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 wheel brakes, discussing the cause of 'jaggers' and proposing modifications to the brake action, springs, and dampers.
Identifier | ExFiles\Box 30\6\ Scan129 | |
Date | 3rd October 1923 | |
To Hs.{Lord Ernest Hives - Chair} from R.{Sir Henry Royce} RG.{Mr Rowledge} c. to CJ. X1559 R3/ME3.10.23. RE. FRONT WHEEL BRAKES. X.9940 X.1559 Referring to your 2 reports, and my 3 telegrams. You will notice that I have corrected 2 mistakes in my telegrams, which were the cause of hurried and imperfect conclusions. I think you are mistaken that the brakes increase their application by the movement of the axle. We have designed these so that no change should take place, but naturally we may have overlooked something. My instructions for alterations are such that whatever is the cause of the jaggers we think it will be advisable to make the brakes so that they actually wind themselves off. We shall by this means possibly get a smoother acting brake and also may be able to use this feature to limit the amount that the front brakes can be applied, because when the front axle turns round excessively the pedal will reach the floorboards. The 'servo' must be arranged to skid the back wheels by the time the pedal reaches the floorboards. You will notice that I have continually suggested that we must use stiffer front springs. The top rebound leaf may also be of some use to help. The real reason for the jaggers is I think due to the ferodo surface peculiarity of having a varying co-efficient of friction with speed, coupled with the torsional elasticity of the axle mounting. We ought to do all we can to decrease this flexibility, and damp what flexibility we are bound to have. DOUBLE RADIUS RODS. The use of double radius rods suggested by me increases the complication beyond that which is reasonable unless we can in some way combine the upper one with the shock damper. SHOCK DAMPERS. You will notice that I have suggested double shock dampers for torsion also, so arranged that the vertical damping is as usual, but both dampers will work vigorously if there is any torsional vibration of the axle. [DIAGRAM of an axle assembly] SAY 10" contd:- | ||