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).
Investigation into an inconsistent 4-wheel braking system.
| Identifier | ExFiles\Box 73\2\ scan0087 | |
| Date | 15th November 1923 | |
| R.R. 493A (40 H) (SL 42 12-7-23). J.H., D.{John DeLooze - Company Secretary} X. 9940 Expl. No. 9940 REF: Hs{Lord Ernest Hives - Chair}2/LG15.11.23. EXPERIMENTAL REPORT. To R.{Sir Henry Royce} from Hs.{Lord Ernest Hives - Chair} c. to CJ. c. to Rg.{Mr Rowledge} c. to Da.{Bernard Day - Chassis Design} c. to BY.{R.W. Bailey - Chief Engineer} 4-WHEEL BRAKES. On the car fitted with 4-wheel brakes, after we had relieved the wrapping shoes to avoid the jaggers which also considerably reduced the braking at the front, we still found the braking very inconsistent. On investigation we found that the epicyclic distribution device locked itself so that no pull was transmitted to the servo. If the pedal was put on quickly it operated alright, but if the pedal was pressed slowly, the device tightened up like a self-locking freewheel - the more pressure that was put on the tighter it got. We could actually disconnect the connection to the servo brake and press hard on the pedal so that the device was locked and all the power went to the front brakes only. When we examined the device we could not see anything obviously wrong except that clearances were all fine and the pinions of the epicyclic gear did not all take up the load together. The D.O. have since revised the clearances and limits which will most probably overcome this trouble. We simply point out this as a fault which has occurred. We have not done any serious endurance tests with the brakes but it was noticeable that when we had the majority of the braking on the rear brakes only, the servo brake gets very hot. At the present time the drum is blue with heat. Hs.{Lord Ernest Hives - Chair} | ||