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).
Design and modification of the J.III Headlamp Control Switch, noting issues with the original knife switch design.
| Identifier | ExFiles\Box 168a\2\ img069 | |
| Date | 31th March 1932 | |
| X6139 R.{Sir Henry Royce} from E.{Mr Elliott - Chief Engineer} c. Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} H / 1st. E.2/HP.31.3.32. J.III Headlamp Control Switch - N.Sch.3432. In its early stages the design of the above was found to consist of a knife switch made up from our standard switchbox parts direct coupled to the steering column control, and with a toggle to hold it either way. This did not appear to have much chance of lasting, as the speed of break and make could be retarded by the driver, and with frequent use the contacts might get badly burned. The Bosch footswitch is arranged for an independent rapid break, and I also obtained a sample of the Lucas, and one of the latest pattern house lighting switches both of which have an independent toggle action to give rapid make and break. We accordingly modified the J.III scheme along these lines, at the same time reducing the bulk of the switch, and re-arranging the operation of the mechanism so that its action could be observed when desired. This electrical work is of such a highly specialised nature that N.Sch.3432 may require further work in it yet. A print of this design has already been sent to you. E.{Mr Elliott - Chief Engineer} | ||