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 of dipping headlights for the Goshawk, comparing a dimmer switch to using side lights.
| Identifier | WestWitteringFiles\I\October1922\ Scan40 | |
| Date | 26th October 1922 | |
| TO RH.{R. Hollingworth} FROM R.{Sir Henry Royce} c.c. to EJ. WOR.{Arthur Wormald - General Works Manager} c.c. to PM. BT.{Capt. J. S. Burt - Engineer} c.c. to HS.{Lord Ernest Hives - Chair} MP. ORIGINAL 3 RECEIVED X.4291. RE. DIMMER. X 4555. We have decided to make the designs for the dipping head lights for the Goshawk. This we consider is a far better scheme than a dimmer. It is not a difficult job and I expect DA.{Bernard Day - Chassis Design} and BV. will complete it within the next 10 days. We think a dimmer is not a good solution of the problem: We find it difficult to make a space for it (on the instrument board) which would be convenient to the driver's hand. The dimmer would therefore in case of absolute necessity have to be placed in a position somewhat off the instrument board with a pull-rod and knob to make it operate. My own habit is to turn out the head lights altogether and drive by the present side lights which seem to be sufficient for shewing the road close to the car, and I have further thought that these side lights instead of being reduced in power could be so placed as to shine on the road close to the car in much the same way as a dipping head light or a dimmed headlight. This is the easiest and simplest way out of the difficulty for the moment, and will avoid the side lights making a glare forward. I have asked The Works to test this idea, and I send a copy of this memo. to Mr. Spinney. We never considered the dimmer was needed because of the extra side lights which are not used in America, where therefore the dimmer was a necessity until the idea of the dipping headlights. In England the situation seems rather different. We have to provide side lights and these might serve the purpose. Finally the dimmer interferes with our wiring and leads to a waste of current, both of which should be avoided. I attach a memo. from Da{Bernard Day - Chassis Design}/Bv in which you will see a few points which I have not mentioned, and others which are slightly different to mine. TMW R.{Sir Henry Royce} | ||