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).
Modifications to improve instrument board lighting on 20/25 and 40/50 models.
| Identifier | ExFiles\Box 62\2\ scan0109 | |
| Date | 20th June 1932 | |
| X6141 To By.{R.W. Bailey - Chief Engineer} from Hs{Lord Ernest Hives - Chair}/Wst. c. to Cx.{Major Len W. Cox - Advertising Manager} E.{Mr Elliott - Chief Engineer} c. to Wor.{Arthur Wormald - General Works Manager} BY/RD. Hs{Lord Ernest Hives - Chair}/Wst.2/KT.20.6.32. 20/25 and 40/50 INSTRUMENT BOARD LIGHTING. Our experiments on improving the lighting of the instrument patch have shewn that the following modifications are necessary to gain maximum even illumination with the existing designs, at the same time eliminating glare. (1) Painting the reflecting plate and the front surface of the instrument mount dead white. At present the reflecting plate is polished and the instrument mount black-enamelled, and the reflection efficiency is correspondingly very poor. (2) The fixing of the blue celluloid rings round each instrument so that the light to each instrument is diffused and prevents glare from the lamp filaments. (3) Putting the lamps as far forward as possible so that the lamp bulb glass just clears the reflecting plate. (4) Using 12 - 14 volt. 4 watt. lamp bulbs. A further advantage which we have not tried would be to increase the distance between the reflecting plate and the instrument mount on the 20/25 to the same dimensions as the 40/50. Will you please arrange to incorporate these modifications on present production as early as possible. The use of green or white lamps is, we suggest, entirely a matter of preference. It should be noted, however, that the maximum illumination suffers when green lamps are used. Hs{Lord Ernest Hives - Chair}/Wst. | ||