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 flaws and potential modifications for a headlight changeover switch.
| Identifier | ExFiles\Box 82\4\ scan0119 | |
| Date | 17th April 1935 | |
| Rm{William Robotham - Chief Engineer} 4200 W/S. To -Hm.{Capt. W. Hallam - Head Repairs} from E.{Mr Elliott - Chief Engineer} E.5/HP.17.4.35. c. Hs.{Lord Ernest Hives - Chair} By.{R.W. Bailey - Chief Engineer} Cx.{Major Len W. Cox - Advertising Manager}JLE.{J. Lee Evans - Chassis Test Manager} IA. Hs{Lord Ernest Hives - Chair}/Wst. Ey/RD. Headlight Control - Changeover Switch. With reference to the sample switch suggested for use with the headlight control, this is of the variety where the spring contacts slide from a brass to an ebonite surface during the switching operation. This is not the most desirable form of switch we should have used for handling the headlamp current as in course of time the insulation tends to get burnt. The contact blades also on this switch are not too well secured, being clamped against a small local area of ebonite and the current passing via the screw. We think, however, that this switch may be used pro-tem, subject to two small modifications:- One is the body of the switch, which is in ebonite, is secured to the flange by about one thread, and we are instructing the makers to turn off the brass boss spigotting the switch cover and make this into thread and ebonite to improve the fixing of the switch body. The other point refers to the absence of space allowed for wood where the wood screws securing the switch screw into the instrument board. With the red fibre switch cover in position the screw holes are altogether too close. We are calling for a larger flange, possibly oval, to correct this feature as unless some alteration is made we think that coachbuilders will criticise this point. If this scheme of headlight control continues later on to form a permanent feature of our chassis, we shall have to make a small switch of our own of sounder electrical and mechanical construction, more suitable for dealing with headlight current. E.{Mr Elliott - Chief Engineer} | ||