GB1508424A - Reflectors - Google Patents

Abstract

1508424 Reflex reflectors ASSOCIATED ENG Ltd 30 June 1975 [1 July 1974] 29154/74 Heading G2J [Also in Division E1] A refracting retro-reflector has a reflective surface 12 which is made up of alternating portions 16, 18, 20 of greater reflectivity and portions 22, 24, 26 of lesser (e.g. zero) reflectivity so that, when illuminated by an approaching off-axis source (e.g. car head-lamps above the axis), light is returned in a succession of flashes. The reflected beams have successively increasing angles of divergence to allow for the increasing angle subtended at the reflector by the distance between the headlamps and the driver's eyes. In Fig. 1, the radii R A -R D are equal; to avoid the "stepped" rear surface 12, the radii may be made unequal Fig. 8 (not shown). Also, in Fig. 1, the returned light is symmetrical about axis 11; to produce an upwardly biased distribution, the centres of curvature O A -O C may be displaced from the axis 11, Figs. 7 and 9 (not shown). In the above embodiments, only the lower part of the rear surface 12 is operative; if the axis 11 is inclined relative to the roadway in which it is used, Fig. 10 (not shown) the entire rear surface may be effective. In the embodiment of Figs. 11 and 12 (not shown) the reflector is generally frusto-conical with the rear surface of smaller diameter than the front face. In Fig. 13 (not shown) the alternating portions are applied only to a lower quadrant of the rear surface, the reflector being of use as a kerb marker. In Fig. 14 (not shown) opposite halves of the alternating portions reflect red and white, the reflector being of use as a lane marker. In Fig. 15 (not shown), the reflector is injection moulded and the sprue is used as an attachment to a housing. In Fig. 16 (not shown) the reflector is of generally rectangular form to allow a larger number of reflectors to be assembled in given area.