GB571933A - A new or improved anti-dazzle device - Google Patents

Abstract

571,933. Anti-dazzle devices. BEATON & SON, Ltd., G., and ELLIS, R. J. L. Jan. 3, 1944, No. 56. [Class 103 (ii)] An anti-dazzle device used in combination with a vehicle windscreen comprises a pair of polarizing filters mounted with their planes parallel and means for effecting relative rotation of the filters about an axis normal to their planes, and a support for holding the anti-dazzle device in operative position in relation to the windscreen. In Figs. 1 and 2, a pair of filters 10, 11, preferably made of material known as polarized glass, which comprises birefringent material sandwiched between a pair of glass plates, are mounted to turn in opposite directions in a casing 14 by means of a pinion 28 engaging racks 26, 27 on the filter mountings. The casing 14 is hinged to the edge 18 of the windscreen 17 by a hinge 21, 23 adapted to be engaged in the operative and inoperative positions by notches 24 engaged by spring pressure. The casing may be fixed to the windscreen, and the pinion 28 engaged by a rack moved by a Bowden cable against the pressure of a spring. In another modification, the casing is fixed by a bracket to a portion of the vehicle structure adjoining the side of the windscreen and one filter operated by a lug protruding through the casing, the opposing filter being moved in the opposite direction through the pinion 28. In a further modification, one of the filters is cemented to the outside of the windscreen, the other filter being rotatably mounted in a ring of plastic material cemented to the inside of the windscreen. The fixed filter may be constituted by the whole or part of the central lamination in cases where the windscreen is made of laminated glass. In the Provisional Specification it is stated that the device is appropriate for dimming the light beams of motor car headlights and other lamps.