FIELD OF THE INVENTION

The present invention relates to a bending moment resistant con- struction element comprising a first pipe having a first end with a first end portion and a second pipe having a second end with a second end portion, the first and second pipe being connected to each other with a joint between the first end portion of the first pipe and the second end portion of the second pipe and more particularly to a bending moment resistant construction element ac- cording to the preamble of claim 1 . The present invention also relates to a bending moment resistant joint between a first pipe and a second pipe for providing bending moment resistant construction element, and more particularly to a bending moment resistant joint according to the preamble of claim 9. The present invention further relates to a tubular construction component to be connected with a joint to another tubular construction component for providing bending moment resistant construction element, the tubular construction component comprising a longitudinal first central axis and a first end and a first end portion provided to the first and extending therefrom along the first central axis, and more particularly to a tubular construction component according to the preamble of claim 12.

BACKGROUND OF THE INVENTION

Pipes and tubular parts made of metal are of then used in construction of buildings and structures as structural parts or elements, such as piles, pillars or other load bearing parts or elements. The pipes and tubular parts have fixed maximum length which in many applications is not sufficient and then to or more pipes have to be connected successively to each other with joints. It is complicate to connect pipes together with a bending moment resistant joint. Conventionally the pipes or tubular parts are connected to each other by welding during the construction work at the site of the construction to achieve same bending moment resistance than tubular part. Alternatively successive pipes are connected to each other by using an external sleeve arranged around the joint and secured to the ends to the successive pipes.

The disadvantage of the other conventional prior art joints between successive pipes or tubular parts used in construction is that they do not with- stand bending moment as well as tubular parts. Therefore their usability in construction is very limited as in many applications the pipes or tubular elements are subjected to bending moments during installation or during use, or both. Accordingly, the resistance or bending strength of the prior art joints to bending moments is considerably lower than the resistance of the body of the pipe to bending moments. This causes damages to the joints when building elements comprising to each other connected pipes are subjected to bending moments. Furthermore, welding pipes together in the joints may also cause variations in the quality of the joint and subject the joint to further damages later. On the other hand inspecting the welds is difficult and time consuming at constructions sites. Using external sleeve around the joint is one option to make the joint resistant to bending moments, but using external sleeves makes the joint complicated and slows down the construction work. Furthermore, external sleeves require a lot of extra work to form threads to both the sleeve and the pipes. BRIEF DESCRIPTION OF THE INVENTION

An object of the present invention is to provide a bending moment resistant construction element and a bending moment resistant joint between pipes for forming a bending moment resistant construction element so as to overcome or at least alleviate the above mentioned prior art problems disad- vantages. The objects of the invention are achieved by a pending moment resistant construction element according to the characterizing portion of claim 1 . The objects of the present invention are also achieved by a bending moment resistant joint according to the characterizing portion of claim 8 and by a tubular construction element according to the characterizing portion of claim 10.

The preferred embodiments of the invention are disclosed in the dependent claims.

The invention is based on the idea of providing a bending moment resistant construction element comprising a first pipe having a first end with a first end portion and a second pipe having a second end with a second end portion. The first and second pipe being connected to each other with a joint between the first end portion of the first pipe and the second end portion of the second pipe for forming the bending moment resistant construction element. The first end portion of the first pipe comprises conical portion or an expansion expanding towards the first end of the first pipe, a female thread, and a first support surface provided between the female thread and the first end of the first pipe. The conical portion or conical expansion means that the first pipe is expanded at the first end portion such that the first pipe has an increased diameter in the conical portion. Therefore, the conical portion expands towards the first end of first pipe such that inner and outer diameter of the are in- creased towards the first end of the first pipe. The female thread and the first support surface are provided to the conical portion. The second end portion of the second pipe comprises a second support surface to be supported against the first support surface of the first end portion of the first pipe in the joint, and a male thread provided between the second support surface and the second end of the second pipe to be coupled with the female thread of the first end portion of the first pipe for forming the joint.

Accordingly the bending moment resistant construction element comprises a bending moment resistant joint between a first pipe and a second pipe in which the second end portion forms a male connection part and the first end portion forms a female connection part receiving the male connection part. Therefore in the joint the female connection part is provided to the first end of the first pipe and has a first conical portion expanding towards the first end of the first pipe, a female thread, and a first support surface provided between the female thread and the first end of the first pipe. Similarly in the joint the male connection part of the second pipe comprises a second support surface, and a male thread provided between the second support surface and the second end of the second pipe. The female thread and the male thread are connected to each other such that the male connection part is arranged inside the female connection part and the first support surface is supported against the second support surface on the second end portion for forming the joint. When the first support surface provided to the first conical portion of the male connection part extends substantially parallel to the longitudinal central axis of the first pipe, the bending moment strength of the joint increase remarkable.

The bending moment resistant joint is achieved by providing a tubu- lar construction component or pipe to be connected with the joint to another tubular construction component or pipe for providing bending moment resistant construction element. The tubular construction component comprises a longitudinal first central axis, a first end, and a first end portion provided to the first and extending therefrom along the first central axis. The first end portion forms the male connection part and comprises a first conical portion expanding towards the first end, an inner surface and outer surface, a female thread portion provided to the first conical portion and on the inner surface, and a first plane support portion provided to the first conical portion and on the inner surface between the first end and the female thread portion.

According to the above mentioned the present invention provides bending moment resistant construction element, a pending moment resistant joint between a first and second pipe and a tubular construction element for forming the bending moment resistant joint. The construction element and the joint according to the present invention have bending strength that is at least equal to or greater than the bending strength of the tubular construction com- ponents of pipes between which the joint is provided. Furthermore, this is achieved without separate joint parts and without excessive welding or other corresponding time consuming and difficult installation works. Therefore, the present invention provides forming a bending moment resistant joint by preforming the tubular construction component or pipes. Thus the joint according to the present invention is simple and easy to form in construction sites.

BRIEF DESCRIPTION OF THE DRAWINGS

In the following the invention will be described in greater detail by means of preferred embodiments with reference to the attached [accompanying] drawings, in which

Figure 1 shows schematically one embodiment of a first end portion of one pipe according to the present invention;

Figure 2 shows schematically one embodiment of a second end portion of one pipe according to the present invention; and

Figure 3 shows schematically one embodiment of a bending mo- ment resistant construction element comprising joint according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Figure 1 shows schematically part of a first tubular construction component or first pipe 2 having a first longitudinal central axis A and a first end 19. The first pipe 2 has a substantially circular cross section. The first pipe 2 is provided with a first end portion 8 provided in vicinity of the first end 19 for connecting the first pipe 2 to another pipe or tubular construction component with a joint for providing bending moment resistant construction element. As shown in figure 1 the first end portion 8 comprises a first conical portion 10 or expansion expanding towards the first end 19 of the first pipe 2. Thus the first end portion 8 forms a female connection part for the joint between pipes or tubular construction components. The first conical portion 10 comprises an inner surface 6 and outer surface 4. The first conical portion 10 extends from the first end 19 of the pipe to a distance from the first end 19 such that the cross sectional area of the first conical portion 10 increases towards the first end 19 of the first pipe 2. The first conical end portion 10 has a first coning angle a, which may be between 1 to 6 degrees in relation to the first central axis A of the pipe 2. In one preferred embodiment the first coning angle a may be preferably 2 to 4 degrees in relation to the first central axis A of the first pipe 2. The first pipe 2 has a first longitudinal wall direction C parallel to the first central axis A and the second longitudinal wall direction D in the first conical part 10. The first coning angle a is presented between the first longitudinal wall direction C and the second longitudinal wall direction D. This means that the first conical portion 10 has an opening angle which corresponds the first coning angle a. The wall of the first pipe is bended for providing the first conical portion 10, as shown in figure 1 .

In the present invention the first conical portion 10 is provided as an expansion expanding towards the first end 19 of the first pipe. Therefore, the first conical portion 10 is provided as an expansion having an increasing diam- eter towards the first end 19 of the first pipe 2. Accordingly, at least the outer diameter of the first pipe 2 increases, at least along a part of the length of the first conical portion, in the first end portion 8 towards the first end 19 of the first pipe 2. In one embodiment both the inner and outer diameter increases, at least along a part of the length of the first conical portion, in the first end por- tion 8 towards the first end 19 of the first pipe 2. The first end portion 8 also comprises a female thread portion 12 provided to the first conical portion 10 and on the inner surface 6 of the first end portion 8. The female thread portion 12 comprises female thread 14. In one embodiment the female thread 14 is provided as a trapezoidal thread. The female thread portion is provided to the conical portion 10 and therefore the female thread 14 is also conical such that the cross sectional area of the female thread portion increases towards the first end 19 of the first pipe 2. The female thread portion 12 and the female thread 14 have a second coning angle, which may be between 1 to 8 degrees in relation to the first central axis A or first longitudinal wall direction C. In one pre- ferred embodiment the second coning angle may be 3 to 5 degrees in relation to the first central axis A or the first longitudinal wall direction C. According to the present invention and the above mentioned the second coning angle may be greater than the first coning angle a. In one preferred embodiment the second coning angle may be 0,5 to 2 degrees greater than the first coning angle a, because this way the joint has improved combination of bending strength and manufacturing properties. This means that the angle between the first conical portion 10 or the second longitudinal wall direction D and the longitudinal direction of the female thread portion 12 or the female thread 14 may be 0,5 to 2 degrees.

The first end portion 8 further comprises a first plane support portion 16 provided to the first conical portion 10 and on the inner surface 6 of the first end portion 8. The first plane support portion 16 is provided between the first end 19 of the first pipe 2 and the female thread portion 12. Accordingly and as shown in figure 1 , the first plane support portion 16 extends from the first end 19 of the first pipe 2 and the female thread portion 12 starts and extends from the first plane support portion 16. In other words the first plane support portion 16 and the female thread portion 12 are provided successively to the first end portion 8 starting from the first end 19 of the first pipe 2. In the embodiment of figure 1 the first plane support portion 16 and the female thread portion 12 are provided to the first conical portion 10. The first conical portion 10 has length that the greater than the total length of both the first plane support portion 16 and the female thread portion 12 and the first conical portion 10 extends from the first end 19 of the first pipe. However, in another embodiment the length of the first conical portion 10 may be substantially equal to the total length of both the first plane support portion 16 and the female thread portion 12 and the first conical portion 10 extends from the first end 19 of the first pipe. In an alternative embodiment the first conical portion 10 may start from the boundary between the first plane support portion 16 and the female thread portion 1 and the first plane support portion 16 may not be conical but parallel to the first longitudinal wall direction C and the first central axis A of the first pipe 2. Thus in that case the length of the first conical portion 10 may be substantially equal or greater than the length of the female thread portion 12. In a yet alternative embodiment the first conical portion 10 may start from or after the female thread portion 1 first plane support portion 16, female thread portion 12 and the first conical portion 10 are provided successive in that order from the first end 19 of the first pipe 2. Thus the female thread portion 10 and the first plane support portion 16 may not be conical but parallel to the first longitudinal wall direction C and the first central axis A of the first pipe 2. As shown in figure 1 , the outer diameter increases towards the first end 19 along the whole length of the first conical portion 10, but the inner diameter increases only along a part of the first conical portion 10. The inner diameter is substantially constant along the first plane support portion 16.

The first plane support portion 16 comprises a first planar support surface 18 extending parallel to the first central axis A and the first longitudinal wall direction C. Accordingly the inner diameter of the first pipe 2 and the first end portion 8 is substantially constant in the first plane support portion 16 in the direction of the first central axis A. The outer surface 4 of the first end portion 8 may be conical as described above. The length of the first plane support portion 16 or first planar support surface 18 in direction of the first central axis A is at least two times the wall thickness of the first pipe 2 or at least 25 mm.

Figure 2 shows schematically part of a second tubular construction component or second pipe 20 having a second longitudinal central axis B and a second end 21 . The second pipe 20 has a substantially circular cross section, preferably corresponding the circular cross section and diameter of the first pipe 2. The second pipe 20 is provided with a second end portion 26 provided in vicinity of the second end 21 for connecting the second pipe 20 to an- other pipe or tubular construction component, having the first end portion 8, with a joint for providing bending moment resistant construction element. The second end portion 26 forms a male connection part for the joint between pipes or tubular construction components such that the second end portion 26 of the second pipe 20 may be arranged inside the first end portion 8 of the first pipe 2. The second end portion 26 comprises an inner surface 24 and an outer surface 22. The second pipe 20 further comprises a third longitudinal wall direction E parallel to the second central axis B.

The second end portion 26 comprises a male thread portion 30 provided on the outer surface 22 of the second end portion 26. The male thread portion 30 comprises a male thread 32. In one embodiment the male thread 32 is provided as a trapezoidal thread. The male thread portion 30 and male thread 32 are provided to second end portion 26 by machining the outer surface 22 of the second end portion 26 and formed as a conical thread portion, as shown in figure 2. Thus the second end portion has a conical outer surface at least along the male thread portion 30 such that the male connection part for the joint is formed. The direction of the conical male thread portion 30 is shown in figure 2 as fourth longitudinal wall direction F. The male thread portion 30 and the male thread 32 have a second coning angle β in relation to the second central axis B. The second coning angle β corresponds the second coning angle of the female thread portion 12 and the female thread 14 of the first end portion 8 of the first pipe 2. The second coning angle β of the male thread portion 30 and male thread 32 may be between 1 to 8 degrees in relation to the second central axis B. The second coning angle β is presented between the third longitudinal wall direction D, or the second central axis B, and the fourth longitudinal wall direction F. In one preferred embodiment the second coning angle β may be 3 to 5 degrees in relation to the second central axis B or the third longitudinal wall direction D.

The second end portion 26 further comprises a second plane support portion 28 provided at the distal part of the second end portion 26 in relation to the second end 21 of the second pipe 20. As shown in figure 2 the sec- ond plane support portion 28 is provided adjacent to the male thread portion 30 at the side distant to the second end 21 . The second plane support portion 28 comprises a second planar support surface provided on the outer surface of the second end portion 26 or the outer surface 22 of the second pipe 20 forms the second planar support surface. The second planar support surface 22 ex- tends parallel to the second central axis B, or the third longitudinal wall direction D to which wall of the second pipe 20 it is formed. Accordingly the outer diameter of the second pipe 20 and the second end portion 26 is substantially constant in the second plane support portion 28 in the direction of the second central axis B.

The second end portion 26 of the second pipe 20 may further comprise a third support portion 34 provided on the inner surface of the second end portion 26 and between the male thread portion 30 and the second end 21 of the second pipe 20. Accordingly and as shown in figure 2, the third plane support portion 34 extends from the second end 21 of the second pipe 20 and the male thread portion 30 starts and extends from the third plane support portion 34. In other words the third plane support portion 34 and the male thread portion 30 are provided successively to the second end portion 26 starting from the second end 21 of the second pipe 20. The thirds plane support portion 34 comprises a third planar support surface 36 on the outer surface of the second end portion 26. The third planar support surface 36 may extend parallel to the longitudinal second central axis B of the second pipe 20 or parallel to the direc- tion of the male thread 32 in the second coning angle β, as in figure 2. The length of the third support portion is at least 2 times the wall thickness of the second pipe 20 or at least 25 mm.

In the embodiment of figure 2 the second end portion 26 of the sec- ond pipe 20 comprises successively from the second end 21 the third plane support portion 34, the male thread portion 30 and the second plane support portion 28. The third plane support portion 34, or the third plane support surface 36, and the male thread portion 30 extend in the second coning angle β in relation to the second central axis B and the second plane support portion 28, or the second planar support surface 22, extends parallel to the second central axis B and the third longitudinal wall direction D. Thus the third plane support portion 34, or the third plane support surface 36, and the male thread portion 30 together form a second conical portion on outer surface of the second end portion 26. In an alternative embodiment also the second plane support portion and the second planar support surface 22 may be may extend in the second coning angle β. In a yet alternative embodiment the male thread portion 30 and the male thread 32 and/or the third plane support portion 34 and the third planar support surface 36 may extend parallel to the second central axis B and the third longitudinal wall direction D, and in that case also the female thread portion 12 and female thread 14 extend parallel to the first central axis A of the first pipe 2.

The first and second pipe 2, 20, or tubular construction components, may be connected to each other with a joint 3 for forming a bending moment resistant construction element, as shown in figure 3. The construction element is formed connecting the first and second end portion 2, 26, or the female and male connection parts, of the first and second pipe 2, 20 to each other. Accordingly the bending moment resistant construction element comprises two or more pipes 2, 20 or tubular construction components connected to each other with the joint 3. This means that the pipe 2, 20 or the tubular construction com- ponent may comprise only the first end portion 8, the female connection part, or the second end portion 26, the male connection part, or both the first and second end parts 8, 26 if it is connected to two other pipes. In figure 3 some reference numerals are omitted for simplicity and for making the figure clear, however, all the features of the first and second pipe 2, 20 may be found in figures 1 and 2 with reference numerals.

As shown in figure 3 the bending moment resistant construction el- ement comprising the first pipe 2 having the first end 19 with the first end portion 8 in the vicinity thereof and the second pipe 20 having the second end 21 with the second end portion 26 in the vicinity thereof. The first and second pipe 2, 20 are connected to each other with the joint 3 provided with and between the first end portion 8 of the first pipe 2 and the second end portion 26 of the second pipe 20. The first end portion 8 of the first pipe 2 comprises the first conical portion 10 expanding towards the first end 19 of the first pipe 2, a female thread 14, and a first support surface 18 provided between the female thread 14 and the first end 19 of the first pipe 2. The female thread 14 and the first support surface 18 are in this embodiment provided to the first conical portion 10. The second end portion 26 of the second pipe 20 comprises the second support surface 22 to be supported against the first support surface 18 of the first end portion 8 of the first pipe 2 in the joint 3. The second end portion 26 further comprises the male thread 32 provided between the second support surface 22 and the second end 21 of the second pipe 20 to be coupled with the female thread 14 of the first end portion 8 of the first pipe 2 for forming the joint 3. Accordingly, the first end portion 8 of the first pipe 2 forms the female connection part of the joint 3 as the female thread 14 and the first support surface 18 are provided on the first inner surface 6 of the first end portion 8. Fur- ther, the second end portion 26 forms the male connection part of the joint 3 as the male thread 32 and the second support surface 22 are provided on the second outer surface 22 of the second end portion 26.

The first conical portion 10 of the first end portion 8 has the first coning angle a between 1 to 6 degrees, preferably between 2 to 4 degrees, in relation to the longitudinal first central axis A of the first pipe 2, and also the longitudinal second central axis B of the second pipe 20, such that the second end portion 26 may be fitted in to the first end portion 8. The female thread 14 and the male thread 32 are conical threads having the second coning angle β between 2 to 8 degrees, preferably 3 to 5 degrees, in relation to the longitudi- nal first and second central axis A, B of the first and second pipe 2, 20 such that the female and male threads 14, 32 are coupled when the second end portion 26 is installed into the first end portion 8. The second coning angle β is greater than the first coning angle a, as shown in figure 3, such that the second end portion 26 fits tightly in the first end portion 8 as it wedges into the first end portion 8. In one preferred embodiment the second coning angle β is 0,5 to 2 degrees greater than the first coning angle. As described above, the second end portion 26 may further comprises the third support surface 36 provided between the male thread 32 and the second end 21 of the second pipe 20 and on the outer surface of the second end portion 26. In the bending moment resistant construction element the third support surface 36 may be supported against a fourth planar support surface provided to the inner surface of the first end portion 8 or on the inner surface 6 of the first pipe 2. Thus the fourth support surface may be in the conical portion 10 or along the first pipe 2 in the direction of the first central axis A and the third support surface 36 may extend parallel to the longitudinal second cen- tral axis B of the second pipe 20 or parallel to the direction of the male thread 32.

The bending moment resistant construction element may be pile, steel pile, column, pillar or another longitudinal construction element. Furthermore, the bending moment resistant construction element may comprise two or more pipes or tubular construction components connected to each other with the joint 3.

Accordingly the first and second end portion 8, 26, or female and male connection parts, provide a bending moment resistant joint 3 between the first pipe 2 and the second pipe 20 for providing the bending moment resistant construction element. The joint 3 comprises the female connection part 8 provided to the first end 19 of the first pipe and having the first conical portion 10 expanding towards the first end 19 of the first pipe 2, the female thread 14, and the first support surface 18 provided between the female thread 14 and the first end 19 of the first pipe 2. The joint 3 further comprises the male connection part 26 of the second pipe 20 having the second support surface 22, and the male thread 32 provided between the second support surface 22 and the second end 21 of the second pipe 20. In the joint 3 the female thread 14 and the male thread 32 are connected to each other such that the male connection part 26 is arranged inside the female connection part 8 and the first support surface 18 is supported against the second support surface 22 on the second end portion 26. The first support surface 18 extends parallel to a longitudinal first central axis A of the first pipe 2 and the longitudinal second central axis B of the second pipe 20 such that it is pressed or wedges tightly against the second support surface 22 in the joint 3. The length of the first support surface 18 in direction of the first central axis A is at least two times the wall thickness of the first pipe 2 or at least 25 mm. Therefore the first support surface 18 forms a flange which extends from the female thread 14 and is arranged and pressed tightly against the second support surface 22 or the outer surface of the second end portion 26 of the second pipe 20. For providing the tight fitting in the joint 3 the conical portion 10 of the female connection part 8 has the first co- ning angle a between 1 to 6 degrees, preferably 2 to 4 degrees, in relation to the longitudinal first and second central axis A, B of the first and second pipe 2, 20, and the female thread 14 and the male thread 32 are conical threads having a second coning angle β between 2 to 8 degrees, preferably 3 to 5 degrees, in relation to the longitudinal first and second central axis A, B of the first and second pipe 2, 20 such that the male connection part 26 is close fitted inside the female connection part. In the joint 3 the third support surface 36 provided on the outer surface 22 of the male connection part 26 between the male thread 32 and the second end 21 of the second pipe 20 is further supported against the fourth support surface 6 on the inner surface of the female connection part 8.

According to the above described the present invention provides a bending moment resistant construction element and joint such that the bending strength of the joint 3 is at least equal, or greater, than the bending strength of the pipe 2, 20 or the tubular construction component. This is achieved by the co-operation of the features of the first and second end portions. The conical portion 10 of the first end portion 8 and the conical threads 14, 32 and their respective coning angles provide tight connection between the pipes 2, 20. The bending strength is achieved by male-female coupling with the threads and with the first and second support surfaces 18, 22 pressed against each other in the joint 3. The strength may further be enhanced with the third and fourth support surfaces 36, 6. Preferably the first end portion 8 and/or the second end portion 26 are integral part with the pipe 2,20 which means that they formed from same tubular material, because this decrease production costs.

It will be obvious to a person skilled in the art that, as the technology advances, the inventive concept can be implemented in various ways. The invention and its embodiments are not limited to the examples described above but may vary within the scope of the claims.