The invention is directed to a guardrail run along a roadway according to the features in the preamble of claim 1.
Guardrail runs of this type are known in the art and are disclosed, for example, in FR 2 811 344. They have a rail made of round timber sections which extends essentially parallel to the roadway, with the rail supported via spacers on posts anchored in the ground. The end faces of two consecutive round timber sections abut one another. The round timber sections have on their bottom side a vertical groove in which a steel band is arranged. The steel band protrudes lengthwise over the ends of the round timber section. In the installed state, the steel bands therefore overlap in the grooves at the respective ends. Studs extend through the round timber sections and the steel bands and optionally also the spacers, which are thereby coupled to one another, with the coupled steel bands forming a tension chord.
The guardrail run in the aforedescribed embodiment is specifically designed for roadways in rural areas, in particular wooded areas, in order to visually blend with the environment.
The connections between two round timber sections is relatively unstable and can therefore only produce a small resistance for heavy vehicles, such as mid-sized and full-sized passenger cars and trucks. It should be noted that the round timber sections can inevitably only have a certain maximum diameter so as not to disturb the desired visual appearance.
The conventional guardrail run is also disadvantageous with respect to its installation. The steel bands must overlap in the grooves. To this end, the free ends of the steel bands must be threaded into the respective adjacent end of a round timber section, which has proven to be extremely difficult in practical applications. In addition, the studs must be inserted through the round timber sections and the overlapping ends of the steel bands, before they can be attached to the spacers.
An attempt to remedy these disadvantages has been proposed in the prior filed utility model DE 20 2005 013 218 U1, which shows a guardrail run with metal bands that are coupled by locking plates. The locking plates are provided in the form of flat metal plates which contact one side of the metal bands. The locking plates can be easily inserted through slots provided in the round timber sections.
Based on the state of the art, it is an object of the invention to improve a guardrail run of the aforedescribed type so that the guardrail provides increased resistance to impacting objects.
This object is attained with the features recited in claim 1.
The core idea of the invention is that the locking plates are U-shaped in the form of two legs connected by a web, and that the locking plates overlap with the ends of two adjacent metal bands, wherein the ends are received between the legs.
With this design, the metal bands are coupled together by the locking plates, thereby forming a continuous tension chord in the rail. In the event of an impact by a truck, the guard rail run can withstand very high tension loads due to the shape of the locking plates, whereby the tension chord ensures the protective function of the guardrail run, even if individual posts break off, for example, as a result of a direct impact.
With the design of the locking plate according to the invention, which overlaps with the metal bands, the guardrail run is securely stabilized at the coupling locations. This counters the introduction of damaging torques in the round timber sections, formation of kinks at the coupling location or splicing of the round timber sections. Due to the high dimensional stability, the tensile strength of the tension chord is substantially greater than with conventional embodiments. Advantageously, the locking plates are configured symmetric.
Advantageous embodiments and modifications of the inventive concept are recited in dependent claims 2 to 8.
According to an advantageous embodiment, the web has a slot extending in a longitudinal direction of the web. The locking plates are fabricated from a single metal plate by stamping and bending. Incorporation of the slot facilitates bending of the locking plate.
Advantageously, the web may be disposed along upper longitudinal edges of the legs. The locking plate can then pushed during installation of the guardrail run onto the ends of the metal bands from above and thereafter secured to the post together with the metal bands. To this end, the round timber sections have at their ends insertion slots which extend parallel to the groove, with the looking plates inserted into the insertion slots. The locking plates can be inserted through the insertion slots, after the round timber sections have been loosely attached to the posts.
Advantageously, the ends of the round timber sections may be attached to the posts with interposed spacers. The spacers operate here as a buffer between the round timber sections and the posts, so that the posts are not damaged in an accident causing only a minor impact. In addition, the posts can be also be anchored along the side of the roadway.
The locking plates, the metal bands, the round timber sections, and the spacers have aligned bores and are connected with one another by studs extending through the bores. During installation, one end of a round timber section together with a locking plate can initially be loosely attached to a spacer with a stud. In the next step, a second round timber section is then positioned and the locking plate is inserted into the adjacent slot. When the bores in the second round timber section and in the spacer are aligned, a stud can be inserted for establishing a secure connection. In a final step, the stud at the first round timber section is tightened.
The bores in the locking plates and/or spacers may be implemented as slots oriented in the longitudinal direction of the rail. The slots facilitate installation because they allow for compensation in the length. The slots can also support yielding of a guardrail run, because in a crash, the play in the connection can advantageously be utilized, before the entire load effects the connection region. The capability of compensating for length variations provides also advantages under stationery conditions, because the materials of the employed components have different thermal expansion coefficients. Possible harmful tension forces can thereby be countered.
In a particularly advantageous embodiment, the locking plates can be placed transversely on the studs via slots disposed on the outer bores. With this feature, the round timber sections can initially be loosely attached to the spacers by way of the outer bores; the locking plates to be coupled are then inserted from above through the slots, whereafter the inner studs are inserted. All studs are then tightened so as to establish a secure connection. Accordingly, this embodiment significantly simplifies the installation.
Exemplary embodiments of the invention will now be described with reference to the drawings. It is shown in:
In all the figures, identical elements of the guardrail run have identical reference symbols.
The rail 2 extends essentially parallel to the roadway, with the sections of the rail 2 composed of round timber sections 5 which abut in the region of the posts 4. Each round timber section 5 has on its bottom side 6 a vertical groove 7. A metal band 8 is arranged in the groove 7, with the band 8 extending between the end faces 9 of the round timber section 5. The metal band 8 is made of steel and has typically a thickness of 5 mm. The circumference of the round timber sections 5 facing the posts is flattened. In these flat regions 10, a corresponding spacer 3 is interposed in the connecting region between two raw timber sections 5 and a post 4.
The ends 11, 12 of the round timber sections 5 have insertion slots 13 which extend parallel to the groove 7 and are adapted for insertion of a locking plate 14. The locking plate 14 establishes the connection between the metal bands 8 of adjacent round timber sections 5, thereby forming a continuous tension chord in the guardrail run 1. At each end 11, 12 of the round timber sections 5, in the region of the insertion slot 13, two studs 15, 16 connect the round timber section 5, the metal plate 8, the locking plate 14 and the spacer 3. The aforedescribed components 5, 8, 14, 3 have aligned bores 17 to 20 (see
The studs 15, 16 are arranged at the same height and in parallel, with a horizontal spacing therebetween. On the side facing the post, the studs 15, 16 are tightened with nuts 22 and interposed washers 21. When installed, the locking plate 14 overlaps with the ends 43, 44 (see
The spacer 3 has a C-shaped center section 23, which is essentially trapezoidal when viewed from the top. The center section 23 consists of a web 24, from which two legs 25 extend in a wing-like configuration. The legs 25 are bent outwardly in the longitudinal direction of the rail 2. The legs 25 are also connected with one another by an edge plate 26. The edge plate 26 is welded to the legs 25 and is flush at its lateral edges with the lateral edges of the bent sections of the legs 25. Two bores in the form of slots 20 are provided on each leg 25 and in the edge plate 26 at those locations where the spacer is penetrated by the studs 15, 16 of the rail 2. An additional slot 27 in the web 24 is provided for releasable attachment of the spacer 2 to the post 4.
The post 4 has an inner profile 28 made of steel with a C-shaped cross-section and is secured in the ground. The inner profile 28 is covered with a wooden cover 30 on the side 29 facing the roadway and on the sides pointing in the longitudinal direction of the rail 2. The top end 31 of the wooden cover 30 has an oblong opening. In this region, the web 24 of the spacer is attached with a screw. A stud 32 extends through the spacer 3, the wooden cover 30 and the inner profile 28.
The groove 7 and the insertion slot 13 are arranged in the center without a spacing therebetween. The locking plate is pushed from above through the insertion slot 13 onto the metal band 8. The ends of the metal bands 18 are hereby received between the legs 33, 34. As seen in
The guardrail run 1 of the invention is able to particularly withstand high tensile loads and can be easily installed. By coupling the metal bands 8 by way of the locking plates 14 and the spacers 3, the guardrail run 1 of the invention provides the same protection as steel guardrails.
During installation, the posts 4 are first anchored in the ground. The spacers 3 are then installed on the posts 4. The round timber sections 2 together with the metal bands 8 arranged therein are delivered to the construction site ready for installation. The round timber sections 5 are then loosely attached on the outer slots 20 of the spacers 3 with the outer studs 16. A locking plate 14 is then inserted from above into the insertion slot 13, and the locking plate 14 can drop or can be pushed onto the outer stud. Finally, the inner studs 15 are inserted, and all the studs 15, 16 are tightened.
Number | Date | Country | Kind |
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20 2005 013 218.7 | Aug 2005 | DE | national |
20 2006 004 364.0 | Mar 2006 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/DE2006/001336 | 8/1/2006 | WO | 00 | 2/15/2008 |