From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
The operation and specifications of Bosch double-filament headlights and the associated foot switch.
| Identifier | ExFiles\Box 61a\1\ scan0331 | |
| Date | 11th June 1928 guessed | |
| Page 6: bends is therefore considerably enhanced. From the point of view of the driver the distribution of the light is, owing to the diffusion lense, equally efficient with both the main light and the anti-dazzle light so that when he changes over from main to anti-dazzle his vision is unaffected. In this way a speed of about 30 m.{Mr Moon / Mr Moore} p. h.{Arthur M. Hanbury - Head Complaints} can be maintained without the safety margin being overstepped. As it is free from dazzle and yet brilliant, the anti-dazzle light of the double filament bulb is particularly efficient as a town light, especially in small towns and villages with their often inefficient street lighting. Finally the anti-dazzle light is invaluable in the fog. The rays of the main light running parallel to the road are on meeting the screen of fog partly reflected back, striking the eyes of the driver and dazzling him. The rays of the anti-dazzle light, deflected diagonally downwards do not create the same “white sheet” which is so familiar to the car driver. Fig. 5. Switch. 7345 The Switch. In order that the driver may give his undivided attention to the road when changing over from main light to anti-dazzle light and keep both hands on the steering-wheel, it is advisable to mount a foot switch (Fig. 5). This switch is a Double Switch. It consists of the connecting plate with switch roller, contact springs and terminals, press-button with holder and the cover. The press-button with holder - 6 - Page 7: and the connecting plate, screw into each other. The cover is demountable, the screws of the terminals being then accessible. Manipulation. When driving through towns and villages or on approaching other vehicles, a pressure on the press-button switches off the main light and switches on the anti-dazzle light. When the road is clear a further pressure on the switch reverses the process. Bosch headlight with double-filament bulb. The Bosch headlight with double-filament bulb is supplied in three different sizes, having respectively reflectors of 110, 160 and 200 mm diameter. These three models can not only be supplied having the double-filament bulb situated in the focus of the headlight reflector, but also having a tubular pilot bulb, of small watt consumption, in the upper part of the headlight reflector. The double-filament bulbs are manufactured as shewn in table below. Order No. of Headlights | Finish | Type numbers of Spherical bulbs*) (double filament bulbs) | tubular bulbs --- | --- | --- | --- IL 200x2/107, IL 160x2/107 | Housing enamelled black, Headlight ring nickelled | 12 V 35/20 W, 12 V 25/20 W, 6 V 25/20 W | 12 V 5 WR, 6 V 5 WR IL 160x2/108, IL 110x2/107 | | 12 V 20/15 W, 6 V 20/15 W | IL 200/107 | | 12 V 35/20 W, 12 V 25/20 W, 6 V 25/20 W | — Headlights I 170, I 200, I 240, IG 200, IG 240 and all IL headlights can be altered so that double-filament bulbs can be *) The number preceding the stroke indicates wattage consumption of the main light (i. e.{Mr Elliott - Chief Engineer} 35, 25, or 20 watt) and the number following the stroke indicates the wattage consumption of the anti-glare filament (i. e.{Mr Elliott - Chief Engineer} 20 or 15 watt). Headlights IL have clear glass double filament bulbs. - 7 - | ||