Description

Technical field of the invention

The invention relates to a screw connection for mounting a platform support to a building. More precisely, the invention relates to a screw connection for mounting a platform support where welding of safety-sensitive structures on site is avoided. The invention also includes a method for mounting the screw connection.

Background

Fitting balconies to buildings are a process that places high demands on safety. Users must be sure that the balcony or platform will not loosen or fall down during the lifetime of the building. At the same time, it is desirable to avoid external structures, such as support struts or pillars that go down to the ground, which follow the outer edge or side edge of the balcony and thus screen the view and results in a reduced aesthetic experience.

In order to be able to mount a balcony or platform that does not display support struts or pillars, it has been common practice to weld a connection unit to which a platform support can be attached. However, this requires demanding welding of safety-sensitive welding lines at height under difficult conditions. Therefore, the work also depends on good weather and the presence of personnel who can handle the work.

An object of the invention is to provide a screw connection where no on-site welding is necessary when attaching cantilevered platform supports to a building.

Summary of the invention

In a first aspect of the invention, a screw connection for mounting a cantilevered platform support is described, where the screw connection is attached to a horizontal building part near an outer wall of a building. The screw connection comprises a mainly horizontal tension band to be attached to an upper side of the horizontal building part, where the tension band comprises at least one throughgoing bolt hole at an outer end of the tension band, and a first locking structure on the underside of the tension band at the outer end. Furthermore, the locking structure comprises a mainly vertically oriented vertical plate to be attached to a vertical part of the horizontal building part against the outer wall. The vertical plate comprises an upper surface with at least one threaded bolt hole for receiving a bolt in each bolt hole and a second locking structure on the upper surface which cooperates with the first locking structure and fasteners (8) for attaching the cantilevered platform support to the vertical plate. One of the first and second locking structures protrudes outwards and the other of the first and second locking structures is a recess. The two locking structures are configured to cause the two bolt holes to be concentric with each other when the first and second locking structures cooperate and configured to stop a relative vertical movement of the tension band and the vertical plate toward each other a distance A, when the at least one bolt is tightened . Furthermore, the two locking structures are configured to stop relative horizontal movement between the two plates when they are at a distance A from each other.

In one embodiment of the invention, the first locking structure comprises an elongate projecting cylindrical shape attached substantially perpendicular to the longitudinal direction of the tension band at the outer end. The second locking structure comprises a corresponding elongated recess with a cross-section with an inner downwardly sloping surface with a angle between 45 and 75 degrees with the horizontal plane and an outer upward sloping surface with an angle between 25 and 45 degrees with the horizontal plane.

In another embodiment of the invention, the first locking structure comprises an elongated projecting shape with a triangular cross-section fixed essentially perpendicular to the longitudinal direction of the tension band at the outer end and where the second locking structure comprises an elongated recess with a corresponding triangular cross-section.

In yet another embodiment of the invention, the first locking structure comprises an elongated recess with a triangular cross-section and the second locking structure comprises an elongated projecting shape with a corresponding triangular cross-section fixed essentially perpendicular to the longitudinal direction of the tension band at its outer end.

In yet another embodiment of the invention, the projecting locking structure of the first and second locking structure is attached by welding.

In yet another embodiment of the invention, the at least one bolt hole for the tension band is located on the inside of the first locking structure and the at least one threaded bolt hole in the upper surface of the vertical plate is located on the inside of the second locking structure.

In yet another embodiment of the invention, the tension band is attached to the horizontal building part by means of one or more reinforcing steel which protrudes from the underside of the tension band and which is cast firmly into the horizontal building part.

In yet another embodiment of the invention, the horizontal building part is provided with holes for the one or more reinforcing steel and a cavity that can be filled with concrete to lock the reinforcing steel.

In another aspect of the invention, a method for mounting a screw connection is described, where the method comprises the steps: a) to attach the vertical plate to the horizontal building part at a position where the platform support is to be positioned, b) attaching the tension band 1 to the horizontal building part so that the first locking structure in the tension band 1 can engage with the second locking structure in the vertical plate, c) attaching the vertical plate to the tension band 1 by attaching the bolts that pass through at least one bolt hole in the tension band and are screwed into the at least one threaded bolt hole in the vertical plate.

In one embodiment, point b of the method includes that the tension band is attached by positioning the reinforcing steel in a cavity 18 in the horizontal building part which is filled with concrete.

In one embodiment, point a of the method includes the vertical plate being welded to a construction structure which in turn is attached to the horizontal building part before the horizontal building part is assembled in the building.

Brief description of the figures

To improve understanding of the invention, figures are presented where like reference numbers in different figures refer to the same feature.

Fig. 1 shows the screw connection attached to the building with a platform support mounted.

Fig. 2 shows the screw connection's tension band and vertical plate.

Fig. 3 shows a section of the screw connection fitted to a building.

Fig. 4 shows how the tension band and the vertical plate are attached to each other.

Fig. 5a and b show some designs of the locking structures.

Fig. 6a-d shows an advantageous embodiment of the locking structures in different perspectives.

Detailed description

In this text we refer to the directions inward and outward and inner and outer. These expressions are to be understood in relation to an outer wall of the building where the platform support is to be mounted so that inwards and inner is the direction towards the interior of the building and vice versa. Upper and lower, vertical and horizontal and above and below refer to the screw connection when it is in a mounted position.

The invention describes a screw connection for mounting a cantilevered platform support 20 as shown in fig. 1. Typically, such a platform support will be arranged to support a balcony on an external wall of a building and a plurality of platform supports will be used for each balcony. The screw connection is fixed to a horizontal building part 22 near an a) to attach the vertical plate to the horizontal building part at a position where the platform support is to be positioned, b) attaching the tension band 1 to the horizontal building part so that the first locking structure in the tension band 1 can engage with the second locking structure in the vertical plate, c) attaching the vertical plate to the tension band 1 by attaching the bolts that pass through at least one bolt hole in the tension band and are screwed into the at least one threaded bolt hole in the vertical plate.

In one embodiment, point b of the method includes that the tension band is attached by positioning the reinforcing steel in a cavity 18 in the horizontal building part which is filled with concrete.

In one embodiment, point a of the method includes the vertical plate being welded to a construction structure which in turn is attached to the horizontal building part before the horizontal building part is assembled in the building.

Brief description of the figures

To improve understanding of the invention, figures are presented where like reference numbers in different figures refer to the same feature.

Fig. 1 shows the screw connection attached to the building with a platform support mounted.

Fig. 2 shows the screw connection's tension band and vertical plate.

Fig. 3 shows a section of the screw connection fitted to a building.

Fig. 4 shows how the tension band and the vertical plate are attached to each other.

Fig. 5a and b show some designs of the locking structures.

Fig. 6a-c shows an advantageous embodiment of the locking structures in different perspectives.

Detailed description

In this text we refer to the directions inward and outward and inner and outer. These expressions are to be understood in relation to an outer wall of the building where the platform support is to be mounted so that inwards and inner is the direction towards the interior of the building and vice versa. Upper and lower, vertical and horizontal and above and below refer to the screw connection when it is in a mounted position.

The invention describes a screw connection for mounting a cantilevered platform support 20 as shown in fig. 1. Typically, such a platform support will be arranged to support a balcony on an external wall of a building and a plurality of platform supports will be used for each balcony. The screw connection is fixed to a horizontal building part 22 near an

4

RECTIFIED SHEET (RULE 91) ISA/EP outer wall of a building and comprises two main parts which can be seen in fig 2: A mainly horizontal tension band 1 and a mainly vertical vertical plate 4. The tension band 1 is fixed to the horizontal building part 22 and comprises at least one throughgoing bolt hole 2 at an outer end of the tension band and a first locking structure 3 on the underside of the tension band 1 at the outer end.

The plate 4 comprises an upper surface 9 with at least one threaded bolt hole 5 for receiving a bolt 6, preferably with a washer 17, in each of the threaded bolt holes. The vertical plate further comprises a second locking structure 7 which cooperates with the first locking structure 3 and fastening means 8 for attaching the cantilevered platform support 20 to the vertical plate 4. The fastening means are not a central part of the invention and will not be described in more detail. We assume that they are present and have the function of transferring the forces from the platform support 20 to the vertical plate 4.

One of the first locking structure 3 and the second locking structure 7 project outwards from the one of the tension band 1 and the vertical plate 4 to which it belongs. The other of the first and second locking structure 3, 7 is a recess in the corresponding tension band 1 or vertical plate 4.

Fig 4 shows an advantageous embodiment of the locking structures. The two locking structures are configured to cause the two bolt holes 2, 5 to be concentric with each other when the first and second locking structures 3, 7 cooperate. The two locking structures are further configured to cause the underside of the tension band 1 and the upper surface 10 of the vertical plate 4 to have a distance, A, to each other when the at least one bolt hole 2 in the tension band 1 is concentric with the at least one threaded bolt hole 5 in the vertical plate 4 and at least one bolt 6 is tightened. That is, the locking structures are configured to stop a relative vertical movement of the tension band 1 and the vertical plate 4 towards each other in the distance A, when the at least one bolt 6 is tightened because the two locking structures contact each other. The two locking structures are also configured to stop relative horizontal movement between the tension band and the vertical plate when they are at a distance A from each other because any horizontal relative movement between the two plates means that the projecting locking structure 3, 7 must be lifted out of the recessed locking structure 3 , 7 and this movement is prevented by the at least one bolt. In this way, all horizontal forces between the two plates will be taken up by the two cooperating locking structures 3, 7 and all vertical forces between the two plates will be taken up by the at least one bolt 6. This situation makes it easy to calculate the dimensions needed on the bolts and locking structures. The distance A does not have to be large, but it must be present. 0.5 - 2 mm is beneficial, but 0.2 to 5 mm will also work.

One of the first and second locking structures comprises a concave shape and the other of the first and second locking structures comprises a convex shape. When the two locking structures approach each other in a direction towards a position with a locking engagement, relative horizontal movement of the two locking structures will be impossible without a simultaneous movement away from the position with a locking engagement. Such movement is stopped by the bolt. If there had been only one bolt and no locking structures, the shear forces between the tension band and the vertical plate would have been taken up by the frictional force between the plates and the bolt. With a screw connection according to invention, the horizontal shear forces between the tension band and the vertical plates will be taken up by the locking structures.

With a loaded platform support, there are large forces that pull the upper part of the vertical plate 4 away from the wall in a direction mainly parallel to the tension band 1, while there are no large forces acting perpendicularly and horizontally to this direction. Therefore, it is advantageous if the locking structures are elongated in a direction perpendicular to the longitudinal direction of the tension band.

The first locking structure 3 comprises, in an advantageous embodiment shown in fig. 4, an elongated projecting cylindrical shape, e.g. a round steel, and is fixed perpendicular to the longitudinal direction of the tension band 1 at the outer end and where the second locking structure 7 comprises an elongated recess with a cross-section with an inner downward sloping surface 12 with an angle with the horizontal plane between 45 and 75 degrees and an outer upward inclined surface 13 with an angle between 15 and 45 degrees with the horizontal plane. The two surfaces 12, 13 describe a second locking structure 7 shaped as a V-groove 7. In an advantageous embodiment, the first locking structure is a round steel that is welded to the outer end of the tension band perpendicular to the longitudinal direction of the tension band 1, as indicated in fig. 6c where a weld 9 is marked.

The first locking structure 3 comprises, in an embodiment shown in fig. 5a, an elongated projecting shape with a triangular cross-section attached perpendicular to the longitudinal direction of the tension band 1 at the outer end of the tension band. The second locking structure 7 comprises an elongated recess with a corresponding triangular cross-section in the upper surface 10 of the vertical plate 4.

The first locking structure 3 comprises, in an embodiment shown in fig. 5b, an elongated recess with a triangular cross-section and the second locking structure 7 comprises an elongated projecting shape with a corresponding triangular cross-section attached perpendicularly to the longitudinal direction of the tension band 1 at its outer end.

In an advantageous embodiment, the projecting locking structure, whether it is attached to the tension band 1 or the vertical plate 4, is attached to the associated plate 1, 4 by welding. It is also possible to attach protruding locking structures with bolts.

The at least one threaded bolt hole 5 in the upper surface 10 of the vertical plate 4 is, in an advantageous embodiment which is best shown in Fig. 4, located on the inside of the second locking structure 7. It is also possible to imagine the opposite where the threaded bolt hole is on the outside and the locking structure on the inside, but this will give somewhat less resistance to forces on the upper part of the vertical plate acting outwards and it is precisely this force that is the greatest.

In an advantageous embodiment, the tension band is attached to the horizontal building part 22 by means of one or more reinforcing steel bars 14 which protrude from the underside of the tension band 1 and which is cast firmly into the horizontal building part, where the horizontal building part 22 is provided with holes for the one or more reinforcing steel bars 14 and a cavity 18 or pocket which can be filled with concrete to lock the reinforcing steel 14 to the horizontal building part. It is also conceivable that the tension band 1 is attached to the horizontal building part 22 by means of bolts. It is conceivable that the screw connection is attached directly to the horizontal building part, but usually the horizontal building part 22 will not be dimensioned so that a screw connection according to the invention can be attached directly to the horizontal building part. The vertical plate 4 can then advantageously rest against a resting structure 21 in the form of a profiled metal beam 21 as shown in fig. 3. Many variations of resting structures for the vertical plate 4 will work. In fig. 3, a rectangular steel beam constitutes a wellfunctioning resting structure. The most important thing about a resting structure 21 is that it can withstand the forces acting on the resting structure via the vertical plate 1 when the platform support 20 is fully loaded. These forces mainly consist of horizontal and vertical forces which both propagate through the vertical plate 4. When the platform support is loaded, a horizontal outward force occurs in the upper part of the vertical plate 4. The tension band 1 absorbs the horizontal outward forces in the upper part of the vertical plate by to be attached to the horizontal building part, e.g. in that the reinforcing steel is fixed in the cavity 18 with concrete. The facility structure 21 absorbs downward forces by being firmly attached to the horizontal building part 22. The facility structure 21 also absorbs inward forces in the lower part of the vertical plate 4 by distributing the pressure.

In most cases, the fastening means 8 for the platform support will comprise retaining bolts 15 which are screwed into the vertical plate 4. Retaining bolts mounted at the top of the vertical plate will be subjected to tension and retaining bolts mounted at the bottom of the vertical plate will be subjected to pressure. As a bolt can withstand more pressure than tension, it will be advantageous to use larger dimensions for the upper holding bolts as shown in fig. 3. Fig. 3 also shows a membrane 16 to prevent the penetration of moisture.

The invention also describes a method for using the screw connection. The procedure includes the steps: a. Attaching the vertical plate 4 to a vertical part of the horizontal building part 22 at a position where the platform support is to be positioned. Preferably, an upper surface 10 of the vertical plate 4 is flush with the upper side of the horizontal building part 22. b. Attaching the tension band 1 to the horizontal building part 22 so that the first locking structure 3 in the tension band 1 can engage with the second locking structure 7 in the vertical plate 4. The tension band 1 is preferably attached by positioning the reinforcing steel in a pocket in the horizontal building part 22 which filled with concrete. c. Attaching the vertical plate to the tension band 1 by attaching the bolts 6 that pass through at least one bolt hole in the tension band and are screwed into at least one threaded bolt hole in the vertical plate.

In a preferred embodiment, the vertical plate is attached to a resting structure 21 which in turn is attached to the horizontal building part 22. The vertical plate 4 is attached to the construction structure preferably by welding so that the horizontal building part 22 can be placed in the building with resting structure 21 and vertical plate 4 attached. References

1 Tension band

2 Bolt holes

3 First locking structure / Round steel

4 Vertical plate

5 Threaded bolt hole

6 Bolt

7 Second locking structure / V-groove

8 Fastening means for platform support

9 Weld to attach round steel

10 Upper surface of the vertical plate

12 Downward sloping locking surface

13 Upward sloping locking surface

14 Reinforcing steel for attaching the tension band

15 Retaining bolts

16 Membrane

17 Washer

18 Cavity for fixing reinforcing steel with concrete

20 Platform support

21 Resting structure / Profiled metal beam

22 Horizontal building part