Abstract: An airfield marker light, comprising a casing to be flush-mounted in the ground and having a lower light source (4), an upper, a transparent cover plate (8) lying substantially in the ground plane M, and a refractive member (7) which divides the light bundle from the light source, so that two light beams (L.sub.12, L.sub.34) are emitted from the upper surface of the cover plate (8) in opposite directions at a small angle to the ground plane. The light source (4) emits a collected, substantially vertical light bundle, and the refractive member includes a light dividing prism (7) situated between the light source and the cover plate and having refractive planar surfaces (7a, 7b, 7c, 7d) obliquely oriented in opposite directions, so that the vertical light bundle is divided into two light bundle portions, directed obliquely upwardly in oppoiste directions, the light bundle portions upon passage through the cover plate being refracted in opposite directions in the upper surface (8a, 8b) of the cover plate.

Abstract: An airfield marker light, e.g., for runways or taxi strips, comprising a casing (1) with a lower light source (4) and an upper, transparent cover plate (8) situated substantially in the ground plane. An abrasive resistant material, preferably in the form of particles partially embedded into the surface of the cover plate, protrudes upwardly from the cover plate exclusively in at least one dead zone (11, 12, 13), which does not emit any light. The hard material protects the cover plate (8) against mechanical abrasion, for example during snow-clearance by steel scrapers.

Abstract: A sealing element adapted to be disposed in a slitshaped, preferably annular gap, comprises an internal gas-filled cavity with an inlet in one end and an outlet in the other end for a hardening filling medium adapted to be introduced into the cavity under pressure so that the cavity is filled and the element is expanded so that the gap is sealed. The outlet (15) is connected to a closed chamber (14) adapted to receive the gas which is driven out of the cavity (2) in the flexible element when the cavity is filled with filling medium (16), so that the displaced gas can be compressed in the closed chamber (14') and exert a counter pressure on the filling medium (16') in the sealing element while the filling medium is hardening.