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 Ferodo Limited regarding tests on composite brake drums and servo linings.
| Identifier | ExFiles\Box 141\1\ scan0048 | |
| Date | 12th September 1935 | |
| X1180 Exptl. Dept. Hs{Lord Ernest Hives - Chair}/Gry.{Shadwell Grylls}16/KW. 12th September, 1935. J.N. Longley, Esq. Messrs. Ferodo Limited, Chapel-en-le-Frith. Dear Mr. Longley, We have decided to do some more tests with aluminium and steel composite brake drums. We think the only way in which we can make sure that there is contact between the steel and aluminium is to use an austenitic steel liner and then cast the aluminium on to it. We are sending you a specification of the steel we contemplate trying, but cannot at the moment send you a microphotograph of its structure. We wonder whether you can let us know from its composition whether you think it will be successful as a brake drum material. We do not think with the present cast-iron drums that we can keep the temperature under hard driving conditions below 300°C., but with the aluminium drums we are hoping to use, we think the temperature might be kept down to about 200°C. As regards VM.30 servo linings, we had to take these off production because of the squeaks that occurred while they were fully floating. On a later design of the servo we are trying the splined linings, and so far have not had any trouble from squeaks. We hope shortly to standardise this material. Yours sincerely, FOR ROLLS-ROYCE LIMITED. | ||