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).
Experiments and recommendations to improve 40/50 instrument patch lighting.
| Identifier | ExFiles\Box 62\2\ scan0081 | |
| Date | 11th May 1932 | |
| X6141 E.{Mr Elliott - Chief Engineer} From Hs{Lord Ernest Hives - Chair}/Wst. c. to By.{R.W. Bailey - Chief Engineer} c. to Cx.{Major Len W. Cox - Advertising Manager} Hs{Lord Ernest Hives - Chair}/Wst.11/MA.11.5.32. 40/50 INSTRUMENT PATCH LIGHTING. With reference to your request for us to improve the lighting of the above we have carried out a number of experiments in a dark room and have arrived at what we consider the best arrangement of the existing patch without altering design. This we have accomplished by painting both the reflecting plate and the inside surface of the instrument mounting a matt white finish. On the present standard patch the reflecting plate is polished and the instrument mounting painted black. The resulting illumination is very patchy, inefficient and provides much glare. Painting both of these surfaces dead matt white gives a reasonably high percentage reflection efficiency and a perfectly even reflection. This results in a better general illumination. A further modification which assisted in the light diffusion and certainly reduced glare was the fitting of blue celluloid rings round each instrument. The fitting of these celluloid rings also hides any internal fittings on the patch which would otherwise be visible. These rings could be held in position in the patch by machining small circular grooves in either the reflecting plate or the instrument mount. We recommend the above modifications to the standard patch. Further experiments are in hand using bevelled glass fronts to the instruments so that the light reflects through the rim. We are obtaining from Smiths some bevelled glasses for this experiment and the drawing office are looking into the question of modifying an existing patch to suit. Hs{Lord Ernest Hives - Chair}/Wst. | ||