DE7723293U1 - Dowel with sleeve and expansion body - Google Patents

Description

l'ATKXTAXWÄLTE """,,,■""■"" _h , _BH

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I> iri, .- ING. IT. SCHMITT · "iIhkiköjSjosth. Ia

... ",,, _ΛΙΤρη TKI.EKON: (07Cl) 7 07 73

I) IPL-ING. W. MAUCIIKR 70774

company

Upat GmbH & Co,
Freiburger Strasse 9
7830 Emmendingen

P 77 200

Dowel with sleeve and expansion body

The invention relates to a dowel which has an at least partially radially flexible sleeve and a sleeve that can be retracted therein and it has a widening spreader body and possibly a rotation lock, this spreader body has a preformed internal thread for receiving an externally threaded fastener.

We already know dowel-like wall anchors where a '

The expansion body and often also the sleeve to be expanded is made of metal, with a metric or Whitworth thread being provided in the expansion body. Such known VJsnd anchors are relatively expensive to manufacture and '. ) not suitable for working with common wood screws.

One also already knows dowels of the type mentioned in which both the sleeve and the conical expansion body made of plastic and provided in the latter a nut thread for receiving a wood screw thread is. However, wood screws have in the area of their thread, both in terms of the pitch of the thread as well as with regard to the outer thread diameter and the thread core diameter, relatively large tolerances already in the normal range. In addition, there are also wood screws on the market whose tolerances are above certain go beyond standardized limits. Such, practically one

S / Re

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Wood screws covering a large tolerance field are sufficient the usual fastening requirements are quite proportionate cheap and readily available from the craftsman and numerous do-it-yourselfers. Such wood screws or the like. Fasteners provided with wood screw threads are due to their large tolerance range in the the aforementioned plastic dowels with the usual nut thread not really useful in practice in the expansion body. That is also connected with the fact that with this previously known Dowels of the expansion body made of hard material u'.id its nut thread is so geometrically designed in comparison to the external thread of the screw that a good match of screw thread and nut thread not guaranteed to a sufficient degree even with a plastic body is. In this known embodiment, only screws with a shaft diameter that is relatively is small compared to the borehole diameter. The holding forces are * correspondingly low. Also this has been previously known Plastic expansion anchor a metric thread or the like. not proven in practice, partly because also when used of very qualified plastics the resilience of such a nut thread makes difficulties. Because of the aforementioned The ratio of the diameter between the drill hole and the screw shaft is usually the diameter of the The screw head is smaller than the diameter of the drill hole. According to you, e.g. with push-through assembly, this would usually be as additional element to add a washer. Overall, this known anchor is for a push-through installation not very suitable, because then its sleeve can get stuck in the object to be fastened when the expansion body is pressed into the deepest part of the drill hole with the aid of the fastening screw.

One already knows a dowel with a sleeve to be expanded and a partially conical expansion body in which a preformed internal thread is located. This is with regard to its pitch on the external thread of the associated fastening screw matched, which has a wood screw thread or a wood screw-like thread whose

Outline shape tapers conically at the screw-in tip of this fastening screw. The nut thread in the expansion body narrows accordingly at the inner end, so that the expansion body is also widened there. This dowel loads || there is also a connecting nose between the expansion cone and the sleeve, so that when the expansion screw is inserted, the sleeve can be brought into the borehole by pulling it over the expansion cone and its nose. In practice, this | However, well-known for many decades dowels can not f lead single, which among other things may be related to that is the unavoidable tolerances on the screw thread sufficient compensation possibility and that the mating of the screw and the nut thread for actuating accuracy with respect to the FER C Requirements that are too high would have to be made in practice. In addition, with this dowel there is the risk that the threads of the cone or the screw will not be able to cope with the load when the screw is screwed in. The narrowing of the clear diameter in the expansion core in relation to the other dimensions affecting the load-bearing capacity of the screw and the expansion cone also plays a role, especially if this expansion cone is made of metal. In addition, the following has a negative effect: The expansion sleeve is designed on the outer jacket with a strongly profiled cägezahnprofile. Corresponding to the mode of operation given by the other geometric relationships, there is a particular risk that the inner end of the expansion sleeve will bend open and that there will be overall narrow, ring-like fastening areas between the expansion sleeve and the surrounding hole wall in the axial direction. A secure fixing over an elongated cylindrical surface, as is desired for generating large holding forces, is not guaranteed here. With this dowel, too, the screw shaft and screw head diameters are in an unfavorable relationship to the necessary drill hole diameter.

Finally, a dowel-like device for attaching objects to walls is already known especially zum.-Hä j: terf 'yön'jFaÄsaden cladding and the like.

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is provided. It has an elongated, tubular, longitudinally slotted sleeve and one at its inner end attached expansion cone and a fastening screw for it. This is also done with a wood screw type Provided thread and this must then either work into the expansion cone with a corresponding effort and / or otherwise perform significant displacement work. Or there is no exact collaboration between the thread of this screw and the nut thread of the usually made of metal Expansion cone. After tightening the fastening screw, a comparatively narrow, annular fastening zone at the inner end of the elongated expansion sleeve. About the task and how it works this device is therefore not quite comparable with a dowel according to the invention.

The previously known, provided with an expansion cone Accordingly, dowels still have numerous disadvantages, including their increased manufacturing effort and their strong Dependence on relatively precisely manufactured wood screws heard.

One also already knows plastic dowels, usually formed in one piece, with their expansion part Spread open with the help of wood screws and thereby in the drill hole is set; With these dowels, the wood screw cuts its "nut thread", at least for the most part even into the expansion leg of the dowel. Accordingly, the tolerances of such wood screws mentioned at the beginning no great demands made. As a result, these one-piece plastic dowels and the for it suitable wood screws or the like. manufactured comparatively cheaply and easily relocated Averden, possibly also by non-experts. Such a plastic dowel and one Fastening screw or the like. However, existing fasteners with wood screw threads have the significant Disadvantage that a relatively large amount of force is required to set them. This can happen when fastening

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νοη several dowels in one closed operation already lead to a considerable impairment of work performance even for workers trained for this purpose, especially when it comes to dowels with a medium and larger diameter, i.e. those with a diameter of around 8 mm and acts bigger. But even when installing dowels with a smaller diameter, this usually has to be done by hand Screwing in is a considerable burden, especially when numerous dowels have to be screwed in. In addition, for both large and small diameter dowels, a relatively large number of revolutions must be carried out at the fastening screw and accordingly the expenditure of time is large.

Furthermore, these well-known and proven plastic dowels have the following disadvantage: The pull-out values scatter relatively strongly and include on the tolerances of the diameter of the mounting hole. and on the size and possibly also the depth of penetration of the selected Strongly dependent on the fastening screw. Under unfavorable conditions, which, however, often cannot be calculated in advance,

γ. ■ ■ the minimum load capacity can drop considerably.

The invention has therefore set itself the task of creating a 'dowel, on the one hand with respect to a light Can be manufactured with the last-mentioned one-piece plastic dowel is at least roughly comparable and by means of a wood screw or the like. Having wood screw threads Fastening element spread or set in the borehole wall can be. On the other hand, this dowel should have the best possible and above all uniform pull-out values. On the one hand, this wood screw or the like. the usual ones May have tolerances and, on the other hand, in particular the effort and time required to screw in the Fixing screw can be reduced significantly. Through this should then the total cost of production and assembly of the anchor at least about the same as the known one-piece Plastic dowels, but better if possible.

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If necessary, the anchor should at least partially, preferably made entirely of plastic and if possible both in hard wall material such as concrete and in Softer wall material such as aerated or aerated concrete can be used.

To solve this problem, it is proposed in particular for the dowel of the type mentioned that the undeformed Internal thread of the expansion body Internal thread gaps compared to the associated external profile of the external thread turns are provided with some axial clearance, and that the expansion body at least with respect to one essential Section of its threaded area is somewhat axially flexible such that the contact surface between the external thread and the internal thread enlarged under load.

With such a dowel, the matching wood screw can easily be screwed into the internal thread of the expansion body without any particular expenditure of force, even if this wood screw or the like. Fastening element have greater tolerances both with regard to the Geivindestei supply and with regard to the outer thread and the thread core diameter, as is customary in the case of such wood screws. The cutting of the thread turns and the displacement of considerable proportions of dowel material, as is usual with previously known dowels that interact with wood screws with corresponding tolerances, is largely avoided. It has been shown that the subsequent fixing of the expansion dowel can be done with significantly fewer revolutions and with much less effort than is required when fixing previously known one-piece plastic dowels by means of wood screws. There is also evidence that due to the special design of the internal thread of the expanding body or the like at first only a small contact area between the male screw thread, although in intentionally, in the preformed Innenge \ ^ inde of Spreizkqr.pe.rs .besteht _{t <dijeser} located but when you first arrive

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pull something in the axial direction and because of its conical guidance in the expansion sleeve also to a certain extent slightly deformed inward in the radial direction. Experiments have shown that the internal thread with respect to the external thread existing gaps when setting the dowel essentially disappear and this internal thread becomes the expansion body to the external thread of the fastening screw or the like. adapts. Here comes the dowel according to the invention Design particularly beneficial, namely that to compensate for tolerances The spaces provided in the thread area are relatively uniform over the entire internal thread-C Distribute the course. Accordingly, the individual material particles of the expansion body only need comparatively small amounts To cover displacement or displacement paths so that the internal thread is completely or at least almost can fully adapt to the contour shape of the external thread of the fastening screw. During this process, the force transmission area between the Außengeionde- and the internal threads are enlarged and there is practically such a precise axial fixing of the fastening screw, as if there were an internal thread specially adapted to the individual fastening screw used would. In addition to the special, inventive / according to the design of the internal thread a corresponding axial flexibility of the expansion body as well as that during this of the spreading process occurring, directed radially inward Forces at. With a screw or the like that matches the dowel. the tolerance deviations permissible according to the industrial standards have an effect and also tolerance deviations that go beyond this, which are customary in practice in the trade, for screws of this type not detrimental. Such dowels can, for example, be produced comparatively cheaply in two pieces from plastic and provided with wood screws, which are also comparatively cheap to manufacture because there are no special ones Dimensional accuracy requirements must be made.

/ B

Preferably, the sleeve of the dowel can at least over a few threads at the beginning of the drawing in of the expansion body enclose. This ensures that the internal thread turns radially after the first load internally directed forces occur in the expansion sleeve, in particular its threaded area. According to the invention in general The desired reinforcement of the thread turns is favored from the start.

Additional developments of the inventions are listed in the features of the further subclaims. They give Features of the 3. Demand more detailed geometric designs of the thread of the expansion body.

It has been shown that when the dowel is manufactured from materials customary for plastic dowels and used in a hard wall material such as concrete that allows the tightening the fastening screw or the retraction of the expansion body takes approximately the following sequence: It exists at the beginning of fastening the initial situation that a normal, tolerance-affected wood screw with at least one thread or a thread section in the internal thread of the expansion body comes to rest. When the wood screw is then tightened, | the thread expansion cone expands slightly. The danger that there- |

6 in the event of excessive stretching and thus a tearing off of plastic |

( Threads can occur, is avoided because of the cooperation of the tapering expansion body with the corresponding | conical or similar.

If the material in which the anchor is to be fastened is

is softer, e.g. if aerated concrete falls below values of around 35 kg / cm strength, you will be asked to ensure that it is functional to improve the anchor according to the invention or even safer to make, take additional measures to avoid overloading the individual threads or thread sections of the To avoid expansion body. One measure is, for example, the expansion body er-aiis.'ei'n-em plastic with the material.

Values according to the H. "AnBf> T% ich ' ^: zvr" provided.

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Such a design of the expansion body then makes the dowel according to the invention both during use

a with hard wall materials v / ie concrete as well as with

softer wall building materials possible. Another measure

to achieve high strength values in the expansion body is specified in the 5th claim, the measures of s 4th and 5th claim both individually

as well as in combination with each other

can.

Claim 6 gives - comparable to claim 3 - a geometric configuration of the thread of the expansion body at.

In the axial direction, the adaptability of the expansion body to the possibly different loads} of threads or thread sections due to the measures of the 7th claim facilitated.

A lighter fitting to diameter tolerances of the wood screw, more particularly to the thread core diameter, but also generally easier deform in the radial inward direction is favored by the measures of claim 8. ''.

The measures of claims 9 and 10 favor above all the push-through installation. By this measure, the expansion sleeve pulled by the expansion body that is in (until then still loosely) connection with the fastening screw, see above that an undesirable spreading in this assembly stage the expansion sleeve is avoided.

The measures of claims 11 to 14 represent aids for assembling the expansion body and expansion sleeve. As a result, production can also be kept inexpensive.

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According to claim 15, the expansion body preferably has an outer cone and the expansion sleeve is designed accordingly.

According to the measures of the 16th claim you can use the spreading effect of the expansion body.

It has been found that the expansion area of the sleeve axially considerably through the measures of the 17th claim can extend and thereby increase the pull-out force.

By the measures of the 18th claim, setting the anchor can favor then especially in something softer wall material, especially because the mentioned spreading \ tongues radially dive deeper into the material

can than the rest of the expansion sleeve. At the same time, the forces directed radially inward are thereby exerted on the Expanded expansion sleeve, which is especially important because of the aspects already mentioned, especially with softer wall material is desired.

An important object of the invention is to design the -J dowel so that it is equally suitable in one or a few embodiments for different areas of application, e.g. for mounting in soft or hard wall material, but especially for push-through installation . The measures according to claims 20 to 25 show different features which, individually or in combination with one another, favor the insertion through a part to be fastened (for example wooden battens). In practice, it is common that, for example, wooden battens are drilled through the wall behind with the same stone drill bit, which is less suitable for drilling out wood. This results in slightly smaller clear diameters in the wooden battens than in the rock. Correspondingly, inserting the expansion sleeve would hit a \ lf: 'elfk'dbi-itoh ^ A-'WxdBrstand there. this will

largely reduced by the aforementioned measures, As in claims 20 to 24. The measures of claim 23, the advantages of an unslotted Sleeve combined with those of a slotted sleeve. In the case of a slotted sleeve, a certain Disadvantage with regard to the retraction of the expansion body occur; this can namely when the slot is axially continuous, deform with a part into this slot. This will then be in one area less material is offered, which, within narrow limits, leads to a somewhat worsened expansion effect or reduced pull-out values can lead. A jagged or overlapping slot formation makes it relatively the same Material supply over the entire circumference of the cone 'of the expansion body achieved.

Through the measures of claim 24, in particular through the sharp-edged outer edge of the annular bead a kind of expander for the wooden hole or the like. formed, whereby the subsequent pushing through of the expansion sleeve is made much easier.

Due to the measure of the 25th claim, because of the flat sides an improved anti-twist protection of the expansion body is achieved, with very simple means just then, when the greatest screw-in forces occur.

By the measures according to claims 27 and 28, the possibility of clawing the expansion sleeve is increased, and although according to the 28th claim by relatively minor profiling. This has the major advantage that a comparatively large dowel material volume in a uniform manner in the actual fastening zone Available. This is beneficial for producing high levels of extract.

A good z'usaräme'n.viirkenl'between expansion cone and expansion sleeve results in slcK'TxS'isdHfle'i'S J * if the cone angles of the

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made of plastic expansion body according to claim 35 selects. Known versions of expansion bodies made of metal often have a comparable cone angle of around 15. For the dowel according to the invention in the plastic version on the other hand has a cone angle o <. about 10 ° particularly proven. According to a further development of this embodiment the clear angle of the inner cone in the expansion sleeve is about 2 to 3 smaller compared to the ent ^ Speaking outer cone angle in the expansion body (see. Claim 36). It is true that wall anchors are already made of metal known, the angles ζλ-Jischen corresponding Inner cone and outer cone surfaces to make about 2 to 3 different. In the metal version of wall anchors but if one intends to achieve a line-like contact and thereby a reduction in the friction when drawing in. In the subject of the application, especially where both the expansion sleeve and the expansion cone are made of plastic and accordingly with these parts there is a greater deformability than with metal, which can be achieved by the measures of claims 35 and 56 quickly create a large area between the cone of the expansion body and the corresponding inner cone of the expansion sleeve and, accordingly, a quick grip of this sleeve on the borehole wall.

In a more modified dowel according to the invention, according to a further development of the invention, the inner cavity of the sleeve is at least partially in the. Cross-section approximately matched to the outer diameter of the fastening element _; at least at one point in this area having a cross-sectional reduction projecting radially into the threaded area of the associated fastening element, and the fastening element at the outer end having a thread-free shank section which corresponds at least approximately to the outer thread diameter. The anchor is preferably suitable for eig ^ne ν through mounting because the fastening element is approximately positively connected with the sleeve in the preassembly position, and this dragging after directly when applied to the Wandboiirloch. The possibly provided connection between the expansion body and the sleeve remains practically unloaded and can even be omitted under certain circumstances.

A thread section is expediently used as a cross-section reduction, preferably a single internal thread, which is preferably matched to the thread of the fastening element is. A sleeve with a single internal thread is easy to manufacture, especially with one off Plastic existing dowels.

The measure according to claim H2 expands the function of the cross-sectional reduction of the sleeve, in that the sleeve is somewhat widened in the area of the cross-sectional reduction by the shaft of the fastening element penetrating there and thereby additionally fixed. The wall hole cross-section is practically completely filled in this area, so that the dowel can also withstand more shear forces.

A further development of the invention provides that the inner cavity of the expansion body with its internal thread at least in the pre-assembly position is closed in particular at its plug-in end. This prevents a not cleaned borehole drill dust or the like. Dirt in the

Threads of the expansion body can penetrate and then hinder the installation of the dowel.

If necessary, the thread of the fastening element and possibly the internal thread of the expansion body can have a sawtooth-like cross-section, with the flank that is steeper to the longitudinal axis of the dowel or the fastening element and expediently at least approximately perpendicular to the longitudinal axis facing the outer end. With such a saw-tooth thread, when the pressure flanks, which are oriented approximately perpendicular to the longitudinal axis, are loaded - that is, when the fastening screw is screwed in - practically no radial forces occur, so that a displacement work widening the expansion body is avoided.

Further details of the invention can be found in the following description in conjunction with the drawing can be found in the individual features of the claims.

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• *

It show in different scales:

Fig. 1 is a perspective view of an inventive Dowel with expansion body separated from the sleeve,

Fig. 2 is a partial longitudinal section of one with a conventional one Threaded cone body with screw that does not correspond to the invention,

Fig. 3 is an approximately 2 shows a view corresponding here but each with inventive thread, and in accordance with the dowel according to the invention;

Fig. 4 is a partial longitudinal section of a dowel with a loose " turned and

Fig. 5 with firmly screwed in the fastening screw and retracted expansion body,

5a shows a partial longitudinal section of an expansion body with a modified one Inner thread,

6 shows a half-side longitudinal section of an expansion body,

Fig. 7 shows greatly enlarged, partial longitudinal sections of ^1S expansion bodies with fastening screws with different tolerances,

Fig.io different views of a longitudinally slotted

up to 12 _c . , ..

Expansion body,

13 shows a partial longitudinal section and

Fig. 14 is a side view and

15 shows an end view of an expansion body,

16 shows a part longitudinally. one in a borehole located dowel with screw,

17 shows the inner end of a dowel sleeve with different; up to 19 deeply drawn-in expanders,

Fig. 20 is an end view of the inner end of a with

an insertion aid equipped dowel sleeve and

• Fig. 21 is a longitudinal sectional view of this dowel sleeve end,

22 is a perspective view of a modified version of the invention Dowel,

23 is a partial longitudinal sectional view of one in a borehole

located dowel according to Fig. 22 in unspread as well

Fig. 24 in the spread state,
• Fig. 25 a partially longitudinally slit dowel in a longitudinal section,

26 is a perspective view of a modified embodiment an anchor according to the invention,

Fig. 27 shows a partially drilled through by a masonry drill ( wood facing,

28 shows a fastening point on a wall with a to

fastening wood veneer as well as an attached dowel with fastening screw,

29 shows a further modified embodiment of a dowel according to the invention,

30 shows an expansion body, shown in section on one side,

FIG. 31 is an end view of that shown in FIG Expansion body,

Fig. Yd

and y $ very schematically shows the inner end area of a

longitudinally slotted dowel sleeve, Fig. 3 ^ a dowel anchored in a wall borehole and

Fig. 3 ^ a an enlarged section of the profiled dowel jacket shown ^{in Fig. 3 1 *,}

FIG. 35 is a partially inserted in a borehole wall | i,. Dowels and one to be fastened by means of push-through assembly

lower wood connection,

36 shows a cross section according to the section line A-A 'in Fig. 35,

37 shows a partial longitudinal section through part of the dowel and a corresponding V / and section similar to FIG. 2k, this wall material here consisting of a hard material such as concrete,

38 shows a partial cross-section through the dowel according to the section line B-B 'in FIG. 37,

39 shows a side view of a modified embodiment of a dowel according to the invention,

FIG. 10 shows an expansion body belonging to the dowel according to FIG. 39,

Fig. Kl is a longitudinal section view of a more modified dowel,

Fig. K2 an approximately Fig. Kl corresponding illustration, but here with eingedrehtem fastener

- 18th

Pig. * <3 a longitudinal section of one in a wall borehole inserted dowel with a fastening screw located with its shaft inside the dowel sleeve and

Pig. ¹ Ih a partially shown dowel in partial longitudinal section.

A dowel 1 shown in Fig. 1 has a sleeve 2 and a Spreader 3, which are shown here separately for clarity.

The expansion body 3 can be drawn into the sleeve 2 from the inner plug-in end H , with its outer cone 8 expanding the sleeve jacket 5 in some areas. In this exemplary embodiment, the expansion zone of the dowel sleeve 2 is slotted to facilitate expansion. A fastening screw 7 can be pushed through from the outer end 6 of the dowel sleeve 2 and screwed into the expansion body (see FIG. 28). For this purpose, the expansion body has a preformed internal thread which makes it easier to screw in the screw 7.

In order to better explain the invention in Figure 2 is a introduced into a nut part M Inncnge \\ ^r is shown inde J, which corresponds to a üblichen.Befestigungsschraube 7 the threads of the external thread 11 from the outline forth.

Since the commercially available fastening screws are subject to considerable tolerances, especially with regard to the contour shape of the area penetrating into the expansion body, difficulties in screwing in would generally arise even with preformed internal threads J. For this reason, the internal thread 90 belonging to the invention has a different shape than previously known internal threads, and the essential difference can in principle be seen well from a comparison of FIGS. 2 and 3. The internal thread 90 designed according to the invention also allows the use of fastening screws 7 with strong tolerances. In this case, the internal thread spaces 10 are designed with axial clearance compared to the contour profile of the external threads 11a of the fastening screw 7, which is also the case, for example, with the arrangements according to the invention according to FIG. 7 to '9 is clearly visible. This axial clearance is distributed evenly over the thread area (see, for example, FIGS. 6-9 and 23, 24 and 37). In the case of a fastening screw with a nominal size (FIG. 9), there is an axial clearance between the screw through the spaces 10 7 and the expansion body are present, this axial mobility corresponding to the clear width of the spaces 10. The clear distance between the spaces 10 delimited by the inner thread flanks 12 is dimensioned so that both screws with the largest dimension (Fig. 7) and those with the smallest dimension (Fig. 8) without material deformation _/ at least without essential material processing, one can graze properly. In particular, the distance a corresponds to the mutually facing inner flanks 12a (FIG. 7) of the first and last threads of the

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Internal thread 9o approximately the distance between these flanks 12a facing flanks 13a of the external thread 11 of a tolerance-affected fastening screw · 7 with the largest dimension. on the other hand however, the distance b also corresponds to the one assigned to the first and last internal thread turn Outer flanges 12b the distance between these flanks 12b facing Flanks 13b of the external thread 11 of a tolerance-afflicted Fastening screw 7 with the smallest dimension (Fig. 8). This allows within this maximum tolerance limit Horizontal screws 7 can be used without any material deformation or displacement when screwed in loosely takes place. The edge distances a and b used in FIGS. 7 and 8 are here, for example, in the middle based on the radial height of the internal threads. However, the aforementioned spacing relationships apply to everyone Area of the corresponding flank

In the exemplary embodiments, the internal thread has 9o of the expansion body 3 threaded interstices 1o with approximately trapezoidal cross-section, \\ 'obei the thread depth corresponds approximately to that of the thread 11 of the fastening screw 7.

It is also essential that the expansion body 3 is designed to be approximately axially flexible at least over a substantial part of the threaded area. this can be achieved by selecting the appropriate material, plastic is preferred. For example, the material of the expansion body can have a modulus of elasticity of at least 7.5oo N / now 2 with a tensile strength of at least 100 N / mm. The compliance of the expansion body 3 with sufficient strength at the same time and also good dimensional stability of the outer cone 8 is of essential importance in the dowel 1 according to the invention,

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21 -

Indeed, it is provided that with increasing load on an internal thread section in addition to the initially existing bearing contact surface between the internal and external thread, further sections of the external thread come into play on the internal thread. This load occurs when the expansion body 3 is drawn into the sleeve 2. The aforementioned process is easy to understand using FIGS. 4 and 5. First of all, in the exemplary embodiment according to FIG. 4, only the inner flank 12a assigned to the first thread turn of the internal thread 9o located in the sleeve "carries". As the expansion body 3 is drawn in further, the tensile force to be transmitted from the screw to the expansion body 3 increases. As a result, a desired deformation occurs in the thread area of the expansion body 3, further threads of the internal thread ^Q o being applied to the threads of the external thread 11 of the fastening screw 7. The load-bearing contact surface of the internal thread is thus enlarged, so that finally the situation shown in FIG. Optionally / besides, also the internal thread 9oa shown in Fig. 5a lann be advantageously used because of its more favorable under certain circumstances, adaptability in the deformation. This thread 9oa has rounded upper transitions of the thread flanks to the intermediate spaces of the internal thread 9oa.

Because of the contradicting demands, namely on the one hand the desired deformability in the thread area and. on the other hand, a good dimensional stability of the outer cone, it may be useful in certain applications, if the expansion body has a fiber insert or the like. Has reinforcement, which is preferably mounted in the cone area.

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♦ · tt

In order to facilitate the deformability of the expansion body 3 in the axial direction, it can also have a weakening point 15 which, as shown in Fig. 6, suitably is formed by a circumferential, open-edged radial ring groove 16. This is about here in the central region of the axial extent of the expansion body 3. Through this weakening point 15 can the expansion body 3 altogether also change a little in its length in the event of a load in its threaded area, see above that the deformation in the actual thread area can optionally be reduced. In addition, through a or several such weakening points create a division of the expansion body into several axial areas, in which the dimensioning of the internal thread gaps Io only to the tolerance deviation of the external thread 11 of the fastening screw occurring in this axial area must be coordinated. The total length deviation of an external screw thread depends on the given individual tolerance of adjacent thread turns namely also from the number of thread turns. The smaller the axial extent the areas of the Spreizi.örpers delimited by weak points, the smaller it can be be the clearance formed by the spaces 1o. The attenuation dividers then deform under load « veibtärkt, so that also thereby a good adaptation with increasing enlargement of the supporting contact surface of the Thread is reached.

The outer cone 8 is roughly matched to an inner cone located in the sleeve 2, i-ubeh the cone angle (Λ of the outer cone 8 is only approx. 2 ° to 3 ° larger than the cone angle β of the inner cone of the sleeve 2 C Fig. 25, 10 , 14, 16). As a result, when the expansion body 3 is drawn into the sleeve 2, the two conical surfaces quickly come into contact over a large area and

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HH · ι

- 23 reach the sleeve on the borehole wall. ^;

In order to increase the expansion of the sleeve 2, the threaded hole of the expansion body 3 can close narrow conically towards their end with the largest diameter, as shown in FIG. There are axially oriented ones Slots 17 are provided (Fig. 14, 15), the

facilitate spreading of the cone body. The ι

The spreading of the cone body caused by the fastening screw 7 is transferred to the sleeve 2, see above that this on the one hand by the axial retraction of the expansion body 3 and also by its radial Spreading is widened. If the pull-in path is short, this can result in good anchoring of the Dowel 1 can be achieved. |

14 shows that the outer cone 8 - J

a cylindrical section 18 adjoins whose Öurch- ■ j

measurement corresponds approximately to the outer diameter of the sleeve 2!.

(Fig. 16). This cylindrical portion 18 holds the Sleeve jacket in the expanded position even when the expansion body 3 is drawn into the sleeve over the conical area, so that as a result the axial extent of the effective contact surface on the Borehole wall is comparatively large.

The dowel 1 is itself formed from a unit of sleeve 2 and expansion body 3, as shown, for example, in Figs. 22 and 25].

is recognizable. To connect these two parts are, in] ..

Insertion direction acting driver elements 19 provided (Tig. 13, p 14, 16), which in the exemplary embodiment on the one hand by two opposite> -ri legend, approximately radially protruding lugs 2o are formed. Point on their side facing the insertion end 4 these lugs 2o stop surfaces 21 and opposite, facing the outer end 6, inclined slopes 22. To the On the other hand, driver elements 19 also include window-like recesses 23 provided in the sleeve 2 (FIG. 17 to 19), which work together with the noses 2o of the expansion body 3. The noses 2o snap in when they are loosely inserted

-21

of the expansion body 3 into the recesses 23 of the sleeve 2; the sleeve 2 is not yet expanded (Fig. 16). The above-described "latching" of the two dowel parts with one another also prevents the expansion body 3 rotates when screwing in the fastening screw 7, because the sleeve 2 already after Insertion into the wall borehole 24, e.g. by means of ribs 25 (Fig. 1) or the like. Anti-twist protection already somewhat determined is.

For joining the sleeve 2 and the expansion body 3 in the correct position, insertion aids 26 are provided on the sleeve 2 (Figures 17 to 21). This is done in an axial | Direction with the window-like recesses 23 aligned, approximately V-shaped edge recesses 27 of the one] jjj Stuck 4 of the dowel facing edge of the sleeve 2. |

• Fig. 17 to 19 show, in different phases, how the * edge recesses 27 center the expansion body 3 in the radial direction through the noses 2o running onto their inclines, so that the noses into the window-like | Recesses 23 are guided and snap into place there. In the embodiment shown in FIGS. 2o and 21, the edge recesses 27 are covered by the outer jacket of the sleeve. Have ^; these edge recesses 27 have a smaller radial depth than the wall thickness of the sleeve. The arrows drawn on the inside are intended to illustrate the centering effect.

22 to 24 show an expanding tongue 28 on the sleeve 2. On the opposite side of the Sleeve 2 is preferably provided a further expanding tongue. These can be expanded radially from the cone body, the noses 2o with their bevels engage under the free ends of the expansion tongues 28 when the expansion body is drawn in (FIG. 24). The tongues 28 provide for additional anchoring of the anchor 1, which is particularly advantageous when setting in softer building materials can be.

The dowel 1 according to the invention is also well suited for a so-called push-through assembly, in which, as can be seen in FIGS. 28 and 35, the dowel 1 is partially screwed in Fastening screw 7, but unspread sleeve 2 through the part to be fastened into the Wall borehole 24 is introduced. When drilling through the part to be fastened, e.g. from wooden battens 31 or the like. can exist (Fig. 27), and at simultaneous drilling of the wall hole 24, masonry drills 29 with special cutting surfaces are usually used. This creates a slightly smaller clear bore hole diameter in the wood than in the rock. This can the insertion of the anchor 1 encounter considerable resistance there. Therefore, in the invention Dowels 1 various means are provided to reduce the friction, in particular on the push-through part (e.g. wooden battens 31) to reduce. For this purpose, the dowel sleeve 2 can have one or more axial sections, from the outer end over an axial section extending slots 3o (e.g. Figs. 28 and 29), the width of which is towards that caused by deformation bridging radial tolerance is matched. The dowel sleeve 2 can thereby be pushed through the borehole give somewhat radially in the wooden battens 31, se that the push-through resistance is thereby reduced. the Srhlitze 3o can also have a zigzag shape 29) and / or an overlapping (Fig. 32 and 53) edge fillet 32 have. The jagged slot formation or overlapping slot formation is a Reached relatively the same material supply over the entire circumference of the cone 8. This allows the Advantages of an unslit sleeve are combined with those of a slotted sleeve.

As a further means for facilitating push-through assembly, in the area of the expansion body 3 a radially protruding annular bead. 33 - as in Fig. 3o e

-26 -

recognizable - be provided. This has on its side facing the sleeve 2 an expansion bevel 34 and a sharp-edged outer edge 35 on its side facing the insertion end. The radial height the annular bead 33 is based on the diameter ratios of the bores of the push-through part (31) and the Wall borehole 24 or their differences in diameter matched after drilling at a push-through mornings. For example, with a largest cone diameter of the expansion body 3 of 7.8 mm is the outer diameter of the circular bead 33 be 8.1 mm. The ring-

·. Bead 33 is used when inserting the dowel 1 through the KJ

Push-through part (e.g. wooden battens 31) to widen the slightly narrower hole compared to the wall drill hole 24 in the wooden battens 31 or the like. This will make the pushing through the sleeve 2 is made much easier. Also with these spreading t, which are provided with an annular bead 33 body 3, the sleeve can be provided with the already mentioned slot 3o, which also makes it easier Pushing through the dowel 1 contributes. Finally, the sleeve 2 can also at least for the same purpose In one area of its axial extent there is a reduction in the diameter of the junction exhibit.

'J The cross-section of a part in a Watidbohrloch 24 and partly still in a located to be fastened wood part sleeve 2 36. accordance with FIG. The section runs while the section line A ¹ in Fig. 35. Significantly is in the timber 37 compared to the wall drill hole 24 smaller diameter of the wooden drill hole recognizable. In order to obtain a comparatively low penetration resistance in the area of the wood 57 in spite of this narrowing of the borehole, the sleeve 2 here has a special longitudinal profile 38 which promotes elastic, radial yielding of the sleeve jacket 5. The jacket is brought together somewhat radially in the narrower wooden drill hole.

presses while it is shaped like an accordion. |.

Fig. 31 and 'e.g. Fig. 28 also shows that the at the cone 8 of the expansion body 3 adjoining cylindrical section 18 oriented approximately tangentially Has flat sides 36 which allow the dowel unit to rotate when the fastening screw 7 is tightened &. can hinder.

In addition to the often considerable tolerances regarding the &

axial distances between the threads 11a of the fastening screw 7, this usually also has larger tolerances of its thread core diameter. To the solution this problem can, as shown in Fig. 1o to 12, the expansion body 3 be formed longitudinally slotted (slots 17a), so that by opening a good adaptation to different Core diameter is possible.

In the expansion area of the anchor 1, an external profile can also be provided to improve the pull-out values (Fig. 34, 34a), here by a sawtooth-like circumferential protruding radially only slightly e.g. o, 2mm Ribbing 39 is formed, the approximately radially oriented surfaces of which point towards the outer end of the sleeve 2. Because of the uniform spreading effect and the flat contact with the borehole wall in the case of the one according to the invention Dowel 1, one can advantageously get by with this small profile depth t.

In the case of soft building materials in particular, a somewhat longer Shank of the dowel sleeve 2 may be advantageous. The actual spreading and holding zone becomes something as a result moved deeper into the wall borehole, so that excessive edge loading of the wall material is avoided.

/ 28

With conventional wood screws can according to the standard regulations a thread turn already have a tolerance of - 0.2 mm.

With five threads, this can mean a tolerance of 2 mm, which is on the order of magnitude the pitch of a thread. As already mentioned, there are also numerous wood screws on the market where the tolerance is even greater than the norms.

It is an essential advantage of the invention that, in the case of the dowel described above, wood screws with the aforementioned Tolerances can be used without further ado and that nevertheless that displacement work in the penetration of the Fastening screw can be largely avoided, which are used in previously known plastic dowels Not only can a typical wood screw thread be used on a fastening element, but also, for example, a round thread or the like. Which has correspondingly large pitches to be in an adapted thread of the To set expansion body 3 can.

An essential aspect of the present invention is that the internal thread 90 of the expansion body 3 in the undeformed state intentionally from the course of the associated External thread 11 of the fastening screw or the like. .does, taking into account their practicality Tolerance range.

As practical tests have shown, no practical result occurs during the first penetration of the fastening screw significant deformation of this internal thread 90, with dcnnorh a sufficiently accurate axial connection between the fastening screw or the like. and the expansion body 3 reached is to insert the entire dowel 1 in its mounting hole and put in the desired position.

/ 29

While the fastening screw is being tightened, a certain deformation of the thread turns takes place in a desired manner 90 and the associated part of the expansion body This achieves that as many as possible, expediently even all threads are used. Nevertheless, this screwing-in and fixing process remains for the screw relatively smooth. Another essential aspect of the invention is that on the one hand no hard, brittle and also not too tough plastic is used for the expansion body 3, but this on the other hand on the one hand, the loads on its internal threads 90 'holds off, on the other hand it is elastically deformable to the extent that

its central area can adapt, as can be seen particularly well from a comparison of FIGS. 4 and 5. In the invention, the cooperation between the outer cone 8 of the expansion body is systematic and the inner cone of the expansion sleeve 2 is used in the sense that radially inwardly directed forces arise help adapt the inner area of the expansion body to the outer contour of the fastening screw 7, as can also be seen particularly well from FIG. The invention also includes the aspect that the previously described mode of action, especially when attached of the anchor 1 in hard materials such as concrete., without special Difficulties are possible, it has been found that the pull-out forces in such anchors normally

J are at least as big, usually a little better are compared to comparable one-piece plastic

S iiiibles of known construction. The invention also includes

that with very soft building materials such as aerated concrete, their Strength is below 35 kg / cm, special precautionary measures should be taken to ensure this soigen that the adaptation of the internal thread area of the Spreader 3 to the outer contour of the fastening screw according to Figures 4 and 5 also takes place when the material of the surrounding wall is somewhat softer. According to the invention, care must therefore be taken that the

Spreader 3 sufficiently tough. and is stable, on the other hand, that sufficiently strong inwardly directed radial forces are effective. One measure of favoritism is that Selection of plastics with the physical constants specified in claim 4. Another measure is related illustrated and described with FIGS. 23 and 24.

An essential inventive feature consists in the following: The volume encompassed by the expansion body 3 provided with a cylinder section 18 and the sleeve 2 in their undeformed state in an axial section 41 of the later pressing area is slightly larger than the assigned volume of the wall borehole 24 in the same axial section 41 of this contact area. Here, it is assumed that the cylinder portion 18 having ι of one third of the diameter D5 of this section of the expansion body 3 at least -β a length and that the corresponding wall of the borehole does not exceed the usual tolerance dimensions. When the expansion body 3 is drawn into the sleeve 2, if this is done outside a wall borehole, the dowel 1 would expand in such a way that a volume protrudes radially from the dowel material in this section 41, which is the wall thickness d of the sleeve 2 corresponds in this area. See in particular FIGS. 23, 24 and 37 and 38. The diameter of the cylinder section 18 of the expansion body 3 is at least almost equal to the diameter D4 of the dowel sleeve in the undeformed state. If this process is carried out within the dowel borehole -4, the dowel 1 accordingly offers, at least approximately over the length 11 of the cylinder section 18 of the expansion body, an excess volume exerting pressure in the radial direction in comparison to the corresponding volume of the wall borehole. Accordingly, the expansion body 3 in particular deforms and its internal thread adapts on the one hand to the external thread 11 of the associated fastening screw 7, on the other hand the expansion body 3 presses the sleeve 2 there against the warehousing element 24 and. ] .e.gts the dowel 1 in

■ HM · * ·

at least one axial section 41 secured firmly. As has been found in tests, the anchor is securely fixed and the pull-out values are high even when the conditions are unfavorable. Such unfavorable conditions within the permitted tolerances · as the coincidence of a wall bore hole 24 with large precipitated borehole diameter | together with the use of a fastening screw 7 <with a small thread diameter. This training according to the invention is also promoted by further measures. As can be seen well from FIG. 34, the

(Sleeve 2 essentially cylindrical with an approximately smooth man- J

central surface 40 formed. Although it has a section i

their spreading area, which is connected to a wall anchorage f

help, namely a rib 39 is provided. This is ; but with the dowel according to the invention only slightly radially | profiled. It is a sawing in the axial direction | tooth-shaped ribbing 39, whose radially oriented surfaces. ' point to the outer end 6 of the sleeve 2. The profile depth t of the ribbing 39 is only about 0.2 mm large | (Fig. 54a). Stronger incisions, circumferential grooves or the like. | Profiling of the dowel outer jacket is avoided. |

r The above-discussed, desired volume ratios can be reached according to an embodiment of the invention are well characterized in that the screw shank diameter D1 to the diameter D2 of the wall of the well bore and dowel diameter D4 is at least approximately as 3 at the non-deformed dowel 1: behave 4. 5 In addition - see FIGS. 34 and 19 - the screw head diameter D3 is related to the wall drill hole diameter D2 and to the dowel diameter D4 at least approximately 6: 5: 4. In practice this means that, for example, for a dowel with a diameter D4 = 8 mm, the screw head diameter D3 = 11.8 mm, the wall drill hole diameter D2 = 10 mm and the screw shaft diameter D1 approximately 6.6 mm. On the one hand, this has the advantage that the screw head diameter D3 is so much larger than the wall hole

Diameter D2 that you often find on a washer can do without. On the other hand, it entails that the area of the threads 11 of the fastening screw comes to lie very close to the edge of the dowel. This measure, which is not harmless in itself, is, however, in the Invention exploited to a further advantage. In connection with the special design of the internal thread 90 of the expansion body 3 results in comparatively short paths for the individual participating in the deformation Particles of the expansion body 3.

C. ' As already explained, according to an embodiment according to the invention, the cylinder section 18 of the expansion body 3 has a diameter D5 which is at least approximately the same as the outer diameter D4 of the dowel 1 or the dowel sleeve (see FIGS. 19 and 23). The above-described volume ratios, which favor the high and uniform pull-out values, can be achieved according to a further development of the anchor 1 according to the invention by the following measures. When the dowel 1 is not deformed, the dowel sleeve 2 has a wall thickness d of et \\ ^T a 0.8 mm in the expansion area for dowels with a small dowel diameter D4 and one that initially increases as the dowel diameter D4 increases

ζ Wall thickness d, which for anchors with an anchor diameter D4 of 10 mm and larger is d = 1.6 mm. In FIG. 37, the wall thickness at the outermost end of the sleeve 2 is denoted by d2. However, this outermost run-out area of the sleeve is less suitable for characterization. The value of the wall thickness d lying in the conical area or the value dl which covers the full wall thickness (FIG. 37) is characteristic. The wall thickness d in question relates to the full wall thickness d1 or the mean wall thickness d in the conical area, not the wall thickness d2 at the inner end of the sleeve, which is weakened for one reason or another (see also, for example, FIG. 20).

/ 33

Dowels with a small diameter should be understood to mean those with a D4 of about 6 mm, and dowels with larger diameter those with a diameter D4 of 10 mm and more. The to the explained volume ratios The contributing wall thickness d is therefore for dowels with a diameter D4 of about 6 mm to d of about 0.8 mm, then increases approximately linearly with increasing dowel diameter up to dowels with D4 from 10 mm to d = 1.6 mm and remains then essentially constant with even larger dowels.

The previously discussed design of the anchor according to the invention with its diameter ratios, those of its sleeve 2 and its expansion body 3 and the wall thickness d of this sleeve and the volume ratios of dowel material and wall / . Boreholes in the pressing area 41 interlock and support each other in individual combinations or in total combinations together. Even if the axial section 41 of the pressing area (see Fig. 34) is relatively long, e.g. according to the invention of the length of a dowel diameter D4 or, is even longer and if this is very favorable, i.e. l large pull-out values are achieved, however, there is no need for too great a deformation of the material of the dowel sleeve 2 and of the expansion body 3 to be carried out. Accordingly, you can get there with much less effort than with comparable ones Plastic dowels. Nevertheless, tolerance, e.g. Bridging large, failed drill hole diameters or small, failed fastening screws. That also depends a bit together with the fact that in the dowel according to the invention, the displacement of the dowel material is not on the inside of the attack surface the fastening screw mainly causes and on the jacket area of the dowel at the wall of the borehole must be brought into effect; rather, in comparison to the one-piece plastic dowel, in the case of the invention Dowels also partially relocated the displacement in the thread area. The deformations take place on the anchor according to the invention more in the vicinity of those places where the corresponding introduction of force takes place, and also the conical formation of the expansion body 3 and the comparatively thick screw shaft contribute. These favorable ratios will be also not adversely

flows when the axial section 18 or the entire Expansion body 3 and its internal thread 7 a accordingly large axial extension stroke. This greater axial extension, in particular the corresponding length of the cylinder section 18 favor the size of the extract values.

In FIGS. 23 and 24, a dowel 1, which is equipped with two opposite tongues 28 (see FIG. 22), is shown how it works in a comparatively soft wall material such as aerated concrete. Its expansion () sleeve 2 and expansion body 3 are made of suitable tough, elastic plastics. In FIG. 37 one can clearly see how the dowel 1, which is also equipped with tongues 28, is brought into contact with a hard wall material such as concrete. When the sleeve 2 and the expander 3 ^r corresponding to the representations of FIG. 28 or to 31 .. is formed 28 to 36 for a plug assembly, such a plastic dowel is universally applicable, namely in both hard and soft materials as well as threader as well as with push-through assembly. At the same time, the dowel according to the invention is inexpensive in terms of its total cost of manufacture and assembly.

The dowel according to the invention can also be used as a complete, Assemble the fastening unit already provided with the fastening screw 7 and thus bring it into circulation. You then have a certain guarantee that a fastening screw of the appropriate size is used, This also ensures the corresponding minimum Aus.:iigs\%erte are. Under "suitable fastening screw 7" A% 'ird This does not, however, mean a screw that has been specially selected for the internal thread of the expansion body with regard to its tolerances. It is only a matter of the fact that the screw of the appropriate size is already provided for the dowel.

· · ■ ·· tx

- 35 -

A more strongly modified embodiment of a dowel 1a according to the invention is shown in an overall side view in FIG. 39 and in longitudinal section in particular in FIG. 4l. This dowel la also has an expansion body 3a and a sleeve 2a. In contrast to the exemplary embodiments described above, however, the inner cavity 42 of the sleeve 2 a has a radially inwardly pointing cross-section reduction 43 here. This engages at least in the pre-assembly position (Fig. 42) in which engages through the fixing screw 7a, the sleeve 2a and loosely screwed into the expansion body 3a, in the external thread 11 of the fastening screw 7 _a 7a. This creates a direct axial connection between the sleeve 2a and the fastening screw 7, which is particularly advantageous in the case of a push-through installation. This is because considerable transmission forces can occur between the fastening element and the dowel, since the through-hole through the object to be fastened is often comparatively narrow and accordingly the sleeve jams when it is pushed through.

Hp-; In the exemplary embodiment described at the outset, the expansion body 3 drags the sleeve when it is inserted into a wall. after. As a connection between the expansion body 3 and the sleeve, window-like recesses 23 and latching therein make sense Lugs 20 provided (see e.g. Fig. 17 - 19) This connection is now made by the direct connection of the fastening element and the sleeve 2a practically relieved during a push-through assembly. This allows an additional connection between the dowel sleeve and the expansion body are omitted. The axial slot 44 provided in the sleeve 2a (Fig. 39) forms in this case - especially in the case of the open-edged version indicated by dashed lines - only a guide for the lug 20a of the expansion body 3a engaging therein, and thus an anti-twist device between the sleeve 2a and the expansion body 3a. Also in the case of the embodiment of the slot 44 closed at the insertion end, an essential one axial holding function (drag function) not provided here.

/ 36

• ·

-36 -

The lugs 20a, which are on the insertion side, are also designed accordingly End have no stop surfaces (cf. also Fig. 44). The connection (slot 44, nose 20a) is used in the present case Trap to complete the dowel, that is to say to form a dowel unit consisting of the expansion body 3a and the sleeve 2a. The length of the slot 44 is matched to the pull-in length of the expansion body 3.

In order to ensure that the cross-sectional reduction kj> engages in the thread 11, the inner cavity 42 of the sleeve 2a is matched in cross-section to the core diameter of the thread of the fastening screw 7, at least in the area of the cross-sectional reduction 43. In addition, the shaft or the outer thread diameter dl is matched to the clear diameter Λ2 of the inner cavity 42.
A thread section is expediently used as the cross-sectional reduction 43, a single internal thread 45 being provided, in particular because of the ease of manufacture and also because of the sufficient strength shown in practice.

43 shows that the cross-sectional reduction 43 can also have another additional function. For ■ "■ ^Qr>" ending a fixing screw 7a, in which the length CvS unthreaded shank of the sleeve is matched 2a 50 to the position of the cross-sectional reduction 43, the screw occurs namely when the screw by the penetrating in the region of the cross-sectional reduction 43 shaft 50 has a radial expansion of the sleeve 2a. As a result, the sleeve 2a is additionally fixed. Since the cross-sectional reduction 43 is preferably provided at a short distance near the outer end 6 of the sleeve 2a, the dowel is additionally fixed in particular near the wall hole edge, the wall hole cross-section in this area being completely filled by the widened sleeve 2a. The shear strength of the anchor la is improved. It should be noted that the cross-sectional reduction 43 is close to the outer end 6, but still

/ 37

k. ■ *

- 37 -

provided with as much distance therefrom and thus also from the wall hole edge when the dowel 1a is in the functional position is ,, that when expanding the sleeve 2a in this area overloading of the wall hole edge is avoided.

If necessary, the transition between the thread of the fastening screw 7a and its shaft 5o can initially also be serve as a stop so that the expansion body is already retracted when the fastening screw 7a with its On the switch-side thread end has reached the cross-section reduction 43. With a corresponding tensile load However, the shaft then also enters the area of the cross-sectional reduction 43 in the manner described above a. The pull-in forces are then due to the support of the fastening screw 7a on the object to be fastened initiated.

In the pre-assembly position (FIG. 42) the internal thread is 9oa

y of the expansion body 3a advantageously from the thread

part of the fastening screw 7 filled. This avoids that when inserting the dowel-screw assembly unit get into a wall borehole, drill dust and the like into the threads of the expansion body internal thread 9o, 9oa can and then at least obstructs the installation of the fastening screw 7, 7a. To the aforementioned pre-assembly position (Fig. 42), the total lengths of the fastening element and the dowel 1, 1a are accordingly coordinated.

I sees a somewhat different solution to the above problem
before that the expansion body 3, 3a at its insertion end 4 has a removable closure of its internal thread cavity, preferably in the form of a destructible membrane or the like. having. This membrane also prevents drilling dust and the like from penetrating into the internal thread 9o, 9oa

, of the expansion body 3, 3a, with the fastening

screw 7, 7a be slightly shorter in length

^ can, so that in the pre-assembly position only one

Fills part of the internal thread of the expansion body. When attaching the dowel, the screw can do that Pierce skin or the like. Instead of a skin a cover can also be provided, which then either rotates through the fastening screw or durchj bump or is pushed away. The type of closure can in particular correspond to the manufacturing method -. of the anchor, in particular the expansion body. be.

In the modified embodiment (e.g. Fig. 41, 4 2) has the internal thread 9oa of the expansion body 3a, as well as the thread H of the fastening element a sawtooth-like Cross-section. The steeper, more expedient, axis points to the longitudinal axis L of the dowel or the fastening element at least approximately perpendicular to the longitudinal axis L flank to the outer end of the dowel 1a. This thread has the advantage that when the expansion body 3a is drawn in, there are practically no radial expansion forces within it occur, so that displacement work is practically avoided and the friction is kept correspondingly small. This can make it easier to screw in the fastening screw.

In the case of the modified thread shape described above, those described in particular with reference to FIGS. 7 to 9 can also be used Measures according to the invention be provided. As a rule However, in the embodiment according to FIGS. to 44, the internal thread 9oa and the external thread 11 in its Match shape.

In particular with the buttress thread of the expansion body 3a and preferably also of the fastening screw 7a the thread root 46 or the flank tip 4? be flattened. This creates a cutting penetration of the external thread dcf'lSe'jib ^ tji'gUngss'cJrraiube in the bottom 46 of the

Internal thread 9oa and thus also a possibly weakening notch effect avoided.

39 shows that the dowel sleeve 2a is a turnstile, in particular in the form of at least two, in particular having radially opposite, disengageable tabs 48, which here in the area of the cross-sectional reduction-> tion 43 of the sleeve 2a are provided. These tabs 48 are resiliently connected to the sleeve 2a and are in relaxed position radially over the sleeve jacket. In transverse

^ - section they show an approximately spiral arrangement, whereby

their free tab ends 49 in the screwing direction of the loading '.

fixing element show. This allows them to feel good at | the borehole wall and thus effectively prevent the dowel 1 or 1a from turning. At the insertion end 4 j of the dowel 1a pointing end, the tabs run 48 r

obliquely to the sleeve jacket in these practically merging, ■ so that they run cone-like when inserted and deflect radially in the process. The arrangement of the tabs 48 in the area; the cross-section reduction 43 of the sleeve is particularly 2a \ vorLeilhaft because it is ensured by the fact that the I;

Lugs 48 even with a wall that is a little too large *

( drill hole by spreading the sleeve 2a (Fig- 43) to engage.

In the embodiment described above, the internal thread 9oa preferably has a sawtooth shape, and that too Thread 11 of the fastening element has a corresponding, adapted shape.

It should also be mentioned that when completing the dowel 1a, at least the sleeve 2a is connected to the expansion body 3a an exact rotational position of the expansion body relative to the sleeve 2a is not required. This is achieved by that the noses 2oa have a comparatively small radial height

/ 4o

- Ίο -

and therefore not with the slots 44 in one case aligned rotational position the sleeve jacket when axially pushed together reach under the sleeve and the expansion body and spread them open slightly. When assembling then takes place the rotation of the screw 7a entrains the expansion body 3a with a rotation relative to the sleeve 2a, to the lugs 2oa snap into the slots 44. The expansion body 3a is then connected to the sleeve 2a in a rotationally fixed manner. Of the The entire dowel 1a is then also the one on the wall borehole 24 attacking turnstiles (tabs 48) secured against turning, so that a final screwing in of the fastening element 7a can take place. This previously described handling allows that in the pre-assembly of the expansion body 5a and the sleeve 2a, these do not necessarily have to be interlocked, so that the completion particularly is easy.

All of the features listed in the description and the claims can be used individually or in any combination with one another be essential to the invention.

- patent claims -

Claims (1)

J in Proverbs 2. Dowel, the one at least partially radially flexible sleeve, one retractable therein and it thereby widening expansion body and possibly a rotation lock, this expansion body a preformed Internal thread for receiving a fastening element provided with an external thread, in which the Outline shape of the area penetrating the expansion body possibly subject to considerable tolerances, characterized in that at the undeformed internal thread (90) of the expansion body (3) Internal thread ZAsdschonzimmer (10) .are provided such that in relation to the associated contour profile of the external threads (11a) of the fastening screw some axial clearance remains, and that the expansion body (3) at least with respect to a substantial Section of its threaded area somewhat axially flexible is designed such that the contact surface between the external thread and the internal thread enlarged under load. Dowel according to Claim 1, characterized in that the sleeve (2) at the beginning of the drawing-in of the expansion body (3) encloses this at least over a few thread turns (11). S / Re / 2 - 2 - 3. Dowel according to claim 1 or 2, characterized in that that in the known manner at least two • internal threads (90) of the expansion body (3) the clear distance between the% traveling from each other Internal thread flanks (12a) delimited intermediate spaces (10) larger than the corresponding axial extent Set the external threads and that the existing in a known manner from somewhat deformable material Spreader body (3) is designed so resiliently at least in the axial direction that when a load / one ~ \ Internal thread section, further sections of the external thread (11) on the internal thread (90) come into play, with preferably the internal thread (90) of the expansion body (3) thread spaces with an approximately trapezoidal cross-section has and expediently the thread depth is about des Geiv'indes of the fastening elements. 4. Dowel according to one or more of claims 1 to 3, characterized in that at least the expansion body is made of plastic, preferably with plastic a modulus of elasticity of at least 7500 N / mm and one 2 tensile strength of at least 100 N / mm and that one from Plastic existing sleeve (2) preferably an elastic modulus of at least 2000 N / mm with a tensile strength 2
has a speed of at least about 60 N / mm. / 3 lift »· · ■ · · · 5. Dowel according to one or more of claims 1 i to 4, characterized in that the expansion body (3) has a fiber insert or the like. Reinforcement | having. "| 6. Dowel according to one or more of claims 1] to 5, characterized in that the distance the facing flanks (12a) of the first j . and the last thread turn of the internal thread (9o) | or an internally threaded portion thereof about that Distance between these edges in the functional position to- · I facing flanks (13a) of the external thread (11) under | Consideration of the tolerance-related maximum dimension i corresponds to the spacing of the external threads and " that the distance of the outer, respectively the first and ^ flanks (12b) associated with the last internal thread turn f approximately the distance between these flanks in functional | position facing flanks (13b) of the outer ί wind (11) taking into account the tolerance I conditional smallest dimension of the distances between the external threads j course corresponds. I. 7. Dowel according to one or more of claims 1 to 6,
characterized in that the expansion body has at least one weakening point (15) for relief
a change in its axial length that
preferably approximately in the middle of the axial
Extension of the expansion body (3) is provided and
more practical: \ 'iron through -a circumferential, open-edged / 4 Radial ring groove (16) is formed. S. dowel according to one or more of claims 1 and 7, characterized in that the expansion body (3) has at least one longitudinal slot (17) at least in some areas, the width of which is matched to the radial tolerance to be bridged by deformation. 9. Dowel according to one or more of claims 1 to 8, f, characterized in that the expansion body (3) engages the sleeve at least by means of a driver element (19) acting in the insertion direction. 1o. Dowel according to Claim 9, characterized in that as a driver element (19) on the expansion body (3) at least one approximately radially protruding nose (2o) and on the sleeve (2) a cooperating with this window-like recess (23) or the like. intended is. / 5 11. Dowel according to claim 1o, characterized in that the expansion body (3) preferably 'two opposite- \ ν .. lying noses (2o), which at their the insertion end (4) facing sides each one approximately radially oriented stop surface (21) and opposite this, to the outer end (6) of the dowel (1 ") pointing, each have a run-up slope (22). 12. Dowel according to one or more of claims 1 to 11, characterized in that for joining together in the correct position the sleeve (2) and the expansion body (3) insertion aids (26) are provided. / I « ti • t 13. Dowel according to claim 12, characterized in that as an insertion aid (26) in each case in the axial direction Preferably V-shaped edge recesses aligned with the window-like recesses (23) of the sleeve (2) (27) of the rear end (4) of the sleeve (2) facing edge are provided. 14. Dowel according to claim 12 and 13, characterized in that the edge recesses provided as an insertion aid (26) (27) have a smaller radial depth than the wall thickness of the sleeve (2) in this area V- / and that they are provided inside the sleeve. 15. Dowel according to one or more of claims 1 to 14, characterized in that the expansion body (3) in In a manner known per se, it has an outer cone (8) which / at least approximately matches the inner cone of the sleeve (2) is. 16. Dowel according to one or more of claims 1 to 15, characterized in that the threaded hole of the The expansion body (3) towards the dowel insertion end (4) v ^ iengt, preferably conical, and there a one ζ) Has a weakening point that facilitates spreading. 17. Dowel according to one or more of claims 1 to 16, characterized in that the cone (8) . of the expansion body (3) towards the insertion end (4) is connected to a cylindrical section (18), the axial length of which (1 1) preferably makes up at least 1/3 of the outer diameter (D5) of this section (18). 18. Dowel according to one or more of claims 1 to 17, characterized in that the sleeve (2) at least / 6 Cl · · I ϊ * • ff " - 6 - ϊ has an expansion tongue (28) which can be disengaged approximately radially from the expansion body (3), that preferably two opposing expansion tongues (28) are provided which are approximately axially oriented and preferably with the window-like recesses (23) of the sleeve (2) are axially aligned and have their free end to the insertion end (4) dex sleeve (2). 19. Dowel according to one or more of claims 1 to 18, df. characterized in that the sleeve (2) in the plug-in (Λ area has one, preferably two opposite, in particular axial expansion slots, which are preferably offset by 90 ° with respect to the window-like recesses (23) of the sleeve (2). 20. Dowels in particular for carrying out push-through assemblies according to one or more of claims 1 to 19, characterized in that on the sleeve (2) to reduce the sleeve friction on the Loclwand, especially the perforated wall of the push-through part (wooden battens 31) Means are provided for reducing the friction between the dowel sleeve (2) and the push-through part are. 21. Dowel according to claim 2o, characterized in that the sleeve (2) has a decrease in diameter in at least one area of its axial extent. 22. Dowel according to one or more of claims 1 to 21, characterized in that the sleeve (2) has one or more axial slots (3o) extending from the outer end over an axial section of the sleeve. / 7 23. Dowel according to claim 22, characterized in that the long sides of a slot (30) in the sleeve (2) have a W overlap profile, in particular a zigzag-shaped and / or an overlapping edge profile (32) | having. ■ · · 1 24. Dowel according to one or more of claims 1 to 23, j§ characterized in that in the enlarged diameter | Area of the expansion body (3) has a radially protruding | Annular bead (33) or the like. is provided that at their the sleeve (2) side facing an expansion bevel (34) and ^ on its side facing the insertion end (4) preferably one Has sharp-edged outer edge (35). 25. Dowel according to one or more of claims 1 to 24, characterized in that the cylindrical section adjoining the cone (8) of the expansion body (3) (18) has approximately tangentially oriented flat sides (36). 26. Dowel according to claim 1 to 25, characterized in that which is provided with a cylinder section (18) expanding C body (3) and the sleeve (2) in the undeformed state in a later axial section (41) of the pressing area is slightly larger than the volume of the wall borehole (24) in the same axial section (41) of this pressing area, the expansion body (3) at or after the pulling into the sleeve (2) adapts with its internal thread area to the external thread (11) of the screw (7) and pressing the sleeve (2) firmly against the wall borehole. 27. Dowel according to one or more of claims 1 to 26, characterized in that the sleeve (2) at least in Expansion area essentially cylindrical with approximately smooth Lateral surface (40) is formed and optionally at least in a section of its spreading area preferably one has only slightly radially protruding wall anchoring aid. 28. Dowel according to claim 27, characterized in that the wall anchoring aid is a sawtooth-shaped, circumferential Ribbing (39) or the like. Profiling owns whose approximately radially oriented surfaces point to the outer end (6) of the sleeve (2), and that preferably the profile depth (t) is more Ribbing (39) or the like. is only about 0.2 mm (see Fig. ' and 34a). 29. Dowel according to claim 1 to 28, characterized in that when the dowel (1) is undeformed, the screw shaft diameter (DI) to the wall hole diameter (D2) and to the dowel diameter (D4) at least roughly as 3: 5: 4. 30 .. A dowel according to claim 1 to 29, characterized in that \ at the non-deformed dowel (1) of the screw head diameter (D3) to the wall of borehole diameter (D2) and the dowel diameter (D4) at least in etAva as 6: 5: 4 restrained. 31. Dowel according to claim 1 to 30, characterized in that ζ when the dowel (1) is undeformed, the dowel sleeve (2) in the expansion area has a wall thickness (d) of about 0.8 mm for dowels of smaller dowel diameter (D4). 32. Dowel according to Claim 1 to 30, characterized in that If the dowel (D1) is not deformed, the dowel sleeve (2) has a wall thickness (d) of around 1.6 mm in the expansion area Dowels with a diameter (D4) about 10 inches and larger. 33. Dowel according to claim 1 to 32, characterized in that the largest outer diameter (D5) of the expansion body (3), preferably its cylinder section (18) or the like. Expansion body part, corresponds approximately to the outer diameter (D4) of the undeformed dowel (1) (see. Fig. 19). 34. Dowel according to claim 1 to 32, characterized in that at least the transitions of the thread flanks [M ~) to the
Gaps of the internal thread are rounded. 35. Dowel according to claim 1 to 34, characterized in that the cone angle (pC) of the conical part of the plastic
existing expansion body (3) is about 7 to 13 °, preferably about 10 °. 36. Dowel according to Claim 1 to 35> characterized in that the cone angle Cl3) of the expansion sleeve eti ^ a 2 to 3 ° smaller than the angle (cQ is the cone angle. 37. Dowel according to claim 1 to 36, characterized in that the expansion body (3) with respect to its cross-section below. has chemical mechanical strength, preferably aiieise a higher elasticity in the thread area than in the edge area having. Dowel according to Claim 37, characterized in that the
Reinforcement of the expansion body (3) is distributed differently over its cross section, for example by a corresponding distribution of a glass fiber reinforcement. fit 39. Dowel according to claim 1 to 38, characterized in that 'it is designed as a complete fastening unit and contains the fastening screw (7) that matches it. / 10 - 10 - 4o. Dowel the one at least partially radially flexible Sleeve, a retractable therein and thereby expanding • it expanding body and possibly a rotation lock has, this expansion body having a preformed internal thread for receiving one with an external thread provided wood screw-like fastening element possesses, in particular according to claims 1-39, characterized in that the inner cavity (42) of the sleeve (2a) at least in some areas in cross section approximately on the Core diameter of the fastening element is matched, and that they at least at one point of this loading) rich in a threaded portion of the associated Be fastening element has radially protruding cross-sectional reduction (43), and that this fastening element has at its outer end a thread-free shank section which is at least approximately the same as the outer diameter of the thread is equivalent to. 4-1. Dowel according to Claim 4o, characterized in that as a cross-sectional reduction (43) a thread section, preferably a single internal thread (45) di ent, which is preferably on the thread (11j of the fastening element is matched. 42. Dowel according to claim 4o or 41, characterized in that the cross-sectional reduction (43j "with little spacing provided near the outer end c (6) of the sleeve (2a) and that the length of the threadless shaft (5o) of the fastening element depends on the position of the cross-sectional reduction (43) of the sleeve (2a "". Is tuned in such a way that to lie in the functional position of the shaft (5oJof the fastening element at the cross-sectional reduction (43) comes (Fig. 43). 43. Dowel according to one or more of claims 4o to 42, characterized in that the inner cavity (42) of the / 11 - 11 - Expansion body (3a) with its internal thread (9oa) at least is closed in the pre-assembly position in particular at its Einsteckseitencü end (4). 44. Dowel according to claim 4 3, characterized in that the total lengths of the fastening element and the Dowels (1, 1a) are matched to one another in such a way that the internal thread (9o, 9oa) of the expansion body (3, 3a) in Pre-assembly position is filled by the threaded part of the fastening element. 45. Dowel according to claim 43 or 44, characterized in that the expansion body (3, 3a) at its insertion end (4) a removable closure of its internally threaded cavity preferably in the form of a destructible skin or the like. having. 46. Dowel according to one or more of claims 4o to 45, \ characterized in that the sleeve (2a) at least an axial, at its insertion end (4) expedient ( wise closed slot C44) and the expansion body | (3a) at least one nose (2oa) engaging in it- } · point, where the position and length of the slot (44) * f matched to the retraction length of the expansion body (3a) | is. I. 47. Dowel according to one or more of claims 1 to 46, I characterized in that the thread (11) of the fastening element and optionally the internal thread (9o, 9oa) of the expansion body (3, 3a) has a sawtooth-like cross-section, wherein the flank that is steeper to the longitudinal axis (L) of the dowel (1, 1a) or of the fastening element and expediently at least approximately perpendicular to the longitudinal axis (L) points to the outer end (6). / 12 - 12 - 48. Dowel according to claim 47, characterized in that the buttress thread at least of the expansion body (3, 3 a) has a flattened base (46). 49. Dowel according to one or more of claims 1 to 48, characterized in that its sleeve (2, 2a) has a Turnstile, in particular in the form of at least two, in particular radially opposite, disengageable Has tabs (48) which are preferably provided in the area of the cross-sectional reduction (43) of the sleeve (2a) r , are. kl (H ISfc Patent Attorney Patent Attorney