Safety device for the beginnings of crash barriers

The present invention relates to a safety device for guardrail beginnings, in particular a collision protection, which is capable of the movement energies of a vehicle ascending a guardrail startⁱabsorb and dismantle in a harmless manner.

The heads of guardrail strands made of sheet steel, Béton and the like, which are still to be found all too often and protrude horizontally above the last post, are known to act like ram spurs into which the impacting vehicles drill. Driving onto such an obstacle always results in severe damage to the vehicle and very often serious to life-threatening injuries to the occupants.

Also, more and more people go over the end of each guardrail beginning that extends parallel to the road ₍ ! a short distance and to let it into the ground to prevent a vehicle from being impaled in the event of an impact. However, this training has the so-called ramps ·; »

R,, effect that gives the vehicle a vertical acceleration, 6, / -. Issued component and leads to its overlap to the right or left of the guardrail line. 'Z^f'·; In view of the obvious inadequacy of the known designs of guardrail beginnings, the present invention was based on the object of creating a guardrail start which is able to bring a vehicle ascending into a well-dosed braking process which is tolerable for the vehicle occupants without stopping.

Said task of the invention is solved by a collision protection device which, like a conventional guardrail start, is slanted into the ground and which is characterized by the fact that it consists of a box-like spar with a length of at least 25 m, which extends from the guardrail head with ge ' ring inclination extends to the floor level and is held by at least one support / element designed to be flexible against vertical stress.

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The elongated, oblique Holni · advantageously has a substantially flat surface which ensures a wide contact surface with the underside of the carriage.

It is designed either as a full or as a hollow body. Spars made of metallic box girders with thicker walls (up to 6 mm for sheet steel) are suitable for the purposes of the invention. As a result of their greater bending stiffness, they are preferably used in cooperation with supporting elements that are flexible or breakable under stress. Solid bodies made of reinforced plastic materials or foamed box profiles with a relatively thin wall thickness (1-3 mm for sheet steel) are preferably used in conjunction with resilient 3 flexible support elements. The cross-section of the spar is, for example, square or rectangular, in the latter case the beam with its greatest moment of inertia is arranged transversely to the road. The spar is non-positively connected to the guardrail end. If necessary, the guardrail end shows a progrès »

end into the cross-sectional shape of the spar. Suitable guardrail shapes, such as the designs having a * full or hollow profile cross section, / can be used directly as a spar for the collision protection according to the invention.

The resilient, vertically arranged support elements preferably consist of elastically deformable intermediate pieces, so that they are able to exert a restoring force effective from below for the spars which are pressed down from the rest position. For example, the support elements arranged between the spar and the ground can be rubber buffers, or two telescopically interlocking metal pipe pieces, which are supported against one another by means of a hydraulic cylinder or a coil spring. Plastically deformable support elements, such as bellows-shaped metal bodies that are completely or partially filled with plastic foam, can also be used.

While the foot part of the support elements is embedded in the ground or in a concrete foundation, the upper part of the latter is preferably inserted into the interior of the spar and anchored there, so that the tendency of the spar to tilt when stressed is counteracted. Other column attachments, such as cradle-like pads, etc. are also applicable. · Depending on the cross-sectional shape and dimensions of the support element, it is desirable to widen its upper part so that it can be secured against tilting. The support elements are arranged at intervals of 2-8 m from each other depending on the stiffness of the bars and their own compressibility.

A deformable wedge-shaped cushion placed under the spar, for example made of plastic foam, is also suitable as a support element. Such an underlay consists of one or more pieces arranged head to head, which are connected to the underside of the spar and possibly to one another by gluing.

In the borderline case, the wedge-shaped underlay could even be expanded by suitable material selection and arrangement in such a way that a separate spar is unnecessary and that a ramp-like, collapsible collision protection that rests on the floor is created.

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When a vehicle strikes the guardrail start according to the invention, the spar is pressed down by the carriage which slides over it. The kinetic energy is converted into the energy required for the deformation of the support elements and possibly the spar, as well as into friction energy, and the vehicle is brought to a standstill with a tolerable delay. By bending the spar and by giving way to the support elements, be it plastic, elastic or due to breakage, the risk of the vehicle lifting off and tipping over is drastically reduced.

Because of the large length and the weak slope of the spar, the opened vehicle initially experiences a relatively gentle braking, which is progressively reinforced with greater impact energy due to the increasing resistance to deformation of the spar and the increasing spring action of the supporting elements in front of the vehicle. In order to be able to fully exploit the effect of the guardrail start even with high-impact vehicles or trucks *, at least the first post of the horizontal guardrail line is expediently designed as a support element according to the invention which is flexible in the vertical direction.

The braking effect when a vehicle glides along a metal spar is only insignificant. For this reason, each spar having a metallic surface is roughened at least on its upper side that comes into contact with the underside of the car or provided with a brake pad of known composition.

Overall, the collision protection can be designed very differently with regard to its design and dimensioning, in particular with regard to the column shapes, materials, spacing and flexibility, as well as the length, stiffness and support, provided that it is less than that of »

a vertically downward force originating from a moving vehicle, and against a restoring force that is inherent in the uprights or that is applied by the pillars or that is applied by the posts, can be depressed to such an extent that sufficient energy dissipation can take place without excessive force causing the vehicle to tip over vertical acceleration component comes into play.

The protection system is usually still functional to an acceptable extent after opening, so that safety is guaranteed until the post may need to be straightened or individual posts replaced.

In the accompanying drawing, for example, an embodiment of a collision protection according to the invention is shown. 1 shows a vertical section through a guardrail beginning which is supported by variously designed support elements.

According to the embodiment shown, a bar 2 is arranged upstream of the guardrail device 1 which is slowly connected to a road to be driven in the direction of the arrow. This spar extends from the guardrail head, with which it is non-positively connected, into a wedge-shaped trough 3 which is at least 25 m further away and is adapted to the dimensions and the inclination of the spar.

Depending on the desired resistance, which is determined by the choice of material and the design of the spar and post, the start of the rail can rest freely in the trough or be anchored in it.

The actual guardrail device 1 consists, for example, of box sections made of relatively thin sheet steel, which are foamed with an adhesive connection with the metal and plastic and are supported by supports which are at a distance of 8 and more meters from each other, which are in the longitudinal direction of the guardrails have greater bending stiffness than in the transverse direction of the crash barriers and which are provided with a predetermined breaking point near the ground. This is not the subject. The crash barriers forming the present application are described in DT-PS 2.026.225. · / '

At the end of the guardrail line 1, if necessary, a transition piece is provided, which ensures the transition from the cross section of the guardrail to the cross section of the spar. The guardrail head is non-positively connected to the end of the spar by means of glued insert tabs or by riveting or screwing.

According to the preferred embodiment shown, the spar is designed similarly to the guard rails described above. It consists of a box profile (25x15 cm) made of sheet steel (1.2 mm) with a polyurethane foam_tfoamed to a density of approx. 50 kg / m.

The spar is supported by supports that are spaced about 3.5 m apart. Here, each support, viewed in the direction of travel, is in each case one length greater than the support arranged in front of it, in accordance with the spar inclination and the support distance. ,

As already mentioned, the support elements can be designed in different ways, provided that they are flexible under vertical stress. Thus, as can be seen from the figure, the support elements can consist of two nested tubes or box parts 51, 52 and 61, 62, which are designed to be compressible by hydraulic cylinders 54 or coil springs 64. The upper part of each of these at least two-part supports is firmly connected to the underside of the spar or the guardrail rail or anchored in the interior thereof, in order to be largely secured against tilting under stress. The middle part and the foot part, which may be embedded in a concrete foundation, can rest against a bead of an intermediate piece, for example made of non-tempered cast iron and designed as a predetermined breaking point. These predetermined fragments can be sheared off under load in the transverse direction, so that the necessary pliability of the plank when a vehicle approaches the side in the area of ​​the Holmes' transition into the guardrail rail is given and the movement energy of the vehicle is reduced by deflecting and running out on the guardrail strand without disturbance and to a standstill of the vehicle can be built.

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

Supporting elements of the last-mentioned type, as well as simple rubber buffers, such as roller 8, are particularly suitable as supporting elements for the part of the spar near the ground.

In order to make maximum use of the mode of operation of the safety device according to the invention, even in the case of heavy driveways of passenger cars, as well as when driving on lorries, at least the first support of the actual horizontal guardrail strand is, according to the invention, flexible in the vertical direction. j, · «

The surface of the Holmes and the top of the guardrail transition piece are provided with a brake pad 9.

For example. is a plastic adhering to the metal suitable to act in the sense of the invention. Said brake pad can be applied by sticking on strips of material or by spraying. If necessary, the entire spar can be provided with a jacket that completely surrounds it, so that the metal spars provide effective rust protection at the same time.

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- 8 years

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The significant technical progress that the invention offers is compared to devices of conventional design in the guarantee of a tolerable braking process. If a vehicle comes off the road while moving in the direction of the arrow and hits the guardrail start, the spar is progressively pressed down. The compressing supports then exert a resetting force on the spar which increases progressively. Part of the kinetic energy of the vehicle is converted into an elastic or plastic compression energy of the supports. The remaining energy is consumed by friction on the surface of the spar that acts as a brake.