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).
Brake and steering system testing and proposed improvements.
| Identifier | ExFiles\Box 72\3\ scan0288 | |
| Date | 21th January 1924 guessed | |
| contd:- -2- they will be found consistent but we await further tests. No-one would desire to change from the standard more or less rigid shoes and fixed fulcrum brakes unless some definite advantage can be gained, as these are the most practical, but the long lapping shoe type with the fixed fulcrum does not (I understand) give consistent braking effect when worn, and this is the cause of variations in brakes both on 4 wheel and 2 wheel types, but I should like it definitely proved if condition of surface also has any effect. At present we do not definitely know. Owing to the efficiency of the servo being greater than anticipated the braking on the front wheels has been proportionately less than anticipated. This DA.{Bernard Day - Chassis Design} and I adjusted before I left WW. but if the proportions are still different to those desired another adjustment can be made, but care should be taken not to increase the required torque needed from the servo because of the heat and also we must not greatly increase the leverage (from the foot) to the front brakes because we do not want frequent adjustment or insufficient clearance. There is insufficient stroke in some of the parts of the temporary arrangement which Hs.{Lord Ernest Hives - Chair} has fitted, and an examination of the fitted car would give a better idea of some better arrangement. Forces low and stroke long I should prefer. I also understood that it was experimentally desirable to force the servo shoes apart with a stronger spring, and possibly alter the lower lever (i.e. 1.4-5") to some other proportion (say 2.4 - 4) so as to keep the pull on the rod T. about the same as originally, and it was also desired to alter the direction of this pull so that follow up was necessary by the pedal. DA.{Bernard Day - Chassis Design} can shew how this can be conveniently and easily arranged. Perhaps some of these ideas will be on trial at the moment, but I mention them for fear they have been forgotten. They had for their object the less sudden way the rear brakes take up their clearance. The report does not suggest which form of shoe is to be preferred. I had the impression that possibly for consistent and smooth action short lapping shoes would be preferred on the front, and backwards long or jointed shoes, and if with fixed fulcrum the single pull off stop should not be impractical. RE. STEERING. Consistent brakes and effective equalisers should keep both front brakes equal except in case of oil or water upon the braking surfaces. (In passing several materials are available and I hope being tested). This there seems little chance of providing for except that every care should be taken to provide avoid oil getting in from an overfilled hub. contd:- | ||