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 from Ferodo Limited discussing the development and properties of a new oil-retaining asbestos clutch lining.
| Identifier | ExFiles\Box 26\4\ Scan181 | |
| Date | 2nd May 1923 | |
| R.H. 109 (2SOT) (S.D.676 19-7-17) MP 180865 COPY. FERODO LIMITED, SOVEREIGN MILLS, CHAPEN-EN-LE-FRITH. 2nd May.1923. Wednesday. R.{Sir Henry Royce} Harvey Bailey Esq., Messrs. Rolls Royce Limited., DERBY. Dear Mr Bailey.. You will remember my bringing down what I though was a wonderful clutch, and one that would make no noise, but my calculations were based on no oil being present. I have been experimenting with another type - one made of a material so bonded that you can boil the lining in oil, at any temperature, and for any length of time, without affecting the binder in any way. Moreover it is made of asbestos reinforced with wire, and it is so thoroughly porous that it will retain oil throughout its body. We are sending the clutch to you, after it has already been immersed in oil and allowed to drain, but in the dry state before oil goes in if you pour oil on one side of the lining it goes right through to the other in less than half a minute. I want you to know that these linings of ours are so constructed that they do not stretch; there is no danger in any circumstance of the lining coming away after it has been riveted on; stitching is entirely unnecessary with a quality like Ferodo Bonded Asbestos. We can make such linings without the wire, and they would be quite strong enough, but we should put more binder in. The tendency of this lining is to shrink and not expand. You can do anything you like - put it through any test - and I think you are going to find, as I have now for several weeks, a more powerful clutch. We calculated that your spring pressure was 750 lbs, which is enormous in our opinion, so this lining has been made thicker so that it does not come right home and has reduced the spring pressure and made the clutch much sweeter. I have tried it on all sorts of hills and I find it alright. contd. | ||