DE202013103906U1 - Sleeper screw for fastening a rail and combination of such a sleeper screw and a plastic anchor - Google Patents

Abstract

Sleeper screw for fastening a rail to a solid base, wherein the sleeper screw (2) has a screw head (30) and a longitudinal direction (LR) of the sleeper screw (2) on the screw head (30) following threaded shaft on which a circumferential screw thread ( 33) is formed, characterized in that the core (35) of the sleeper screw (2) at least in the region in which the screw thread (33) is present, in the direction of the screw tip (36) tapers.

Description

The invention relates to a sleeper screw for fastening a rail on a solid base. The sleeper screw has a screw head and a threaded shaft which follows the screw head in the longitudinal direction of the sleeper screw and on which a circumferential screw thread is formed. A sleeper screw of this kind is for example from the DE 298 20 415 U1 known.

Likewise, the invention relates to a combination of a plastic dowel and a sleeper screw.

In order to meet the demands made on modern rail transport, track railways are now commonly laid as so-called "fixed lanes" in which the tracks of the track are laid on concrete sleepers or slabs. Likewise, in conventional ballast superstructure today usually cast sleepers are placed in a ballast bed.

The intended for the attachment of the rails attachment points usually comprise a against the solid base formed by the respective threshold or plate supported guide plate which acts against the foot of the rail and so the rail leads laterally, a supported on the guide plate, with at least one Spring arm acting on the rail foot spring element, which applies the elastic hold down the rail required, directed against the solid ground holding down forces on the rail, an embedded in the solid ground dowel and usually designed as a screw or threaded bolt sleeper screw in the dowel is screwed and braced the spring element against the solid ground.

The thresholds or slabs forming the solid foundation are usually cast from concrete or another flowable material. The dowels required in the respective attachment points are usually poured directly into the material of the solid ground so that they are aligned with their dowel hole flush with the free, the footprint for the rail to be fastened top of the solid ground.

The dowel, which sits in the respective solid ground, performs different functions. First, it allows easy attachment of the sleeper screw. In doing so, it absorbs the tensile forces required for tensioning the spring element when the rail is fully assembled and directs them, as well as the dynamic loads occurring when a rail vehicle traverses the respective rail fastening point, into the solid ground.

On the other hand, the dowel serves as an electrical insulator, through which the usually made of conductive steel sleeper clamping element is electrically isolated from the solid ground.

At the same time the dowel should accommodate different thread forms and can be replaced in the case of its wear in the simplest possible way.

Finally, a dowel of the type in question should also be such that it can be positioned in the correct position in the production of the solid substrate forming element in a simple manner.

Made of plastic dowels of the type described above are for example from the EP 0 785 308 B1 or the DE 10 2011 103 127 A1 known. The production of the anchor made of plastic has the advantage that there are only slight restrictions in the shaping of plastic dowels and also the insulator effect can be achieved easily.

Practical experience has shown that under the high loads occurring today in the vicinity of the dowel, especially in a layer close to the surface of the subsurface, there are cracks in the respective solid substrate. These can go to the destruction of the respective solid substrate forming component.

It is known that in dowels with smooth peripheral surfaces in the installed state only minimal pollution of the environment arise. Therefore, in the installed state adjacent to the contact surface of the solid substrate shaft portion of plastic dowels of the type in question usually has a smooth, uniform cylindrical or tapered in the direction of the dowel tip peripheral surface.

However, to accommodate the forces required to tension the spring element in a rail attachment point, there must always be some clamping between the cast material (concrete) of the solid foundation and the dowel. This is achieved in practice in that at least one projection is formed on the holding section of the dowel, over which in the installed state a positive connection of the dowel to the surrounding material of the solid substrate is guaranteed. Thus, dowels are known in which the holding section in the longitudinal direction of the anchor arranged at regular intervals, collar-shaped circumferential projections are provided.

Dowels in which the projection provided on the outside of the holding section is designed as external thread are also widely used. The thread form has the advantage that the dowel in the event that it must be replaced because of wear, in a manner relatively simple manner in the manner of a screw from his intended recording of the solid ground can be unscrewed. The external thread is usually designed so that the tensile forces applied in the finished installation state to the dowel via the sleeper screw screwed into it are conducted via the flanks of the external thread into the material of the solid substrate surrounding the dowel. Therefore, even in the case of the plastic anchors designed in the above-described manner, there is always an unavoidable risk that cracks will occur as a result of the stresses occurring in practical use in the vicinity of the plug installed in the respective solid substrate.

In the DE 10 2011 103 127 A1 As a cause of this cracking stress peaks have been identified, which are passed over the thread formed on the holding portion of the anchor in the adjacent material of the solid ground. To avoid these voltage spikes, is in the DE 10 2011 103 127 A1 proposed to give the thread a certain shape by which a more uniform, larger-scale stress distribution is to be achieved.

The forces acting on the plastic dowel and guided by him in him receiving material of the solid ground forces are applied by the screwed in at the ready installation in him sleeper screw. Thus, the forces required to hold down the respectively used spring element forces in the sleeper screw act as tensile forces, which are absorbed by the plastic dowel and discharged into the solid ground. In this case, the thread of the sleeper screw must be designed so that a self-loosening or pulling out of the screw is excluded from the dowel due to the dynamic loads occurring in practical operation.

Against the background of the prior art explained above, the object of the invention was to specify a sleeper screw with which the risk of formation of near-surface cracks in the solid ground is minimized in the installed state.

Furthermore, a combination of a sleeper screw and a plastic anchor should be specified, which also minimizes the risk of crack formation when installed.

With respect to the screw, this object has been achieved by a trained according to claim 1 sleeper screw.

With regard to the combination of a plastic dowel and a sleeper screw, the above-mentioned object has been achieved according to the invention by designing such a combination according to one of claims 7 or 9.

Advantageous embodiments of the invention are specified in the dependent claims and are explained below as the general inventive concept in detail.

A sleeper screw according to the invention has, in accordance with the prior art described at the outset, a screw head and a threaded shank following in the longitudinal direction of the sleeper screw, on which a circumferential screw thread is formed. According to the invention, the core of the sleeper screw now runs conically in the direction of the screw tip at least in the region in which the screw thread is present.

The tapered in the direction of the screw tip shape of the threaded core of the sleeper screw has the advantage that when screwed into a plastic anchor sleeper screw in the threads between the core of the screw and the inner wall of the plastic anchor remains a space in which dirt can collect without the To screw in and unscrew the sleeper screw. In this case, there is no contact between dowel wall and screw core as a result of decreasing in the direction of the dowel tip core diameter of the sleeper, which in the final installation state also the power transmission (pressure) is prevented by the screw to the dowel wall and from there into the vicinity of the dowel. In this way, in the installed state, the lateral forces acting on the plastic dowel and the plastic dowel material of the solid base are minimized by the sleeper screw. As a result, the risk of cracking in the solid ground is minimized.

A particularly important embodiment of the invention for practical use is that the core diameter of the sleeper screw at least in the region in which the screw thread is present in the direction Screw tip decreases, the diameter of the screw thread over the entire length of the threaded shaft remains constant, that is always sufficient in the radial direction to a cylindrically shaped envelope of the threaded shaft. In such an embodiment on the one hand ensures that can penetrate into the plastic dowel penetrating dirt in the dowel, without hindering its function and the entry and removal of the screw. On the other hand, a maximum effective length is achieved by the constant outer diameter of the thread of the sleeper screw according to the invention, via which the frictional clamping of screw and plastic dowel takes place. In this way, in the installed state despite the decreasing in the direction of the dowel tip core diameter of the sleeper screw optimal cold the screw in the plastic dowel and, consequently, a maximum resistance to an automatic release of the sleeper screw secured.

According to a further embodiment of the invention, which also makes a significant contribution to the prevention of cracks in the solid ground, the thread flank of the screw thread associated with the screw head is oriented at an angle of 90 ° ± 3 ° relative to the longitudinal axis of the sleeper screw. As a result, the sleeper screw according to the invention transmits only minimal forces in the radial direction radially directed away from the longitudinal axis of the plastic plug. Optimally, the thread head of the screw thread associated with the screw head is aligned as accurately as possible at a right angle with respect to the longitudinal axis of the sleeper screw. Accordingly, the invention provides that the screw head associated with the thread flank of the sleeper screw in the context of manufacturing tolerances with respect to the longitudinal axis of the sleeper screw at an angle of 90 ° ± max. 1 ° is aligned.

In a sleeper screw according to the invention thus the thread of the screw is optimized so that almost exclusively in the screw axis acting through the almost perpendicular transition from the screw core to the thread flanks with axial tensile load in the screw creates a tensile force and thus transverse and tangential forces at right angles to the screw in the direction are greatly reduced to the dowel wall and beyond in the surrounding the dowel material of the solid ground.

By the ratio of the screw diameter to the diameter of its core becomes larger to the lower end of the screw, in the area of the dowel interior over conventional screw / dowel combinations by up to 50% greater free volume between the screw and dowel is obtained, thereby reaching the dowel impurities (z B. Sand) during assembly / disassembly of the rail fastening system cause less interference when re-screwing. In addition, the tapered shape of the screw core, a corresponding tapering of the interior of the dowel in the direction of the dowel tip, so that there is a larger contact / overlap surface between the material of the solid substrate and the plastic dowel according to the invention with the same outer diameter of the anchor. As a result, this also contributes to the increase of Ausziehwiderstands, by which an automatic release of the sleeper screw due to acting in practical use dynamic forces is avoided.

Also on the threshold screw used according to the invention can be present to reduce in this area in the radial direction transmitted stresses between the screw head and the threaded portion a shaft portion whose peripheral surface is smooth, preferably the envelope of the peripheral surface of the shaft portion a jump-free extension of the cylindrical envelope of the Threaded portion of the sleeper screw forms.

In a combination according to the invention of a threshold screw designed according to the invention and a plastic dowel for fastening a rail to a fixed base, the plastic dowel has a dowel opening formed on an end face of the plastic dowel for inserting the sleeper screw into the plastic dowel, a dowel interior surrounded by the plastic dowel, a shank section, seen in the longitudinal direction of the plastic dowel connects to the dowel opening, and a holding portion, which seen in the longitudinal direction of the plastic dowel connects to the shaft portion and which is provided on its outside with at least one radially projecting, circumferential around its projection, the engages in the finished installation state in the material surrounding the plastic dowel solid ground. According to the invention, the dowel opening associated upper edge of the projection of the holding portion of the plastic dowel is aligned at an angle of 90 ° ± 3 ° with respect to the longitudinal axis of the plastic dowel.

The protrusion present on the holding section of the plastic dowel is typically an external thread.

According to the independently claimed further inventive combination of a sleeper screw according to the invention and a plastic dowel for the attachment of a rail a firm base, the plastic dowel also has a dowel opening formed at a front end of the plastic dowel for inserting a sleeper screw into the plastic dowel, a dowel interior surrounded by the plastic dowel, a shank portion which adjoins the dowel opening in the longitudinal direction of the plastic dowel, and a holding section, seen in the longitudinal direction of the plastic dowel connects to the shaft portion. In this case, in this case, the holding portion on its inner side an internal thread, in which the dowel opening associated edge of the internal thread of the plastic dowel according to the invention is oriented at an angle of 90 ° ± 3 ° with respect to the longitudinal axis of the plastic dowel.

Both combinations according to the invention, when taken in the respective solid underground dowel in each case contribute to a minimization of the entry of shear forces and stress peaks in the environment of the anchor. Therefore, each of these combinations in itself already solves the task given in relation to a plastic anchor intended for rail fastening. An optimal effect of the invention occurs when both combinations are realized simultaneously, ie when the shank portion of the plastic dowel is formed flat on both its outer and on its inside and both on the outside of the holding portion a preferably formed as an external thread projection as also on the inside of the holding portion, an internal thread are present, wherein the dowel opening associated flanks of both existing on the outside projection of the plastic dowel and formed on the inside inner thread of the plastic dowel with each adjacent, axially parallel to the longitudinal axis of the plastic dowel aligned wall wall surface of the holding portion enclose an angle of 90 ° ± 3 °.

Both combinations are based on the finding that the entry is determined by a suitable orientation of the dowel opening associated with the dowel opening of the projection or thread provided in the respective holding section (radially protruding projection or external thread and / or internal thread of the holding section) can be reduced to a minimum by transverse forces and voltage peaks in the material of the solid substrate surrounding the plastic dowel in the installed state. The more precisely the dowel opening facing flanks of the respective projection or thread are aligned at a right angle with respect to the longitudinal axis of the plastic dowel, the lower the environment of the anchor is loaded by stresses in the installed state in the radial direction of the plastic dowel in the spread solid ground.

If the dowel opening associated edge of the respective thread or projection is aligned exactly at an angle of 90 ° with respect to the dowel axis, no forces in the radial direction can be passed through this edge in the surrounding material of the solid ground. Accordingly, in such an orientation, the proportion of tensile forces which are applied in the finished installation state of screwed into the plastic dowel sleeper and are passed over the dowel opening associated edge of each thread in the radial direction in the vicinity of the dowel, equal to "0".

Therefore, an advantageous embodiment of the invention, that the dowel opening associated dowel edge in the holding portion with respect to the longitudinal axis of the plastic dowel each at an angle of 90 ° ± 1 °, in particular exactly below 90 °, is aligned. In this case, it may be expedient in terms of manufacturing reasons, in particular with respect to the provided on the outside of the holding portion of the plastic dowel, in particular designed as external thread projection, the range of the angle at which aligned the dowel opening edge associated with the projection with respect to the longitudinal axis of the plastic dowel is to be limited within the manufacturing tolerances to 90-91 °, in order to avoid undercuts.

In a plastic dowel according to the invention, in particular formed as an external thread, provided on the outside of the holding portion projection and provided on the inside of the holding portion internal thread thus each shaped so that in the installed state not only in the region of the particular flat upper shaft portion of the plastic dowel, but also in the region of the holding section, at most minimal stresses of the material surrounding the plastic dowel of the solid substrate result from radially propagating stresses. As a result, in the region of the holding section designed according to the invention, there is at most a minimal risk that cracks will occur.

In a combination according to the invention, therefore, the length range of the anchor, in which it comes in practical use to a minimum load on the environment of the anchor, extended by a considerable amount. At the same time the plastic dowel is clamped in the installed state already in the holding section with the solid ground by material form fit.

In order to improve the safety of anchoring the inventively designed plastic anchor in the respective solid surface, seen in the longitudinal direction of the plastic anchor to the first holding portion, a second holding portion connect, in which provided on the outside of the holding portion at least one projection or on the outside of the Holding portion provided as a projection provided external thread and possibly the respective internal thread of the holding portion are continued.

Here, the dowel opening associated thread flank of the provided on the outside projections or the external thread and the internal thread in the threaded portion with respect to the longitudinal axis of the plastic dowel at an angle of more than 93 ° is arranged or rounded.

"Rounded out" here means that the dowel opening associated flank of existing on the threaded portion projections or formed therein thread in the radial direction seen in a continuously curved course in the dowel tip associated edge of the respective projection or thread passes.

For manufacturing reasons or to avoid notch effect on the plastic dowel according to the invention, the transition between the dowel opening associated flank of existing on the outside of the respective holding portion projection or the internal thread and associated, axially parallel to the longitudinal axis of the plastic dowel aligned outer or inner peripheral surface of the plastic dowel may be formed rounded , D. h., The dowel opening associated edge of the holding section present at least one projection (external thread) can pass in a throat in the aligned in the longitudinal direction of the plastic dowel peripheral wall of the dowel. Likewise, the transition between the dowel opening associated edge of the internal thread of the holding portion and aligned in the longitudinal direction of the plastic dowel inner peripheral surface of the holding portion may be rounded or be phased.

The shaping of the dowel tip associated edge of the outer projection can also be designed in each case such that on this edge only minimal forces in the radial direction from the dowel, starting in the surrounding material of the solid ground are passed. Thus, the lower edge may be aligned obliquely in the direction of the dowel tip or bulged convex outwards.

Similarly, the dowel tip associated edge of the internal thread of the holding portion can be selected depending on the shape of the threaded shaft of the sleeper screw thread formed and the greatest possible compatibility with different thread shapes. Here it has proven to be practical if the dowel tip associated flank of existing on the outside of the holding portion projection (external thread) or internal thread of the first holding portion is formed in each case convexly curved.

The introduced in the installed state in the region of the second holding portion in the vicinity of the plastic dowel stresses according to the invention can be made uniform in that seen in longitudinal section, the transition between the dowel opening associated flank of the projection or the internal thread of the second holding portion to the dowel tip associated edge of the relevant projection or Internally threaded as a convex curved, continuous curve is rounded. In particular, by the rounded shape of the present on the outside of the second holding portion projection high extraction forces of the anchor can be achieved in the installed state, since in deeper regions of the solid underground by far the largest share of Gesamtausreißwiderstand a cast anchor.

The voltages introduced into the surrounding material of the solid substrate in the region of the first plastic dowel in the installed state can be further reduced by providing at least one web connected to the shaft section in the region of the first holding section in the longitudinal direction of the plastic dowel is formed, the width of which in its foot corresponds to at least one fifteenth, in particular at least one twelfth of the circumference of the plastic dowel, which crosses the projection (external thread) of the first holding portion and the apex surface seen in the radial direction at most extends to the imaginary extension of the envelope of the shaft portion , The width of each existing web is optimally limited in its foot to a maximum of a quarter of the circumference of the plastic anchor.

The relevant extending in the longitudinal direction of the plastic dowel web represents with its apex an extension of the smooth peripheral surface of the shaft portion, without thereby the positive interlocking between the solid substrate and the first holding portion of the plastic dowel is substantially impaired. Preferably, at least two or more are each at uniform angular intervals provided distributed around the longitudinal axis of the dowel arranged webs.

According to the invention, in the region of the first holding section adjoining the shank section, due to the shaping according to the invention of the projection present on its outer side, in particular formed as an external thread, and the smooth outer surfaces of the optionally available webs, which are aligned at right angles to the threshold longitudinal axis in the installed state, only low lateral forces on the surrounding concrete effective. In a dowel according to the invention transverse forces are thus not rotationally symmetrical around the dowel distributed distributed in the solid ground, but selectively directed in a direction in which the material of the solid ground, for example, due to embedded in the solid underground reinforcements can safely absorb these loads.

In a corresponding manner, one or more groove-shaped recesses extending in the longitudinal direction of the plastic dowel may be formed in the region of the first threaded section in the peripheral surface associated with the dowel interior. These grooves interrupt the transmitted via the internal thread radially propagating stresses and thus also lead in the installed state to a reduction of the loads of the environment of the plastic dowel according to the invention. In this case, in the case that the above-explained webs are formed on the outside of the plastic dowel, a weakening of the dowel can be avoided in that the respective groove is formed in the region of the respectively associated web provided on the outside of the plastic dowel.

The invention will be explained in more detail by means of exemplary embodiments. Show it:

1 a screw-plastic dowel combination in an exploded perspective view;

2 the plastic dowel screw-plastic dowel combination in perspective view;

3 the plastic dowel in a first side view;

4 the plastic dowel in a longitudinal section;

5 the plastic dowel in a relation to the illustration in 3 rotated by 90 ° about the longitudinal axis of the plastic anchor position in a lateral view;

6 the sleeper screw of the screw-plastic dowel combination in side view;

7 the sleeper screw according to 6 in a longitudinal section;

8th the screw-plastic dowel combination with inserted into the plastic dowel sleepers and longitudinally shown plastic dowel.

The screw-plastic dowel combination K includes a plastic dowel 1 and a sleeper screw made of a steel in a conventional manner 2 ,

The plastic dowel 1 has a dowel opening bounded by an edge formed in the manner of a collar 3 a shaft section 4 extending longitudinally LR of the plastic dowel 1 at the dowel opening 3 connects, a first holding section 5 in the longitudinal direction LR of the plastic anchor 1 following the shank portion, a second holding portion 6 in the longitudinal direction LR to the first holding section 5 is connected, a dowel tip 7 and a dowel interior 8th on, of the shaft portion 4 and the holding sections 5 . 6 is bounded. In the dowel tip 7 is a coaxial with the longitudinal axis L of the plastic anchor 1 aligned passage opening 9 molded over the plastic dowels 1 can drain away moisture.

The outer peripheral surface 10 of the shaft portion 4 is cylindrical and smooth, so that the peripheral surface 10 with the cylindrical envelope U of the shaft portion 4 coincides.

At the first holding section 5 is a lead 11 formed in the form of an external thread, which in a uniform slope starting from the boundary between the shaft portion 4 and the first holding section 5 in the direction of the dowel tip 7 around the first holding section 5 circulates. The lead 11 has one of the dowel hole 3 assigned upper edge 12 on, which is oriented relative to the longitudinal axis L of at an angle β1 of 90 °. Accordingly, the upper flank closes 12 with the adjacent thereto, axially parallel to the longitudinal axis L aligned peripheral wall surface 13 the plastic dowel 1 the same right angle β1. For manufacturing reasons and to avoid a notch effect, is the transition 14 between the upper flank 12 and the relevant wall surface 13 rounded in the manner of a throat.

At its free, from the peripheral wall surface 13 the edge facing away from the upper edge 12 of the projection 11 to a crest surface 15 of the projection 11 substantially parallel to the longitudinal axis L of the plastic dowel 1 is aligned. The crest surface 15 also lies on the cylindrical envelope U of the shaft portion 4 ,

To the crest surface 15 closes the the dowel tip 7 assigned lower edge 16 of the projection 11 at. The lower flank 16 of the projection 11 is convex rounded to the outside and goes in a rounded throat in the peripheral wall surface 13 the plastic dowel 1 above.

In the area of the holding section 5 is formed in the manner of an external thread projection 11 through two bridges 17 . 18 interrupted, which are opposite each other as an extension of the shaft portion 4 over the height H1 of the first holding section 5 extend. The bridges 17 . 18 have at their foot region a width which is about 14% of the circumference of the shaft portion 4 equivalent. In cross-section are the webs 17 . 18 arched outward in a semicircular shape, being in its apex area 19 the radius of the envelope U are flattened accordingly. The vertex area 19 also lies on the envelope U of the shaft portion 4 so that the vertex area 19 of the bridges 17 . 18 jump-free in the peripheral area 10 of the shaft portion 4 passes.

In the area of the second holding section 6 is formed as an external thread projection 11 of the first holding section 5 as a lead 20 continued, which is also designed as a rounded external thread. Accordingly, that of the dowel opening 3 associated edge of the male thread projection 20 in a continuous convexly outwardly curved curve in the apex region of the projection 20 about, in the same way in the dowel tip 7 associated edge of the male thread projection 20 passes. Also the vertex of the projection 20 lies on the cylindrical envelope of the plastic anchor 1 ,

Into the inner peripheral surface 23 the plastic dowel 1 is an internal thread 21 molded, extending over the first and second holding section 5 . 6 extends and over both holding sections 5 . 6 is uniformly shaped.

The dowel opening 3 assigned upper edge 22 of the internal thread 21 is at an angle β2 of 90 ° with respect to the longitudinal axis L of the plastic anchor 1 aligned so that the upper flank 22 with the axially parallel to the longitudinal axis L aligned inner peripheral surface 23 the plastic dowel 1 includes the same right angle β2. The transition 24 between the inner peripheral surface 23 and the upper flank 22 of the internal thread 21 is also rounded.

At the same time the upper flank goes 22 in a continuously convexly outwardly curved apex area 25 on, in turn, a concave vaulted, the dowel tip 7 assigned lower edge 26 connected. The lower flank 26 runs so steplessly in the inner peripheral surface 23 the plastic dowel 1 out.

In the area of the first holding section 5 is the internal thread 21 by groove-shaped recesses 27 interrupted, which are opposite to the jetties 17 . 18 on the inside of the plastic dowel 1 over the height H1 of the first holding section 5 extend. From the recesses 27 is due to the selected view in 4 only the bridge 18 associated recess 27 to see. Like the bridges 17 . 18 also wear the recesses 27 in the sense of an extension of the smooth inner peripheral surface 28 of the shaft portion 4 to that from the first holding section 5 outgoing propagation of shear forces in the plastic dowels 1 minimized in the installed state surrounding solid ground.

The shape and dimensions of the upper flank 22 , the vertex area 25 and the lower flank 26 of the internal thread 21 are designed so that sleeper screws 2 with differently shaped threads in the plastic dowels 1 can be screwed.

Preferably, however, comes in the screw plastic dowel combination K, a sleeper screw 2 the type described here for use. Such a sleeper screw 2 has a screw head 30 , a longitudinal direction LR of the sleeper screw 2 to the screw head 30 connected shaft section 31 and a longitudinal direction LR to the shaft portion 31 connected threaded section 32 on, an external thread 33 wearing.

The cylindrically shaped shaft portion 31 has a smaller diameter than the screw head in a conventional manner 30 and a smooth peripheral surface 34 on. It extends over approximately 24% of the height HS of the sleeper screw 2 ,

In the area of the threaded section 32 the core tapers off 35 the sleeper screw 2 towards the top 36 the sleeper screw 2 , The core is running 35 in an upper, to the shaft portion 31 adjacent area 37 that is about a quarter of the length of the threaded section 32 assumes, initially with a greater pitch conical to over the remaining length of the threaded portion 32 with a uniform slope conical towards the screw tip 36 zuzulaufen.

The screw head 30 assigned upper edge 38 of external thread 33 as well as the screw tip 36 assigned lower edge 39 of external thread 33 are each aligned at an angle β3 of 90 ° with respect to the longitudinal axis L of the sleeper screw. At the same time he describes the flanks 38 . 39 connecting vertex area 40 of external thread 33 a convex convex semicircle. The vertex of the vertex area 40 lies on the cylindrical envelope US of the shaft portion 31 the sleeper screw 2 ,

Due to the conical in the direction of the screw tip 36 tapered core 35 arises as in the plastic dowel 1 screwed in sleeper screw 2 in the dowel tip 7 associated lower portion of the dowel interior 8th an enlarged white space 41 in which are in the plastic dowels 1 can collect collecting dirt without screwing or unscrewing the sleeper screw 2 to hinder.

Due to the shaping according to the invention it is achieved that in the installed state in the region of the first holding section 5 at most even to a minimum extent transverse to the longitudinal axis L of the plastic dowel 1 oriented forces in the radial direction R directed away from the plastic dowel in the plastic dowel 1 surrounding material of the plastic dowel 1 to be guided on a firm ground. Accordingly, the risk of crack formation in this area is minimized as well as in the region of the shaft portion 4 , beyond its smooth peripheral surface 10 also no lateral forces in the plastic dowels 1 be passed surrounding material.

LIST OF REFERENCE NUMBERS

1

Plastic anchors

2

sleeper screw

3

dowel hole

4

Shank section of the plastic anchor 1

5

first holding portion of the plastic dowel 1

6

second holding section of the plastic dowel 1

7

Dowel tip of the plastic dowel 1

8th

Dowel interior of the plastic dowel 1

9

Through opening of the dowel tip 7

10

outer peripheral surface of the shaft portion 4

11

as external thread on the outside of the first holding portion 5 trained lead

12

upper flank of the projection 11

13

Peripheral wall surface of the plastic anchor 1

14

Transition between the upper flank 12 and the peripheral wall surface 13

15

Vertex surface of the projection 11

16

lower flank of the projection 11

17, 18

Stege

19

respective apex area of the webs 17 . 18

20

formed as a rounded external thread projection of the second holding portion 6

21

Internal thread of the plastic anchor 1

22

the dowel opening 3 associated upper edge of the internal thread 21

23

Inner peripheral surface of the plastic dowel 1

24

Transition between the inner peripheral surface 23

25

Vertex area of the internal thread 21

26

the dowel tip 7 associated lower edge of the internal thread 21

27

groove-shaped recesses

28

smooth inner peripheral surface of the shaft portion 4

30

Screw head of the sleeper screw 2

31

Shank portion of the sleeper screw 2

32

Threaded portion of the sleeper screw 2

33

External thread of the sleeper screw 2

34

Peripheral surface of the shaft portion 31

35

Core of the sleeper screw 2

36

Tip of the sleeper screw 2

37

to the shaft portion 31 adjacent area of the threaded portion 31

38

the screw head 30 assigned upper edge of the external thread 33

39

the screw tip 36 associated lower edge of the external thread 33

40

Vertex area of external thread 33

41

Empty space in the plastic dowel 1 with the screw screwed in

H1

Height of the first holding section 5

HS

Height of the sleeper screw 2

K

Screw plastic anchors combination

L

Longitudinal axis of the plastic anchor 1

LR

longitudinal direction

R

radial direction

β1

between the longitudinal axis L and the coaxial with the longitudinal axis L aligned peripheral wall surface 13 and the upper flank 12 of the projection 11 included angle

β2

between the longitudinal axis L and the coaxial with the longitudinal axis L aligned inner peripheral surface 23 the plastic dowel 1 included angle

β3

Angle under which the upper and the lower flank 38 . 39 of external thread 33 with respect to the longitudinal axis LS of the sleeper screw 2 each aligned

U

cylindrical envelope U of the shaft portion 4 and the holding sections 5 . 6

US

Envelope of the shaft section 31

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 29820415 U1 [0001]
• EP 0785308 B1 [0010]
• DE 102011103127 A1 [0010, 0015, 0015]

Claims (9)

Sleeper screw for fastening a rail to a fixed base, the sleeper screw ( 2 ) a screw head ( 30 ) and in the longitudinal direction (LR) of the sleeper screw ( 2 ) on the screw head ( 30 ) has the following threaded shaft, on which a circumferential screw thread ( 33 ), characterized in that the core ( 35 ) of the sleeper screw ( 2 ) at least in the area in which the screw thread ( 33 ), in the direction of the screw tip ( 36 ) tapers. Sleeper screw according to claim 1, characterized in that the screw head ( 30 ) associated upper edge ( 38 ) of the screw thread ( 33 ) relative to the longitudinal axis (LS) of the sleeper screw ( 2 ) is oriented at an angle (β3) of 90 ° ± 3 °. Sleeper screw according to claim 2, characterized in that the upper flank ( 38 ) relative to the longitudinal axis (LS) of the sleeper screw ( 2 ) is oriented at an angle (β3) of 90 ° ± 1 °. Sleeper screw according to one of the preceding claims, characterized in that the screw thread ( 33 ) extends over the entire length of the threaded shaft in the radial direction (R) to a cylindrical envelope (US) of the threaded shaft. Sleeper screw according to one of the preceding claims, characterized in that the sleeper screw ( 2 ) between the screw head ( 30 ) and the threaded portion a shank portion ( 31 ), whose peripheral surface is smooth. Sleeper screw according to one of the preceding claims, characterized in that the envelope (US) of the peripheral surface of the shaft portion (US 31 ) with the cylindrical envelope (US) of the threaded section (US Pat. 32 ) coincides. Combination of a sleeper screw formed according to one of claims 1 to 6 ( 2 ) and a plastic dowel ( 1 ) for the attachment of a rail on a solid base, with a front end of the plastic dowel ( 1 ) formed dowel opening ( 3 ) for inserting the sleeper screw ( 2 ) in the plastic dowels ( 1 ), with a plastic anchor ( 1 ) surrounded dowel interior ( 8th ), with a shank portion ( 4 ), which extends in the longitudinal direction (LR) of the plastic anchor ( 1 ) seen at the dowel opening ( 3 ), and with a holding section ( 5 ), which extends in the longitudinal direction (LR) of the plastic anchor ( 1 ) seen at the shaft portion ( 4 ) and at its outer side with at least one in the radial direction (R) projecting, around its circumference circumferential projection ( 11 ) is provided in the finished installed state in the plastic dowels ( 1 ) engages surrounding material of the solid substrate, characterized in that the dowel opening ( 3 ) associated upper edge ( 12 ) of the projection ( 11 ) of the holding section ( 5 ) of the plastic anchor ( 1 ) at an angle (β1) of 90 ° ± 3 ° with respect to the longitudinal axis (L) of the plastic anchor ( 1 ) is aligned. Combination according to claim 7, characterized in that the projection ( 11 ) of the holding section ( 5 ) is designed as an external thread. Combination of a sleeper screw formed according to one of claims 1 to 6 ( 2 ) and a plastic dowel ( 1 ) for the attachment of a rail on a solid base, with a front end of the plastic dowel ( 1 ) formed dowel opening ( 3 ) for inserting the sleeper screw ( 2 ) in the plastic dowels ( 1 ), with a plastic anchor ( 1 ) surrounded dowel interior ( 8th ), with a shank portion ( 4 ), which extends in the longitudinal direction (LR) of the plastic anchor ( 1 ) seen at the dowel opening ( 3 ), and with a holding portion extending in the longitudinal direction (LR) of the plastic anchor ( 1 ) seen at the shaft portion ( 4 ) and the on its inside an internal thread ( 11 ), characterized in that the dowel opening ( 3 ) associated edge ( 22 ) of the internal thread ( 21 ) of the plastic anchor ( 1 ) at an angle (β2) of 90 ° ± 3 ° with respect to the longitudinal axis (L) of the plastic anchor ( 1 ) is aligned.

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