This invention relates to a wind direction indicator for airports and the like, which comprises, in using position, an essentially horizontal windsock, which is made of a fabric or the like, and which is open in its front end, which is fastened to a device, that is rotatable about an essentially vertical shaft, so that the wind sock easily can put itself into the wind direction. The invention also relates to a wind sock for use in wind direction indicators.

This type of wind direction indicator is previously known and is preferably used at airports so that the wind direction at the airport can be clearly indicated. The problem with known wind direction indicators has been that these ones have been difficult to discover in darkness but also in the daytime when there is strong sunlight. This invention intends to eliminate the problem with known technique and to provide a wind direction indicator, which is easily discovered at night but also in the daytime when there is strong sunlight. This has been made possible by a wind direction indicator of the kind mentioned by way of introduction, which is characterised in that it comprises a lamp, which emits ultraviolet light, and that the fabric is coated with such a colour that this one fluoresces when being irradiated by the ultraviolet light. Due to that fact the windsock will be strongly outlined against the surroundings also in the daytime, when there is strong sunlight, wherefore that moment of the airport-work comprising the determination of the wind direction is essentially facilitated.

An embodiment of the invention shall be described more closely below with reference to the accompanying drawing, where Fig. 1 shows the wind direction indicator, seen from the side, and Fig. 2 shows the wind direction indicator according to figure 1 , seen in the direction of the arrows II-II.

The wind direction indicator according to the invention comprises, in using position, an essentially horizontal windsock 1 , which has a front end, that is open, and a rear end. that normally also is open. The windsock in accordance to the regulations for this range of application has evident orange 4 and white 5 fields, which are alternately positioned, i.e. an orange field, a white field, an orange field etc. The front end 3 of the wind sock is fastened on an essentially vertically arranged, first rod 6, which via a bearing 7 is ratable about a second, essentially vertically arranged rod 8. Due to that fact the windsock can easily put itself into the wind direction.

The windsock 1 is made of a fabric, preferably of polyester plastic, which has been subjected to a crochet work and has a sparse structure, wherefore the windsock resists moisture and air pollutions better than a normal fabric. The sparse structure of the fabric has a

positive influence on its drying time, which makes the windsock easier and more stable regarding the direction.

The fabric of the windsock is according to the invention coated with a colour, which has such a character that it fluoresces when being irradiated by ultraviolet light. That fact that the colour of fabric of the windsock fluoresces means that the windsock will well be made properly clear in darkness as well as in daylight, when the sunlight flows. Furthermore, the colour according to the invention has such a character that a white surface, which is coated with the colour, and which is irradiated by ultraviolet light, will reflect ice-white light, which fact is extremely important in this connection, because the different red and white fields of the windsock must be able to be discovered clearly in the day as well as in the night.

When using a conventional colour, coated on a white surface, a bluish light would be re-reflected, which should be unacceptable in this connection.

In order to achieve the mentioned fluorescense-effect, the wind direction indicator is provided with a lamp 9, which emits ultraviolet light, and which is arranged in front of the front end 2 of the windsock 1, so that the lamp can light straightly into the wind sock. This UV-lamp is built together with a reflector and is fastened on a third, essentially vertically arranged rod 10, which is built together with the first rod 6, on which the front end of the windsock 1 is fastened. This means that the lamp 9 follows the windsock during the turning of this one in relation to the second rod 8 and has accordingly the same position in relation to the windsock all the time.

As has already been mentioned, previously known wind direction indicators have had that drawback that they have not presented desired visibility in the daytime when there is strong sunlight. Due to the design of this new wind direction indicator, its fabric will fluoresce in daylight, even if the UV-lamp is not lighted, because the fluorescence-effect in daytime is achieved by the ultraviolet rays of the daylight, which irradiate the fabric of the wind direction indicator.

The wind direction indicator according to the invention, due to its special design, will of course be clearly made evident for those concerned, even if the weather should be foggy or rainy or if sleet should prevail. The invention is not limited to the shown and described embodiment but can be modified within the scope of the following claims.