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).
Issues and solutions for the 20/25 HP instrument patch illumination.
| Identifier | ExFiles\Box 62\2\ scan0173 | |
| Date | 8th February 1933 | |
| X6141 RECEIVED 9 FEB 1933 BY/Cgh.{W Clough}1/G.8.2.33. W/S S. Sgt. O.{Mr Oldham} Pry c. Hs.{Lord Ernest Hives - Chair} 20/25 HP. INSTRUMENT PATCH ILLUMINATION. -------------------------------------- With reference to Cx.{Major Len W. Cox - Advertising Manager}9/KW.7.2.33. the instrument patch on the above chassis is, we presume, one of the present standard type, in which case we agree that the illumination is inadequate. The reason for the poor illumination is that the space between the faces of the instruments and the mount is not sufficient to enable the lamp bulbs to stand up sufficiently high so that the filaments are above the level of the dials. We have experimented with an instrument patch, and have proved that if the lamps are lifted so that the filaments are above the dials quite good lighting can be obtained. This, however, results in a 'dazzling' effect from the filaments, but this can be minimised by fitting say celluloid rings round the dials in order to conceal the bulbs. If we use lamp bulbs with flat tops then the distance between the dials and the mount can be reduced so that the bulbs are less exposed to vision of the driver. The Experimental Department are just about to complete another patch in which these points are being embodied, and we are hoping that the results will be satisfactory. BY/Cgh.{W Clough} | ||