DE6809589U - REFLECTIVE REFLECTORS FOR TRAFFIC PURPOSES AS SLOPE ICE WARNING DEVICE - Google Patents

Description

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BadischV'Anilin «· & & © ää« Pabrik AG

Our reference: GM 659 Ms / GP 67ΟΟ Ludwigshafen, 2 · ^l 2 .1968

Reflectors for traffic purposes as a black ice warning device

The invention relates to a reflector with a light reflecting Layer for traffic purposes, in particular for attachment to lane boundary posts, as a black ice warning device.

The methods known in the art for determining the temperature were not previously suitable for being used in road traffic to indicate a hazard due to the possible formation of black ice. On the one hand, the use of temperature sensors of any kind to switch optical signals on and off ^{could not prevail because of the effort involved in their acquisition of ure 1} maintenance, on the other hand, the obvious possibility of attaching temperature measuring colors to road marker posts, for example, was excluded. that the lowest transition temperature of commercially available temperature measuring colors is + 40 ° C. In addition, the color change of these temperature measurement colors is irreversible, that is to say that the color change that once occurred as a result of the action of temperature is retained even when the temperature has again reached its initial value.

This gave rise to the task of setting up a black ice warning device develop that is cheap to manufacture, reliable in its function and practically maintenance-free.

This task was ur.uer using a reflex reflector with a light-reflecting layer solved according to the invention in that in front of the light-reflecting layer, a reflective surface located in a transparent capsule-like container covering liquid is arranged, which when cooled to a temperature just above the freezing point of water as a result a phase transition loses its transparency, which is present at higher temperatures. The one covered by liquid

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The light-reflecting layer can advantageously be colored green and surrounded in the shape of a ring by a red-colored light-reflecting continuous or interrupted layer. The light-reflecting layer covered by the liquid can be embedded in the rear wall of the liquid container. As a container filling a liquid comes into question, preferably solidifies between 10 ° and 0 ⁰ C between 5 ° and 0 ⁰ C. The liquid can consist of a binary solution, with the systems p-xyl oil-naphthalene and cyclohexane-lauric acid achieving particularly favorable results, especially if the composition of the mixture corresponded to the eutectic mixing ratio of the system.

The reflector according to the invention is shown in the drawing in ^ Exemplary embodiments shown and will be described in more detail below.

Figure 1 shows a longitudinal section through a road delimitation post with inserted reflector.

Figure 2 shows a longitudinal section through a reflector designed in the form of a capsule-like insert.

According to Figure 1, a plate-shaped, green-colored light-reflecting layer j5 and in front of this a liquid-filled, capsule-like translucent container 4 is arranged in a recess 1 of a road delimitation post 2, the light-reflecting layer 5 being covered by the liquid-filled container 4. The liquid-filled container 4 can also be protected by a translucent pane 5 placed in front of it, which can be anchored in the recess 1 of the post 2 by means of a fastening ring 6. In the arrangement shown here, the green-colored light-reflecting layer 3 is ring-shaped continuously or interrupted by a red-colored light-reflecting layer J , which can be inserted into the front surface of the post 2.

The installation example shown in FIG. 2 differs from the arrangement shown in FIG. 1 only in that the light-reflecting layer 3, the liquid-filled container 4, the transparent disc and the fastening ring 6 are combined in a capsule-like insert 8, the red colored light reflecting layer 7 in the edge of the insert 8 is arranged. In this exemplary embodiment, the reflector can be inserted into the recess as a fully assembled installation unit 1 of the traffic lane boundary post 2 can be used.

As a material for the production of the light-reflecting layers 3 and 7, the liquid container 4 and the pane 5 can be glass and transparent plastics, for example polyethylene and polyamides can be used, while the insert 8 can be made of metal or plastic, for example.

The liquid filled into the container 4 must meet the condition that when it is cooled to a temperature just above it of the freezing point of water due to a phase change liquid -> fixed their transparency, which is present at higher temperatures loses. While at higher temperatures a light beam impinging on the reflector, the disc 5 and The light beam can penetrate the liquid-filled container 4 and light up the green light-reflecting layer at a temperature below the phase transition point of the liquid in the container 4 no longer penetrate this liquid layer, so that the otherwise green light up Signal fails. This is intended to make the road user aware that temperatures are at least close to the ground prevail where there is the possibility of black ice. The ring-shaped surrounding the green light-reflecting layer 3 red light-reflecting layer 7, which lights up when light falls, mows the road user additionally at the risk of Black ice formation attentively. The luminous intensities of the green and red light reflecting layers can be superimposed in this way be coordinated that when the green light-reflecting layer 3 lights up, the red light-reflecting layer 7 differs from the green Light is outshone. Instead of the light reflecting layer

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th 3 and 7 can of course also be used self-luminous signals, but because of the effort involved on electrical installations can only be used in special cases.

The phase transition point of the liquid in the container 4 is to some possible above the freezing Taqperatürgrads I: are point of water. In this way, account is taken of the fact that the road delimitation post cools down more slowly than the surrounding air. If the air cools down to the freezing point of water relatively quickly, the reflector arranged in the lane boundary post will initially be a few degrees warmer than the surroundings and only slowly adjust to it. But precisely under such conditions a black ice warning device must be effective, since the road user is less endangered by a continuously frozen road than by unexpected slippery roads.

All liquids which have a phase transition point ^{between approximately + 10 °} C. and ⁰ ° C., preferably between + 5 ° C. and ⁰ ° C., are initially suitable as container filling. The following substances, for example, whose solidification point is given in (° C), could be used as pure liquids: Benzene (5.5 ° C). Tetradecane (5.5 ° C), dibenzyl ether (3.6 ° C), formamide (2.2 ° C), (N, N) dimethylaniline (2.5 ° C).

Not only pure liquids but also multi-component mixtures can be used, such as: H ₂ SO ₁ ^ + 11 mol # H ₂ SeO ₁₁ (32 ° C) _r phenol + 57.5 mol # p-xylene, acetic acid + 18 , 5 molJ SbCl, (4 ⁰ C), benzene + 3.3 mol # benzoic acid (4.3 ⁰ C).

As taken into account when choosing the fluids in question should be that the liquid used solidifies quickly, i.e. if possible without significant undercooling, easily and is cheap to manufacture, does not attack the container material and is chemically stable, two pairs of substances in particular have proven successful, the mixture of p-xylene and 18.2 moles of naphthalene,

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speaking a mixing ratio of 86.7 g of xylene and 23.3 β naphthalene, which has a point at eutektisehen + 4.2 ⁰ C and the mixture of cyclohexane and 6.8 mol # Laurlnsäure, corresponding to a mixing ratio of 78.5 g of cyclohexane and 15.6 g Laurln acid, which has a eutectic point at + 3.2 ⁰ C. With both mixtures, it is advisable to set the mixing ratio to that of the respective eutectic point, since the phase transition temperatures then lie ^{in the particularly interesting range between + 5 ° C and 0 ° C.}

The advantage of the reflector according to the invention can be seen, in particular, in the fact that it is cheap, easy to manufacture and reliable Black ice warning device, which is practically maintenance-free and used in every road boundary post can be.

Claims (8)

1. Reflector with a light-reflecting layer for traffic purposes, in particular for attachment to road delimitation posts, characterized in that in front of the light-reflecting layer (3) in a transparent, capsule-like container (4), the reflecting surface covering liquid is arranged, which is arranged on cooling a temperature just above the freezing point of water as a result of a phase change loses its transparency, which is present at higher temperatures. 2. Reflector according to claim 1, characterized in that the rear wall of the fluid container (4) is designed as a light-reflecting layer (3). 3. Reflector according to claims 1 and 2, characterized in that the light-reflecting layer (3) covered by the liquid is colored. 4 = reflector according to claims 1 to 3, characterized in that the light-reflecting layer (3) covered by the liquid is surrounded in the shape of a ring by a red light-reflecting layer (7). (,) 5. reflector to claims 1 to 4, characterized as that the Behälterfü Settin g of a liquid exists, di <
stiffens. which is between 10 ° and ⁰ ° C., preferably 5 and 0 ° C 6. Reflector according to claims 1 to 5, characterized in that the liquid consists of a binary solution. 7. Reflector according to claims 1 to 6, characterized in that the binary solution consists of a mixture of p-xylene and naphthalene, in particular of a mixture corresponding to the eutectic mixing ratio. > I I 111 , j 8. Reflector according to claims 1 to 6, characterized in that the binary solution consists of a mixture of cyclohexane and lauric acid, in particular of a mixture corresponding to the eutectic mixing ratio. Badische Anilin- & Soda-Fa ^v - k AG Draw .