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).
Front brake effectiveness, oil contamination, servo modifications, and chunking in the brake mechanism.
| Identifier | ExFiles\Box 30\6\ Scan153 | |
| Date | 7th January 1924 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H.D. -2- EXPERIMENTAL REPORT. Expl. No. 9940 REF: Hs{Lord Ernest Hives - Chair}4/LGM.7.1.24. running it was noticed that the N.S. front brake was much more affective and the steering ran off in that direction, whenever the brakes ~~are~~ were applied. From examination we consider this is due to oil having got on to the O.S. brake. On the original 20 h.p. cars we found that if we attempted to oil the nose bearing of the shaft which operates the toggles, that with an oil gun the oil flowed freely through this bearing and got on to the brake All 20 HP. cars are running with no lubrication on the toggles and the nose bearing is made of lead alloy and works without lubrication. We propose trying a similar scheme on the front brakes. With the low pressure on the servo we find that the pull off spring for the operating mechanism affects the pressure and the efficiency of the servo when wear occurs and the spring is extended. We propose fixing to this car a spring on the servo itself as shown in N.sch.1723 sent through by Da.{Bernard Day - Chassis Design} We propose using this position of spring on the existing servo parts until the new parts are ready. The car has been driven by drivers who have not done any experimental testing and had not the knack of producing jaggers easily. During the 1,000 miles run, one driver complained of bad jaggers on the front brakes. Chunking in the Brake Operating Mechanism. With any 40/50 cars fitted with 4-wheel brakes when we have brakes working evenly and smoothly we still have the chunking when the brakes are applied quickly caused by the servo taking up the clearance on the rear brakes so rapidly. Although this does not occur when the brakes are applied gently... contd... | ||