GB1375567A - - Google Patents

Abstract

1375567 Vehicle lighting systems JOSEPH LUCAS (INDUSTRIES) Ltd 28 March 1972 [14 May 1971] 15035/71 Heading H2H A vehicle lighting system which comprises main beam and dipped beam headlamps is provided with means whereby should either the main beam or dipped beam filaments fail in use the dipped or main beam filaments are substituted therefore, at least the main beam filaments being reduced in intensity when substituted for the dipped beam filaments. A vehicle lighting system includes main beam headlamps 27, 39 and dipped beam headlamps 31, 43 energized from a battery 11 by way of a lighting switch 12, 13, 14 by means of a dip switch 17, a lamp 15 indicating when the headlamps are illuminated. The main beam headlamp 27 is energized from the battery 11 by way of contact 14 of the lighting switch, contacts 19a, 21 of relay 19, relay winding 25 and fuse 26, the current flowing in winding 25 causing contacts 32 to open thus preventing energization of dipped beam headlamp 31. Should the main beam headlamp 27 fail the relay winding 25 de-energizes, contacts 32 close and the dipped beam filament 31 is illuminated by way of a diode 36 and contacts 32. If it is desired that under these conditions the dipped beam has a reduced intensity a resistor may be placed in series with the diode 36. The operation of headlamps 39, 43 is similar. Dipped headlamp is selected by movement of the dip switch 17 to contact 18 whereupon relay winding 19 energizes to change over contacts 19a, 19b. Dipped beam filament 31 is then energized by way of contacts 19a, 23, relay winding 28 and fuse 29, the current flowing in winding 28 causing contacts 32 to open to prevent illumination of main beam headlamp 27. Failure of dipped beam headlamp 31 causes deenergization of relay winding 28 and contacts 32 close to illuminate main beam headlamp 27 by way of contacts 32 and a resistor 34, the resistor 34 causing the intensity of the headlamp to be reduced to a greater extent than the reduction in the intensity of the dipped beam headlamp when this is reduced by the provision of a resistor. Under these conditions the current flowing in the relay winding 28 is insufficient to cause the contacts 32 to open. Operation of headlamps 39, 43 is similar. Lamps 35, 45 serve to indicate failure of a headlamp, the contacts 33, 45 being operable by the relays 25, 28 and 37, 41 respectively. In a second embodiment the system is provided with means whereby operation is possible without the use of a relay operated by the dip switch and in a third embodiment, lamps are provided to indicate individual failure of the headlamps.