Patent GB-1155841-A (GB)
Title: System For Two Level Vehicle Lighting
Inventor: WILLIAMS MAURICE CLAUDE
IPC: B60Q1/14
Filed: 1965-05-04
Abstract: 1,155,841. Road traffic signals on vehicles. ESSEX WIRE CORP. 1 July, 1966 [4 May, 1965], No. 18848/65. Heading G4Q. [Also in Division H2] In a car lighting system providing dimming for the head and signalling lamps, all the lighting and signalling circuits, with the exception of the circuit for flashing the main beams Lplb and Lp2b, are controlled by a three-position switch SA having four sections SA 1 -SA 4  comprising contact pairs 1, 2; 3, 4; 5, 6, as shown. Positions 1, 2, 3, correspond respectively to the connection of contact pairs 5, 6; 3, 4; 1, 2 of each section (contacts 5, 6 of sections SA 4  and SA 1  not present or not used). The arrangement provides the following features:- Position 1 (and ignition switch SB open).- All circuits broken with the exception of that to main beams Lp1b, Lp2b operable through a flasher switch PB 1 . Closure of switch SB allows energization at normal brilliance of brake/stop lamps Lp9, Lp10 (through section SA 2  and switch PB 2 ) and of direction indicating lamps Lp5-Lp8 and their panel signal lamps SLp2, SLp3 (through section SA 3  and switches SE, SD). Position 2 (and switch SB open).-Closes circuit to the side, rear and registration plate lights (through section SA 1  and lead 13) and to the instrument panel lights (through section SA 1  and lead 14). Closure of switch SB allows energization at reduced brilliance of the lamps SLp2, SLp3, Lp5 . . . Lp10, the reduction being due to resistors in parallel with contacts 5, 6 of sections SA 2 , SA 3 . A compensating resistor R5 is connected for this reduced-brilliance condition to maintain at normal the flashing rate of flasher SE. The dipped beam filaments Lp1a, Lp2a are energized through a resistor R1 and section SA 2  to provide dimmed dipped operation. Position 3 (and switch SB closed).-Energization of lamps SLp2, SLp3, Lp5 ... Lp10 as for position 2. Dimmed dipped circuit is disconnected. Headlamps may be energized dipped or full through section SA 2  according to the position of the switch SC. The following modifications are described:- (1) Combination of the switches PB 1  and SC to form a single switch operable by a threeposition lever, Figs. 2 and 6 (not shown). This prevents simultaneous energization of the main and dipped beam filaments. (2) The provision of a centre-tapped dimming resistor R1 to ensure that if one dipped beam circuit becomes faulty, the other is unaffected. This requires another section for the switch SA having three contacts all connected together in position 3, Figs. 2, 7 and 8 (not shown). (3) An arrangement in which the front direction indicator lamps Lp5, Lp6 always operate at normal brilliance. This also requires an additional section for the switch SA, Figs. 4, 6 ... 9 (not shown). (4) The provision of a dimmer resistor across contacts 5, 6 of one of the sections of switch SA to permit use of panel signal lamps SLp2, SLp3 at normal brilliance for day driving and reduced brilliance for night driving, Figs. 6 and 7 (not shown). (5) A refinement of modification (1) to ensure that, for a four headlamp car, only two of the main beams can be flashed, Fig. 8 (not shown).