| 摘要 |
A portable warning device or marker, as used at roadworks or for traffic control and the like, comprises a wide circular base having a central hollow upstanding projection which either, Fig. 1, consists of a thin-walled dome A having a number of apertures B or, Fig. 3, consists of a hollow truncated triangular pyramid formed by membranes E supported by ribs D. The marker, which may be of plastics, is coloured and reflective; it can be placed on the ground without fixing and, if run over, will deform elastically, resist displacement and then return to its original shape. <IMAGE> |
