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).
Braking leverage, servo efficiency, and the distribution of braking power on cars of varying weights.
| Identifier | ExFiles\Box 5\3\ 03-page144 | |
| Date | 27th May 1925 | |
| -2- the same on any car he may be driving, if full advantage is taken of this power by giving him say a leverage of 25 to 1 to the back brakes, this is a definite part of the braking power available, and if the car is of such a weight that it is all the braking the back wheels can stand, he braking from the servo can be put on the back wheels, and all must go to the front, or, in the case of a heavier car it will necessarily be a smaller proportion of the total braking which can be put on the car. We are speaking of course of design: we do not mean that as the loading of the car is varied so the braking is varied. We are speaking of the design of cars of different weights. It is quite true as you have indicated in a subsequent memo. Hs{Lord Ernest Hives - Chair}/Rm{William Robotham - Chief Engineer}2/LG27.5.25., that it may not be the wisest course to regard the direct braking as a fixed quantity, but instead to make it, by reducing the leverage, a constant proportion of the total braking, which would have the effect of moving the braking further up the curves until it was on the flat part, where variations in the servo efficiency do not so greatly alter the distribution of braking. We will discuss this with Mr. Royce at the first opportunity, but in view of our previous instructions, we thinK we must go on for the present with the 25 to 1 ratio already instructed. DA.{Bernard Day - Chassis Design} | ||