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).
Five recommendations for a modified Phantom III clutch.
| Identifier | ExFiles\Box 93\3\ scan0178 | |
| Date | 8th October 1936 | |
| X312 To E.{Mr Elliott - Chief Engineer} c. to Da.{Bernard Day - Chassis Design} c. to Hdy.{William Hardy} Hs{Lord Ernest Hives - Chair}/Smth.2/KW.8.10.36. Phantom III Clutch. We give herewith recommendations for a modified Ph.III clutch. (1) Ventilation and provision for centrifuging out the Ferodo dust. (2) 20% more separation by giving the pedal 1" more travel. This is to enable us to use more cushioning in the driven plate. We understand that certain manufacturers in the States (Oldsmobile for one) are having to use .080" cushioning in order to get a reasonable take-up. If we find we do not need this, we shall utilise the extra pedal travel to reduce the load, which is now excessive. (3) Wider facings - we suggest 2.500" wide. There is evidence that this modification improves jaggers, presumably because the friction surfaces are kept cooler and hence do not change their chemical composition so readily. In any case it ought to increase the life of the facings. (4) We think we ought to abandon the oilite bush, which is the principal cause of spinning clutches, and adopt the Bentley method of bearing the 1st motion shaft. If this is done, the tail bearing will tend to stop the clutch instead of dragging it round. Incidentally this will cheapen the clutch. (5) Four release fingers instead of six. This will cheapen the clutch and the weight saved will help to compensate for the heavier pressure ring - due to (3). We also have evidence that this is a better arrangement for jaggers. | ||