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).
The performance of different vehicle braking schemes and servo assistance.
| Identifier | ExFiles\Box 182\M20\M20.2\ img024 | |
| Date | 28th April 1924 | |
| R.R. 494a (20H) (D.A. 652 20-3-24) J.H.D. EXPERIMENTAL REPORT -2- Expl. No. 9940 / 4214 REF: Hal/LG28.4.24. The RR.M. scheme is working remarkably well. It is practically impossible under any condition to know that there is any relay system between the pedal and the brakes. Any variation in the brake pedal load is immediately felt on the brakes under all conditions. We are still getting more rear braking than front but tests show we are getting considerable assistance from the servo. It would appear therefore that the front brakes are inefficient owing to incorrect bedding or shortening of shoes. With the RR.M. scheme we could produce front brake jaggers. We reduced these so that they could only be obtained under difficulty by removing the 2" of Ferodo from the wrapping shoe. AGREED SCHEME. The first tests with the 'Agreed' scheme as it was run to Le CanadelHenry Royce's French residence proved that we were getting very little assistance from the servo and therefore as most of the brake power was coming from direct pedal pressure, any lag in operation would not be noticeable. The modifications to the servo and also to the angle of the thread increased the power of the servo so that we were more powerful than the Hispano. When we arrived at this condition the lag on the servo was shewn up to a marked degree especially when driving the car slowly and quickly applying the brakes such as experienced by E.{Mr Elliott - Chief Engineer} and DA.{Bernard Day - Chassis Design} in London traffic. There are two effects of this lag felt by the driver on the contd:- | ||