| 摘要 |
<p>The device consists of a reflector marking 2, arranged on a column 1, and of a cylinder cover 3 which encloses the reflector marking 2 and allows reflected light to pass through from the latter, and blade wheels 7 arranged rotatably around the cylinder cover 3. These blade wheels 7 are provided with wiper blades 8 which bear against the outside of the cylinder cover and, upon rotation of the blade wheels 7 caused by wind movements, are designed to move along the jacket surface of the cylinder cover and scrape off dirt which has settled on the latter. <IMAGE></p> |
