Safety device for the beginnings of crash barriers

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t Issued on: Inventor:

DIFFEROANGE

1979 11 15

1980 06 25

GLAESEN ERNEST

LUXEMBOURG © Dependence:

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FR-PS2020054 G8-PS1369425 GB-PS1375318 US-PS 2927513

US-PS 3589681 US-PS 3690619

DIRECTIVES OF »» DAV INTERNATIONAL SA ·· IN ZUG (SWITZERLAND) ·· STEEL GUIDELINES SECURAIL SYSTEM UN 96 / 11-3045 ·· »JULY 1966» FIGURE 1 AND DRAWING 31-1203.1

No. 357192

The invention relates to a Auffahrsehutz for guardrail ends, consisting of an outgoing from the region of the crash barrier end, inclined and with its lower end in the ground recessed Holm with hollow profile cross-section.

The still common, encountered, freely over the last post horizontally protruding ends of guardrail strands of sheet steel, concrete or the like. are known to act as ramming spurs, which bore into impacting vehicles. Driving onto such an obstacle always causes serious damage to the vehicle and very often serious or lethal injury to the occupants.

Also, it is becoming more and more about to make the parallel to the roadway projecting end of each guardrail strand on a short distance at an angle and let into the ground to prevent the on spit of a vehicle on impact. However, this training has the so-called "ramp effect" result, which gives the vehicle a vertical acceleration component and leads to its rollover.

In view of the obvious inadequacy of the known designs of crash barrier ends, the invention is based on the object to provide a collision protection, which is able to bring up vehicles in a tolerable for the vehicle occupants, well-metered braking without overturning to a halt.

This object is achieved by a Auffahrschütz of the type mentioned fact that according to the invention, the length of at least 25 m having a box-shaped spar is held by at least one flexible support in the vertical direction and that the guard rail end is tired in the vertical direction yielding.

The elongate, obliquely extending spar advantageously has a substantially flat, a broad contact surface with the car underside ensuring surface. He is either tired as a full or as a hollow body. From metal box girders with thicker wall thickness (up to 6 mm in steel) existing spars are suitable to act within the meaning of the invention. Due to their high flexural strength, they are preferably used in conjunction with flexible or crushable support members under stress. Full body made of reinforced plastic or foam-filled box sections with a relatively thin wall thickness (1 to 3 mm in steel) are preferably used in conjunction with resilient supporting elements. The spar cross-section is eg square or rectangular, in the latter case, the beam with its largest moment of inertia is arranged transversely to the roadway. The spar is frictionally connected to the crash barrier end. In this case, the guard rail end, if necessary, a progressively in the cross-sectional shape of the spar on transition tail. Suitable rail forms, such as the one Voü- or Hohlprofüquerschnitt embodiments, can be used directly as a spar for the Auffahrschutz invention.

Preferably, the resilient, vertically arranged support elements of elastically deformable spacers, so that they are able to exert an effective from below restoring force for the depressed from the Ruhesteüung spars in a position. Thus, the support elements arranged between the spar and the ground can be rubber bumpers, or two telescopically intermeshing pieces of metal pipe, which are supported against one another by means of a hydraulic cylinder or a helical spring. Also plastically deformable support elements, such as bellows-tanned and completely or partially filled with plastic foam filled metal body can be used.

While the Fußteü the support elements in the ground, or, is embedded in a concrete foundation, the Oberteü the same is preferably inserted into the interior of the spar and anchored there, so that the given faults occurring when tipping tendency of the spar is counteracted. Other column mounts, such as cradles, etc. are also applicable. Depending on the cross-sectional shape and dimensions of the support element widening its Oberteües is desirable so that a secured against tilting suspension can be achieved. The support elements are arranged at intervals of 2 to 8 m from each other depending on the stiffness of the spars and their own deformability.

Also suitable as a support element is a deformable wedge-shaped cushion placed under the spar.

eg made of plastic foam. Such a base consists of one or more head-to-head pieces, which with the spar side and given gewüs by gluing together

No. 357192

- 3 are connected. In the limiting case, the wedge-shaped base could by suitable choice of materials and

Arrangement even be expanded so that a separate spar is unnecessary and that one on the

Floor-lying ramp-like compressible Auffahrschutz arises.

Upon impact of a vehicle on the collision protection according to the invention, the spar of the car, which slips over it, depressed. In this case, the kinetic energy is converted into the energy necessary for the deformation of the support elements and optionally of the spar, as well as into frictional energy, and the vehicle is brought to a standstill with a tolerable delay. By bending the spar and by the yielding of the support elements, be it plastic, elastic or by breakage, the risk that the vehicle lifts off the ground and tilts, significantly reduced.

Because of the great length and the weak slope of the spar, the vehicle is initially experiencing a relatively gentle deceleration, which is progressively increased at greater Auffahrenergie due to the increasing resistance to deformation of the spar and the increasing spring action of lying in front of the vehicle support elements. In order to be able to fully exploit the effect of the crash barrier end even when vehicles hit with high energy or in trucks, at least the first post of the horizontal guide rail strand is expediently designed as a support member according to the invention which is yielding in the vertical direction.

The braking effect when sliding along a vehicle over a metallic spar is only insignificant. For this reason, each having a metallic surface spar is roughened at least on its coming into contact with the underside of the car top or provided with a coating with a high coefficient of friction.

Overall, the collision protection in terms of its design and dimensioning, in particular with regard to the support forms, materials, spacings and compliance, and the Holmlänge, -Steifigkeit and support can be very varied, provided he is under the originating from an approaching vehicle, vertically downwardly directed force t, and against a vertically upwardly acting the spars own or caused by the post restoring force, so deep depressible that a sufficient energy destruction can take place without too strong, the vehicle to overturn bringing vertical acceleration component occurs.

The collision protection is usually functional after a ride-up to an acceptable extent, so that the safety remains guaranteed until straightening the spar or replacing individual posts.

In the drawing, an embodiment of the Auffahrschutzes invention is shown. The drawing shows a vertical section through a crash barrier end, which is supported by variously ausgebüdete support elements.

According to the illustrated embodiment, the arranged along a direction in the direction of the arrow road to be driven guardrail -l- a spar -2- upstream. This Holm -2- extends from the guard rail end, with which it is firmly connected, to a at least 25 m far away, the dimensions and inclination of Holmes -2- adapted wedge-shaped trough -3-. The rail start may be free to rest or be anchored in the well -3-, depending on the desired resistance determined by the choice of material and the post and beam configuration.

The actual guardrail -1- is preferably made of box sections of relatively thin steel sheet, which are foamed by means of a adhesive bond with the Metaü incoming plastic - 4 and are supported by columns, which have a distance of 8 and more meters from each other, which in the longitudinal direction the guardrail -l- have a greater bending stiffness than in the transverse direction of the guardrail -1- and which are provided near the ground with a Soübruchsteüe. These guard rails, which are not subject of the invention, are described in DE-PS No. 2026225.

At the end of the guardrail - 1 - is required, faüs, a transition piece provided which the

Transition from the cross section of the guardrail -1- guaranteed to the cross section of the spar -2-. The

The guardrail end is firmly connected to the end of the bar by means of glued-in push-in latches or by riveting or screwing.

No. 357192

According to the illustrated embodiment, the beam -2- is similar to that described above

Guardrail - 1- trained. It consists of a box profile (25 x 15 cm) made of sheet steel (1.2 mm), which is covered with a polyurethane foam with a density of about 50 kg / m³ is foamed.

The spar -2- is supported by supports, which are arranged at intervals of about 3.5 m from each other. In this case, each support, seen in the direction of travel, in each case by one of the rail pitch and the Stützenentfemung corresponding length greater than the arranged in front of her prop.

As already mentioned, the support elements, provided that they are yielding under vertical load, may be formed in different ways. Thus, the support elements, as can be seen from the drawing, consist of two nested tubes or box parts -51, 52 and 61, 62-, which are designed to be compressible by hydraulic shock absorbers -54 and / or Schraubenfedem -64-. The upper part of each of these at least two-part supports is firmly connected to the underside of the spar -2- or the guardrail - 1- or anchored in the interior, so as to be largely secured against tilting under stress. The middle part and optionally embedded in a concrete foundation foot can against a bead of eg from ungetempertem cast iron existing and as a predetermined breaking point tired intermediate piece -53, 63- rest. This Soübruchsteüen are sheared under load in the transverse direction, so that the necessary flexibility in lateral access of a vehicle in the transition area of ​​the Holmes -2- is given in the guard rail - 1- and the kinetic energy of the vehicle by deflecting and leakage at the crash barrier end smoothly reduced and can be reduced to the standstill of the vehicle.

The support element also shown -7- consists of a bellows-folded metallic shell, which is completely or partially with elastic filling material, preferably plastic foam, ausgefüüt.

Support elements of the latter type, as well as simple rubber buffers, such as a Roüe -8-, are suitable as support elements for the ground closer Teü the Holmes -2-.

In order to maximally exploit the effect of the Auffahrsehutzes invention even with heavy driveways of passenger cars and driveways of trucks, and at least the first support of the horizontal guardrail in the vertical direction is yielding gebüdet.

The surface of the spar -2- and the top of the guard rail transition piece are provided with a lining -9- with high friction coefficient. For example, a plastic adhering to the metal is suitable for acting within the meaning of the invention. The pad -9- can be applied by sticking on strips of material or by spraying. If necessary, the entire rail can be provided with a jacket which surrounds it completely, so that at the same time an effective corrosion protection is provided.

The significant technical progress that the invention offers is compared with devices of conventional design in ensuring a tolerable deceleration process. If a vehicle comes while moving in the direction of the arrow from the road and gets it on the guardrail end, the beam -2- is pushed progressively down. The thereby compressing supports then exert on the spar -2- a restoring force, which increases progressively. Hiebei a part of the kinetic energy of the vehicle is converted into an elastic or plastic deformation energy of the supports. The rest of the energy is consumed by friction on the braking effect performing spar surface.