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).
Modifications to clutch servo assistance and linkages for the 20/25 and Phantom III models.
| Identifier | ExFiles\Box 95\4\ scan0129 | |
| Date | 25th May 1936 guessed | |
| (sheet 2) The condition of control on the valve is much less frequently reached on the 20/25 (There is one car fitted with a vacuum servo) as the relative assistance on this car is much less. Fortunately less delicacy of control is needed for gear changing than for starting. However, the relatively large servo assistance which we are attempting to obtain on the Phantom III may also make the control at starting less perfect as the opening of the throttle, as the clutch is engaged, must reduce the vacuum and therefore increase the pedal plate load to a greater extent than occurs on the 20/25. In obtaining the increased separation the inclination of the connecting link between the pedal and the clutch has become altered and in consequence we feel that some alteration is necessary to the inclination of the stay between the engine and the pedal shaft. We show this stay dropped at the front end which means that the boss on the clutch casing for this stay must be moved down. The hole in the frame cross is dropped to correspond. We suggest that experimentally the stay is tried in both old and new positions so that it may be known whether a change is necessary. The increased clutch separation will require modifications to the clutch thrust bearing and we shall be sending a scheme for these. There will of course be the vacuum connection on the induction pipe. We are assuming that details of this will be supplied by the engine section. E/HDY.{William Hardy} | ||