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 A480-14b 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 16a, 16b, 16c, 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 9a and 9b, 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 9a, 9b, 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 16a, 16b 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 9a, 9b 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 9a, 9b 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 71a, 71b and 71c 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 71a, a wide support section 10a is achieved. When bending in the bending lines 10a, 10b or 10c, 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 10a provides the lowest height of the fastening section 11. Using the bending line 10b provides a lower height of the fastening section 11 than using the bending line 10a. Finally, using the bending line 10c 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 72a, 72b and 72c 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 71a, 71b and 71c 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 71a, a wide support section is achieved. When bending in the bending lines 10a, 10b or 10c, 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 72a, 72b and 72c whereas the substantially parallel layers of sheet metal is achieved as shown in FIG. 6A-6D.
Patent Application
20220213679
