Screw foundation

Abstract

The invention relates to a screw foundation for fastening elements in a substrate, comprising a first tubular body (2) which, starting from a rear end (2a), has a first cylindrical section (2c) and axially adjoining it a conical front section (2d) tapering to an insertion tip (5), wherein the first tubular body (2) is provided at least partially with a thread-like outer contour (6) for screwing into the substrate, and with at least a second tubular body (3) which has a second cylindrical section (3c) and is connectable to the rear end (2a) of the first tubular body (2).According to the invention, the first tubular body (2) has a screw flange (10) at its rear end (2a), the outer diameter of which is not larger than the outer diameter of the first cylindrical section (2c), and the second tubular body (3) has a screw flange (10) connectable to the screw flange (9) of the first tubular body (2), the outer diameter of which is not larger than the outer diameter of the second cylindrical section (3c).

Description

[0001] The invention relates to a screw foundation for fastening elements in a substrate, comprising a first tubular body which, starting from a rear end, has a cylindrical section and axially adjacent to it a conical front section tapering towards an insertion tip, wherein the first tubular body is provided at least partially with a thread-like outer contour for screwing into the substrate, and with at least a second tubular body which can be connected to the rear end of the first tubular body.

[0002] Screw foundations are available in various designs. They can be designed at the rear end for inserting piles or rods, or alternatively, they can have a plate- or flange-like fastening element at the rear end to which other elements, e.g., frames or the like, can be attached.

[0003] To enable screw foundations to be driven deeper into the ground, for example in unfavorable soil conditions, or to compensate for differences in elevation, multi-part screw foundations consisting of at least two parts are also known: a first tubular body and a second tubular body that can be connected to the rear of the first tubular body as an extension element. Such a screw foundation is known, for example, from DE 10 2021 130 720 B3. In this screw foundation, the second tubular element is inserted into the rear end of the first tubular element in a rotationally fixed manner and secured by radial pressing.

[0004] From WO 2022 / 076944 A1, a multi-part screw foundation is known in which the first and second tubular elements are connected by means of a sleeve and screws directed transversely to the longitudinal axis. Similar solutions are known from KR102508176 B1 and KR102620141 B1. From GB 2 477 757 A, a multi-part screw foundation is known in which the first and second tubular elements are connected by means of a bayonet connection.

[0005] However, the known connection solutions could be improved with regard to tensile force (against pulling out the screw foundation) and compressive force when screwing in.

[0006] The object of the invention is to improve a multi-part screw foundation so that it can withstand greater tensile and compressive forces.

[0007] This problem is solved according to the invention in a screw foundation of the type described above by the fact that the first tubular body has a screw flange at its rear end, the outer diameter of which is not larger than the outer diameter of the first cylindrical section, and the second tubular body has a screw flange connectable to the screw flange of the first tubular body, the outer diameter of which is not larger than the outer diameter of the second cylindrical section.

[0008] Such a multi-part screw foundation with a flanged connection between the first tubular body and at least one second tubular body can withstand high compressive forces when screwed into the ground and high tensile forces when pulled out. The outer diameter of the first and second cylindrical sections refers to the maximum outer diameter, i.e., that of the threaded outer contour, if present.

[0009] When the second tubular body is used as an intermediate extension element, it is designed to have a screw flange at each end. The second tubular body can then be connected to a first tubular body and a second tubular body, or to two second tubular bodies.

[0010] Depending on the nature of the subsoil into which the screw foundation is to be installed, it is provided that the second tubular body has at least a thread-like outer contour in some areas.

[0011] In a particularly preferred embodiment, it is provided that a star-shaped contour with internal and external teeth is formed in the rear end of the first tubular body and in both ends of the second tubular element, wherein the contour at one end of the second tubular body corresponds to the contour at the rear end of the first tubular body and the contour at the other end of the second tubular body is designed such that the other end of the second tubular body can be inserted into or onto the rear end of the first tubular body in a force-fit and / or form-fit manner.

[0012] As described in detail in DE 10 2021 130 720 B3, to which explicit reference is made, the rear tubular end of the first tube can be formed radially from the outside without an internal counter-form, such that the contour is star-shaped with internal and external teeth. The ends of the second tubular body can be formed analogously. The contour at the rear end is thus formed from the outside without the use of chips, creating both internal and external teeth. The external and internal teeth serve for a rotationally fixed connection with a screw-in tool having a complementary tooth contour, while the internal teeth are suitable for the rotationally fixed retention of a second tubular body as a tubular extension element. The star-shaped contour allows for the transmission of high torques, enabling screwing into substrates with various soil conditions.The star-shaped contour can be designed similarly to a screw drive profile with the standard designation internal hexagon or external hexagon, whereby the number of teeth is arbitrary.

[0013] In the aforementioned embodiment, it is particularly preferred that the screw flanges have circumferentially shaped bores for connecting screws. This ensures that torques are transmitted not via the connecting screws of the respective flange connection, but exclusively via the star-shaped toothed contour, so that the connecting screws are not subjected to shear forces.

[0014] In an alternative embodiment, the bores in the screw flanges are round, and the screw flanges essentially also serve for torque transmission. A contour, e.g., star-shaped, with internal and external teeth, is formed into the rear end of the first tubular body and into both ends of the second tubular element. The contour at one end of the second tubular body corresponds to the contour at the rear end of the first tubular body, and the contour at the other end of the second tubular body is designed such that the other end of the second tubular body can be positively inserted into or onto the rear end of the first tubular body. The star-shaped contour can also have only a single "tooth" in the inner or outer contour. The contour then serves to forcefully insert the ends into one another so that the bores of the screw flanges are aligned.Alternatively, the ends can be designed not to fit together; in this case, flanges are provided at the free ends.

[0015] Furthermore, it is preferably provided that the screw flanges are welded on.

[0016] The invention is explained in more detail below with reference to the drawing. This drawing shows a perspective view in each case. Fig. 1 an exploded view of a two-part screw foundation, Fig. 2 an enlarged detail of the Fig. 1 and in Fig. 3 the assembled screw foundation.

[0017] In the exemplary embodiment, a two-part screw foundation is generally designated by 1. In the exemplary embodiment, this screw foundation 1 exhibits the following characteristics: Fig. 1The first tubular body 2 comprises a first tubular body 2 and at least one second tubular body 3. The first tubular body 2 has a rear end 2a and a front end 2b. Preferably, a star-shaped contour 4, having internal and external teeth, is formed into the rear tubular end 2a, preferably in the manner described in DE 10 2021 130 720 B3. Axially adjacent to this star-shaped contour 4, the first tubular body 2 has a first cylindrical section 2c and, adjoining this to the front, a front section 2d that tapers conically to an insertion tip 5 at the front end 2b.

[0018] Both the front section 2d and the first cylindrical section 2c are provided, at least partially, with a thread-like outer contour 6, which is preferably formed exclusively by pressure rolling. For a more detailed explanation, reference is made to publication DE 10 2019 128 030 B3.

[0019] The second tubular body 3, serving as an extension element, has a rear end 3a and a front end 3b. Both the front end 3a and the rear end 3b have a star-shaped contour 7, 8 formed in the same way as the first tubular body 2, each having internal and external teeth.

[0020] The contour 7 at the front end 3b of the second tubular body 3 is dimensioned such that the front end 3b can be inserted into the rear end 2a of the first tubular body 2 in a force-fit and / or form-fit manner. In contrast, the star-shaped contour 8 at the rear end 3a corresponds to the star-shaped contour 4 of the first tubular body 2, so that the rear end 3a of the second tubular body 3 is suitable either for being coupled to the screw-in tool or for receiving a further second tubular body 3.

[0021] A second cylindrical area 3c between the two ends 3a and 3b of the second tubular body 3 can also be provided with a thread-like outer contour by means of pressure rolling, but this can also be omitted - as shown.

[0022] To achieve a secure connection between the first tubular body 2 and the second tubular body 3, the invention provides that the first tubular body 2 has a screw flange 9 at its rear end 2a, the outer diameter of which is not larger than the outer diameter of the first cylindrical section 2c or its threaded outer contour, and that the second tubular body 3 has a screw flange 10 connectable to the screw flange 9 of the first tubular body 2, the outer diameter of which is not larger than the outer diameter of the second cylindrical section 3c. Both screw flanges 9, 10 have bores 9a, 10a for connecting screws circumferentially on a common radius, the bores 9a, 10a preferably being elliptically shaped in the circumferential direction. The screw flange 9 is attached to the outside of the rear end 2a of the first tubular body 2, preferably by welding.The screw flange 10 is spaced apart from the front end 3b at the end of the star-shaped contour 7 on the second tubular body 3, preferably welded in place. This allows the front end 3b with the star-shaped contour 7 to be fully inserted longitudinally into the rear end 2a with the star-shaped contour 4 until the two screw flanges 9, 10 abut each other. Then, fastening screws (not shown) are inserted into the aligned bores 9a, 10a and secured with fastening nuts. The bores 9a, 10a are arranged relative to the respective star-shaped contours 4, 7 such that they automatically align when the front end 3b with the star-shaped contour 7 is inserted into the rear end 2a with the star-shaped contour 4.

[0023] The second tubular body 3 also has a screw flange 11 with bores 11a at its rear end 3a, which corresponds in design and arrangement to the screw flange 9 on the first tubular body 2. Thus, the front end 3b of a further second tubular body 3 can be inserted into the rear end 3a of the second tubular body 3 and secured to it.

[0024] Of course, the invention is not limited to the illustrated embodiments. Further embodiments are possible without departing from the basic concept. For example, instead of the star-shaped contours 4, 7 and 8, a different connection contour with a suitable arrangement of the screw flanges 9, 10, 11 can also be chosen. Reference symbol list:

[0025] 1 Screw foundation 2 First tubular body 2a Rear end 2b Front end 2c First cylindrical section 2d Tapered front section 3 Second tubular body 3a Rear end 3b Front end 3c Second cylindrical section 4 Star-shaped contour 5 Lead-in tip 6 Threaded outer contour 7 Star-shaped contour 8 Star-shaped contour 9 Screw flange 9a Bores 10 Screw flange 10a Bores 11 Screw flange 11a Bores

Claims

1. Screw foundation for fastening elements in a substrate, comprising a first tubular body (2) which, starting from a rear end (2a), has a first cylindrical section (2c) and axially adjoining it a conical front section (2d) tapering to an insertion tip (5), wherein the first tubular body (2) is provided at least partially with a threaded outer contour (6) for screwing into the substrate, and with at least a second tubular body (3) which has a second cylindrical section (3c) and is connectable to the rear end (2a) of the first tubular body (2), characterized by thatthe first tubular body (2) has a screw flange (10) at its rear end (2a) whose outer diameter is not larger than the outer diameter of the first cylindrical section (2c), and the second tubular body (3) has a screw flange (10) connectable to the screw flange (9) of the first tubular body (2), whose outer diameter is not larger than the outer diameter of the second cylindrical section (3c).

2. Screw foundation according to claim 1, characterized by that the second tubular body (3) has a screw flange (10,11) at each of its ends.

3. Screw foundation according to claim 1 or 2, characterized by that the second tubular body (3) has at least in some areas a thread-like outer contour.

4. Screw foundation according to claim 1, 2 or 3, characterized by thatA star-shaped contour (4, 7, 8) having internal and external teeth is formed in the rear end (2a) of the first tubular body (2) and in the two ends (3a, 3b) of the second tubular element (3), wherein the contour (8) at one end (3a) of the second tubular body (3) corresponds to the contour (4) at the rear end (2a) of the first tubular body (2) and the contour (7) at the other end (3b) of the second tubular body (3) is designed such that the other end (3b) of the second tubular body (3) can be inserted into or onto the rear end (2a) of the first tubular body (2) in a force-fit and / or form-fit manner.

5. Screw foundation according to one or more of claims 1 to 4, characterized by that the screw flanges (9,10,11) have circumferentially shaped bores (9a,10a,11a) for connecting screws.

6. Screw foundation according to one or more of claims 1 to 5, characterized by that the screw flanges (9,10,11) are welded on.

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