DE20220515U1 - Ground spike for post or mast has a conical plastic moulded screw tip topped by a metal support sleeve - Google Patents

Abstract

A ground spike for securing a post or a mast has a plastic moulded conical tip (3) with an outer self cutting thread (5) and an upper cylindrical metal sleeve (2) into which the mast/post is fitted. The tip is made of an elastic, tensile plastic which easily slides around stones in the soil. Internal ribs and a shaped outer tip (4) complete the moulding. A corrosion protected metal sleeve (2) is fitted to the top of the tip via a shaped seat. The top of the sleeve is fitted with holes for a tommy bar and for threaded fasteners to secure the post.

Description

Fastening device in the form of a sleeve-like body for rods, posts, masts or the like in the ground

The invention relates to a fastening device in the form of a sleeve-like body for rods, posts, masts or the like in the ground, consisting of a holding part for receiving the rod, post, mast or the like and an anchoring part serving for anchoring in the ground, which is designed as a displacement body with at least one conical region and is provided with a thread over at least part of its length.

A fastening device of this type is also referred to as a ground anchor and is known, for example, from DE 93 13 258 Ul. It consists of a one-piece, sleeve-like body which is tubular in its upper part and can therefore serve as a holding part for holding rods, posts, masts or the like. In its lower part, the sleeve-like body of the known fastening device is designed as an anchoring part. The anchoring part consists of a threaded section which can be conical or cylindrical and ends in a point at the bottom. In its upper part, the threaded section merges into the holding part with a conical area which forms the actual displacement body. Through-holes are formed in the holding part through which a tool can be inserted to rotate the fastening device. It is thus screwed into the ground like an earth drill. Although screwing in the threaded section loosens the ground surrounding the fastening device somewhat, this does not affect the stability of the fastening device. but the conical area adjacent to the threaded area causes a compaction of the loosened soil, so that overall the loosening of the soil remains relatively low and a good hold of the fastening device in the soil is guaranteed. There are also versions

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A fastening device is conceivable in which the holding part has conical sections or the anchoring part is partially cylindrical.

The fastening device known from DE 93 13 258 Ul can be made of various metals or high-strength plastics. Each of these materials has its advantages and disadvantages. Of the metals, steel is the most suitable. This has the advantage of being very strong and is particularly resistant to bending stresses, such as those that occur when a lateral bending force is exerted on a rod or post that has already been inserted. However, steel has the disadvantage that it is more expensive to process, particularly for more complicated shapes. This is particularly true for fastening devices in which the sleeve-like body is made up of cylindrical and conical sections of different conicities, with the addition of the thread and the tip making it more difficult. The simpler types of steel, such as those used for the fastening device to be manufactured as a mass product, still have the problem of susceptibility to rust. This can be counteracted by galvanizing the finished fastening device made of steel. However, it is particularly difficult to achieve a uniform zinc coating for more complicated shapes. Another disadvantage is that the zinc coating of such a fastening device is damaged by stones when it is screwed into the ground. This means that increased corrosion of the steel fastening device inserted into the ground cannot be prevented. Another disadvantage of fastening devices of the type in question that is known from practice is that power lines are sometimes cut when they are inserted. If the fastening device is made of steel, accidents due to electric shock cannot be ruled out.

In contrast, fastening devices made of plastic of the type known from DE 93 13 258 Ul have the advantage that they can be manufactured economically even in more complicated shapes. The sliding properties of the plastic can be adapted to the soil, and a fastening device made of plastic easily avoids stones. Furthermore, fastening devices made of plastic are corrosion-resistant and electrically

-3- insulating,
so that the risk of electric shocks is largely avoided if power lines are accidentally cut. The disadvantage of such fastening devices made of plastic is that they are often not robust enough. This is particularly true if a lateral bending moment is exerted on a post or mast that has already been installed. This can be counteracted by using hard plastics that are reinforced with glass fibre and have a high modulus of elasticity. However, this partially negates the price advantage of a fastening device made of plastic. The hard plastics also have poorer sliding properties; they are more brittle, so that they cannot avoid stones as well when screwed into the ground, which can cause the tip of the anchoring part to break off in extreme cases.

Also known is a fastening device with conical and cylindrical sections of the anchoring part, which is hammered into its basic shape from an essentially cylindrical tube, see DE 198 36 370 A1. The thread is then welded onto the base body produced in this way, while the tip located at the bottom is pressed on. The production of this fastening device is to be made from metal, which is given an anti-corrosion treatment, and is also very complex.

The invention is therefore based on the object of creating a fastening device of the type mentioned at the outset which has balanced usage properties while being cost-effective to manufacture.

According to the characterizing part of claim 1, this object is achieved according to the invention by a multi-part design in which the anchoring part consists of plastic and the holding part consists of a metallic material.

In the fastening device according to the invention, the anchoring part to be screwed into the ground is made of a plastic. It can therefore be manufactured economically, which is particularly important in view of the more complicated shapes of this part with its various conical and possibly cylindrical areas as well as its thread and tip.

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The properties of the plastic to be used can be optimally tailored to the function of the anchoring part. It does not have to be a hard plastic, but rather a tough and elastic one that avoids stones when screwed in, has less friction and is also more cost-effective. When such a two-part fastening device is screwed into the ground, the plastic, which has adjustable sliding properties, slides easily in the ground; it can also avoid stones and act as an electrical insulator if a power line is cut. In addition, the part of the fastening device that is completely in the ground is then optimally protected against corrosion. The metal holding part, on the other hand, has the increased bending strength, which is important when bending forces act on the pile or post used. The holding part will generally have a simple shape, usually a cylindrical or partially conical shape, which is easy to galvanize. In this way, the metal holding part can also be protected against corrosion with reasonable effort. In addition, if the conical areas of the fastening device are only present on the anchoring part and the metal holding part has the largest diameter of the entire fastening device while remaining cylindrical throughout, the holding part no longer comes into contact with stones, a protective zinc layer is not damaged and the risk of corrosion for the holding part is significantly reduced.

Advantageous embodiments are specified in the subclaims.

Of these, claims 2 to 4 show embodiments of the anchoring part which are relatively complicated for an article of the type in question here, but which can be manufactured inexpensively and with great precision when using plastic.

Claims 5 to 7 show that the holding part of the fastening device according to the invention has a relatively simple basic shape, which is well suited for economical production from steel and for corrosion protection by galvanizing.

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Claims 8 to 13 contain details of the connection between the holding part and the anchoring part.

The features of claims 14 to 22 are directed to additional measures with which a reliable positive connection between the holding part and the anchoring part can be achieved.

Claim 23 includes a special design in which the holding part is inserted into a shaft-shaped adapted end region of the anchoring part.

Claims 24 to 27 further develop the multi-part design of the fastening device according to the invention based on the materials plastic and metal by providing further plastic parts and by additionally protecting exposed edges of the metal holding part that are exposed to corrosion by plastic.

The fastening device according to the invention is explained in more detail below using exemplary embodiments shown in the drawings. The following is shown in the drawings:

Figure 1 shows the fastening device according to the invention in a side view.

Figure 2 is a detail of the fastening point between the holding part and the anchoring part in the fastening device according to Figure 1.

Figure 3 shows a top view of the fastening device according to Figure 1.
Figure 4 shows detail A of the illustration in Figure 3.

Figure 5 is a three-dimensional, partially sectioned representation of a fastening device according to the invention, in which the connection point between the holding part and the anchoring part is modified compared to the previously shown embodiments.

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Figure 6a shows a connection point with additional tabs and recesses as a measure for the positive connection between the holding and the anchoring part.

Figure 6b illustrates ribs and longitudinal grooves as a measure for positive locking at the joint.

Figure 6c is a three-dimensional, partially sectioned representation of the connection point, where tongues and openings are provided as means for positive locking.

Figure 6d shows another connection point where snap-in buttons and openings serve as positive locking measures.

Figure 7a shows the connection point of a fastening device according to the invention, which is designed to be detachable.

Figure 7b is the corresponding overall view in the assembled state.
Figure 7c shows the fastening device of Figures 7a and 7b in its transport position.

Figure 8 is a longitudinal section through an anchoring part of a fastening device according to the invention.

Figure 9a illustrates a particular embodiment in which the holding part 2 is inserted into the anchoring part 3.

Figure 9b shows the fastening device according to Figure 9a in a partially sectioned view.

Figure 10a shows that the fastening device according to the invention can be closed at the top by a cover and can also be otherwise protected.

Figure 10b is an enlarged view of the additional plastic part shown in Figure 10a.

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Figure 11 shows a detail according to which the operational lower edge of the holding part is protected against corrosion.

Figure 1 shows a fastening device according to the invention in the form of a sleeve-like body, which is also known as a "ground anchor". The sleeve-like body 1 comprises a holding part 2 and an anchoring part 3. The sleeve-like body is screwed into the ground using the anchoring part 3, which ends in a tip 4 at the bottom. For this purpose, the anchoring part 3 is provided with a thread 5.

The anchoring part essentially consists of a first conical region 12 and a second conical region 13, wherein the cone angle of the second conical region 13 is slightly larger than that of the first conical region 12. This design serves to ensure that the soil loosened by the thread 5 and the first conical region 12 when screwing in is compacted again by the region 13. The anchoring part is therefore designed as a displacement body overall.

The holding part 2 has a continuous cylindrical shape in the representation according to Figure 1 and is tubular, see Figure 2. A rod, post, mast or the like is inserted into this tube after the sleeve-like body 1 is in the ground. For this purpose, a bore base 11 is attached, in which there is a threaded bore. The rod or post located in the holding part 2 can be screwed tight using a fastening screw, for example a wing screw 22 (Figure 7b). The through-bore 10 is used to insert a crossbar or to attach a motor-driven turning tool. In this way, the sleeve-like body 1 can be rotated and the fastening device can be screwed into the ground.

The illustration according to Figure 1 is to be understood as an example only. The anchoring part 3 can also have cylindrical sections and the holding part 2 can have a conical section that tapers downwards. For example, the thread 5 can be formed on a section of the anchoring part that has a

has a cylindrical shape, corresponding to a normal screw. The thread could also extend over the entire length of the anchoring part and also start at a greater distance from the tip 4 than is shown in Figure 1.

The fastening device shown as a whole in Figure 1 has a multi-part design in which the holding part 2 consists of a metallic material and the anchoring part 3 consists of plastic.

This design offers the advantage that the relatively complicated shaped anchoring part can be manufactured inexpensively as a plastic part in many different variations and with great dimensional accuracy. The shape of the thread 5 can be easily varied, as can its axial extension on the anchoring part 3. The shape of the tip can also be designed differently depending on the intended use, as can be seen from a comparison of all the figures containing the representation of the tip.

In addition to the advantages in terms of production, the anchoring part 3 made of plastic also has the advantage that it is corrosion-resistant and forms an insulator. This significantly reduces the risk of electric shocks if a power line in the ground is accidentally cut. A further advantage of the plastic displacement body is that its sliding properties can be adapted to different types of soil and that the anchoring part avoids stones in the ground.

In contrast, a relatively simple shape is sufficient for the holding part 2. It has the basic shape of a tube and is made of metal, in many practical applications of steel. This opens up the possibility of producing the holding part from a tube, whereby in many cases a longitudinally welded tube is sufficient, which is cheaper than a drawn steel tube. Furthermore, galvanized tubes can be used in production. This leads to further cost savings because a galvanized tube manufactured as a semi-finished product is less expensive than galvanizing the entire prefabricated holding part with the same corrosion resistance. Finally, producing the holding part 2 from a metal, in particular from a steel, offers the advantage of greater bending strength.

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In the fastening device according to the invention, particular care is taken with the connection point between the holding part 2 and the anchoring part 3. For this purpose, in Figures 1 and 2, the fastening point on the holding part 2 is designated 6a and the fastening point on the anchoring part 3 is designated 6b. Figure 2 shows a first possibility of how the fastening point can be designed. For this purpose, the anchoring part 3 is provided with a cylindrical extension 7, which is tubular in the embodiment shown. This cylindrical extension 7 of the anchoring part 3 made of plastic is inserted with a press fit into the fastening point 6a of the holding part 2. The holding part 2 is made from a longitudinally welded galvanized pipe. 9 designates the longitudinal weld seam of the pipe, which protrudes inwards into the pipe in the usual way like a ridge or a small rib. This design, which is rather disruptive in other applications, is used here as an additional anti-twisting device, in that the weld seam 9 penetrates into the surface of the cylindrical extension 7 and thus reliably prevents the holding part 2 from twisting relative to the anchoring part 3. The holding part 2 is thus secured to the anchoring part 3 in a form-fitting manner against twisting, while the protection against lifting upwards is ensured by the press fit, i.e. by force-fitting. Figures 3 and 4 show further details of this type of connection, and it can be seen in particular from Figure 2 that a front edge is formed at the fastening point 6b between the cylindrical extension 7 and the rest of the anchoring part 3, against which the front edge of the tubular holding part 2 abuts bluntly, so that an overall smooth outer contour is created.

The projection 7 extending into the open, adapted end of the holding part 2 at the common fastening point 6a, 6b does not necessarily have to have a cylindrical outer contour. Figure 5 shows the example of a partially cylindrical projection 8, which passes from an outer, cylindrical area 8a via a conical area 8b into the displacement body 3. The holding part 2 is adapted accordingly at its fastening end 6a, so here too it has a conical outer contour. The design offers the advantage that the lower area of the holding part 2 also acts as a displacement body.

·

·

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In the embodiment according to Figure 5, the anchoring part 3 and the holding part 2 can no longer be joined together by simply pushing them together. In this case, it is advisable to inject the anchoring part 3 onto the holding part 2 by inserting it in the mold of the injection molding machine in a known manner for producing the anchoring part.

Furthermore, in the embodiment according to Figure 5, it is possible to connect the holding part 2 to the anchoring part 3 by plastically deforming the holding part. For example, the holding part 2, which initially has a continuous cylindrical contour, can be rolled around the plastic. This gives the fastening end 6b of the holding part 2 its conical shape and creates a positive lock against axial pulling apart. Hammering until plastic deformation occurs, as is known from the aforementioned DE 198 63 370 A1, also brings about a reliable connection between the holding part and the anchoring part.

Finally, the connection method of plastic deformation is not limited to the embodiment shown in Figure 5. It can also be used, for example, in the connection shown in Figure 2, by rolling two circumferential cylindrical beads into the pipe, which are pressed into the plastic of the cylindrical extension 7. This plastic deformation also provides a positive locking mechanism to prevent axial pulling apart. The anti-twisting mechanism must be ensured by the press fit created during rolling.

Figures 6a to 6d show various embodiments of fastening points in which particular emphasis is placed on the anti-twisting protection.

Thus, Figure 6a shows that tabs 14 are provided at the connection point 6a, 6b, which engage in recesses 15. The tabs 14 can be provided on the anchoring part 3 and the recesses 15 on the holding part 2; the reverse arrangement is also possible. The formation of a rotation lock by means of interlocking tabs and recesses is essential, while the security against pulling apart of the holding part 2 and

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3 by the press fit between the cylindrical extension 7 and the holding part 2.

The fastening point shown in Figure 6b between the holding part 2 and the anchoring part 3 is based on the use of a holding part 2 which consists of a tube provided with longitudinal grooves 17. Such a tube is available on the market as a semi-finished product in the form of an extruded aluminum profile, and is therefore relatively inexpensive and corrosion-resistant. The counterpart required for this in the form of the cylindrical extension 7 on the anchoring part 3 with adapted ribs 16 can be manufactured economically and very precisely from plastic. In this way, a reliable connection by means of a press fit is also possible here.

The connection point according to Figure 6c is a further development of the anti-twist device shown in Figure 6a. Instead of tabs and recesses, tongues 18 are provided on the holding part, which engage in openings 19 formed on the cylindrical extension 7. The cylindrical extension 7 is pushed into the holding part 2, and only then are the pre-punched tongues 18 pressed into the openings 19. In a modification of the embodiment shown, however, the tongues do not even need to be pre-punched, and there do not need to be any openings 19. Instead, after joining, it is sufficient to press the tubular holding part in at certain points in the area of the cylindrical extension, whereby the pressed-in areas are not separated from the rest of the tube. These areas pressed into the plastic form a reliable positive lock against twisting and against pulling apart.

Figure 6d illustrates a connection point that is particularly suitable for the injection molding technique. The cylindrical projection 7 has locking buttons 20 that engage in adapted locking openings 21 of the holding part 2. The holding part 2 is inserted into the mold of the injection molding machine, and when the plastic is injected, the locking openings 21 are filled with the material of the locking buttons 20. This connection is particularly reliable and precise in its design.

•4 4 ·* ·

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The fastening device shown in Figures 7a to 7c uses neither a press fit nor any of the other fastening types described so far. Rather, only a sliding fit is formed between the cylindrical extension 7 and the holding part 2. Tabs 14, which engage in recesses in the holding part, also provide a positive locking mechanism to prevent rotation. The locking against axial pulling apart is provided here by springy snap locks 27, two of which are shown in the example. In many cases, however, a single snap lock may be sufficient, or three or more snap locks may be attached. The springy snap lock 27 is formed on the cylindrical extension 7 by forming a springy tongue 25 there by means of two slots 24, which engages in an engagement opening 28 on the holding part 2 by means of a locking button 26. However, it is also possible to attach the snap lock to the holding part and the engagement opening to the anchoring part. The latch can also be an additional part that has to be attached separately to the holding part or the anchoring part.

The fastening point illustrated in Figures 7a to 7c has the advantage that the connection only needs to be made at the location of the fastening device. The holding part 2 is simply pushed over the cylindrical projection 7, with the snap locks 7 initially giving way in a springy manner and then falling with their locking button 26 into the engagement opening 28 of the holding part 2. This design has the advantage that the fastening arrangements can be transported in a disassembled state, taking up less space. It is even possible to push the holding part 2 onto the anchoring part 3, as can be seen from Figure 7c. The wing screw 22 used to clamp the post or rod is used as a transport lock, as can be seen from Figure 7c.

Figure 8 shows a particularly advantageous design of the anchoring part 3 for many practical applications. This is hollow over most of its length and is closed at the bottom by a one-piece tip 4. Furthermore, the anchoring part 3 has inner ribs 29 running in its longitudinal direction, which serve to stiffen it and at the same time open up a possibility for connection to the holding part. Recesses 15 are provided

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into which the tabs on the holding part can engage in a form-fitting manner.

Figures 9a and 9b illustrate the connection of an anchoring part 3 designed according to Figure 8 with a holding part 2, which in this case is inserted into the end region 30 of the anchoring part 3. The holding part 2 has open longitudinal slots 31 at its fastening end, which engage around the inner ribs 29 of the anchoring part 3. After the holding part 2 has been inserted into the shaft-shaped, adapted end region 30 of the anchoring part 3, a connection is created that is reliably secured against twisting. Here, too, a press fit can be used to secure against axial pulling apart.

With the embodiment shown in Figures 10a and 10b, for example, the idea of the multi-part design of the fastening device according to the invention is continued in that the holding part 2 made of metal is also provided with a plastic part at its upper end, namely with a pipe cap 32. A cover 33 is molded onto the pipe cap 32 via a film hinge 34. The cover 33 does not lie directly on the metal of the holding part 2, but on the pipe cap 32, which covers the upper front edge of the holding part 2 by means of a bead-shaped edge 41. For the through-hole 10 located on the holding part, through-openings 35 are provided in the pipe cap 32, which engage in the through-holes by means of an edge bead 36 and thus also cover the inner edges of the through-holes.

The advantage of the pipe cap 32 with the cover 33 is that the opening of the holding part 2 is closed so that rainwater, snow and dirt cannot get into the interior of the holding part. If the rods or masts are only used temporarily, but the fastening arrangements according to the invention remain unused in the ground for a longer period of time, this also improves the appearance. A striking color can also prevent people from tripping over the protruding ends of the holding parts.

-14- About
In addition, there is another very important advantage. For economic reasons, it is advantageous to manufacture the holding parts 2 from galvanized steel pipes. The galvanization is naturally lost on the cut edges and holes in the holding parts made from this, which means that there is an increased susceptibility to rust at this point. By reliably covering the cut edges and hole edges using the pipe cap described, the risk of corrosion for the holding parts is largely eliminated. In this way, even rust film on the front edges of the holding parts is reliably avoided because the pipe cap always ensures a perfect appearance. This is certainly important, for example, after long periods of storage in sales stands or outdoors.

Figure 11 illustrates a special design of the fastening end 6b on an anchoring part 3. The plastic of the anchoring part 3 forms an edge protection 37 at its abutment with the front edge 40 of the holding part 2, which by means of a raised edge 38 forms a receiving groove 39 in the form of a circumferential ring into which the front edge 40, i.e. the fastening end 6a, of the holding part 2 engages. In this way, the lower front edge of the holding part 2, which consists of a sawn-off galvanized pipe, is also reliably protected against corrosion.

Plastic tip

Reference numbers sleeve-like body 1 Holding part 2 Anchoring part 3 Great 4 thread 5 Fastening point (holding part) 6a Fastening point (anchoring part) 6b cylindrical approach 7 partially cylindrical approach 8th cylindrical area 8a conical area 8b Weld 9 Through hole 10 Bore base 11 first area 12 second area 13 Tabs 14 Recess 15 Longitudinal rib 16 Longitudinal groove 17 Tongue 18 Breakthrough 19 Locking button 20 Latching opening 21 Wing screw 22 slot 23 ····· ··· · ······ &igr;
··· ···· ··· « *
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24 slot 25 springy tongue 26 Locking button 27 spring-loaded latch 28 Intervention opening 29 Inner rib 30 End area 31 Longitudinal slot 32 Pipe cap 33 Lid 34 Film hinge 35 Push-through opening 36 Edge bead 37 edge protection 38 raised edge 39 Receiving trough 40 Front edge 41 bead

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Claims (27)

1. Fastening device in the form of a sleeve-like body for rods, posts, masts or the like in the ground, consisting of a holding part for receiving the rod, post, mast or the like and an anchoring part serving for anchoring in the ground, which is designed as a displacement body with at least one conical region and is provided with a thread over at least part of its length, characterized by a multi-part design in which the anchoring part ( 3 ) consists of plastic and the holding part ( 2 ) consists of a metallic material. 2. Fastening device according to claim 1, characterized in that the thread runs continuously over the entire length of the anchoring part. 3. Fastening device according to claim 1 or 2, characterized in that the anchoring part ( 3 ) comprises two adjoining regions with different cone angles, of which at least the first region ( 12 ) located at the bottom when the fastening device is inserted is provided with the thread ( 5 ), while the second region ( 13 ) adjoining the first has a larger cone angle than the first and forms the connection to the holding part ( 2 ). 4. Fastening device according to one of the preceding claims, characterized in that the anchoring part ( 3 ) is hollow over most of its length and is closed by a tip ( 4 ) at its bottom when the fastening device is inserted, and that it is provided on its inner wall with inwardly projecting inner ribs ( 29 ) running in the longitudinal direction of the anchoring part ( 3 ). 5. Fastening device according to one of the preceding claims, characterized in that the holding part ( 2 ) has the basic shape of a tube. 6. Fastening device according to one of the preceding claims, characterized by steel as the metallic material. 7. Fastening device according to claim 5, characterized in that the holding part ( 2 ) is galvanized. 8. Fastening device according to one of claims 1 to 7, characterized in that the holding part ( 2 ) is connected to the anchoring part ( 3 ) by a press fit. 9. Fastening device according to one of claims 1 to 7, characterized in that the holding part ( 2 ) is connected to the anchoring part ( 3 ) by injection molding. 10. Fastening device according to one of claims 1 to 7, characterized in that the holding part ( 2 ) is connected to the anchoring part ( 3 ) by plastic deformation of the holding part ( 3 ). 11. Fastening device according to one of claims 8 to 10, characterized in that the anchoring part ( 3 ) extends at the common fastening point ( 6a , 6b ) with a projection ( 7 , 8 ) into the open, adapted end of the holding part ( 2 ). 12. Fastening device according to claim 11, characterized by a cylindrical outer contour of the projection ( 7 ). 13. Fastening device according to claim 11, characterized by a partially cylindrical projection ( 8 ) which passes from an outer, cylindrical region ( 8a ) via a conical region ( 8b ) into the displacement body ( 3 ). 14. Fastening device according to one of claims 8 to 13, characterized by an additional positive connection between the holding part ( 2 ) and the anchoring part ( 3 ) at the fastening point ( 6a , 6b ). 15. Fastening device according to one of claims 5 to 14, characterized in that the holding part ( 2 ) is formed from a longitudinally welded tube. 16. Fastening device according to claim 14, characterized in that the positive connection is formed by tabs ( 14 ) and recesses ( 15 ) formed on the holding part ( 2 ) and/or on the anchoring part ( 3 ), which are designed to engage with one another at the common fastening point ( 6a , 6b ) running in the longitudinal direction of the holding part and anchoring part. 17. Fastening device according to claim 14, characterized in that the positive connection is formed by longitudinal ribs ( 16 ) and longitudinal grooves ( 17 ) formed on the projection ( 7 ) of the anchoring part ( 3 ) and/or on the inside of the holding part ( 2 ), which engage in one another. 18. Fastening device according to claim 14, characterized in that the positive connection is formed by inwardly bent tongues ( 18 ) located on the holding part ( 2 ), which engage in openings ( 19 ) or depressions formed on the projection ( 7 ) of the anchoring part ( 3 ). 19. Fastening device according to claim 14, characterized by a positive connection in the form of locking buttons ( 20 ) formed on the projection ( 7 ) of the anchoring part ( 3 ), which engage in locking openings ( 21 ) of the holding part. 20. Fastening device according to one of claims 1 to 7, characterized in that the holding part ( 2 ) is connected to the anchoring part ( 3 ) by at least one resilient snap lock ( 27 ). 21. Fastening device according to claim 20, characterized in that the anchoring part ( 3 ) extends with a projection ( 7 ) into the holding part ( 2 ) and that the resilient snap lock ( 27 ) is formed on the end of the projection ( 7 ) facing the holding part ( 2 ). 22. Fastening device according to claim 20 or 21, characterized in that the outer diameter of the anchoring part ( 3 ) including the thread ( 5 ) is matched to the inner diameter of the tubular holding part ( 2 ) in such a way that the latter can also be plugged onto the anchoring part ( 3 ) from the side of the thread ( 5 ). 23. Fastening device according to claims 4 to 7, characterized in that the tubular holding part ( 2 ) is inserted into a shaft-shaped adapted end region ( 30 ) of the anchoring part ( 3 ) and has open longitudinal slots ( 31 ) at the end which encompass the inner ribs ( 29 ). 24. Fastening device according to one of the preceding claims, characterized by a closure cap made of plastic at the end of the holding part ( 2 ) which is located at the top when the fastening device is inserted. 25. Fastening device according to claim 24, characterized in that the closure cap is designed as a tube cap ( 32 ) to which a cover ( 33 ) covering the front opening of the holding part ( 2 ) is pivotally connected. 26. Fastening device according to claim 25, characterized in that through-openings ( 35 ) are arranged in the pipe cap ( 32 ), which are aligned with through-bores ( 10 ) located in the holding part ( 2 ) and penetrate these with edge beads ( 36 ) which are formed on the edges of the through-openings ( 35 ). 27. Fastening device according to one of claims 11 to 22 and 24 to 26, characterized in that the anchoring part ( 3 ) is provided at its abutment with the front edge ( 40 ) of the holding part ( 2 ) with an edge protection ( 37 ) in the form of a circumferential ring which, by means of a raised edge ( 38 ), forms a receiving groove ( 39 ) for the front edge ( 40 ) of the holding part ( 2 ).