Patent Publication Number: US-2022213679-A1

Title: Column Shoe Manufactured From One Piece of Sheet Metal

Description:
TECHNICAL FIELD 
     The present invention relates to a bent column shoe formed from one piece of sheet metal. 
     BACKGROUND OF THE INVENTION 
     Light building structures such as carports, pergolas, outhouses and similar are often not built on a stone or concrete foundation. They are typically constructed from a wooden structure coated with boards or sheet material. However, the posts of the wooden structure cannot be inserted directly into the ground, as in the long term, this would cause the wood to weaken due to moisture from the soil. Therefore, column shoes, also called post bases, are used to lift the columns a distance off the ground, so that there is no contact between the columns and the soil. In addition, the column shoes are also used to ensure that the columns can be easily placed at the same level, thereby minimising the need to adapt each column/post. 
     Since the column shoe is thus the part in contact with the soil or the substrate for the building structure, the column shoe is required to be able to withstand the moisture in the substrate, direct rain impact, and rainwater collected at the column shoe. Column shoes manufactured from metal are typically galvanised in order to be able to withstand this moisture impact for a sufficient period of time. However, galvanisation is an expensive part of the manufacturing process, as the column shoe cannot be subjected to a galvanisation process until after completed machining and assembly. This is due to the fact that joints and burrs etc. will exist which require the galvanisation process to be the last process to be carried out. 
     The column shoe needs to carry the load from the structure above it. The column shoe being a substantially slim elongated structure, the properties are often made using Euler formula but typically supported by experimentally obtained values as well. As a starting point, such calculation uses the load subjected to the column shoe directly on the support section and hence directly on the anchor section i.e. in an angle of zero degrees to the longitudinal axis of the anchor section. In this ideal situation, the amount of material in a cross-sectional view is important. 
     Typically, the particular part in contact with the column shoe is a column or post made of wood, concrete or wood-fibre composite having a greater cross-sectional area or radial extension than the body of the column shoe. Hence, there is a risk that the column shoe is subjected to a load a distance away from the centre of the body of the column shoe and therefore a torque is applied. Hence, apart from the direct load on the column shoe, it is highly necessary to pay attention that a slim anchor section of the column shoe could be in risk of buckling due to the torque also. 
     It is a first object of the present invention to provide a column shoe that is strong and still simple and cheap to manufacture. 
     It is a further an object of the present invention to provide a column shoe that can be produced in a sufficiently strong design, in which galvanisation is carried out before production and assembly. 
     The present invention is hereinafter referred to as a ‘column shoe’, wherein column shoe is a broad term for an element on which both a column or a post or similar building element of a structure can be supported. 
     BRIEF SUMMARY OF THE INVENTION 
     The present invention relates to a bent column shoe formed from one piece of sheet metal with a material thickness comprising:
         an anchor section with a longitudinal axis and a width axis, wherein the anchor section has a first end and a second end,   a supporting section with a first supporting end and a second supporting end, wherein the first supporting end is in extension of the second end of the anchor section,   a support section with a support face, arranged substantially perpendicular to the longitudinal axis of the anchor section, and wherein the support section is arranged in extension of the supporting section, and   at least one fastening face arranged substantially perpendicular to the support face, and wherein the anchor section, the supporting section, the support section and the at least one fastening face are manufactured from one and the same piece of sheet metal, wherein the anchor section, measured along the width axis, comprises at least three layers of the sheet metal arranged to provide at least three times the material thickness relative to the support section measured along the longitudinal axis.       

     In this way, a high strength is achieved in the anchor section in a simple manner without the sections of the column shoe being welded together. This strength has thus been obtained by folding alone. As no welding is used to connect the sections, additional freedom is obtained in choice of material. It is thus possible to use e.g. galvanised sheet material, where the sheet material is galvanised before the column shoe is bent. This results in a higher corrosion resistance, as it is easier to control galvanisation when clean sheet material is galvanised. If welding is used, the column shoe must be galvanised after welding, and as welding often causes burrs, galvanising after welding will incur much greater risk of having areas with low-quality galvanisation. 
     Furthermore, when the anchor section is bent in this way a high mass of material i.e. the amount of material in relation to the total cross-sectional area is achieved. This means that the anchor section is capable of withstanding high loads subjected from the structure the column shoe supports. When bending the column shoe only, a small amount of energy is used during the manufacturing process, and hence the final product achieves a low carbon footprint compared to e.g. welded column shoes. 
     In an embodiment, the at least three layers are substantially parallel. 
     In an embodiment, the second end of the supporting section may extend to be flush with the support face. 
     In an embodiment, the second end of the supporting section may have a layout of the sheet metal wherein the two layers the furthest apart from each other are connected via at least one additional layer in a bent or curved line i.e. a line different from straight. In this way it is achieved that the second end of the supporting section in particular the rim of the second end of the supporting section provide a larger surface to additionally support the beam, post or column to be supported by the support face. Having a line different from straight the second end of the supporting section adds additionally to the total area of the supporting face compared to a straight line. 
     In an embodiment, the column shoe is formed from one piece of sheet metal, wherein the width of the anchor section comprises four layers of sheet metal i.e. four times the material thickness of the support section. In this way, additional strength in the anchor section is obtained. 
     Furthermore, bent column shoes can be formed from one piece of sheet metal, wherein anchor sections comprise three 180° bends and four substantially parallel flat areas. 
     In this way, it is achieved in a simple manner that the anchor section has a strong overall material thickness in the width direction. It is possible in this way to achieve the strong overall material thickness alone by folding. 
     The bent column shoe may be formed from one piece of sheet metal, wherein the supporting section comprises a supporting end part, the end face of which comprises a support edge at substantially the same level as the support face of the support section. 
     In this way, an additional support face is obtained under the column or post, which is maintained resting on the support face. Furthermore, it is achieved that the load from the post or the column is partially distributed in a straight line across the anchor section. Over this area, the pressure from the post or the column thus only affects the column shoe with a minimal moment. 
     Furthermore, the bent column shoe may be formed from one piece of sheet metal, wherein the second supporting end of the supporting section has a width which is wider than the first supporting end. In this way, increased strength is achieved in the transition between the support section and the supporting section. The transition can thus absorb a larger moment applied to the support section. 
     Furthermore, the bent column shoe may be formed from one piece of sheet metal, wherein the supporting section expands evenly in width from the first support end to the second supporting end. In this way, production of the column shoe is facilitated. In this way, it is also possible to adjust the width of the support section, as an increased width of the second supporting end may also expand the support section. 
     In an embodiment, the width of the anchor section may comprise four layers of sheet metal providing four times the material thickness of the support section. 
     In an embodiment, the layers of the anchor sections may have at least two substantially parallel layers and one or more slanted or curved layer(s). In this way, it is achieved that a certain overall width of the anchor section may be achieved. Furthermore, the manufacturing process may be adjusted to a specific end use of the column shoe. 
     In an embodiment, the bends for providing the layers of the anchor section may be less than 180°. In this way, it is achieved that the material subjected to smaller stress. 
     In an embodiment, the material of the sheet metal constitutes more than 25% of the cross-sectional view of the anchor section. In this way, the anchor section is more resistant to buckling. 
     In an embodiment, the galvanized material for manufacturing the column shoe may be comprise a steel material according to EN10346 and a coating equivalent to 50 μm Zn achieved by hot galvanization. In this way, it is achieved that the pre-galvanized material i.e. galvanized before the manufacturing of the column shoe has galvanic migration of the coating, and hence effectively the full column shoe is automatically galvanized when in final use. 
     Likewise, the bent column shoe may be formed from one piece of sheet metal, wherein the side faces of the anchor section comprise recesses, and/or wherein the bent areas of the anchor sections comprise recesses. In this way, good adhesion is obtained when embedding in e.g. concrete. 
     The bent column shoe may be formed from one piece of sheet metal, wherein the recesses of the side faces have an inclined longitudinal axis relative to the longitudinal axis of the anchor section. In this way, longer recesses are achieved without weakening the anchor section. 
     In an embodiment, the bent column shoe is formed from one piece of sheet metal, wherein the column shoe is manufactured from galvanised high-strength steel such as S220GD, S250GD, S280GD, S320GD or S350GD. In this way, a high-strength column shoe is achieved, which can still be manufactured in e.g. a follower tool. 
     In an embodiment, the sheet metal may be stainless steel according the EN10088 having a molybdenum content of 2% or more. In this way, the sheet metal is still formable in a multi station stamping/die process and hence the column shoe is suitable for use near particular salty conditions e.g. near the sea. 
     Reference is made above to European standard specifications. The corresponding US standard specifications are i) ASTM A653 for pre-coated metal, ii) ASTM A924-18 for general requirements for steel sheet, metallic-coated by the hot-dip process, and iii) ASTM A480-14 b  for general requirements for flat-rolled stainless and heat-resisting steel plate, sheet, and strip. 
     Furthermore, the column shoe may be formed from one piece of sheet metal, wherein the material thickness of the initial plate metal is 1 mm-5 mm, or 1.5 mm-4.5 mm, or 2 mm-4 mm, or 2.5 mm-3.5 mm. 
     Moreover, the bent column shoe may be formed from one piece of sheet metal, wherein the fastening section and/or the support section comprise a number of holes for fastening between the column shoe and the post to be mounted. 
     In an embodiment, the support section is deeper than the anchor section. Wherein the support section is more than 50% deeper than the anchor section. In this way, it is achieved that the support section can receive and cover the entire cross-sectional area of the post which is mounted in the column shoe. 
     In an embodiment, the at least one fastening section comprises cut-off corners. In this way, the risk of injury to workers handling the column shoes is decreased. 
     In addition, the holes in the one fastening section may be offset in relation to the holes in the other fastening section. 
     In this way, it is achieved that e.g. a post or column of wood to be fastened through the holes are less likely to crack. 
     Further, a circular cross-sectional shadow area of the anchor section may be 10 mm-50 mm, or 12.5 mm-40 mm or more preferred 15 mm-30 mm. 
     In this way it is achieved, that the anchor section of the column shoe may be inserted in a drilled hole. This is particularly relevant in situations wherein the column shoe is anchored in existing solid concrete, cliff or other hard material that is not e.g. poured around the anchor section. In these situations, it is a significant reduction in time and expenses to have the hole to be drilled as small as possible. 
     The present invention relates to a method of manufacturing a column shoe wherein the base material is a coil and the column shoe is manufactured having the longitudinal axis of the anchor section arranged transversely to the longitudinal axis of the base material during the bending of the entire column shoe. 
     Finally, the width of the support section may be changed without changing the transverse dimension of the base material. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
       The drawings only serve as explanation of the present invention and should in no way be considered as limiting to the description of the present invention. It furthermore applies that shapes and sizes in the drawings of various parts are schematic and intended to provide a better understanding of the invention and should therefore not be used to specifically limit the shapes and sizes of various parts in the present application. Those skilled in this area will be able to select the possible shapes and sizes to implement the invention under the guidance of the present application. 
         FIG. 1A  perspectively shows a column shoe according to the invention, 
         FIG. 1B  shows a side view of the column shoe of  FIG. 1A , 
         FIG. 1C  shows a bottom view of the column shoe of  FIG. 1A , 
         FIG. 1D  shows a front view of the column shoe of  FIG. 1A , 
         FIG. 1E  shows a cross-section along the line A-A of the column shoe shown in  FIG. 1D , 
         FIG. 2A  shows an additional embodiment of a column shoe according to the invention, 
         FIG. 2B  shows a bottom view of the column shoe of  FIG. 2A , 
         FIG. 2C  shows a cross-section along the line A-A of the column shoe shown in  FIG. 2A , 
         FIG. 3A  perspectively shows the column shoe of  FIG. 1A  embedded in a block, 
         FIG. 3B  shows a top view of the column shoe of  FIG. 3A , 
         FIG. 3C  shows a section along the line A-A of the column shoe shown in  FIG. 3A , 
         FIG. 4  perspectively shows the column shoe shown in  FIG. 3A  with a post mounted, 
         FIG. 5  shows a light wooden structure, e.g. a carport in which four posts are held by column shoes as shown in  FIG. 1A , 
         FIG. 6A-6C  show a further embodiment of the column shoe according to the invention, 
         FIG. 7A  shows the flat sheet metal piece before bending to the embodiment shown in  FIG. 1 , and 
         FIG. 7B  shows the flat sheet metal piece before bending to the embodiment shown in  FIG. 6A . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     With reference to the accompanying drawings, the present invention will be described in more detail in the following. 
       FIGS. 1A through 1E  all show the column shoe  1  in different perspectives and sections, and all sub-elements can be mutually referenced to the figures in order to see reference numerals.  FIG. 1A  perspectively shows a bent column shoe  1  formed from a single piece of sheet metal having a thickness wt. The column shoe  1  has an anchor section  2  with a longitudinal axis LA and a width axis BA, wherein the anchor section  2  has a first end  3  and a second end  4 . Seen in immediate extension of the anchor section  2  is a supporting section  5  with a first supporting end  6  and a second supporting end  7 , wherein the first supporting end  6  is thus in direct extension of the second end  4  of the anchor section  2 . The supporting section  5  is connected to a support section  9  via a joint section  8 . The support section  9  has a support face  10 , which is arranged substantially perpendicular to the longitudinal axis LA of the anchor section  2 . The support section  9  may also be arranged at angles other than approximately perpendicular to the longitudinal axis of the anchor section. It is seen in this embodiment that the support section  9  is divided into two sub-sections which cooperate as one support section  9 , and therefore both are indicated with the same reference numeral. Each of the sub-sections of the support section  9  furthermore have a fastening face  11  arranged substantially perpendicular to the support face  10 . Perpendicular to both the longitudinal axis LA and the width axis BA is defined a depth axis DA, so that the total support area  10  can be found by measuring (and multiplying) the length parallel to the width axis from fastening face to fastening face i.e. along the support width BW and parallel to the depth axis along the support face  10 , respectively. It is seen that the anchor section  2 , the supporting section  5 , the support section  9  and the fastening face  11  are manufactured from one and the same piece of sheet metal. It is seen that the corners  12  of the fastening faces  11  are bevelled/cut off, thereby minimising the risk of injury to the workers handling the column shoes. It should be understood from this figure that the entire column shoe  1  is shaped from bends and punches only and is thus manufactured without welds. 
       FIG. 1B  shows a side view of a column shoe  1 . It is seen that the anchor section  2  has a number of recesses  15  in the actual bends  16 , i.e. the area where the anchor section  2  is bent approx. 180°. In the flat areas  17 , there are likewise a number of inclined recesses  18 . It is stressed that the shown recesses  16 ,  18  are examples of embodiments and that they can have several forms. The purpose of the recesses  16 ,  18  is to ensure a good connection between the column shoe  1  and a material in which it is embedded, e.g. concrete. It is seen that the depth of the supporting section  5  measured parallel to the depth axis DA grows from the first supporting end  6  to the second supporting end  7 . It is seen that the supporting section  5  along the depth axis DA stretches, substantially, to the back edge of the support section (not visible) and the fastening face  11 , respectively. It is also seen that the fastening face  11  has holes  18  for receiving e.g. screws, bolts or nails. 
       FIG. 1C  shows a bottom view of a column shoe  1 , i.e. from the first end  3  of the anchor section  2 . It is thus the underside of the support section  9  that is seen, wherein the underside of the support section  9  is opposite the support face  10  (not visible). In this view, the folds  16  are clearly visible. Furthermore, it is seen that the bends  16   a,    16   b,    16   c,  jointly referred to as  16  when distinction is not necessary, are folds of approximately 180°, and each layer  17  of the fold has a flat extent, i.e. layers or flat areas  17 . In this embodiment, it is seen that the layers  17  (flat areas  17 ) are substantially parallel, but it should be understood that one or more of the layers  17  in another embodiment may have another angle different from 180° relative to each other. In a later embodiment, it is shown that the layers  17  do not need to be flat but could be curved. 
       FIG. 1D  shows a front view of a column shoe  1  perpendicular to the width axis BA (see  FIG. 1A ). The figure shows that the support section  9  comprises the entire area between the fastening faces  11 . The figure also shows that this embodiment, between the two sub-sections  9   a  and  9   b,  comprises an upwardly extending supporting end part  20  with an end face having a support edge  21 . It is seen that the support edge  21  is substantially in the same plane as the support face  10 . In this way, an additional support face is thus obtained between the two sub-support faces. A joint area  25  is found in the transition between the support section  9  and the supporting section  5 . As there are two sub-sections  9   a,    9   b,  there are thus also two joint areas  25 . In this view, it is clearly seen in this embodiment of the column shoe  1  that the two folds  16   a,    16   b  have an angle a relative to each other. In this embodiment, the angle is below 45°. In this way, a wider support section  9  is obtained. It is furthermore achieved that the moment of resistance of the support section  9  is increased, as the supporting section  5  supports the support section  9  further away from the centre of the support section. A properly positioned post or column (not shown) will abut the entire support face  10  including the supporting edge  21 , and thus have its centre located centrally above the centre axis of the column shoe  1 . The supporting section thus increases the strength, as part of the force impact will be transferred to the supporting section rather than the sub-section  9   a,    9   b  of the support section  9 . In this embodiment of the column shoe  1 , it is thus seen that measured along the width axis BA, the overall material thickness in the supporting section  5  as well as in the anchor section, respectively, is more than four times the amount of material in each sub-section  9   a,    9   b  of the support section  9  measured along the longitudinal axis LA. 
       FIG. 1E  shows a cross-section of the second supporting end  7  of  FIG. 1D . It is seen that the material thickness wt of the sheet metal measured accumulated along the width axis BA is four times the material thickness wt of the support section measured along the longitudinal axis LA (see  FIG. 1A ). In this embodiment, the substantially layers  17  (flat areas) of sheet metal are not all parallel. The two outermost ones are, in any cross-section, parallel, but as can be seen in  FIG. 1D , there is not the same distance between the layers  17  in two different cross-sections. 
       FIGS. 2A-2C  show an embodiment of a column shoe  1  according to the invention, wherein the supporting section  5  along the longitudinal axis is a direct extension of the anchor part  2 , i.e. a direct extension in which the layers  17  (flat areas) are parallel, and in which the folds  16  are 180° in both the supporting section  5  and the anchor section  2 . As seen in  FIG. 2C  the metal thickness wt of the sheet metal provide four times the metal thickness across the width i.e. providing 12 mm of metal if the sheet metal thickness is 3 mm. Similar to the embodiment shown in  FIG. 1 , the supporting section  5  has an upwardly extending supporting end part  20  with a support edge  21 . It is seen that in this embodiment, the angle between the support section  9  and the outermost layers  17  of the supporting section is substantially 90°, wherein in the embodiment shown in  FIGS. 1A-1E , the angle between the outermost flat areas is greater than 90°. It is furthermore seen (best in  FIG. 2B ), similar to the embodiment shown in  FIGS. 1A-1E , that the second supporting end  7  has a greater extent along the depth axis DA than the first supporting end  6 . 
       FIGS. 3A-3C  show a column shoe  1 , as shown in  FIG. 1A , embedded in a concrete block  30 . It is seen that the supporting part  5  is not embedded in the concrete block. In this way, a distance is obtained from the substrate to the support face  10 , wherein the substrate in this case is the surface  31  of the concrete block  30 . In this way, it is avoided that the support face  10  and thus the bottom of a post (not shown, see possibly  FIG. 4 ) is at risk of being underwater or generally coming into contact with moisture from the soil/substrate. It is also seen that recesses  15  are embedded in the concrete block  30  and thereby help to increase the contact between the concrete block  30  and the column shoe  1 . The column shoe  1  is thus harder to pull out of the concrete. The fastening faces  11  are substantially perpendicular to the surface  31  of the concrete block  30 . 
       FIG. 4  shows an embedded column shoe  1  as shown in  FIG. 3A  with a post  40  mounted. The post  40  stands on the support face  10  (not visible) and is attached to the fastening faces  11  using a number of screws  41 . 
       FIG. 5  shows a carport  50 , in which the supporting posts  40  are mounted in embedded column shoes  1  according to the invention. In this case, the column shoes  1  are embedded in concrete blocks  30  but might as well be embedded in an entire concrete slab or other material. 
       FIG. 6A-6F  show a further embodiment of the column shoe  1  having an anchor section  2  comprising a curved layer  60  of sheet metal.  FIG. 6A  shows is a perspective view of a column shoe  1  having the curved layer  60 . It is shown that in similar way as the other embodiment the anchor section  2  is bent, in this embodiment two times, to achieve that three layers of sheet metal form the width BA of the anchor section  2 . Hence, the width BA comprises at least three times the material of the sheet metal. This is simply due to the thickness of the sheet metal. It is to be understood that at some particular positions the edges of the sheet metal may not be fully aligned with a bend and/or another edge and therefore at some particular positions it may have less material. However, this is taken into account when calculating the overall capabilities i.e. load resistance. In this embodiment, the width of the anchor section  2  and the supporting section  5  is the same. However, it is to be understood that the width of the supporting section may be expanded in a similar way as shown in  FIG. 1A  by straightening the curvature of the S-shape towards the support surface. 
       FIG. 6B  shows a front view of the column shoe  1 . It is shown that the anchor section  2  continues has the same width BA as the supporting section (not indicated with reference in this view). Hence, it is shown that that the entire upright structure i.e. the anchor section and the supporting section ends in the same level as the support surface  10 . Hence, in this embodiment the second end of the supporting section i.e. the second end of the entire upright structure  61  is substantially flush with the support surface  10 . 
       FIG. 6B  shows a top view of the embodiment of the column shoe  1  shown in  FIG. 6A and 6B . In this view, the curved layer  60  is clearly visible. 
       FIG. 6D  shows a sideview perpendicular to the sideview shown in  FIG. 6A . Similar to the embodiment shown in  FIG. 1B  the supporting section  5  increases in width i.e. along the support depth BA (se  FIG. 1B ) in the direction towards the support section. 
       FIG. 6E  shows a cross-sectional view of the anchor section  2  in e.g.  FIG. 6D . In this cross-sectional view, it is seen that that in this embodiment the layers of sheet metal  60 ,  65 ,  66  (similar to the layers  17  in other embodiments) constitute at least three times the material thickness wt seen along the width of the anchor section BA. It is shown that the two layers  65 ,  66  are substantially parallel. The layer  60  between the two layers  65 ,  66  forms an S-shape connecting the two parallel layers  65 ,  66 . It is to be understood that the two substantially parallel layers in another embodiment may be angled to each other since the amount of material would not change. 
       FIG. 6F  shows the cross-sectional view of the anchor section  2  as shown in  FIG. 6E  arranged in a circle indicating the minimal circular shadow area  69  of the anchor section. Hence, it is shown that the anchor section has a circular shadow area  69  having a diameter DSA. In particular, when the column shoe is to be installed in cliff material as is often the case in e.g. Norway and Sweden it is highly advantageous to minimise the size of the drill needed to drill the hole into which the anchor section should be put. Larger drills are themselves more expensive, but the drilling machine needs to be more powerful the bigger the drill and hence require more power etc. 
       FIG. 7A  shows the outline of the flat sheet material before bending into the embodiment shown in  FIG. 1A . It is to be understood that this piece of flat sheet metal is a part of a long coil to be fed into the press and bending machine. When manufacturing the column shoe, the centre line  70  is kept in the same position in the tool during the whole manufacturing process, and hence the centre line  70  is used to fix the sheet metal. Bending lines  71   a,    71   b  and  71   c  shown how the same piece of flat sheet metal in an easy manner may be manufactured into column shoes having different support surface  10  (see e.g.  FIG. 1D ). Using the bending line  71   a,  a wide support section  10   a  is achieved. When bending in the bending lines  10   a,    10   b  or  10   c,  the material above (in the view shown in  FIG. 7A ) result in a certain height of the fastening section  11 . This means that using the bending line  10   a  provides the lowest height of the fastening section  11 . Using the bending line  10   b  provides a lower height of the fastening section  11  than using the bending line  10   a.  Finally, using the bending line  10   c  provides the highest height of the fastening section  11  and hence the overall smallest width of the support surface  10 . It is to be understood that the actual dimensions may be varied if a broader initial sheet metal material is used. It is seen that the initial sheet metal material is substantial symmetrical around centre line  70 . In order to achieve the anchor section  2  and supporting section  5  as shown the embodiment in  FIG. 2A , the sheet metal is bend around bending lines  72   a,    72   b  and  72   c  whereas the substantially parallel layers of sheet metal is achieved as shown in  FIG. 2C . 
       FIG. 7B  shows similar to  FIG. 7A  the initial material used to form an embodiment as shown in  FIG. 6A . 
     It is to be understood that this piece of flat sheet metal is a part of a long coil to be fed into the press and bending machine. When manufacturing the column shoe, the centre line  70  is kept in the same position in the tool during the whole manufacturing process, and hence the centre line  70  is used to fix the sheet metal. Bending lines  71   a,    71   b  and  71   c  show how the same piece of flat sheet metal in an easy manner may be manufactured into column shoes having different support surface  10  (not shown, see e.g.  FIG. 1D ). Using the bending line  71   a,  a wide support section is achieved. When bending in the bending lines  10   a,    10   b  or  10   c , similar to the above description of  FIG. 7A , different width of support sections are achieved. Likewise, similar to the description above, this also results in a different height of the fastening section  11 . It is seen that the initial sheet metal material is substantial symmetrical around centre line  70 . It is furthermore seen that the initial sheet metal material is substantial symmetrical around the centre line  70 . In order to achieve the anchor section  2  and supporting section  5  as shown the embodiment shown in  FIG. 6A  the sheet metal is bent around bending lines  72   a,    72   b  and  72   c  whereas the substantially parallel layers of sheet metal is achieved as shown in  FIG. 6A-6D .