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).
Adopted scheme for brakes, detailing leverage and servo modifications.
| Identifier | Morton\M20.3\ img014 | |
| Date | 4th June 1924 | |
| B.R. 493A (20H) (D.A. 652 20-8-24) J.H.D. ORIGINAL Expl. No. 9940 REF: Hs{Lord Ernest Hives - Chair}3/LG 4.6.24. EXPERIMENTAL REPORT. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. RG.{Mr Rowledge} c. to DA.{Bernard Day - Chassis Design} E.{Mr Elliott - Chief Engineer} c. to EY. WOR.{Arthur Wormald - General Works Manager} S E C R E T. ADOPTED SCHEME OF BRAKES. We have several cars now running fitted with the adopted scheme of brakes. One car will be leaving for France tomorrow. The car we are sending to WW. today we hope will cross over on Saturday. Attached herewith are prints which show the final leverages which are fitted to the cars. The only alteration on this scheme from N.Sch.1801 is that the direct leverage to the rear brakes has been decreased slightly; one lever being reduced from 2.3 to 1.8. Also the cams operating the servo, the angle has been modified from 45º to 55º. It will be seen that the proportion of front and rear braking is approximately - rear 10 units - front 7 units. This will vary according to the efficiency of the servo and brakes but on the three or four cars we have tried they have come out reasonably consistent. We have taken 3" of brake liner off each brake shoe - 1.5" at each end. This is to reduce the tendency to jagger. The reason for reducing the leverage to the direct brake was for increasing the time before adjustment. We have now done away with any easy and quick adjustments for the brakes. We also lose a small amount of pedal movement in taking up the servo clearance. We also lose a certain amount of pedal movement owing to the deflection of the brake parts when the servo operates. contd:- | ||