1110  and dowels, rods and sleeves commonly referred to in this example by reference numeral  1120 , having been pre-mounted on the building element  1110 . 
         [0061]    A house—or any other kind of building—is shown in  FIG. 12 . There are shown different examples for linking the building elements  1210  using the linking systems according to the invention.  FIG. 13  shows a magnified view of the links shown in  FIG. 12 . 
         [0000]    
       
         
               
             
               
               
             
           
               
                   
               
               
                 Reference List 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 Linking system 
               
               
                 20 
                 First building element 
               
               
                 30 
                 Second building element 
               
               
                 40 
                 First hole 
               
               
                 50 
                 Second hole 
               
               
                 60 
                 First dowel 
               
               
                 62 
                 First dowel upper part 
               
               
                 63 
                 Dowel inner hole axis of the first dowel upper part 
               
               
                 64 
                 First dowel lower part 
               
               
                 65 
                 Dowel inner hole axis of the first dowel lower part 
               
               
                 66 
                 Adaptor 
               
               
                 70 
                 Second dowel 
               
               
                 72 
                 Second dowel upper part 
               
               
                 73 
                 Dowel inner hole axis of the second dowel upper part 
               
               
                 74 
                 Second dowel lower part 
               
               
                 75 
                 Dowel inner hole axis of the second dowel lower part 
               
               
                 76 
                 Adaptor 
               
               
                 80 
                 First dowel inner hole 
               
               
                 82 
                 First upper dowel inner hole 
               
               
                 84 
                 First lower dowel inner hole 
               
               
                 90 
                 Second dowel inner hole 
               
               
                 92 
                 Second upper dowel inner hole 
               
               
                 94 
                 Second lower dowel inner hole 
               
               
                 100 
                 Sleeve 
               
               
                 110 
                 Roo 
               
               
                 200 
                 Dowel 
               
               
                 220 
                 Dowel lower part 
               
               
                 222 
                 Nut 
               
               
                 225 
                 Dowel inner hole diameter of the dowel lower part 
               
               
                 230 
                 Dowel upper part 
               
               
                 232 
                 Spring 
               
               
                 240 
                 Retaining hook 
               
               
                 250 
                 Dowel inner hole diameter of the dowel upper part 
               
               
                 255 
                 Middle portion 
               
               
                 300 
                 Dowel 
               
               
                 301 
                 Dowel inner hole axis of the dowel lower part 
               
               
                 310 
                 Dowel upper part 
               
               
                 315 
                 Dowel inner hole diameter of the dowel upper part 
               
               
                 316 
                 Dowel inner hole axis of the dowel upper part 
               
               
                 320 
                 Dowel lower part 
               
               
                 325 
                 Dowel inner hole diameter of the dowel lower part 
               
               
                 330 
                 Middle portion 
               
               
                 400 
                 Dowel 
               
               
                 401 
                 Dowel axis 
               
               
                 410 
                 Dowel upper part 
               
               
                 415 
                 Dowel inner hole of the dowel upper part 
               
               
                 416 
                 Joint axis 
               
               
                 420 
                 Dowel lower part 
               
               
                 425 
                 Dowel inner hole of the dowel upper part 
               
               
                 450 
                 Hole 
               
               
                 800 
                 Rod 
               
               
                 810 
                 Periphery 
               
               
                 910 
                 Bolt 
               
               
                 920 
                 Bolt 
               
               
                 930 
                 Lenghtway groove 
               
               
                 1000 
                 System 
               
               
                 1010 
                 Building element 
               
               
                 1020 
                 Building element 
               
               
                 1030 
                 Dowel 
               
               
                 1040 
                 Sleeve 
               
               
                 1050 
                 Bolt 
               
               
                 1110 
                 Building element 
               
               
                 1120 
                 Dowel, sleeve and bolt