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).
Letter to Rolls Royce of America regarding issues and design features of the front brakes on the 61-RF English Phantom.
| Identifier | ExFiles\Box 66\5\ scan0143 | |
| Date | 19th July 1928 | |
| X 8420 Ho 19 th July 1928 EY1/G19.7.28 Messrs Rolls Royce of America, Inc. Springfield. Mass FOR THE ATTENTION OF M.{Mr Moon / Mr Moore} OLLEY, ESQ. Dear Sir, RE FRONT BRAKES ON 61-RF ENGLISH PHANTOM Referring to OY1/R6.20.28. I have discussed this matter with our Experimental Department in order to make sure that there is no difference of opinion here on the subject raised, and find that they were in agreement with the views that I am now putting forward. We do not consider that the Duralumin flange being of such a diameter that the brake drum rubbed on it was responsible for the car leaving the road. A compara-tively small load at a high speed would cause tearing of the Duralumin with very little retarding effect, the appearance noted being the result of brake application over a considerable period and not the result of the single brake application. We are well aware that with the original form of brake with no control of the axle, other than by the spring, would result in a car leaving the road if the brakes were applied when the wheels were turned, and two or three instances in this country were traced to this particular effect, a point we were well aware of at the time that the brakes were being standardised, and special attention was drawn to it, with the suggestion that a parallel control to the axle was badly needed to overcome this particular feature. The twisting of the axle about an axis passing through the hubs of the wheels transversely to the car causes instability of the steering due to the fact that the inclination of the pivot pin in a fore and aft direction has been reversed that is the pin looks backwards instead of forwards, assuming one is looking down along the axis of the pin, and this effect is exerted if the steering wheels are turned at the moment the brakes are applied. The flexibility of the drum as a feature that was arrived at as a result of our experimental work, our original brake drums had a flange on the inner diameter to prevent distortion when the brakes were applied, but it was | ||