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).
General review of the four-wheel brakes situation, including axles, operation and servo speed.
Identifier | ExFiles\Box 73\2\ scan0293 | |
Date | 24th March 1924 | |
To RG.{Mr Rowledge} DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} FROM R.{Sir Henry Royce} c. to CJ. BJ. HS.{Lord Ernest Hives - Chair} Wor.{Arthur Wormald - General Works Manager} PN.{Mr Northey} MR. CLAREMONT. X.9940 S E C R E T. R1/M24.3.24. E.{Mr Elliott - Chief Engineer} A.{Mr Adams} C. GENERAL REVIEW OF FOUR WHEEL BRAKES SITUATION. X.9940 It will be seen that I have been willing to adopt anything which promises to be worthy of its cost and complication, and to eat my own words if necessary for the good of the work in hand, though this latter is more apparent than real as the following will explain. As it seems generally thought at Derby and WW. that we are getting near to something worth making I think it is advisable to consider how we really stand. PARTS ON AXLES. As far as I remember there have been no material changes from the first to the present, either in the old work on the back axle or the new work on the front axle, except that to simplify we have done away with the radius rods as it is thought that these do not help to save the front springs. So that we have done nothing to the various problems of 'jaggers, etc'. but altered the method of operating the brakes, principally to slow speed servo. My reason for pointing this out is to clear up some misunderstanding and possible injustice to WW. OPERATION. The method of operating has proved to be more important and difficult than was realised. It was anticipated from the first that it was no use to attempt to apply all 4 brakes sufficiently vigorously for forward work, by the energy available from the foot pedal only - (as about 30% braking should be easily available.) So that at least for large cars with brakes on the axles (not countershaft brakes) we were forced to some relay (servo) system, and to clear away the weeds and find the essential features has taken more time than was foreseen, as good results can only be obtained by keeping within fine limits, principally in the speed of application by the servo. I point this out for fear we get away from these limits. SPEED OF SERVO. This or its equivalent speed ANGLE must be kept near that found on Hispano. We must not lose sight of the fact that we have found this (slow speed) to be absolutely necessary, (even for the conversions our new work was always contd:- | ||