System for pile coupling

Abstract

An attachment system (1) for detachably coupling a female pipe end (4) and a male pipe end (5) to each other to form a pile, the attachment system (1) comprising: corresponding cylindrical socket holes (8, 9) in the sockets of the pipe ends (4, 5); a coupling element (6) that fits in and can be turned through an angle in the socket holes (8, 9); a locking pin (13) on the coupling element (6) or one of the socket holes (8, 9); and a locking groove (14) in one of the socket holes (8, 9) or the base (7) such that the locking pin (13) engages in the locking groove (14) when the coupling element (6) is rotated in the socket hole (8, 9); wherein one of the socket holes (8, 9) and the base (7) are provided with corresponding socket grooves (10, 11, 12) to jointly form a fitting hole to fit a locking element (15) therein to prevent the coupling element (6) from rotating in the socket hole (8, 9).

Description

TECHNICAL FIELD

[0001] The present invention relates to an attachment system for detachably coupling a female pipe end and a male pipe end to each other to form a pile, the attachment system comprising:

[0002] - a cylindrical socket hole in a socket of the female pipe end;

[0003] - a corresponding cylindrical socket hole in a socket of the male pipe end, which socket hole is alignable with the socket hole in the female pipe end when the male pipe end is fitted in the female pipe end; and

[0004] - a coupling element comprising a cylindrical base body, which is fittable in the socket holes when the socket holes have been aligned relative to each other to couple the pipe ends to each other. BACKGROUND

[0005] The term "cylindrical" is to be understood to mean that the shape is substantially that of a cylinder with a circular base area. In this case, such a shape can also be provided with protrusions and / or openings and / or bevels relative to this basic cylindrical shape. Thus, for example, the base area of a cylindrical socket hole configured as an opening in a curved socket can also be similarly curved.

[0006] The socket holes are alignable when they can be arranged abutting each other, which makes them together form a substantially cylindrical hole, the shape of which substantially corresponds to the shape of the cylindrical base body of the coupling element.

[0007] The coupling element is fittable in the socket holes when it can substantially extend in these socket holes. In this case, the coupling element can protrude slightly relative to the socket holes, but still extend substantially within the space of the socket holes, for example, whereby the pipe thus formed can be freely arranged in the ground and concrete can be freely poured via the pipe thus formed.

[0008] Generally, the pipe ends must be coupled to each other to produce a pile. These pipe ends can form part of a pipe component to be coupled in order to together form a pipe, or for example form part of a wear component, for example a drill bit to be coupled to a pipe component.

[0009] Today, there are many commercially available attachment systems for coupling pipes for forming foundations or piles in the ground. These attachment systems are often complex and expensive to construct and are often difficult to disassemble in practical applications.

[0010] In many cases, existing couplings use threads to lock all the components together. However, the threads do not bond very well with the ground and the concrete, so this coupling wears very easily.

[0011] JP 5021437 B2 shows an attachment system commonly used to couple pipe ends to each other to form a pile. In this case, coupling elements provided in the pipe sleeve holes of the pipe ends are screwed onto the inner band by means of bolts.

[0012] US 8,397,364 B2 proposes various attachment systems using elastic seals in order to be able to eliminate threads. In this case, the coupling pieces are complex and less suitable for use when pouring concrete to form a pile. SUMMARY

[0013] It is an object of the present invention to provide an attachment system with which pipe ends for forming a pile can be coupled in a simple and durable manner without the use of threads or elastic seals.

[0014] This object of the present invention is achieved by providing an attachment system for separably coupling a female pipe end and a male pipe end to each other to form a pile, the attachment system comprising:

[0015] - a cylindrical pipe sleeve hole in the pipe sleeve of the female pipe end;

[0016] - a corresponding cylindrical pipe sleeve hole in the pipe sleeve of the male pipe end, which pipe sleeve hole can be aligned with the pipe sleeve hole in the female pipe end when the male pipe end is fitted in the female pipe end; and

[0017] - a coupling element comprising a cylindrical base body, which can be fitted in the pipe sleeve holes when the pipe sleeve holes have been aligned relative to each other, to couple the pipe ends to each other;

[0018] - a locking pin arranged on one of the base body or the pipe sleeve holes and extending radially relative to said one of the base body or the pipe sleeve holes; and

[0019] - a locking groove arranged in one of the pipe sleeve holes or the base body, respectively, in which the locking pin can be fitted;

[0020] wherein the locking pin and the locking groove are arranged such that the coupling element can be rotated through an angle after fitting into the pipe sleeve holes, wherein the locking pin is fitted in the locking groove by means of a guiding action;

[0021] and wherein at least one of the pipe sleeve holes and the base body are provided with a corresponding pipe sleeve groove, which pipe sleeve groove extends at least partially axially relative to the respective pipe sleeve hole or the respective base body, such that these pipe sleeve grooves jointly form a fitting hole after the coupling element is fitted into the pipe sleeve holes and the coupling element is turned through said angle, and the attachment system comprises a locking element which can be fitted into this formed fitting hole to prevent the coupling element in the pipe sleeve holes from rotating.

[0022] The coupling element comprising the cylindrical base body mounted in the cylindrical sleeve bore creates a durable coupling, in which the robust cylindrical shape is able to transmit the required forces and torques.

[0023] The coupling element can be locked radially with respect to the sleeve by means of a locking pin and a locking groove, without the use of threads. For this purpose, the locking pin can be simply fitted in the locking groove using a rotational movement by rotating the coupling element in the sleeve bore. The coupling element can be easily prevented from rotating in the opposite direction using the locking element.

[0024] In one specific embodiment, the locking element is designed in such a way that, after the locking element has been mounted in the fitting bore, the locking element prevents the coupling element from rotating in the sleeve bore when a rotational force is applied to the coupling element which is below a specified breakaway rotational force, whereas the locking element breaks away and the coupling element can again be rotated in the sleeve bore when a rotational force is applied to the coupling element which exceeds the specified breakaway rotational force. Under normal operating conditions in which the pipe ends are coupled together, such a coupling cannot be uncoupled. Only when the locking element is intentionally broken away by applying a rotational force to the coupling element which is greater than the specified breakaway rotational force, or when the locking element is removed in some other way, can the coupling be uncoupled.

[0025] In addition to the sleeve grooves, the sleeve bore and the base body can also be provided with additional sleeve grooves which together form one or more additional fitting bores for fitting one or more additional locking elements therein.

[0026] In one preferred embodiment, the sleeve grooves and the locking pin are arranged in such a way that the locking pin is guided in one or more sleeve grooves which act as guide slots during fitting of the coupling element in the sleeve bore. In this way, it is easy to correctly position and fit the coupling element in the sleeve bore so that the locking pin can be fitted in the locking groove by means of the guiding action.

[0027] The sleeve bore in the female pipe end is preferably configured as a through-going perforation of the respective sleeve. The sleeve bore in the male pipe end is also preferably configured as a through-going perforation of the respective sleeve.

[0028] It is easy to fit the coupling element in the entire sleeve bore which has already been formed in the respective sleeve.

[0029] If one of the two sleeve bores is configured as a blind hole and is in this case delimited by a bottom, the coupling element can in this case be fitted in the sleeve bore, but the depth is delimited by the bottom. A blind sleeve bore in the male pipe end has the advantage that the interior of the male pipe end is completely unaffected by the female pipe end. Concrete or cement moisture cannot penetrate between the locking elements, nor can it penetrate between the male pipe end and the female pipe end through this sleeve bore. This makes it easier to break away.

[0030] If no such bottom is provided, the coupling element can easily be installed in and removed from the sleeve hole by fitting it into the sleeve hole via one side as required and tapping the coupling element via one side to pass it through the sleeve hole to remove it. In this case, the coupling element can be installed / removed from the outside of the pipe end inwards or from the inside of the pipe end outwards.

[0031] The fitting hole for fitting the locking element therein is preferably through the sleeve, so that the locking element is also easily fitted therein via one side and can be removed therefrom by tapping via one side of the fitting hole as required. However, this is not essential. Even if the fitting hole only passes through part of the sleeve (for example only through one of the two sleeves), it is possible to fit the locking element therein to prevent the coupling element from rotating in the opposite direction.

[0032] Continuous slots and holes through the sleeve are easier to manufacture and less expensive. Thus, the workpiece only has to be clamped on the machine once and all the work can be done from one side.

[0033] The coupling produced in this inexpensive manner can also be fitted with a wear part by means of the attachment system of the application. Such a wear part can be simply discarded after use, including the corresponding male or female pipe end. However, in this case, the coupling element itself can be reused and, in some embodiments, the locking element can also be reused.

[0034] The attachment system of the application is suitable for coupling round pipes and non-round pipes or elements of various diameters and various wall thicknesses. If desired, it is also possible to couple round pipes to square or polygonal shapes using the system.

[0035] However, it is preferable for the pipe ends to be of a substantially cylindrical design. By making the pipe ends substantially cylindrical, these pipe ends can be rotated relative to one another. Since the pipe ends can be rotated relative to one another, they are easier to connect (disconnect).

[0036] During coupling, the sleeve holes should not yet be brought into the desired position relative to one another when fitting the male pipe end into the female pipe end. The pipe ends should first be brought into engagement with one another and then rotated relative to one another until the sleeve holes are aligned with one another.

[0037] In order to achieve uncoupling, in some embodiments the locking element can first be removed, while in other embodiments the locking element can first be disconnected. Thereafter, after the coupling element has been removed, the male pipe end can be rotated relative to the female pipe end while they are still located within one another.

[0038] The fitting hole formed by the attachment system of the application is preferably also substantially cylindrical. The locking element is therefore also preferably substantially cylindrical.

[0039] In order to achieve a secure coupling, the female pipe end is preferably provided with a plurality of corresponding pipe sleeve holes. The male pipe end is preferably also provided with a plurality of corresponding pipe sleeve holes.

[0040] In this case, it is preferable to select the same number of pipe sleeve holes in the female pipe end and the male pipe end, but this is not a necessity.

[0041] If desired, the pipe sleeve holes can also be provided at different heights and / or at different horizontal levels above one another.

[0042] The number of pipe sleeve holes that can be aligned with one another at the same time is equal to the number of corresponding coupling elements and locking elements provided.

[0043] The pipe formed by coupling the pipe ends with the attachment system of the application preferably has substantially the same internal diameter along its entire length and substantially the same external diameter along its entire length. Thus, there are no protruding parts that could impede the introduction of the pipe into the ground, nor are there any protruding parts that could obstruct the central passage of the space through which the concrete passes. This also makes the pipe ends easier to produce.

[0044] Preferably, the female pipe end is provided with an internal recess delimited by a shoulder. The male pipe end is preferably provided with a corresponding external recess delimited by a shoulder. In this case, the external recess of the male pipe end can be fitted in the internal recess of the female pipe end in order to fit the male pipe end in the female pipe end. In this case, the fit of the male pipe end in the female pipe end is delimited by the shoulders.

[0045] In this case, each pipe sleeve hole in the female pipe end is preferably provided in the internal recess, while each pipe sleeve hole in the male pipe end is preferably provided in the external recess.

[0046] Since there is only one recess per pipe end (apart from any bevels that can be present on the edges in order to facilitate the coupling), the pipe ends can be produced in a very simple and robust manner.

[0047] The attachment system of the application is preferably completely free of elastic seals.

[0048] Thus, recesses for the installation of such elastic seals, which would unnecessarily weaken the coupling, are not required.

[0049] In order to produce a foundation pile, the coupling does not necessarily have to be completely watertight, so the attachment system of the application can be free of elastic seals. Since minimum tolerances are used, liquid substances with a particle size greater than this tolerance cannot in any case enter the coupling. If, for example, liquid in the cement enters the coupling, it remains there and itself begins to act as a seal.

[0050] With limited tolerances, the pipe ends can also be coupled to each other with the aid of grease applied to the recesses. This grease also partly provides the sealing effect.

[0051] Furthermore, a silicone can be used which is applied to one or both of the shoulders. If subsequently the male pipe end is fitted in the female pipe end, the silicone is present between the shoulders.

[0052] Thereby, by limiting the tolerances, the coupling of the pipe ends using the attachment system of the invention achieves a sufficient sealing to ensure that water and dust cannot enter the pipe from the outside and that dust or concrete cannot flow out via the coupling.

[0053] The locking groove of the attachment system of the invention extends over at least a part of the circumference of the cylindrical pipe sleeve hole or of the cylindrical base body of the coupling element. In principle, the locking groove can extend along the entire circumference. Preferably, the locking groove extends over only a part of the circumference over an angle corresponding to the angle over which the coupling element can be rotated, so that the pipe sleeve grooves are automatically aligned relative to each other in the process in order to jointly form the fitting hole.

[0054] More specifically, the locking groove of the attachment system of the invention can be configured conically, so that when the locking pin is fitted in the locking groove, the locking pin is also fitted in the locking groove when the coupling element is not fitted far enough or too far in the pipe sleeve hole. During the rotation of the coupling element, the locking groove guides the locking pin to the desired position, in which the coupling element is also fitted at the desired depth in the pipe sleeve hole. In a simple embodiment, however, the locking groove is configured as a slot which is delimited in length by parallel walls.

[0055] The coupling element is preferably rotated in the pipe sleeve hole only over a limited angle. To this end, the angle over which the coupling element is rotatable is preferably limited to an angle of less than 360°. The angle is more preferably limited to an angle of less than 180°, most preferably to an angle of less than 90° or even less than 45°. As already indicated in the foregoing, in this case the angle can be limited, for example, by delimiting the locking groove accordingly.

[0056] Furthermore, the coupling element preferably comprises an engagement element which is engaged by a hand tool to rotate the coupling element. The engagement element can also be used to insert the coupling element into the pipe sleeve hole during installation and to remove the coupling element from the pipe sleeve hole during disassembly. In this case, one or more such engagement elements can be provided. Such an engagement element is preferably configured as an engagement hole. Such an engagement hole in the locking element can be made as a through-hole or a blind hole through the locking element, or a combination of both.

[0057] In one particular embodiment, the locking pin is provided on the base body and the locking groove ends in the outer sleeve surface of the male pipe end. In this way, the female pipe end can protect the locking groove from wear.

[0058] The application will now be explained in more detail by the following description of some embodiments of the attachment system according to the application. The description is only intended to illustrate some exemplary embodiments and to show further advantages and features of the application, and should therefore not be interpreted as limiting the scope of application of the application or the patent protection defined in the claims. BRIEF DESCRIPTION OF DRAWINGS

[0059] In the detailed description reference is made to the accompanying drawings, in which:

[0060] - Figure 1 shows a perspective view, a sectional view and a top view of a first embodiment of the attachment system according to the application;

[0061] - Figure 2 shows a perspective sectional view of the attachment system when viewed from below Figure 1 ;

[0062] - Figure 3 shows a perspective view of the attachment system when viewed from above Figure 1 , in an assembled state;

[0063] - Figure 4 shows a cross-section of a part of the attachment system according to the application, cut through the coupling element Figure 1 ;

[0064] - Figure 5 shows a perspective view, a sectional view and a top view of a second embodiment of the attachment system according to the application;

[0065] - Figure 6 shows a perspective sectional view of the attachment system when viewed from below Figure 5 ;

[0066] - Figures 7a-7f shows in a schematic view and a perspective view a number of steps of the attachment system according to the application, namely starting from a composite state, when a rotational force higher than the breakaway rotational force is applied, the locking element breaks away and the coupling element can rotate again in the sleeve hole and can be removed from the sleeve hole; Figure 1

[0067] - Figure 8 shows a longitudinal sectional view of a third embodiment of the attachment system according to the application, cut through the coupling element;

[0068] - Figure 9 shows a longitudinal sectional view of a fourth embodiment of the attachment system according to the application, cut through the coupling element.​ DETAILED DESCRIPTION

[0069] The shown attachment systems (1) in each case comprise a female pipe end (4) and a male pipe end (5) of which they form part of a pipe (2, 3) which can be coupled to form an assembled pipe. Alternatively, one of the two pipe ends (4, 5) can also form part of a wear part, for example a drill head.

[0070] In the drawings, the male pipe end (5) is always shown on top and the female pipe end (4) is always shown on the bottom. However, it is easy to place the female pipe end (4) on top and the male pipe end (5) on the bottom.

[0071] The shown pipe ends (4, 5) have a circular cross-section, but can also have a different cross-section, as is the case with pipe ends in the prior art.

[0072] The female pipe end (4) is provided with an internal recess (20) which is delimited by a shoulder (17). Correspondingly, the male pipe end (5) is provided with an external recess (21) which is delimited by a shoulder (18). The external recess (21) of the male pipe end (5) can be fitted in the internal recess (20) of the female pipe end (4). Along the edges of the recesses (20, 21) there are bevels (22) to facilitate coupling (uncoupling). The shoulders (17, 18) delimit the fit of the male pipe end (5) in the female pipe end (4). The two pipe ends (4, 5) are dimensioned with limited tolerances. However, in order to be able to fit these pipe ends (4, 5) smoothly to each other with these limited tolerances, grease can be applied in the recesses (20, 21).

[0073] The internal recess (20) of the female pipe end (4) comprises additional cylindrical pipe socket holes (8) which are distributed over the circumference of the pipe end (4). These cylindrical pipe socket holes (8) pass through the socket of the female pipe end (4).

[0074] The external recess (21) of the male pipe end (5) comprises additional corresponding cylindrical pipe socket holes (9) which are distributed over the circumference of the pipe end (5). In the first three shown embodiments, these cylindrical pipe socket holes (9) also pass through the socket of the male pipe end (5). In the last shown embodiment (see Fig. 6), this cylindrical pipe socket hole is a blind hole. Figure 9

[0075] Since the pipe ends (4, 5) are cylindrical, they can be rotated relative to each other. The pipe socket holes (8, 9) are arranged such that the respective male and female pipe socket holes (8, 9) can be aligned with each other. In the shown embodiments, in this case each pipe socket hole (9) in the male pipe end (5) abuts a corresponding pipe socket hole (8) in the female pipe end (4).

[0076] ​For each pair of corresponding sleeve holes (8, 9) aligned in this way, the attachment system (1) shown comprises a coupling element (6). This coupling element (6) has a cylindrical base body (7) which, when the sleeve holes (8, 9) have been aligned relative to one another, can be fitted in these sleeve holes (8, 9) in order to couple the pipe ends (4, 5) to one another. In this case, the base body (7) has the same cylindrical shape as the sleeve holes (8, 9) and is slightly smaller with a minimum tolerance. In the first two embodiments shown, the height of the base body (7) actually corresponds to the thickness of the sleeve of the pipe ends (4, 5), which in turn actually corresponds to the sum of the thicknesses of the recesses (20, 21) of the pipe ends (4, 5). In the third embodiment (see Figure 8 ), the base body 7 of the coupling element (6) is slightly higher, while in the fourth embodiment (see Figure 9 ), the base body 7 is lower.

[0077] In the first three embodiments shown, the sleeve holes (8, 9) run through the sleeve of the pipe ends (4, 5), so that the coupling element (6) can be fitted in or removed from these sleeve holes (8, 9) from the outside as well as from the inside. In an alternative embodiment in which one of the two sleeve holes (8, 9) is designed as a blind hole, the coupling element (6) can only be fitted into or removed from these sleeve holes (8, 9) from one side. This is the case in the fourth embodiment shown. Figure 9

[0078] In the first embodiment shown and in the last two embodiments shown, the coupling element (6) of the attachment system (1) is also provided with a locking pin (13) which is raised radially relative to the sleeve surface of the base body (7).

[0079] In this case, each sleeve hole (9) in the male pipe end (5) is provided with a corresponding locking groove (14). This locking groove (14) is formed on the sleeve surface of the sleeve hole (9) as an arc-shaped section of the circumference. The locking groove (14) ends on the outer circumference of the male pipe end (5) and, when the male pipe end (5) is fitted in the female pipe end (4), is protected by the female pipe end (4) in order to limit wear on the locking groove (14). Alternatively, the locking groove (14) can optionally be provided in the female pipe end (4) and, in this case, can be manufactured in a similar manner.

[0080] In contrast, in the second embodiment shown, each sleeve hole (9) in the male pipe end (5) is provided with a locking pin (13) which is raised radially relative to the sleeve surface of the sleeve hole (9). Alternatively, the locking pin (13) can be provided in the female pipe end (4) if necessary.

[0081] ​In this second embodiment, the coupling element (6) is provided with a locking groove (14) corresponding to the locking pin (13). The locking groove (14) is formed as an arc on the surface of the sleeve of the coupling element (6), through a portion of the circumference of the sleeve.

[0082] In all embodiments, the locking pin (13) and the locking groove (14) are arranged such that, after the coupling element (6) has been fitted in the sleeve hole (9), the locking pin (13) engages in the locking groove (14) when the coupling element (6) is rotated.

[0083] In each case, the locking groove (14) only extends through a portion of the circumference of the sleeve hole (9) of the coupling element (6), so that the rotation of the coupling element (6) in the sleeve hole (9) is limited to an angle corresponding to the length of the arc of the locking groove (14).

[0084] In addition to the locking pin (13) shown and the locking groove (14) shown, further locking pins and corresponding locking grooves can also be provided as required, for example distributed over the circumference of the cylindrical shape.

[0085] In the embodiments shown, the sleeve holes (8, 9) are also provided with corresponding sleeve grooves (11, 12), which extend axially with respect to the respective sleeve hole (8, 9) and are also aligned with one another when the sleeve holes (8, 9) are aligned with one another. The base body (7) is also provided with a sleeve groove (10) corresponding to the sleeve grooves (11, 12) and extending axially with respect to the base body (7) and, after the coupling element (6) has been fitted in the sleeve holes (8, 9) and after the coupling element (6) has been turned through the angle, forms a fitting hole together with the sleeve grooves (11, 12) in the sleeve holes (8, 9). To this end, the dimensions of the sleeve grooves (10, 11, 12) are determined in a corresponding manner.

[0086] For each fitting hole that can be formed in this way, the embodiments shown include a locking element (15) that can be fitted in the fitting hole thus formed in order to prevent the coupling element (6) from rotating in the sleeve holes (8, 9). In the last two embodiments, the fitting hole and the locking element are not shown in the figures, but are provided in an analogous manner.

[0087] Each of the fitting holes shown extends through the sleeve, so that the respective locking element (15) can be fitted into and removed from the fitting hole from the outside and from the inside. In alternative embodiments in which the fitting hole is configured as a blind hole, the locking element (15) can only be fitted into and removed from the fitting hole from one of the two sides, for example because the sleeve grooves (11, 12) described above are only provided in one of the two holes (8, 9).

[0088] For example, this can be because only one of the two sleeve holes (8, 9) is provided with the sleeve slot (11, 12), or because the sleeve slots (11, 12) are respectively provided with the sleeve holes (8, 9) and the coupling element (6) of the sleeve which do not extend through the male pipe end (5) and the female pipe end (4), as shown in the fourth embodiment.

[0089] In the embodiment shown, the fitting hole is cylindrical. In alternative embodiments, the fitting hole can also have a different shape, which is achieved by shaping the corresponding sleeve slot (10, 11, 12) differently.

[0090] In the first and last embodiments shown, the sleeve slot (11, 12) in the sleeve hole (8, 9) also serves as a guide slot for guiding the locking pin (13) when fitting the coupling element (6) in the sleeve hole (8, 9).

[0091] In the second embodiment shown, the sleeve slot (10) in the base body (7) also serves as a guide slot for guiding the locking pin (13) when fitting the coupling element (6) in the sleeve hole (8, 9).

[0092] In the embodiments shown, the coupling element (6) is in each case also provided with an engagement hole (16) which is engaged by a hand tool (23) in order to rotate the coupling element (6) and / or to push the coupling element (6) into or pull it out of the sleeve hole (8, 9), respectively.

[0093] The engagement hole (16) can extend through the coupling element (6) as in the first three embodiments shown, or can be a blind hole as in the last embodiment shown. A combination of the two can also be provided.

[0094] Instead of providing one such engagement hole (16), a plurality of such engagement holes (16) can also be provided.

[0095] The female pipe end (4) and the male pipe end (5) are preferably made of metal. More specifically, they can for example be made of S355 steel material which has been subjected to an additional hardening step. Alternatively, they can for example be made of 42CrMo4 which has been subjected to an additional hardening step. Alternatively, they can be made of nodular cast iron, cast steel or forged steel.

[0096] The coupling element (6) is preferably also made of metal. More specifically, they can for example be made of 42CrMo4 which has been subjected to an additional oil hardening step. Alternatively, they can for example be made of S355 which has been subjected to an additional hardening step.

[0097] For the locking pin (13) and the locking element (15), commercially available standard elements can be selected. In order to secure the locking pin (13), a hole (19) can be drilled in the respective component, as shown inFigure 4 The locking pin (13) can be fitted into the hole as shown.

[0098] To couple the pipe ends (4, 5) by means of the attachment system (1) shown, the male pipe end (5) is pushed into the female pipe end (4). Subsequently, the sleeve holes (8, 9) are aligned with one another (for example by means of guide plugs provided with tapered ends), so that the sleeve holes (8, 9) are guided into the correct position. In this case, the sleeve holes (8, 9) are aligned such that they lie opposite one another in a straight line.

[0099] By introducing the locking pin (13) into the respective sleeve slot (11, 12) or the respective sleeve slot (10), the coupling element (6) is placed in the respective sleeve hole (8, 9).

[0100] The coupling element (6) is then rotated by means of a tool (23) which engages in the engagement slot (16), so that the locking pin (13) lies in the locking slot (14). The coupling element (6) is rotated such that the sleeve slots (10, 11, 12) of both the coupling element (6) and the sleeve hole (8, 9) are aligned. The locking element (15), which prevents the coupling element (6) from rotating, is arranged in the fitting hole thus formed.

[0101] All coupling elements (6) and locking elements (15) can be removed again from the pipe ends (4, 5) by following the reverse order, and can then be used again.

[0102] As shown in Figures 7a-7f The locking elements (15) can also be chosen such that, when the applied rotational force exceeds the break-off rotational force, the locking elements (15) break off and the coupling elements (6) are again able to rotate in the sleeve holes (8, 9). In this case, of course, it is not possible to reuse the locking elements (15).

[0103] The locking elements (15) can for example be made of a material which is weaker than the material from which the pipe ends (4, 5) and the coupling elements (6) are made. If the same material or a stronger material is used, such locking elements (15) must be provided with a weakening, so that it is the weakest link in the whole and will break first.

[0104] Preferably, the locking elements (15) consist of a plastic tube or a tube cap. Such tube caps are relatively inexpensive commercially available parts. The tube caps are provided with a ribbed sleeve surface. The ribbed sleeve surface on the one hand helps to ensure that the locking elements (15) cannot slip out of the fitting hole. On the other hand, the ribbed sleeve surface helps to ensure that the tube cap breaks easily when the coupling element (6) is turned with a rotational force which is higher than the break-off rotational force, but is strong enough to prevent the coupling element (6) from twisting itself.

[0105] The locking elements (15) should be strong enough so that the coupling elements (6) cannot rotate by themselves under normal conditions of use, but weak enough so that the locking elements (15) do not have to exert an excessively high breaking rotational force on the coupling elements (6). This breaking rotational force depends on the material from which the locking elements (15) are made and on the number of locking elements (15) used for each coupling element (6).

[0106] Knowing the rotational forces acting on the coupling elements (6) under normal conditions of use of the attachment system (1), the locking elements (15), their number and their manufacturing material can be chosen wisely.

[0107] For example, it is known that in the first illustrated embodiment, when no locking elements (15) are present in the fitting element, a rotational force of approximately 0.5 Nm is required to rotate the coupling elements (6). If the attachment system (1) is fully assembled with coupling elements (6) and locking elements (15) in the installed position and this is used to create a foundation pile, a maximum torque of approximately 100 Nm can be applied to the coupling elements (6), for example. If the locking elements (15) do not break under this maximum torque, this is strong enough in theory. In practical applications, a safety margin is preferred and the locking elements (15) can be chosen so that they break under a torque of approximately 350 Nm on the coupling elements (6), for example.

Claims

1. An attachment system (1) for detachably connecting a female pipe end (4) and a male pipe end (5) to form a foundation pile, comprising: -The cylindrical sleeve hole (8) in the sleeve of the mother tube end (4); - The corresponding cylindrical sleeve hole (9) in the sleeve of the male pipe end (5) can be aligned with the sleeve hole (8) in the female pipe end (4) when the male pipe end (5) is fitted into the female pipe end (4); and -A connecting element (6) including a cylindrical base (7) is capable of fitting into the sleeve holes (8, 9) when the sleeve holes (8, 9) are aligned relative to each other to connect the tube ends (4, 5) to each other. The attachment system (1) is characterized in that it further includes: - A locking pin (13) disposed on one of the base (7) or the sleeve hole (8, 9) and extending radially relative to one of the base or the sleeve hole; and - Locking grooves (14) are respectively arranged in one of the sleeve holes (8, 9) or the base (7), and the locking pin (13) can be fitted in the locking groove; The locking pin (13) and the locking groove (14) are arranged such that the connecting element (6) can rotate by an angle after being fitted into the sleeve hole (8, 9), wherein the locking pin (13) is fitted into the locking groove (14) by a guiding action. At least one of the sleeve holes (8, 9) and the base (7) is provided with corresponding sleeve grooves (10, 11, 12), which extend at least partially axially relative to the corresponding sleeve hole (8, 9) or the corresponding base (7), such that these sleeve grooves (10, 11, 12) together form a fitting hole after the connecting element (6) has been fitted into the sleeve hole (8, 9) and the connecting element (6) has been rotated through the angle, and the attachment system (1) includes a locking element (15) capable of fitting into the fitting hole thus formed to prevent the connecting element (6) in the sleeve hole (8, 9) from rotating.

2. The attachment system (1) as claimed in claim 1, characterized in that, The locking element (15) is designed such that when the locking element (15) is inserted into the fitting hole, the rotational force on the connecting element (6) remains lower than the disconnecting rotational force. The locking element prevents the connecting element (6) from rotating in the sleeve hole (8, 9). When the rotational force applied to the connecting element (6) is higher than the disconnecting rotational force, the locking element (15) disengages and the connecting element (6) rotates again in the sleeve hole (8, 9).

3. The attachment system (1) as described in any one of the preceding claims, characterized in that, The sleeve grooves (10, 11, 12) and the locking pin (13) are arranged such that during the fitting of the connecting element (6) into the sleeve hole (8, 9), the locking pin (13) is guided in one or more sleeve grooves (10, 11, 12) that serve as guide grooves.

4. The attachment system (1) as described in claim 1 or 2, characterized in that, The sleeve hole (8) in the female pipe end (4) and / or the sleeve hole (9) in the male pipe end (5) are configured as through holes that pass through the respective sleeves.

5. The attachment system (1) as described in claim 1 or 2, characterized in that, The resulting fitting hole penetrates the sleeve.

6. The attachment system (1) as claimed in claim 1 or 2, characterized in that, The tube ends (4, 5) are basically cylindrical.

7. The attachment system (1) as claimed in claim 1 or 2, characterized in that, The resulting fitting holes are basically cylindrical.

8. The attachment system (1) as claimed in claim 1 or 2, characterized in that, The female pipe end (4) is provided with multiple corresponding sleeve holes (8) and / or the male pipe end (5) is provided with multiple corresponding sleeve holes (9).

9. The attachment system (1) as claimed in claim 1, characterized in that, The female tube end (4) is provided with an inner recess (20) defined by a shoulder (17), wherein the male tube end (5) is provided with a corresponding outer recess (21) defined by a shoulder (18), and the outer recess (21) of the male tube end (5) can be fitted into the inner recess (20) of the female tube end (4) to fit the male tube end (5) into the female tube end (4), wherein the fitting of the male tube end (5) into the female tube end (4) is defined by the shoulders (17, 18).

10. The attachment system (1) as claimed in claim 9, characterized in that, Each sleeve hole (8) in the female tube end (4) is located in an inner recess (20), and each sleeve hole (9) in the male tube end (5) is located in an outer recess (21).

11. The attachment system (1) as claimed in claim 9 or 10, characterized in that, The male end (5) is fitted into the female end (4), and silicone resin is applied between the shoulders (17, 18).

12. The attachment system (1) as claimed in claim 1 or 2, characterized in that, The locking groove (14) is configured to be conical.

13. The attachment system (1) as claimed in claim 1 or 2, characterized in that, The connecting element (6) includes an engagement element (16) which is engaged by a hand tool to rotate the connecting element (6).

14. The attachment system (1) as claimed in claim 1 or 2, characterized in that, The locking pin (13) is disposed on the base (7), and the locking groove (14) terminates in the outer sleeve surface of the male pipe end (5).

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