Device for anchoring an object in the ground

Abstract

The invention relates to a device for anchoring an object (1) in the ground (2), the device comprising a ground screw (3) that has a receptacle (13) for the object (1) to be anchored, the screw-core diameter of which ground screw increases from the screw tip (4) to the screw head (5), wherein the ground screw (3) has a thread profile (6) having a thread flank (7a, 7b). Particularly stable anchoring results if the thread flank (7a) facing the screw head (5), viewed from the screw head (5) towards the screw tip (4), is concave, wherein the outer edge (10) of the concave thread flank (7a) projects beyond a trough base (11) towards the screw head (5).

Description

Technical area

[0001] The invention relates to a device for anchoring an object in the ground with a ground screw comprising a receptacle for the object to be anchored, the screw core diameter of which increases from the screw tip to the screw head, wherein the ground screw comprises a preferably single-start thread profile having thread flanks. State of the art

[0002] DE102008037937A1 discloses a device for anchoring a rod-shaped object in the ground. The device comprises a ground screw with a receptacle for the object to be anchored. Because the screw core diameter of the ground screw increases from the screw tip to the screw head, the soil is compacted radially outward when the ground screw is screwed into the ground. However, the disadvantage is that, to ensure the ground screw is properly secured, a hole must be pre-drilled using a ram or screw mandrel before screwing it in, which requires a complex assembly process. Furthermore, due to the small engagement volume of the thread flanks in the surrounding soil, the tensile forces that can be absorbed are relatively low. Ultimately, the device is only suitable for anchoring rod-shaped objects, which limits its application.

[0003] US3736711A discloses a ground screw with a receptacle for a screw-in eyelet on its screw head. This allows various objects to be anchored in the ground. To withstand sufficient tensile force, the ground screw must be driven deep into the ground, which in turn requires complex installation.

[0004] DE102013104773A1 describes a device for anchoring an object in the ground using a ground screw with a constant core diameter. The thread profile of the ground screw can be convex or concave.

[0005] US2063052A discloses a device for anchoring an object in the ground according to the preamble. Description of the invention

[0006] The invention is therefore based on the object of proposing a device of the type described above which can be used to anchor different objects and can be subjected to high tensile forces with low screwing forces, without requiring a complex assembly process.

[0007] The invention achieves the stated object in that the thread flank facing the screw head, viewed from the screw head in the direction of the screw tip, is concave, wherein the outer edge of the concave thread flank projects beyond a valley floor in the direction of the screw head.

[0008] As a result of the measures according to the invention, no hole needs to be pre-drilled to anchor an object, as the ground screw cuts into the ground as it is screwed in thanks to its inventive thread profile. Surprisingly, it has been found that particularly energy-efficient screwing in of the ground screw and, at the same time, the absorption of particularly high tensile loads by the screwed-in ground screw is achieved by the thread flank of the thread profile facing the screw head being concave, viewed from the screw head towards the screw tip. The outer edge, i.e. the edge of the concave thread flank facing away from the screw core, protrudes beyond a trough in the direction of the screw head, so that a kind of groove is formed by the concave thread flank running around the screw core. The trough here is the lowest point of the concave thread flank in an imaginary longitudinal plane section.This means that the edge point on the thread flank is closer to the screw head than the low point, with the edge point and the low point being in the same longitudinal plane. This results in a thread profile whose thread teeth have a shark fin shape in cross-section, creating an undercut that extends into the screw head. As a result, when the ground screw is screwed in, the soil surrounding the ground screw is pushed from the edge of the thread profile towards the screw core, filling the chambers between the thread flanks with additional soil, thereby strengthening the anchoring. By expanding the screw core diameter, this additional soil is simultaneously compacted when the ground screw is screwed in, compacting not only the soil between the thread flanks, but also the soil adjacent to the ground screw.Additional reinforcement of the anchorage is achieved by the screw head being wider than the screw core, which compacts the soil in the direction of screwing in when the ground screw is screwed in as far as the screw head will go. For typical ground screw lengths (12 cm to 17 cm), the measures according to the invention can achieve a tensile force of up to 500 N. The other thread flank, i.e. the thread flank facing the screw tip, can be straight, resulting in a type of buttress thread. The convex thread flank can merge seamlessly into the screw core of the ground screw, which results in a simpler construction. The geometric description of the thread flanks refers to their shape in an imaginary longitudinal plane section. The fastening screw can be made of plastic.The fastening screw can be manufactured using a 3D printing process, particularly due to the undercut of the thread profile according to the invention.

[0009] In order to anchor different objects, it is proposed that the receptacle for the object to be anchored be formed by an internal thread and a fastening screw screwed into the internal thread. The internal thread can be a trapezoidal thread. The fastening screw can form a hook extension at the non-tightened end section. The hook extension can have an eccentrically offset hook mouth open toward the screw head, to which the tensioning devices to be anchored can be attached.

[0010] To ensure that the ground screw can also be screwed into particularly hard soil, a preferred embodiment of the device according to the invention recommends that the screw head of the ground screw has a hole running transversely to the screw's longitudinal axis for inserting a turning aid. In this way, increased torque can be used for screwing in, as the turning aid can be used for lifting. The fastening screw itself, for example, can be used as a turning aid; it is pushed into the hole running transversely to the screw's longitudinal axis for screwing in. After screwing in, the fastening screw can be removed from the hole and screwed into the receptacle, which runs coaxially to the screw's longitudinal axis. In this way, no additional tools are required for assembly.Using a fastening pin inserted into the opening, various attachments can be arranged on the screw head and secured against rotation. For this purpose, the attachments can be designed to be plugged onto the screw head and have openings arranged complementarily to the openings. This allows a fastening pin to be guided through both the openings of the attachment and the opening in the screw head, thus connecting the attachment to the screw head in a tensile and rotationally secure manner. Adapter plates can be used as attachments for attaching tent legs or posts, for example. A screw insert can also function as an attachment to screw in the ground screw using a drill or similar.

[0011] To prevent the ground screw from being screwed in too far, a washer with a spike extending towards the screw tip can be attached to the screw head. The washer can have a larger diameter than the screw head and form a stop for the screw head, making it more difficult for the screw head to accidentally penetrate the ground. At the same time, this can increase the volume of the compressed soil perpendicular to the screwing direction or perpendicular to the screw's longitudinal axis. The spike of the washer extending towards the screw tip is driven into the ground when the screw is screwed in, which not only prevents the washer from twisting but also provides an additional fastening option for straps or the like.

[0012] The washer can preferably accommodate the screw head in a form-fitting manner, at least in sections. This means that the washer forms a stop section for the screw head and has a border section that projects relative to the stop section against the screwing direction and surrounds the screw head, resulting in a stepped shoulder. The washer is therefore thinner in the area of ​​the stop section than in the area of ​​the border section. This has the result that when the washer is screwed in, the edge, i.e. the border section, curves upwards in a plate-like manner against the screwing direction. This generates a radially inward force such that the screw head is clamped by the washer. In this way, the mandrel provided as an anti-twist device also acts on the ground screw as soon as a certain tensile force is reached by tightening the ground screw.

[0013] It has been found that a particularly high tensile force of the device can be achieved if the concave thread flank is described by a circular arc with a radius of 2 mm to 7 mm, especially 4 mm to 5 mm. This refers to the circular arc that results between the screw core and the edge of the concave thread flank in a longitudinal plane section of the ground screw. The circular arc can, in particular, merge smoothly into the surface of the screw core.

[0014] To enable rapid screwing in without weakening the anchorage, the thread pitch can be 10 mm to 20 mm, particularly 13 mm to 17 mm. Advantageously, threads with pitches in these ranges cannot be blocked by typical obstructions found in the ground, such as stones or the like.

[0015] To ensure the device's universal application in soils of varying quality, it has proven particularly advantageous for the opening angle of the ground screw's cone to be between 3° and 10°, particularly between 4° and 6°. This allows for sufficiently strong compaction when screwing in the ground screw, while still allowing the ground screw to retain a certain degree of variability in its screw-in angle, allowing it to be driven into the soil at an angle. Brief description of the invention

[0016] The drawing shows an example of the subject matter of the invention. Fig. 1 is an exploded perspective view of the device according to the invention, Fig. 2 is a view along the line II-II of Fig.1 corresponding section through the device according to the invention in assembled and screwed-in state, Fig. 3 a detailed view of the Fig. 2 on an enlarged scale, Fig. 4 shows an adapter plate according to the invention that can be placed on the screw head, and Fig. 5 shows a screw insert according to the invention that can be placed on the screw head. Ways to implement the invention

[0017] A device according to the invention for anchoring an object 1 in the ground 2 has, for example, the Figs. 1 and 2 , a ground screw 3, which can be screwed into the ground 2. The ground screw 3 has a screw core diameter that increases from the screw tip 4 to the screw head 5, resulting in a conical basic shape. According to the invention, the thread profile 6, as shown in Fig. 2 disclosed, two thread flanks 7a, 7b and a tooth flank 8. The thread flank 7a facing the screw head 5 is concave, viewed from the screw head 5 in the direction of the screw tip 4, i.e. in the screwing direction 9. The thread flank 7b facing the screw tip 4 can be straight. The geometric description of the thread flanks 7a, 7b refers to their shape in an imaginary longitudinal plane section. As best seen from the Fig. 3 As can be seen, the outer edge 10 of the thread flank 7a projects in each imaginary longitudinal plane section beyond a valley floor 11 in the direction of the screw head 5, i.e. opposite to the screwing direction 9. Fig. 3 From the indicated longitudinal plane section, it can be seen that the valley floor 11 of the concave thread surface 7a is formed in a longitudinal plane section by the low point P2, that the edge 10 is formed in a longitudinal plane section by the edge point P1, and that the edge point P1 is closer to the screw head 5 than the low point P2, with the edge point P1 and the low point P2 being in the same longitudinal plane. Thus, a kind of shark-shaped thread tooth 12 is formed.

[0018] The device basically has a receptacle 13 for the object 1 to be anchored. The object 1 to be anchored can, for example, be arranged directly in a receptacle 13 of the ground screw 3. As shown in the Figs. 1 and 2 As is illustrated, however, the receptacle 13 can also be formed by an internal thread 14 and a fastening screw 15 screwed into the internal thread 14, so that the object 1 is fastened via the fastening screw 15.

[0019] For fastening traction means in particular, the fastening screw 15 can have a hook extension 16 on the non-twisted end section, which has an eccentrically offset hook mouth 17 open in the direction of the screw head 5.

[0020] According to the Figs. 1 and 2 The screw head 5 can have an opening 18 through which a turning aid, for example the fastening screw 15, can be inserted. The opening 18 can run transversely to the screw's longitudinal axis 19. The screw head 5 can have a larger diameter than the screw core 19, resulting in a stop 20 that can be used to compact the soil 2.

[0021] The stop surface can be further enlarged by a washer 21, which is assigned to the screw head 5. The washer 21 can have a mandrel 22 projecting toward the screw tip 4 or in the screwing direction 9, which acts as an anti-twist device and can simultaneously anchor any traction means.

[0022] The washer 21 can accommodate the screw head at least in sections in a form-fitting manner. For this purpose, the washer 21 can be Fig. 2 As indicated, the screw head 5 has a stop portion 23 for the screw head 5 and a surround portion 24 projecting relative to the stop portion 23, counter to the screwing direction 9. The screw head 5 can be locked to the surround portion by a catch 25. The catch 25 can be formed by a circumferential groove.

[0023] An embodiment of the device according to the invention can be described with reference to the Figs. 2 and 3be constructed as follows. The concave thread flank 7a can be described in an imaginary longitudinal plane section by a circular arc with a radius R of 4.525 mm. The circular arc can continuously transition into the truncated cone of the screw core 26. The thread flank 7b facing the screw tip 4 can be straight and have a length of 7.061 mm. The tooth flank 8 can be 2 mm long and run parallel to the surface of the screw core 26. The thread profile base 27 can be 7.51 mm long. The angle α between the thread flank 7b and the surface of the screw core 26 can be 114.29°. ( Fig. 3 )

[0024] The thread pitch 28 can be 14.99 mm. The opening angle β of the cone of the ground screw 3 can be 5.28°. The ground screw 3 can have a tip 29 with a larger opening angle at the screw tip 4. ( Fig. 2 )

[0025] Fig. 4 shows an adapter plate 30 according to the invention for mounting on a screw head 5. Posts or the like can be inserted into the adapter plate 30. The adapter plate 30 can have a through-hole extending transversely to the screw's longitudinal axis 19, the opening 31 of which can be complementary to the through-hole 18 of the screw head 5. In this way, the adapter plate 30 can be connected to the screw head 5 in a rotationally and tensile-resistant manner by means of a fastening bolt.

[0026] The same applies to the Fig. 5 shown rotary insert 32, which has a pin 33 for fixing in a drill or the like, whereby the ground screw can be screwed in by various means.

Claims

1. Device for anchoring an object (1) in the ground (2) with a ground screw (3) comprising a receptacle (13) for the object (1) to be anchored, the screw core diameter of which ground screw (3) increases from the screw tip (4) to the screw head (5), wherein the ground screw (3) comprises a thread profile (6) having thread flanks (7a, 7b), characterized in that the thread flank (7a) facing the screw head (5) is concave when viewed from the screw head (5) in the direction of the screw tip (4), wherein the outer edge (10) of the concave thread flank (7a) projects beyond a valley floor (11) in the direction of the screw head (5).

2. Device according to claim 1, characterized in that the receptacle (13) for the object (1) to be anchored is formed by an internal thread (14) and a fastening screw (15) screwed into the internal thread (14).

3. Device according to claim 2, characterized in that the fastening screw (15) forms a hook extension (16) at the non-screwed-in end section.

4. Device according to one of claims 1 to 3, characterized in that the screw head (5) of the ground screw (3) has a through-opening (18) extending transversely to the screw longitudinal axis (19) for inserting a rotary aid.

5. Device according to one of claims 1 to 4, characterized in that the screw head (5) is assigned a washer (21) with a pin (22) projecting in the direction of the screw tip (4).

6. Device according to claim 5, characterized in that the washer (21) receives the screw head (5) in a form-fitting manner at least in sections.

7. Device according to one of claims 1 to 6, characterized in that the concave thread flank (7a) is described by a circular arc with a radius (R) of 2 mm to 7 mm, in particular 4 mm to 5 mm.

8. Device according to one of claims 1 to 7, characterized in that the thread pitch (28) is 10 mm to 20 mm, in particular 13 mm to 17 mm.

9. Device according to one of claims 1 to 8, characterized in that the opening angle (β) of the cone of the ground screw (3) is 3° to 10°, in particular 4° to 6°.

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