GB1277219A - Improvements in vehicle headlamps - Google Patents

Abstract

1277219 Vehicle headlamps ROBERT BOSCH GmbH 29 July 1969 [30 July 1968] 37989/69 Heading F4R In a motor-vehicle headlamp for producing an asymmetric dipped beam comprising a parabolic reflector 1, a halogen bulb 10 situated with its filament located in front of the principal focus F of the reflector and a mask or hood 8 surrounding part of the bulb to define the form of the beam radiated by the headlamp, those parts of the mask which define the upper boundary of the beam, viz. its side edges 9, fit tightly against the envelope of the bulb 10 while the remainder of the mask is spaced from the envelope in order to allow cooling air to flow between the mask and the envelope. As can be seen from Fig. 1 an aperture 12 is cut in the lower part of the mask to permit increased flow of cooling air. A screen 14 preventing direct emission of light is attached to a bracket 15 extending from the mask. Light passing through the aperture 12 and reflected upwards from the reflector 1 is refracted back in a downward direction by means of prismatic ribs 13 in the lower half of the front lens 2. To prevent light refracted upwards by the short stepped portions of the ribs 13 from causing dazzle, these stepped portions are shaped so as to cause an additional sideways deflection of the light. The bulb-holder incorporating the mask 8 is made of aluminium to provide good heat conduction and has a blackened cooling cylinder 19 attached to its rear by a clamp 18.