A POST FOR MARKING ROAD VERGES

Abstract: A verge post for marking road verges or the boundaries of traffic lanes. The invention is characterized in that the post (1) is constructed to fluoresce when illuminated with ultraviolet light, and in that the post is constructed to transmit visible light in two or more directions (9; 10) when illuminated with ultraviolet light from one direction (8).

Description: A Post for Marking Road Verges The present invention relates to a post for marking the verges of roads or traffic lanes. Verge posts are used to enhance optical guidance along primarily ron-ill_α_inated traffic routes. Reflectors are placed en the posts, so that they can be seen in the stray light from dipped headlamps. In Sweden, these reflectors are positioned slightly higher from the road surface than the reflectors in the remainder of Europe, since the reflectors are then less likely to became covered with dirt. The reflectors are placed at a height of 750 mm above the road surface, and consequently only stray -Light will impinge on the reflectors when using dipped headlamps. Reflectors which are turned to face towards bordering woodlands, so- called wildlife mirrors, are said to have a certain deterring effect on wildlife. In Sweden, two round reflectors are used on the left side of the road and one rectangular reflector on the right side of the road, when the road is intended for two-way traffic. The reflectors are coloured white at bus stops, road crossings, etc. Round reflectors cannot be distinguished from rectangular reflectors at short distances, and the public is unable to discern the difference between these reflectors. A number of ∞untries position reflectors of mutually different colours on the right and the left side of a road. These reflectors cannot be distinguished one from the other by people who have defective colour vision. It is difficult to judge the distance to a reflector, since the surface is small and the intensity of the light reflected by the reflector decreases with the'square of the distance, whereas the light reflected from normal objects decreases with the distance raised to the power of four. The difficulties of judging distance cause verge posts to became highly ∞nfusing and tests have shewn that they can also be directly misleading, particularly those posts which are positioned along curved and uridulating roads. The present invention provides a totally novel verge post which eliminates the drawbacks associated with known verge posts. Thus, the present invention relates to a verge post for marking road verges or the boundaries of traffic lanes, and is ciiaracterized in that the verge post is constructed to fluoresce when illuminated with iiltraviolet light; and in that the post is cc_τstruσted so that when i__lu-___nated with iiltraviolet light frcm one direction, the post will -xansmit visible light in two or more directions. The jjrtveπtion will new be described in more detail with reference to exeπplifying __ι___x___π__πts thereof and also with reference to the ac__a__rpanying drawing, in which - Figure 1 illustrates a first side of an inventive post; - Figure 2 illustrates a second side of an inventive post; - Figure 3 is a cross-sectional view of part of the post shown in Figure 2 according to a first ert__odi_nent, the view being taken on the line A-A in said Figure; and - Figure 4 is a cross-sectional view of part of a second ernbodirπent taken on the line A-A in Figure 2. Figures 1 and 2 shows a verge post 1 frcm two different directions, said post being intended to mark the verges of a road or the boundaries of traffic lanes. Figure 1 illustrates a post which is intended to be mounted on the left side of the road, and Figure 2 ill__strates a post intended to be mounted an the right side of the road, as seen in the forward direction of the traffic. The posts are provided with visible light reflectors 2, 3, which are of mutually different con- figurations on respective sides 4, 5 of the posts. According to the invention, the post is intended to fluoresce when illiminated with ultraviolet ' light, and is so constructed that when illuminated with ultraviolet light frcm one direction, the post will ansπ t visible light in two or more directions. In recent years, strenuous efforts have been made to enable automotive vehicles, primarily cars, to be fitted with headlamps which emit ultraviolet light as a complement to conventional visible light. This technique is discussed, for instance, in the Swedish Patent Specification No. 8704118-2. According to a first _sτ__cκ__π__nt of the present invention, the verge post is σαnst ucted from a plastic material which is transparent to ultraviolet li t. In this case, two or more sides of the post 1 are coated with a fluorescent material 6, 7, which is pervious to ultraviolet light. Ωiis embodiment is illustrated in Figure 3. The arrow 8 illustrates incident ultraviolet light and the arrows 9, 10 exemplify the visible light emitted as a result of the fluorescence.. Because the verge post is c__n_ ruσted frcm material which is trans¬ parent to ultraviolet light, the incident iiltraviolet light 8 will pass thrαu the post to the layer 6. The fluorescent material used may be any kind of ccmmercially available material. For example, a ccammercially available fluorescent paint can be used. According to a second, alternative embodiment, the verge post is constructed from a plastic material which is transparent to ultraviolet light, this material having been treated so that the material will fluoresce when illiiminated with ultraviolet light. Acxxarding to this en__x_d_j___nt, a fluorescent pigment may be admixed with the plastic material. Such pigments are known and ccπmercially available. It is also possible to use a fibreglass material and to dcpe the material during its manufacture with a given q___πtity of a substance which causes the glass fibres to fluoresce in its presence. This technique of obt___Lning fluorescence is also known and will not therefore be discussed in detail here. Accxϊrding to one preferred einbc iment of the invention, the post is treated on different sides thereof with mutually different materials which fluoresce in mutually different colours, preferably two mutually opposing and substantially parallel flat sides 4, 5 of the post. According to an alternative embcxiiπent, illustrated in Figure 4, the verge post comprises two parts 11, 12, preferably two parallel, plate-like parts, wherein the two parts 11, 12 are treated in mutually different ways so as to fluoresce in mutually different colours. In the case where the verge post consists of two plate-like parts 11, 12, a layer 13 is placed between the two plate-like parts 11, 12 in ac___a_dance with one preferrred ______________ of the invention, this layer 13 cxansisting of a material which is transparent to ultraviolet light but impervicus to visible light. A foil of so-called Wood's glass is an example of such a layer. The resultant effect of this a__ra_-gement is that the visible light trar____itted frcm one side 4; 5 of the post will not be txans-oitted in the other direction, i.e. t_hrαugh the other side 4; 5 of the post subsequent to having been trar__Bitted therethrough. According to one preferred e_bodi____nt of the irrveπtion, the post is pigmented such that when illuminated with visible light, it will have the same, or substantially the same colour as that when ill__r_Lnated with iiltraviolet light. The inventive verge post is preferably provided with the aforesaid reflectors 2, 3. ____zording to another preferred embodiment, the verge post 1 is con¬ structed from panels and is fitted along one side edge 14 and/or the other side edge 15 with a substantially U-shaped edge strip 16 made of a plastic material which is transparent to ultraviolet light and which will fluoresce when illuminated with ultraviolet light, see Figures 3 and 4. The verge post of this embodiment is configured with a teickening 20 along those edges where a strip 16 is located, this tJickening filling the U-shaped strip 16. The strip 16 is indicated in broken lines in Figure 2. A strip of this kind functions as a light guide and will guide light from the panel-like part of the post out through the edges 17, 18 of the strip, as illustrated by the arrows 19. In order to provide verge posts which fluoresce in white light, several different αaiplemeπtary fluorescing substances are used, so that the cαπibined light transmitted by the fluαrescing substances will be observed as white light. The i_r_/eπtive verge post provides a number of advantages over known verge posts. Firstly, the function of the inventive post is less likely to be impaired by dirt, since the scattering of light does not have the same effect as for reflectors. F___t_____mαre, such criteria as positioning and height are not equally as significant as for reflectors. The top part of the post also has a useful fimction. The large surface area of the post as compared with the surface of the reflectors enables the post to be djjsce ned more readily at distance. The surface shall be greater than approximately 50 cm 2 in order for the distance to be judged satisfactory. Fluorescence provides a powerful light within a given wavelength range, as opposed to conventional paints. This enables the posts to be given different colours which can readily be distinguished and discerned at long distances in the dark. Many people suffering from defective colour vision are able to dis- tinguish between different colours of an intensive fluorescent light. As will be evident from the aforegoing, fluorescent verge posts can be cxastructed to emit light in several directions and are not only retrαrefleσtive. This means that the light from mutually meeting vehicles will assist in the fluorescence of verge posts, enabling the posts to be noticed from long distances. As before mentioned, the posts can be constructed so as to have different colours on the right and the left side of the post. This greatly reduces the risk of confusion and misinterpretation. Further, the post trar_3mits light in a direction away from the road, which may possibly have a deterring effect on roadside wildlife. Although the iι_v_atiαn has been described with reference to a number of ______x__ur__πts thereof, it will be understood that the configuration of the post, its εq^pearance and its coiϊstruction can be varied and modified within the scope of the present invention. The invention shall not therefore be considered restricted to the afαredescribed exeπplifying __r__od_j_e__ts, since modifications can be made within the scope of the following Claims.

Claims: Claims 1. A verge post for marking road verges or the boundaries of traffic ^ lanes, c ha r a c t e r i z ed in that the post (1) is constructed 5 to fluoresce when illuminated with ultraviolet light; and in that the ^ post is cor_3truσted such that when illuminated with ultraviolet light from one direction (8) , the post will transmit visible light in two or more directions (9; 10) . 10 2. A verge post according to Claim 1, character i z ed in that it is constructed from a material, preferably a plastic material, which is txcunsparent to ultraviolet light; and in that two (6, 7) or more sides of the post (1) are coated with a fluorescent material which is pertneable to ultraviolet licfit. 15 3. A verge post a∞αrding to Claim 2, character i z ed in that different sides of the post, preferably two mutually opposing, parallel, substantially flat sides (6, 7) of said post, are treated with coatings of different materials such as to fluoresce in different 20 colours. 4. A verge post according to Claim 1, character i z ed in that the post is constructed from a plastic material which is trans¬ parent to ultraviolet light, and which is treated such as to fluoresce 25 when ill____Lnated with ultraviolet liφt. 5. A verge post according to Claim 3 etc 4, charac¬ ter i z ed in that the post includes two parts (11, 12) , preferably two mutually parallel plate-like parts, said two parts (11, 12) being 30 treated differently so as to fluoresce in mutually different colours. 6. A verge post according to Claim 5, character i z ed in that there is arranged between the two plate_-like parts (11, 12) a layer (13) of material which is 1_ransparent to ultraviolet light but 35 iitperviσus to visible liφt. 7. A verge post according to Claim 1, 2, 3, 4, 5 or 6, ch ar ¬ a c t er i z ed in that the post is pigmented so that when illuminated with visible light, it will have the same or substantially the same colour as that when i_l____mated with ultraviolet light. 8. A verge post according to any one of the preceding Claims, character i zed in that the post is formed frcm panels; and in that there is fitted along one side edge and/or the other side edge (14; 15) of the post a substantially U-shaped edge strip (16) which is made of a plastic material which is transparent to ultraviolet light and which will fluoresce when illuminated with ultraviolet light. 9. A verge post according to any one of the preceding Claims, characteri z ed in that several different cx_ple_e_τtary fluorescent substances are used so that the combined light emitted with fluorescence will be observed as white light.

Inventors: FAST PEDER, FAST, PEDER
Applicants: ULTRALUX AB
Application year: 1991
Main classification: G09F13
IPC codes: E01F9, G09F13